| 1. |
- Ahlm, Clas, 1956-, et al.
(author)
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Prevalence of serum IgG antibodies to Puumala virus (haemorrhagic fever with renal syndrome) in northern Sweden.
- 1994
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 113:1, s. 129-36
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Journal article (peer-reviewed)abstract
- A stratified and randomly-selected population sample was identified in 1990 in order to study the seroprevalence of nephropathia epidemica (haemorrhagic fever with renal syndrome) in Northern Sweden. Sera from 1538 subjects (750 men, 788 women), 25-64 years of age, were analysed for the presence of Puumala virus (PUV) specific-IgG by the indirect immunofluorescence antibody test. Specific IgG was detected in sera from 83 subjects (5.4%). Men and women had similar seroprevalence rates. The highest seroprevalences were found in subjects 55 years or older (8.0%) and among farmers and forestry workers (15.9%). The geographic distribution of seropositive individuals was uneven and there were significantly more seropositive persons in rural than in urban areas (P < 0.05).
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| 2. |
- Ahlm, Clas, et al.
(author)
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Seroprevalence of Sindbis virus and associated risk factors in northern Sweden
- 2014
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In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 142:7, s. 1559-1565
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Journal article (peer-reviewed)abstract
- Mosquito-borne Sindbis virus (SINV) cause disease characterized by rash, fever and arthritis which often leads to long-lasting arthralgia. To determine the seroprevalence of SINV and associated risk factors in northern Sweden, a randomly selected population aged between 25 and 74 years were invited to join the MONICA study. Serum from 1611 samples were analysed for specific IgG antibodies. Overall, 2·9% had IgG against SINV. More men (3·7%) than women (2·0%) were SINV seropositive (P = 0·047) and it was more common in subjects with a lower educational level (P = 0·013) and living in small, rural communities (P < 0·001). Seropositivity was associated with higher waist circumference (P = 0·1), elevated diastolic blood pressure (P = 0·037), and history of a previous stroke (P = 0·011). In a multiple logistic regression analysis, adjusting for known risk factors for stroke, seropositivity for SINV was an independent predictor of having had a stroke (odds ratio 4·3, 95% confidence interval 1·4–13·0,P = 0·011).
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| 3. |
- Alqahtani, F. Y., et al.
(author)
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Prevalence of comorbidities in cases of Middle East respiratory syndrome coronavirus : a retrospective study
- 2019
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In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 147
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Journal article (peer-reviewed)abstract
- The Middle East respiratory syndrome coronavirus (MERS-CoV) is a life-threatening respiratory disease with a high case fatality rate; however, its risk factors remain unclear. We aimed to explore the influence of demographic factors, clinical manifestations and underlying comorbidities on mortality in MERS-CoV patients. Retrospective chart reviews were performed to identify all laboratory-confirmed cases of MERS-COV infection in Saudi Arabia that were reported to the Ministry of Health of Saudi Arabia between 23 April 2014 and 7 June 2016. Statistical analyses were conducted to assess the effect of sex, age, clinical presentation and comorbidities on mortality from MERS-CoV. A total of 281 confirmed MERS-CoV cases were identified: 167 (59.4%) patients were male and 55 (20%) died. Mortality predominantly occurred among Saudi nationals and older patients and was significantly associated with respiratory failure and shortness of breath. Of the 281 confirmed cases, 160 (56.9%) involved comorbidities, wherein diabetes mellitus, hypertension, ischemic heart disease, congestive heart failure, end-stage renal disease and chronic kidney disease were significantly associated with mortality from MERS-CoV and two or three comorbidities significantly affected the fatality rates from MERS-CoV. The findings of this study show that old age and the existence of underlying comorbidities significantly increase mortality from MERS-CoV.
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| 4. |
- Amaku, M, et al.
(author)
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Magnitude and frequency variations of vector-borne infection outbreaks using the Ross-Macdonald model : explaining and predicting outbreaks of dengue fever
- 2016
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 144:16, s. 3435-3450
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Journal article (peer-reviewed)abstract
- The classical Ross-Macdonald model is often utilized to model vector-borne infections; however, this model fails on several fronts. First, using measured (or estimated) parameters, which values are accepted from the literature, the model predicts a much greater number of cases than what is usually observed. Second, the model predicts a single large outbreak that is followed by decades of much smaller outbreaks, which is not consistent with what is observed. Usually towns or cities report a number of recurrences for many years, even when environmental changes cannot explain the disappearance of the infection between the peaks. In this paper, we continue to examine the pitfalls in modelling this class of infections, and explain that, if properly used, the Ross-Macdonald model works and can be used to understand the patterns of epidemics and even, to some extent, be used to make predictions. We model several outbreaks of dengue fever and show that the variable pattern of yearly recurrence (or its absence) can be understood and explained by a simple Ross-Macdonald model modified to take into account human movement across a range of neighbourhoods within a city. In addition, we analyse the effect of seasonal variations in the parameters that determine the number, longevity and biting behaviour of mosquitoes. Based on the size of the first outbreak, we show that it is possible to estimate the proportion of the remaining susceptible individuals and to predict the likelihood and magnitude of the eventual subsequent outbreaks. This approach is described based on actual dengue outbreaks with different recurrence patterns from some Brazilian regions.
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| 5. |
- Andersson, T, et al.
(author)
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Syndromic surveillance for local outbreak detection and awareness : evaluating outbreak signals of acute gastroenteritis in telephone triage, web-based queries and over-the-counter pharmacy sales
- 2014
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In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 142:2, s. 303-313
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Journal article (peer-reviewed)abstract
- For the purpose of developing a national system for outbreak surveillance, local outbreak signals were compared in three sources of syndromic data - telephone triage of acute gastroenteritis, web queries about symptoms of gastrointestinal illness, and over-the-counter (OTC) pharmacy sales of antidiarrhoeal medication. The data sources were compared against nine known waterborne and foodborne outbreaks in Sweden in 2007-2011. Outbreak signals were identified for the four largest outbreaks in the telephone triage data and the two largest outbreaks in the data on OTC sales of antidiarrhoeal medication. No signals could be identified in the data on web queries. The signal magnitude for the fourth largest outbreak indicated a tenfold larger outbreak than officially reported, supporting the use of telephone triage data for situational awareness. For the two largest outbreaks, telephone triage data on adult diarrhoea provided outbreak signals at an early stage, weeks and months in advance, respectively, potentially serving the purpose of early event detection. In conclusion, telephone triage data provided the most promising source for surveillance of point-source outbreaks.
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| 6. |
- Aspán, Anna, et al.
(author)
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Microarray-based detection of virulence genes in verotoxigenic Escherichia coli O157:H7 strains from Swedish cattle
- 2011
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 139, s. 1088-1096
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Journal article (peer-reviewed)abstract
- Verotoxigenic Escherichia coli (VTEC) serotype O157:H7 strains from a Swedish cattle prevalence study (n=32), and livestock-derived strains linked to human disease (n=13), were characterized by microarray and PCR detection of virulence genes. The overall aim of the study was to investigate the distribution of known virulence determinants and determine which genes are linked to increased pathogenicity in humans. A core set of 18 genes or gene variants were found in all strains, while seven genes were variably present. This suggests that the majority of VTEC O157:H7 found in Swedish cattle carry a broad repertoire of virulence genes and should be considered potentially harmful to humans. A single virulence gene type was significantly associated with strains linked to human disease cases (P=0.012), but no genetic trait to explain the increased virulence of this genotype could be found.
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| 7. |
- Ayukekbong, James A., et al.
(author)
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Monitoring of seasonality of norovirus and other enteric viruses in Cameroon by real-time PCR : an exploratory study
- 2014
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In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 142:7, s. 1393-1402
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Journal article (peer-reviewed)abstract
- We studied the seasonal fluctuation of norovirus and other enteric viruses in Cameroon. Two hundred participants aged between 1 and 69 years were prospectively followed up. Each participant provided monthly faecal samples over a 12-month period. A total of 2484 samples were tested using multiplex real-time PCR assay for the detection of norovirus, rotavirus and enterovirus. The effect of weather variables and risk factors were analysed by Pearson correlation and bivariate analysis. Overall, enterovirus was the most commonly detected virus (216% of specimens), followed by norovirus (39%) and rotavirus (04%). Norovirus and enterovirus were detected throughout the year with a peak of norovirus detection at the beginning of the rainy season and a significant alternation of circulation of norovirus genogroups from one month to the next. Age <5 years and consumption of tap water were risk factors for norovirus infection. Better understanding of factors influencing transmission and seasonality may provide insights into the relationship between physical environment and risk of infection for these viruses.
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| 8. |
- Ayukekbong, James, et al.
(author)
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Monitoring of seasonality of norovirus and other enteric viruses in Cameroon by real-time PCR: an exploratory study
- 2014
-
In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 142:7, s. 1393-1402
-
Journal article (peer-reviewed)abstract
- We studied the seasonal fluctuation of norovirus and other enteric viruses in Cameroon. Two hundred participants aged between 1 and 69 years were prospectively followed up. Each participant provided monthly faecal samples over a 12-month period. A total of 2484 samples were tested using multiplex real-time PCR assay for the detection of norovirus, rotavirus and enterovirus. The effect of weather variables and risk factors were analysed by Pearson correlation and bivariate analysis. Overall, enterovirus was the most commonly detected virus (216% of specimens), followed by norovirus (39%) and rotavirus (04%). Norovirus and enterovirus were detected throughout the year with a peak of norovirus detection at the beginning of the rainy season and a significant alternation of circulation of norovirus genogroups from one month to the next. Age <5 years and consumption of tap water were risk factors for norovirus infection. Better understanding of factors influencing transmission and seasonality may provide insights into the relationship between physical environment and risk of infection for these viruses.
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| 9. |
- Backhans, Annette, et al.
(author)
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Application of multiblock modelling to identify key drivers for antimicrobial use in pig production in four European countries
- 2018
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 146, s. 1003-1014
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Journal article (peer-reviewed)abstract
- Antimicrobial use in pig farming is influenced by a range of risk factors, including herd characteristics, biosecurity level, farm performance, occurrence of clinical signs and vaccination scheme, as well as farmers' attitudes and habits towards antimicrobial use. So far, the effect of these risk factors has been explored separately. Using an innovative method called multi-block partial least-squares regression, this study aimed to investigate, in a sample of 207 farrow-to-finish farms from Belgium, France, Germany and Sweden, the relative importance of the six above mentioned categories or 'blocks' of risk factors for antimicrobial use in pig production, Four country separate models were developed; they showed that all six blocks provided useful contribution to explaining antimicrobial use in at least one country. The occurrence of clinical signs, especially of respiratory and nervous diseases in fatteners, was one of the largest contributing blocks in all four countries, whereas the effect of the other Mocks differed between countries. In terms of risk management, it suggests that a holistic and country-specific mitigation strategy is likely to he more effective. However, further research is needed to validate our findings in larger and more representative samples, as well as in other countries.
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| 10. |
- Backhans, Annette, et al.
(author)
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Occurrence of pathogenic Yersinia enterocolitica and Yersinia pseudotuberculosis in small wild rodents
- 2011
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 139, s. 1230-1238
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Journal article (peer-reviewed)abstract
- Rodents are a potential source of pathogenic Yersinia enterocolitica and Y. pseudotuberculosis. In order to study this, 190 rodents were captured and sampled on seven pig farms (n = 110), five chicken farms (n = 55) and six other locations (n = 25) in Sweden. Pigs from three of the pig farms were also sampled (n = 60). Pathogenic Y. enterocolitica was detected by TaqMan PCR in about 5% of rodent samples and 18% of pig samples. Only rodents caught on pig farms tested positive for the pathogen. Y. enterocolitica bioserotype 4/O:3 strains isolated from the rodent and pig samples were compared by pulsed-field gel electrophoresis and revealed a high degree of similarity, which was confirmed by random amplified polymorphic DNA. Y. pseudotuberculosis was only detected in one rodent sample. Thus, rodents may be vectors for the transmission of pathogenic Y. enterocolitica to pigs, acting as carriers rather than a reservoir, and should therefore remain an important issue in hygiene control measures on farms.
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| 11. |
- Backhans, Annette, et al.
(author)
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Occurrence of pathogens in wild rodents caught on Swedish pig and chicken farms
- 2013
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 141, s. 1885-1891
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Journal article (peer-reviewed)abstract
- A total of 207 wild rodents were caught on nine pig farms, five chicken farms and five non-farm locations in Sweden and surveyed for a selection of bacteria, parasites and viruses. Lawsonia intracellularia and pathogenic Yersinia enterocolitica were only detected in rodents on pig farms (9% and 8% prevalence, respectively) which indicate that these agents are more likely to be transmitted to rodents from pigs or the environment on infected farms. Brachyspira hyodysenteriae (1%), Brachyspira intermedia (2%), Campylobacter jejuni (4%), Campylobacter upsaliensis (2%), leptospires (7%) and encephalomyocarditis virus (9%) were also detected from rodents not in contact with farm animals. Giardia and Cryptosporidium spp. were common, although no zoonotic types were verified, and Salmonella enterica was isolated from 1/11 mice on one farm but not detected by PCR from any of the rodents. Trichinella spp. and Toxoplasma gondii were not detected.
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| 12. |
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| 13. |
- Berruga-Fernández, Talia, et al.
(author)
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Risk assessment for the transmission of Middle East respiratory syndrome coronavirus (MERS-CoV) on aircraft : a systematic review
- 2021
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 149
-
Research review (peer-reviewed)abstract
- Middle East respiratory syndrome coronavirus (MERS-CoV) causes a potentially fatal respiratory disease. Although it is most common in the Arabian Peninsula, it has been exported to 17 countries outside the Middle East, mostly through air travel. The Risk Assessment Guidelines for Infectious Diseases transmitted on Aircraft (RAGIDA) advise authorities on measures to take when an infected individual travelled by air. The aim of this systematic review was to gather all available information on documented MERS-CoV cases that had travelled by air, to update RAGIDA. The databases used were PubMed, Embase, Scopus and Global Index Medicus; Google was searched for grey literature and hand searching was performed on the EU Early Warning and Response System and the WHO Disease Outbreak News. Forty-seven records were identified, describing 21 cases of MERS that had travelled on 31 flights. Contact tracing was performed for 17 cases. Most countries traced passengers sitting in the same row and the two rows in front and behind the case. Only one country decided to trace all passengers and crew. No cases of in-flight transmission were observed; thus, considering the resources it requires, a conservative approach may be appropriate when contact tracing passengers and crew where a case of MERS has travelled by air.
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| 14. |
- Bett, B, et al.
(author)
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Association between Rift Valley fever virus seroprevalences in livestock and humans and their respective intra-cluster correlation coefficients, Tana River County, Kenya
- 2019
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 147
-
Journal article (peer-reviewed)abstract
- We implemented a cross-sectional study in Tana River County, Kenya, a Rift Valley fever (RVF)-endemic area, to quantify the strength of association between RVF virus (RVFv) seroprevalences in livestock and humans, and their respective intra-cluster correlation coefficients (ICCs). The study involved 1932 livestock from 152 households and 552 humans from 170 households. Serum samples were collected and screened for anti-RVFv immunoglobulin G (IgG) antibodies using inhibition IgG enzyme-linked immunosorbent assay (ELISA). Data collected were analysed using generalised linear mixed effects models, with herd/household and village being fitted as random variables. The overall RVFv seroprevalences in livestock and humans were 25.41% (95% confidence interval (CI) 23.49-27.42%) and 21.20% (17.86-24.85%), respectively. The presence of at least one seropositive animal in a household was associated with an increased odds of exposure in people of 2.23 (95% CI 1.03-4.84). The ICCs associated with RVF virus seroprevalence in livestock were 0.30 (95% CI 0.19-0.44) and 0.22 (95% CI 0.12-0.38) within and between herds, respectively. These findings suggest that there is a greater variability of RVF virus exposure between than within herds. We discuss ways of using these ICC estimates in observational surveys for RVF in endemic areas and postulate that the design of the sentinel herd surveillance should consider patterns of RVF clustering to enhance its effectiveness as an early warning system for RVF epidemics.
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| 15. |
- Bjork, J., et al.
(author)
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Surveillance of COVID-19 vaccine effectiveness: a real-time case-control study in southern Sweden
- 2022
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In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 150
-
Journal article (peer-reviewed)abstract
- The extensive register infrastructure available for coronavirus disease 2019 surveillance in Scania county, Sweden, makes it possible to classify individual cases with respect to hospitalisation and disease severity, stratify on time since last dose and demographic factors, account for prior infection and extract data for population controls automatically. In the present study, we developed a case-control sampling design to surveil vaccine effectiveness (VE) in this ethnically and socioeconomically diverse population with more than 1.3 million inhabitants. The first surveillance results show that estimated VE against hospitalisation and severe disease 0-3 months after the last dose remained stable during the study period, but waned markedly 6 months after the last dose in persons aged 65 years or over.
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| 16. |
- Blanco, N., et al.
(author)
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A simple model for the total number of SARS-CoV-2 infections on a national level
- 2021
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In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 149
-
Journal article (peer-reviewed)abstract
- This study aimed to identify an appropriate simple mathematical model to fit the number of coronavirus disease 2019 (COVID-19) cases at the national level for the early portion of the pandemic, before significant public health interventions could be enacted. The total number of cases for the COVID-19 epidemic over time in 28 countries was analysed and fit to several simple rate models. The resulting model parameters were used to extrapolate projections for more recent data. While the Gompertz growth model (mean R-2 = 0.998) best fit the current data, uncertainties in the eventual case limit introduced significant model errors. However, the quadratic rate model (mean R-2 = 0.992) fit the current data best for 25 (89%) countries as determined by R-2 values of the remaining models. Projection to the future using the simple quadratic model accurately forecast the number of future total number of cases 50% of the time up to 10 days in advance. Extrapolation to the future with the simple exponential model significantly overpredicted the total number of future cases. These results demonstrate that accurate future predictions of the case load in a given country can be made using this very simple model.
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| 17. |
- Boqvist, Sofia, et al.
(author)
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Sources of sporadic Yersinia enterocilitica infection in children in Sweden, 2004 : a case-control study
- 2009
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 137, s. 897-905
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Journal article (peer-reviewed)abstract
- Young children account for a large proportion of reported Yersinia enterocolitica infections in Sweden with a high incidence compared with other gastrointestinal infections, such as salmonellosis and campylobacteriosis. A case-control study was conducted to investigate selected risk factors for domestic sporadic yersiniosis in children aged 0–6 years in Sweden. In total, 117 cases and 339 controls were included in the study. To minimize exclusion of observations due to missing data a multiple non-parametric imputation technique was used. The following risk factors were identified in the multivariate analysis : eating food prepared from raw pork products (OR 3.0, 95% CI 1.8–5.1) or treated sausage (OR 1.9, 95% CI 1.1–3.3), use of a baby’s dummy (OR 1.9, 95% CI 1.1–3.2) and contact with domestic animals (OR 2.0, 95% CI 1.2–3.4). We believe that the importance of Y. enterocolitica infection in children has been neglected and that results from this study can be used to develop preventive recommendations.
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| 18. |
- Borg, O., et al.
(author)
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Expansion of spatial and host range of Puumala virus in Sweden : an increasing threat for humans?
- 2017
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In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 145:8, s. 1642-1648
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Journal article (peer-reviewed)abstract
- Hantaviruses are globally distributed and cause severe human disease. Puumala hantavirus (PUUV) is the most common species in Northern Europe, and the only hantavirus confirmed to circulate in Sweden, restricted to the northern regions of the country. In this study, we aimed to further add to the natural ecology of PUUV in Sweden by investigating prevalence, and spatial and host species infection patterns. Specifically, we wanted to ascertain whether PUUV was present in the natural reservoir, the bank vole (Myodes glareolus) further south than Dalälven river, in south-central Sweden, and whether PUUV can be detected in other rodent species in addition to the natural reservoir. In total, 559 animals were collected at Grimsö (59°43'N; 15°28'E), Sala (59°55'N; 16°36'E) and Bogesund (59°24'N; 18°14'E) in south-central Sweden between May 2013 and November 2014. PUUV ELISA-reactive antibodies were found both in 2013 (22/295) and in 2014 (18/264), and nine samples were confirmed as PUUV-specific by focus reduction neutralization test. Most of the PUUV-specific samples were from the natural host, the bank vole, but also from other rodent hosts, indicating viral spill-over. Finally, we showed that PUUV is present in more highly populated central Sweden.
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| 19. |
- Brewer, T. F., et al.
(author)
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Housing, sanitation and living conditions affecting SARS-CoV-2 prevention interventions in 54 African countries
- 2021
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In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 149
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Journal article (peer-reviewed)abstract
- The feasibility of non-pharmacological public health interventions (NPIs) such as physical distancing or isolation at home to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in low-resource countries is unknown. Household survey data from 54 African countries were used to investigate the feasibility of SARS-CoV-2 NPIs in low-resource settings. Across the 54 countries, approximately 718 million people lived in households with > 6 individuals at home (median percentage of at-risk households 56% (95% confidence interval (CI), 51% to 60%)). Approximately 283 million people lived in households where > 3 people slept in a single room (median percentage of at-risk households 15% (95% CI, 13% to 19%)). An estimated 890 million Africans lack on-site water (71% (95% CI, 62% to 80%)), while 700 million people lacked in-home soap/washing facilities (56% (95% CI, 42% to 73%)). The median percentage of people without a refrigerator in the home was 79% (95% CI, 67% to 88%), while 45% (95% CI, 39% to 52%) shared toilet facilities with other households. Individuals in low-resource settings have substantial obstacles to implementing NPIs for mitigating SARS-CoV-2 transmission. These populations urgently need to be prioritised for coronavirus disease 2019 vaccination to prevent disease and to contain the global pandemic.
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| 20. |
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| 21. |
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| 22. |
- De, Rituparna, et al.
(author)
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Retrospective genomic analysis of Vibrio cholerae O1 El Tor strains from different places in India reveals the presence of ctxB-7 allele found in Haitian isolates
- 2017
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In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 145:11, s. 2212-2220
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Journal article (peer-reviewed)abstract
- A total of 45 strains of Vibrio cholerae O1 isolated from 10 different places in India where they were associated with cases of cholera between the years 2007 and 2008 were examined by molecular methods. With the help of phenotypic and genotypic tests the strains were confirmed to be O1 El Tor biotype strains with classical ctxB gene. Polymerase chain reaction (PCR) analysis by double - mismatch amplification mutation assay PCR showed 16 of these strains carried the ctxB-7 allele reported in Haitian strains. Sequencing of the ctxB gene in all the 45 strains revealed that in 16 strains the histidine at the 20th amino acid position had been replaced by asparagine and this single nucleotide polymorphism did not affect cholera toxin production as revealed by beads enzyme-linked immunosorbent assay. This study shows that the new ctxB gene sequence was circulating in different places in India. Seven representatives of these 45 strains analysed by pulsed - field gel electrophoresis showed four distinct Not I digested profiles showing that multiple clones were causing cholera in 2007 and 2008.
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| 23. |
- Desvars-Larrive, Amélie, et al.
(author)
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High-risk regions and outbreak modelling of tularemia in humans
- 2017
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In: Epidemiology and Infection. - : CAMBRIDGE UNIV PRESS. - 0950-2688 .- 1469-4409. ; 145:3, s. 482-490
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Journal article (peer-reviewed)abstract
- Sweden reports large and variable numbers of human tularemia cases, but the high-risk regions are anecdotally defined and factors explaining annual variations are poorly understood. Here, high-risk regions were identified by spatial cluster analysis on disease surveillance data for 1984-2012. Negative binomial regression with five previously validated predictors (including predicted mosquito abundance and predictors based on local weather data) was used to model the annual number of tularemia cases within the high-risk regions. Seven high-risk regions were identified with annual incidences of 3.8-44 cases/100 000 inhabitants, accounting for 56.4% of the tularemia cases but only 9.3% of Sweden's population. For all high-risk regions, most cases occurred between July and September. The regression models explained the annual variation of tularemia cases within most high-risk regions and discriminated between years with and without outbreaks. In conclusion, tularemia in Sweden is concentrated in a few high-risk regions and shows high annual and seasonal variations. We present reproducible methods for identifying tularemia high-risk regions and modelling tularemia cases within these regions. The results may help health authorities to target populations at risk and lay the foundation for developing an early warning system for outbreaks.
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| 24. |
- Earnest, A, et al.
(author)
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Meteorological factors and El Niño Southern Oscillation are independently associated with dengue infections
- 2012
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 140:07, s. 1244-1251
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Journal article (peer-reviewed)abstract
- Our objective was to determine the association between temperature, humidity, rainfall and dengue activity in Singapore, after taking into account lag periods as well as long-term climate variability such as the El Niño Southern Oscillation Index (SOI). We used a Poisson model which allowed for autocorrelation and overdispersion in the data. We found weekly mean temperature and mean relative humidity as well as SOI to be significantly and independently associated with dengue notifications. There was an interaction effect by periods of dengue outbreaks, but periods where El Niño was present did not moderate the relationship between humidity and temperature with dengue notifications. Our results help to understand the temporal trends of dengue in Singapore, and further reinforce the findings that meteorological factors are important in the epidemiology of dengue.
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| 25. |
- Esteves, A., et al.
(author)
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Genetic diversity of norovirus in children under 5 years of age with acute gastroenteritis from Angola
- 2018
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In: Epidemiology and Infection. - : CAMBRIDGE UNIV PRESS. - 0950-2688 .- 1469-4409. ; 146:5, s. 551-557
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Journal article (peer-reviewed)abstract
- Norovirus (NoV) is a major cause of acute gastroenteritis (AGE). In this study, we investigated the genetic diversity of NoV strains identified in children under 5 years of age with AGE in four provinces of Angola. Faecal samples from 343 children were screened for NoV by an in house real-time PCR assay and genotyping was performed by partial capsid gene sequencing. NoV was detected in 17.4% (58/334) of the samples, with high detection rates in children amp;lt;6 months old (19%) and in children aged 12-24 months (23%). Genotype diversity was large, as demonstrated by the 11 identified genotypes. GII.4 was the predominant genotype (20% of all NoV-positive samples), followed by GII.6 (15%), GI.3 (12%), GII.7 (10%) and by other genotypes to a lesser extent. Two GII.4 variants, New Orleans 2009 and Sydney 2012, were detected and several genetic clusters were observed for genotypes GI.3, GII.6 and GII.7. The present study shows high detection rates and genetic diversity of circulating NoV genotypes in paediatric AGE samples from Angola. This information emphasises the importance of continuous assessment of NoV burden and evolution in the target population.
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| 26. |
- Gotz, HM, et al.
(author)
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A whirlpool associated outbreak of Pontiac fever at a hotel in Northern Sweden
- 2001
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In: Epidemiology and infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 126:2, s. 241-247
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Journal article (peer-reviewed)abstract
- In April 1999, an outbreak of Pontiac fever occurred at a hotel in Northern Sweden. A retrospective cohort study to find the source and define the extent of the outbreak was carried out among 530 Swedish and Norwegian guests. Twenty-nine epidemiological cases (8 % of 378 responders) aged 21–57 years were identified. Antibodies against Legionella micdadei were detected in 17 of 27 tested cases and 3 other symptomatic persons. Visiting the whirlpool area was identified as the sole risk factor (RR 86; 95 % CI 21–352) and infected cases were confined to visitors to this area over three successive days. The attack rate was 71 % (27/38) and 24 cases (83 %) used the whirlpool. Environmental sampling was negative for Legionella sp. But epidemiological investigation strongly suggests that the whirlpool was the source of the outbreak. The possibility of serious legionella infections underlines the importance of strict maintenance practices to maintain hygiene of whirlpools.
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| 27. |
- Gustafsson, Camilla, et al.
(author)
-
Toxoplasma gondii seroprevalence in wild boars (Sus scrofa) in Sweden and evaluation of ELISA test performance
- 2015
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 143, s. 1913-1921
-
Journal article (peer-reviewed)abstract
- Toxoplasma gondii is a zoonotic protozoan parasite, infecting a wide range of warm-blooded animals. The Swedish wild boar population is expanding and increased hunting provides its meat to a growing group of consumers. We performed a spatio-temporal investigation of T. gondii seroprevalence in Swedish wild boars. An ELISA was set up and evaluated against a commercial direct agglutination test, using Bayesian latent class analysis. The ELISA sensitivity and specificity were estimated to 79% and 85%, respectively. Of 1327 serum samples, 50% were positive. Thirty-four per cent of young wild boars and 55% of adults were positive (P<0·001). The total seroprevalence ranged from 72% in 2005 to 38% in 2011 (P<0·001), suggesting a declining trend. The highest seroprevalence, 65%, was recorded in South Sweden. In other regions it varied from 29% in Stockholm to 46% in East Middle Sweden.
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| 28. |
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| 29. |
- Hestvik, Gete, et al.
(author)
-
Francisella tularensis in muscle from diseased hares - a risk factor for humans?
- 2017
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 145, s. 3449-3454
-
Journal article (peer-reviewed)abstract
- Tularemia caused by the bacterium Francisella tularensis is a zoonotic disease. Tularemia is a common disease in the hare, and as a game species can be an important source of infection for humans. In this study, hares diagnosed with tularemia were examined with the aim to investigate whether the muscle (meat) had any pathological changes and/or contained F. tularensis. Real-time PCR and/or immunohistochemistry (IHC) detected the bacteria in muscle samples from 40 out of 43 investigated hares. IHC showed that bacteria were few and most commonly located in the peri- and endomysium. Histopathology showed occasional perimysial necroses and mild inflammation in association to the bacteria. Attempts to culture from 14 muscle samples were successful in two cases, both stored in the freezer <1 year. The result of this study shows that since F. tularensis is present in the muscle of infected hares, there is a risk for human infection when consuming undercooked hare meat. The risk is enhanced by the fact that some hares do not have easily detected gross lesions. The study contributes to a better understanding of sources of infection and risk factors for humans to contract tularemia.
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| 30. |
- Hestvik, Gete, et al.
(author)
-
The status of tularemia in Europe in a one-health context: a review
- 2015
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 143, s. 2137-2160
-
Journal article (peer-reviewed)abstract
- The bacterium Francisella tularensis causes the vector-borne zoonotic disease tularemia, and may infect a wide range of hosts including invertebrates, mammals and birds. Transmission to humans occurs through contact with infected animals or contaminated environments, or through arthropod vectors. Tularemia has a broad geographical distribution, and there is evidence which suggests local emergence or re-emergence of this disease in Europe. This review was developed to provide an update on the geographical distribution of F. tularensis in humans, wildlife, domestic animals and vector species, to identify potential public health hazards, and to characterize the epidemiology of tularemia in Europe. Information was collated on cases in humans, domestic animals and wildlife, and on reports of detection of the bacterium in arthropod vectors, from 38 European countries for the period 1992-2012. Multiple international databases on human and animal health were consulted, as well as published reports in the literature. Tularemia is a disease of complex epidemiology that is challenging to understand and therefore to control. Many aspects of this disease remain poorly understood. Better understanding is needed of the epidemiological role of animal hosts, potential vectors, mechanisms of maintenance in the different ecosystems, and routes of transmission of the disease.
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| 31. |
- Karlsson, Diana
(author)
-
Probabilistic network modelling of the impact of penicillin consumption on spread of pneumococci
- 2011
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 139:9, s. 1351-1360
-
Journal article (peer-reviewed)abstract
- The worldwide increase of resistant S. pneumoniae is a growing clinical problem. In several countries, a more restrictive use of penicillin has been promoted in hope of slowing the rates of resistant pneumococci. However, the consequences of such an action on pneumococcal population dynamics are not fully understood. Thus, a network model was constructed to assess the impacts of penicillin consumption and between-strain competition on the spread of penicillin non-susceptible pneumococci. Model simulations suggest that the age distribution for carriage of penicillin non-susceptible pneumococci, in contrast to susceptible pneumococci, is affected by penicillin consumption. Furthermore, it appears extremely difficult to reduce the incidence of penicillin non-susceptible pneumococci by simply controlling penicillin consumption, assuming that reduced penicillin susceptibility does not confer a fitness cost for the organism. A more judicious use of penicillin together with control measures are in that case required to manage penicillin resistance in pneumococci.
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| 32. |
- Khalil, Hussein
(author)
-
Prevalence of Diarrheagenic Escherichia coli (DEC) and Salmonella spp. with zoonotic potential in urban rats in Salvador, Brazil
- 2020
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 149
-
Journal article (peer-reviewed)abstract
- Studies evaluating the occurrence of enteropathogenic bacteria in urban rats (Rattus spp.) are scarce worldwide, specifically in the urban environments of tropical countries. This study aims to estimate the prevalence of diarrhoeagenic Escherichia coli (DEC) and Salmonella spp. with zoonotic potential in urban slum environments. We trapped rats between April and June 2018 in Salvador, Brazil. We collected rectal swabs from Rattus spp., and cultured for E. coli and Salmonella spp., and screened E. coli isolates by polymerase chain reaction to identify pathotypes. E. coli were found in 70% of Rattus norvegicus and were found in four Rattus rattus. DEC were isolated in 31.3% of the 67 brown rats (R. norvegicus). The pathotypes detected more frequently were shiga toxin E. coli in 11.9%, followed by atypical enteropathogenic E. coli in 10.4% and enteroinvasive E. coli in 4.5%. From the five black rats (R. rattus), two presented DEC. Salmonella enterica was found in only one (1.4%) of 67 R. norvegicus. Our findings indicate that both R. norvegicus and R. rattus are host of DEC and, at lower prevalence, S. enterica, highlighting the importance of rodents as potential sources of pathogenic agents for humans.
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| 33. |
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| 34. |
- Kingamkono, R., et al.
(author)
-
Enteropathogenic bacteria in faecal swabs of young children fed on lactic acid-fermented cereal gruels
- 1999
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 122:1, s. 23-32
-
Journal article (peer-reviewed)abstract
- The influence of consumption of a lactic acid-fermented cereal gruel togwa with pH ? 4 on the presence of faecal enteric bacteria such as campylobacter, enterohaemorrhagic Escherichia coli (EHEC:O157), enterotoxigenic Escherichia coli (ETEC), salmonella and shigella was evaluated. Under 5 years old healthy children listed in an ascending order of age were alternatively assigned and given either a lactic-acid fermented cereal gruel togwa (test diet) or an unfermented cereal gruel uji (control diet) once a day for 13 consecutive days. The presence of the enteropathogens was examined in rectal swabs collected from the children at baseline (before feeding session started), on days 7 and 13, and additionally 14 days (follow-up day) after the feeding session had stopped. The swabs were cultured on to different optimal media for respective enteropathogen and confirmed by standard microbiological and serological methods. Campylobacter spp. dominated among the enteropathogens (62% out of total) followed by Salmonella spp., ETEC and Shigella spp. Children with isolated enteropathogens in the togwa group was significantly reduced (P < 0.001) from 27.6% at baseline to 7.8, 8.2 and 12.7% on days 7, 13 and follow-up day, respectively. The effect was more pronounced in those children taking togwa > 6 times during the study period. In the control group, there was a slight decrease from 16.7% at baseline to 11.4% on day 7 and 8.1% on day 13. On the follow-up day, enteropathogens were found in 22.6% of the children, which was significantly higher than in those children taking togwa > 6 times. We conclude, that regular consumption of togwa with pH ? 4, once a day, three times a week may help to control intestinal colonization with potential diarrhoea-causing pathogens in young children.Campylobacter jejuni/coli, enteropathogenic E. coli, enterotoxigenic E. coli, Salmonella spp., Shigella spp., and rotavirus are consistently implicated with diarrhea in children under age 5 years in developing countries. The influence of consumption of a lactic acid-fermented cereal gruel (togwa) with pH of less than or equal to 4 upon the presence of such fecal enteric bacteria was evaluated. 151 healthy children aged 6-60 months in Majohe village listed in an ascending order of age were alternatively assigned and given either togwa or an unfermented cereal gruel (uji) once a day for 13 consecutive days. The presence of enteropathogens was then examined in rectal swabs collected from the children at baseline before the feeding session started, on days 7 and 13, and 14 days later after the feeding session had stopped. 62% of the enteropathogens identified were of campylobacter spp., followed by Salmonella and Shigella spp. The proportion of children with isolated enteropathogens in the togwa group was significantly reduced from 27.6% at baseline to 7.8%, 8.2%, and 12.7% on days 7, 13, and the follow-up day, respectively. The effect was more pronounced among children taking togwa more than 6 times/day during the study period. In the control group, there was a slight decrease from 16.7% at baseline to 11.4% on day 7 and 8.1% on day 13. On the follow-up day, enteropathogens were found in 22.6% of the children, which was significantly higher than in those children taking togwa more than 6 times. The regular consumption of togwa with pH of less than or equal to 4, once per day, 3 times per week may help to control intestinal colonization with potential diarrhea-causing pathogens in young children.
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| 35. |
- Küchenhoff, Helmut, et al.
(author)
-
Analysis of the early COVID-19 epidemic curve in Germany by regression models with change points
- 2021
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 149, s. 1-7
-
Journal article (peer-reviewed)abstract
- We analysed the coronavirus disease 2019 epidemic curve from March to the end of April 2020 in Germany. We use statistical models to estimate the number of cases with disease onset on a given day and use back-projection techniques to obtain the number of new infections per day. The respective time series are analysed by a trend regression model with change points. The change points are estimated directly from the data. We carry out the analysis for the whole of Germany and the federal state of Bavaria, where we have more detailed data. Both analyses show a major change between 9 and 13 March for the time series of infections: from a strong increase to a decrease. Another change was found between 25 March and 29 March, where the decline intensified. Furthermore, we perform an analysis stratified by age. A main result is a delayed course of the pandemic for the age group 80 + resulting in a turning point at the end of March. Our results differ from those by other authors as we take into account the reporting delay, which turned out to be time dependent and therefore changes the structure of the epidemic curve compared to the curve of newly reported cases.
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| 36. |
- Larsson, C., et al.
(author)
-
Epidemiology and estimated costs of a large waterborne outbreak of norovirus infection in Sweden
- 2014
-
In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 1469-4409 .- 0950-2688. ; 142:3, s. 592-600
-
Journal article (peer-reviewed)abstract
- A large outbreak of norovirus (NoV) gastroenteritis caused by contaminated municipal drinking water occurred in Lilla Edet, Sweden, 2008. Epidemiological investigations performed using a questionnaire survey showed an association between consumption of municipal drinking water and illness (odds ratio 4 center dot 73, 95% confidence interval 3 center dot 53-6 center dot 32), and a strong correlation between the risk of being sick and the number of glasses of municipal water consumed. Diverse NoV strains were detected in stool samples from patients, NoV genotype I strains predominating. Although NoVs were not detected in water samples, coliphages were identified as a marker of viral contamination. About 2400 (18 center dot 5%) of the 13000 inhabitants in Lilla Edet became ill. Costs associated with the outbreak were collected via a questionnaire survey given to organizations and municipalities involved in or affected by the outbreak. Total costs including sick leave, were estimated to be similar to 8700000 Swedish kronor (similar to euro0 center dot 87 million).
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| 37. |
- Liese, J. G., et al.
(author)
-
Incidence and clinical presentation of acute otitis media in children aged < 6 years in European medical practices
- 2014
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 142:8, s. 1778-1788
-
Journal article (peer-reviewed)abstract
- We conducted an epidemiological, observational cohort study to determine the incidence and complications of acute otitis media (AOM) in children aged <6 years. Data on physician-diagnosed AOM were collected from retrospective review of medical charts for the year preceding enrolment and then prospectively in the year following enrolment. The study included 5776 children in Germany, Italy, Spain, Sweden, and the UK. AOM incidence was 256/1000 person-years [95% confidence interval (CI) 243-270] in the prospective study period. Incidence was lowest in Italy (195, 95% CI 171-222) and highest in Spain (328, 95% CI 296-363). Complications were documented in < 1% of episodes. Spontaneous tympanic membrane perforation was documented in 7% of episodes. Both retrospective and prospective study results were similar and show the high incidence during childhood in these five European countries. Differences by country may reflect true differences and differences in social structure and diagnostic procedures.
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| 38. |
- Lopez-Valladares, Gloria, 1963-, et al.
(author)
-
Human isolates of Listeria monocytogenes in Sweden during half a century (1958-2010)
- 2014
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 142, s. 2251-2260
-
Journal article (peer-reviewed)abstract
- Isolates of Listeria monocytogenes (n=932) isolated in Sweden during 1958–2010 from human patients with invasive listeriosis were characterized by serotyping and pulsed-field gel electrophoresis (PFGE) (AscI). Of the 932 isolates, 183 different PFGE types were identified, of which 83 were each represented by only one isolate. In all, 483 serovar 1/2a isolates were distributed over 114 PFGE types; 90 serovar 1/2b isolates gave 32 PFGE types; 21 serovar 1/2c isolates gave nine PFGE types; three serovar 3b isolates gave one PFGE type; and, 335 serovar 4b isolates gave 31 PFGE types. During the 1980s in Sweden, several serovar 4b cases were associated with the consumption of European raw soft cheese. However, as cheese-production hygiene has improved, the number of 4b cases has decreased. Since 1996, serovar 1/2a has been the dominant L. monocytogenes serovar in human listeriosis in Sweden. Therefore, based on current serovars and PFGE types, an association between human cases of listeriosis and the consumption of vacuum-packed gravad and cold-smoked salmon is suggested.
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| 39. |
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| 40. |
- Malmsten, Jonas, et al.
(author)
-
Temporal and spatial variation in Anaplasma phagocytophilum infection in Swedish moose (Alces alces)
- 2014
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 142, s. 1205-1213
-
Journal article (peer-reviewed)abstract
- The occurrence of Anaplasma phagocytophilum was investigated in spleen and serum samples from Swedish moose (Alces alces) in southern Sweden (island and mainland). Samples were analysed for presence of A. phagocytophilum DNA by real-time PCR (n=263), and for Anaplasma antibodies with ELISA serology (n=234). All serum samples had antibodies against A. phagocytophilum. The mean DNA-based prevalence was 26 center dot 3%, and significant (P<0 center dot 01) temporal, and spatial variation was found. Island moose had significantly (P<0 center dot 001) higher prevalence of A. phagocytophilum DNA than moose from the mainland areas. Two samples were sequenced to determine genetic variation in the 16S rRNA and groESL genes. Genetic sequence similarity with the human granulocytic anaplasmosis agent, equine granulocytic ehrlichiosis agent, and different wildlife-associated A. phagocytophilum variants were observed in the 16S rRNA and groESL genes. Our study shows that moose are exposed to A. phagocytophilum in Sweden, and represent a potential wildlife reservoir of the pathogen.
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| 41. |
- Massad, E, et al.
(author)
-
Dengue infections in non-immune travellers to Thailand
- 2013
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 141:2, s. 412-417
-
Journal article (peer-reviewed)abstract
- Dengue is the most frequent arboviral disease and is expanding geographically. Dengue is also increasingly being reported in travellers, in particular in travellers to Thailand. However, data to quantify the risk of travellers acquiring dengue when travelling to Thailand are lacking. Using mathematical modelling, we set out to estimate the risk of non-immune persons acquiring dengue when travelling to Thailand. The model is deterministic with stochastic parameters and assumes a Poisson distribution for the mosquitoes' biting rate and a Gamma distribution for the probability of acquiring dengue from an infected mosquito. From the force of infection we calculated the risk of dengue acquisition for travellers to Thailand arriving in a typical year (averaged over a 17-year period) in the high season of transmission. A traveller arriving in the high season of transmission and remaining for 7 days has a risk of acquiring dengue of 0.2% (95% CI 0.16-0.23), whereas the risk for travel of 15 and 30 days' duration is 0.46% (95% CI 0.41-0.50) and 0.81% (95% CI 0.76-0.87), respectively. Our data highlight that the risk of non-immune travellers acquiring dengue in Thailand is substantial. The incidence of 0.81% after a 1-month stay is similar to that reported in prospective seroconversion studies in Israeli travellers to Thailand, highlighting that our models are consistent with actual data. Risk estimates based on mathematical modelling offer more detailed information depending on various travel scenarios, and will help the travel medicine provider give better evidence-based advice for travellers to dengue-endemic countries.
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| 42. |
- Massad, Eduardo, et al.
(author)
-
Modelling an optimum vaccination strategy against ZIKA virus for outbreak use
- 2019
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 147
-
Journal article (peer-reviewed)abstract
- We present a model to optimise a vaccination campaign aiming to prevent or to curb a Zika virus outbreak. We show that the optimum vaccination strategy to reduce the number of cases by a mass vaccination campaign should start when the Aedes mosquitoes' density reaches the threshold of 1.5 mosquitoes per humans, the moment the reproduction number crosses one. The maximum time it is advisable to wait for the introduction of a vaccination campaign is when the first ZIKV case is identified, although this would not be as effective to minimise the number of infections as when the mosquitoes' density crosses the critical threshold. This suboptimum strategy, however, would still curb the outbreak. In both cases, the catch up strategy should aim to vaccinate at least 25% of the target population during a concentrated effort of 1 month immediately after identifying the threshold. This is the time taken to accumulate the herd immunity threshold of 56.5%. These calculations were done based on theoretical assumptions that vaccine implementation would be feasible within a very short time frame.
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| 43. |
- Massad, E., et al.
(author)
-
On the origin and timing of Zika virus introduction in Brazil
- 2017
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 145:11, s. 2303-2312
-
Journal article (peer-reviewed)abstract
- The timing and origin of Zika virus (ZIKV) introduction in Brazil has been the subject of controversy. Initially, it was assumed that the virus was introduced during the FIFA World Cup in June-July 2014. Then, it was speculated that ZIKV may have been introduced by athletes from French Polynesia (FP) who competed in a canoe race in Rio de Janeiro in August 2014. We attempted to apply mathematical models to determine the most likely time window of ZIKV introduction in Brazil. Given that the timing and origin of ZIKV introduction in Brazil may be a politically sensitive issue, its determination (or the provision of a plausible hypothesis) may help to prevent undeserved blame. We used a simple mathematical model to estimate the force of infection and the corresponding individual probability of being infected with ZIKV in FP. Taking into account the air travel volume from FP to Brazil between October 2013 and March 2014, we estimated the expected number of infected travellers arriving at Brazilian airports during that period. During the period between December 2013 and February 2014, 51 individuals travelled from FP airports to 11 Brazilian cities. Basing on the calculated force of ZIKV infection (the per capita rate of new infections per time unit) and risk of infection (probability of at least one new infection), we estimated that 18 (95% CI 12-22) individuals who arrived in seven of the evaluated cities were infected. When basic ZIKV reproduction numbers greater than one were assumed in the seven evaluated cities, ZIKV could have been introduced in any one of the cities. Based on the force of infection in FP, basic reproduction ZIKV number in selected Brazilian cities, and estimated travel volume, we concluded that ZIKV was most likely introduced and established in Brazil by infected travellers arriving from FP in the period between October 2013 and March 2014, which was prior to the two aforementioned sporting events.
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| 44. |
- Massad, Eduardo, et al.
(author)
-
Two complementary model-based methods for calculating the risk of international spreading of a novel virus from the outbreak epicentre. The case of COVID-19
- 2020
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 148
-
Journal article (peer-reviewed)abstract
- We present two complementary model-based methods for calculating the risk of international spread of the novel coronavirus SARS-CoV-2 from the outbreak epicentre. One model aims to calculate the number of cases that would be exported from an endemic country to disease-free regions by travellers. The second model calculates the probability that an infected traveller will generate at least one secondary autochthonous case in the visited country. Although this paper focuses on the data from China, our methods can be adapted to calculate the risk of importation and subsequent outbreaks. We found an averageR(0)= 5.31 (ranging from 4.08 to 7.91) and a risk of spreading of 0.75 latent individuals per 1000 travellers. In addition, one infective traveller would be able to generate at least one secondary autochthonous case in the visited country with a probability of 23%.
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| 45. |
- Mathabire Rücker, Sekai Chenai, et al.
(author)
-
Transmission of COVID-19 among healthcare workers : an epidemiological study during the first phase of the pandemic in Sweden
- 2022
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 150
-
Journal article (peer-reviewed)abstract
- During the first phase of the COVID-19 pandemic in 2020, concerns were raised that healthcare workers (HCWs) were at high risk of infection. The aim of this study was to explore transmission of COVID-19 among HCWs during a staff outbreak at an inpatient ward in Sweden 1 March to 31 May 2020. A mixed methods approach was applied using several data sources. In total, 152 of 176 HCWs participated. The incidence of COVID-19 among HCWs was 33%. Among cases, 48 (96%) performed activities involving direct contact with COVID-19 patients. Contact tracing connected 78% of cases to interaction with another contagious co-worker. Only a few HCWs cases reported contact with a confirmed COVID-19 case at home (n=6; 12%) or in the community (n=3; 6%). Multiple logistic regression identified direct care of COVID-19 patients and positive COVID-19 family contact as risk factors for infection (adjusted OR 8.4 and 9.0 respectively). Main interventions to stop the outbreak were physical distancing between HCWs, reinforcement of personal hygiene routines and rigorous surface cleaning. The personal protective equipment used in contact with patients was not changed in response to the outbreak. We highlight HCW-to-HCW transmission of COVID-19 in a hospital environment and the importance of preventing droplet and contact transmission between co-workers.
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| 46. |
- Mathabire Rücker, Sekai Chenai, et al.
(author)
-
Transmission of COVID-19 among healthcare workers - an epidemiological study during the first phase of the pandemic in Sweden
- 2022
-
In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 150
-
Journal article (peer-reviewed)abstract
- During the first phase of the COVID-19 pandemic in 2020, concerns were raised that healthcare workers (HCWs) were at high risk of infection. The aim of this study was to explore the transmission of COVID-19 among HCWs during a staff outbreak at an inpatient ward in Sweden 1 March to 31 May 2020. A mixed-methods approach was applied using several data sources. In total, 152 of 176 HCWs participated. The incidence of COVID-19 among HCWs was 33%. Among cases, 48 (96%) performed activities involving direct contact with COVID-19 patients. Contact tracing connected 78% of cases to interaction with another contagious co-worker. Only a few HCW cases reported contact with a confirmed COVID-19 case at home (n = 6; 12%) or in the community (n = 3; 6%). Multiple logistic regression identified direct care of COVID-19 patients and positive COVID-19 family contact as risk factors for infection (adjusted OR 8.4 and 9.0 respectively). Main interventions to stop the outbreak were physical distancing between HCWs, reinforcement of personal hygiene routines and rigorous surface cleaning. The personal protective equipment used in contact with patients was not changed in response to the outbreak. We highlight HCW-to-HCW transmission of COVID-19 in a hospital environment and the importance of preventing droplet and contact transmission between co-workers.
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| 47. |
- Mcelhinney, L. M., et al.
(author)
-
High prevalence of Seoul hantavirus in a breeding colony of pet rats
- 2017
-
In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 145:15, s. 3115-3124
-
Journal article (peer-reviewed)abstract
- As part of further investigations into three linked haemorrhagic fever with renal syndrome (HFRS) cases in Wales and England, 21 rats from a breeding colony in Cherwell, and three rats from a household in Cheltenham were screened for hantavirus. Hantavirus RNA was detected in either the lungs and/or kidney of 17/21 (81%) of the Cherwell rats tested, higher than previously detected by blood testing alone (7/21, 33%), and in the kidneys of all three Cheltenham rats. The partial L gene sequences obtained from 10 of the Cherwell rats and the three Cheltenham rats were identical to each other and the previously reported UK Cherwell strain. Seoul hantavirus (SEOV) RNA was detected in the heart, kidney, lung, salivary gland and spleen (but not in the liver) of an individual rat from the Cherwell colony suspected of being the source of SEOV. Serum from 20/20 of the Cherwell rats and two associated HFRS cases had high levels of SEOV-specific antibodies (by virus neutralisation). The high prevalence of SEOV in both sites and the moderately severe disease in the pet rat owners suggest that SEOV in pet rats poses a greater public health risk than previously considered.
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| 48. |
- Melotti, Roberto, et al.
(author)
-
Prevalence and determinants of serum antibodies to SARS-CoV-2 in the general population of the Gardena valley
- 2021
-
In: Epidemiology and Infection. - : Cambridge University Press. - 0950-2688 .- 1469-4409. ; 149
-
Journal article (peer-reviewed)abstract
- Estimating the spread of SARS-CoV-2 infection in communities is critical. We surveyed 2244 stratified random sample community members of the Gardena valley, a winter touristic area, amidst the first expansion phase of the COVID-19 pandemic in Europe. We measured agreement between Diasorin and Abbott serum bioassay outputs and the Abbott optimal discriminant threshold of serum neutralisation titres with recursive receiver operating characteristic curve. We analytically adjusted serum antibody tests for unbiased seroprevalence estimate and analysed the determinants of infection with non-response weighted multiple logistic regression. SARS-CoV-2 seroprevalence was 26.9% (95% CI 25.2-28.6) by June 2020. The bioassays had a modest agreement with each other. At a lower threshold than the manufacturer's recommended level, the Abbott assay reflected greater discrimination of serum neutralisation capacity. Seropositivity was associated with place and economic activity, not with sex or age. Symptoms like fever and weakness were age-dependent. SARS-CoV-2 mitigation strategies should account for context in high prevalence areas.
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| 49. |
- Mukanyangezi, Marie Francoise, et al.
(author)
-
Sexual risk behaviour in a cohort of HIV-negative and HIV-positive Rwandan women
- 2019
-
In: Epidemiology and Infection. - : Cambridge University Press (CUP). - 0950-2688 .- 1469-4409. ; 147
-
Journal article (peer-reviewed)abstract
- Here we wanted to assess whether sexual risk behaviour differs dependent by human immunodeficiency virus (HIV) status by following 100 HIV- and 137 HIV+ women recruited at two university teaching hospitals in Rwanda. Women were tested for sexually transmitted infections (STIs; trichomoniasis, syphilis, hepatitis B and C) and for reproductive tract infections (RTIs; candidiasis, bacterial vaginosis (BV)) and were interviewed at baseline and 9 months later. BV was the most prevalent infection, while syphilis was the most common STI with a 9-month incidence of 10.9% in HIV+ women. Only 24.5% of women positive for any RTI/STI contacted their health facility and got treatment. More HIV- women than HIV+ women had had more than one sexual partner and never used condoms during the follow-up period. The use of condoms was affected neither by marital status nor by concomitant STIs besides HIV. Our data highlight the importance of public education regarding condom use to protect against STIs in an era when HIV no longer is a death sentence.
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| 50. |
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