| 1. |
- Wallensten, Anders, et al.
(författare)
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Surveillance of influenza A virus in migratory waterfowl in northern Europe
- 2007
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Ingår i: Emerging Infectious Diseases. - 1080-6040 .- 1080-6059. - 1080-6040 ; 13:3, s. 404-411
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Tidskriftsartikel (refereegranskat)abstract
- We conducted large-scale, systematic sampling of influenza type A virus in migratory waterfowl (mostly mallards [Anas platyrhynchos]) at Ottenby Bird Observatory, southeast Sweden. As with previous studies, we found a higher prevalence in fall than spring, and among juveniles compared with adults. However, in contrast to other studies, we found that prevalence in spring was sometimes high (mean 4.0%, highest 9.5%). This finding raises the possibility that ducks are capable of perpetuating influenza A virus of different subtypes and subtype combinations throughout the year and from 1 year to the next. Isolation of the H5 and H7 subtypes was common, which suggests risk for transmission to sensitive domestic animals such as poultry. We argue that wild bird screening can function as a sentinel system, and we give an example of how it could have been used to forecast a remote and deadly outbreak of influenza A in poultry.
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| 2. |
- Haemig, Paul D., et al.
(författare)
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Forecasting risk of tick-borne encephalitis (TBE): Using data from wildlife and climate to predict next year's number of human victims
- 2011
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548. ; 43:5, s. 366-372
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Tidskriftsartikel (refereegranskat)abstract
- Background: Over the past quarter century, the incidence of tick-borne encephalitis (TBE) has increased in most European nations. However, the number of humans stricken by the disease varies from year to year. A method for predicting major increases and decreases is needed. Methods: We assembled a 25-y database (1984-2008) of the number of human TBE victims and wildlife and climate data for the Stockholm region of Sweden, and used it to create easy-to-use mathematical models that predict increases and decreases in the number of humans stricken by TBE. Results: Our best model, which uses December precipitation and mink (Neovison vison, formerly Mustela vison) bagging figures, successfully predicted every major increase or decrease in TBE during the past quarter century, with a minimum of false alarms. However, this model was not efficient in predicting small increases and decreases. Conclusions: Predictions from our models can be used to determine when preventive and adaptive programmes should be implemented. For example, in years when the frequency of TBE in humans is predicted to be high, vector control could be intensified where infested ticks have a higher probability of encountering humans, such as at playgrounds, bathing lakes, barbecue areas and camping facilities. Because our models use only wildlife and climate data, they can be used even when the human population is vaccinated. Another advantage is that because our models employ data from previously-established databases, no additional funding for surveillance is required.
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| 3. |
- Hardestam, Jonas, et al.
(författare)
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Antiviral effect of human saliva against hantavirus.
- 2008
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Ingår i: Journal of medical virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 80:12, s. 2122-6
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Tidskriftsartikel (refereegranskat)abstract
- Hemorrhagic fever with renal syndrome (HFRS) and Hantavirus pulmonary syndrome are zoonotic diseases caused by rodent borne hantaviruses. Transmission to humans occurs usually by inhalation of aerozolized virus-contaminated rodent excreta. Although human-to-human transmission of Andes hantavirus has been observed, the mode of transmission is currently not known. Saliva from Puumala hantavirus (PUUV)-infected patients was shown recently to contain viral RNA. To test if human saliva interferes with hantavirus replication, the effect of saliva and salivary proteins on hantavirus replication was studied. It was observed that saliva from healthy individuals reduced Hantaan hantavirus (HTNV) infectivity, although not completely. Furthermore, HTNV was resistant against the antiviral capacity of histatin 5, lysozyme, lactoferrin, and SLPI, but was inhibited by mucin. Inoculation of bank voles (Myodes glareolus) with HFRS-patient saliva, positive for PUUV-RNA, did not induce sero-conversion. In conclusion, no evidence of infectious virus in patient saliva was found. However, the in vitro experiments showed that HTNV, the prototype hantavirus, is insensitive to several antiviral salivary proteins, and is partly resistant to the antiviral effect of saliva. It therefore remains to be shown if human saliva might contain infectious virions early during infection, that is, before seroconversion.
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| 4. |
- Klingström, Jonas, et al.
(författare)
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Loss of cell membrane integrity in puumala hantavirus-infected patients correlates with levels of epithelial cell apoptosis and perforin.
- 2006
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Ingår i: Journal of Virology. - 0022-538X. ; 80:16, s. 8279-82
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Tidskriftsartikel (refereegranskat)abstract
- Hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome are two diseases caused by hantaviruses. Capillary leakage is a hallmark of hantavirus infection. Pathogenic hantaviruses are not cytotoxic, but elevated levels of serum lactate dehydrogenase (LDH), indicative of cellular damage, are observed in patients. We report increased levels of serum perforin, granzyme B, and the epithelial cell apoptosis marker caspase-cleaved cytokeratin-18 during Puumala hantavirus infection. Significant correlation was observed between the levels of LDH and perforin and the levels of LDH and caspase-cleaved cytokeratin-18, suggesting that tissue damage is due to an immune reaction and that epithelial apoptosis contributed significantly to the damage.
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| 5. |
- Klingström, Jonas, et al.
(författare)
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Passive immunization protects cynomolgus macaques against Puumala hantavirus challenge.
- 2008
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Ingår i: Antiviral Therapy. - 1359-6535 .- 2040-2058. ; 13:1, s. 125-33
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hantaviruses cause two severe and often fatal human diseases: haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Presently, there is no effective prevention available for HFRS or HPS. Here, we studied the effect of passive immunization on the course of infection in cynomolgus macaques challenged with wild-type Puumala hantavirus (PUUV-wt). METHODS: A pool of serum drawn from previously PUUV-wt-infected monkeys was used for immunization; a pool of serum from the same monkeys that was obtained before infection was used as a control. Immunizations were administered 3 days before and 15 days after challenge with PUUV-wt. After challenge, monkeys were sampled once a week and analysed for PUUV-infection markers. RESULTS: All three monkeys treated with non-immune serum became positive for PUUV RNA in plasma and showed PUUV nucleocapsid-specific immunoglobin M (IgM) responses after challenge. In contrast, no PUUV RNA or anti-PUUV-specific IgM response was detected in the three passively immunized monkeys. As seen in PUUV-infected humans, the control monkeys showed a marked decrease in the amount of platelets and increased levels of creatinine, interleukin (1L)-6, IL-10, and tumour necrosis factor (TNF) after inoculation. In contrast, no marked changes in the amount of platelets were observed in the immunized monkeys and they did not show increased levels of creatinine, IL-6, IL-10 and TNF after virus challenge. CONCLUSION: The results show that passive immunization in monkeys, using serum from previously hantavirus-infected monkeys, can induce sterile protection and protect against pathogenesis. Convalescent-phase antibodies may represent a potential therapy that can induce immediate protection against HFRS and HPS.
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| 6. |
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| 7. |
- Rönnberg, Bengt, et al.
(författare)
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Compensating for cross-reactions using avidity and computation in a suspension multiplex immunoassay for serotyping of Zika versus other flavivirus infections
- 2017
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Ingår i: Medical Microbiology and Immmunology. - : SPRINGER. - 0300-8584 .- 1432-1831. ; 206:5, s. 383-401
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Tidskriftsartikel (refereegranskat)abstract
- The recent spread of Zika virus (ZIKV) in the Americas and Asia necessitates an increased preparedness for improved maternal and perinatal health and blood safety. However, serological cross-reactions, especially to Dengue virus (DENV), complicate ZIKV antibody serodiagnosis. A novel "pan-Flavi" suspension multiplex immunoassay (PFSMIA) using 25 antigens, whole virus (WV), non-structural protein 1 (NS1), and envelope (E) proteins, from 7 zoonotic flaviviruses for specific detection of ZIKV and DENV IgM and IgG was developed. Patterns of antibody cross-reactivity, avidity, and kinetics were established in 104 sera from returning travelers with known ZIKV and DENV infections. PFSMIA gave IgM- and IgG-sensitivities for both viruses of 96-100%, compared to an immunofluorescence assay. Main IgM cross-reactions were to NS1, for IgG to the E and WV antigens. Infecting virus yielded reactivity to several antigens of the homologous virus, while cross-reactions tended to occur only to a single antigen from heterologous virus(es). A specificity-enhancing computer procedure took into account antibody isotype, number of antibody-reactive antigens per virus, avidity, average degree of cross-reactivity to heterologous flavivirus antigens, and reactivity changes in serial sera. It classified all 50 cases correctly. Applied to sera from 200 pregnant women and 173 blood donors from Sweden, one blood donor was found ZIKV NS1 IgM positive, and another as ZIKV NS1 IgG positive. These samples did not react with other ZIKV antigens and were thereby judged as false-positives. PFSMIA provided sensitive and specific ZIKV and DENV serology, warranting high-throughput serological surveillance and a minimized need for laborious and expensive virus neutralization assays.
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| 8. |
- Albinsson, Bo, et al.
(författare)
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Distinction between serological responses following tick-borne encephalitis virus (TBEV) infection vs vaccination, Sweden 2017
- 2018
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Ingår i: Eurosurveillance. - 1025-496X .- 1560-7917. ; 23:3, s. 2-7
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis virus (TBEV) is an important European vaccine-preventable pathogen. Discrimination of vaccine-induced antibodies from those elicited by infection is important. We studied anti-TBEV IgM/IgG responses, including avidity and neutralisation, by multiplex serology in 50 TBEV patients and 50 TBEV vaccinees. Infection induced antibodies reactive to both whole virus (WV) and non-structural protein 1 (NS1) in 48 clinical cases, whereas 47 TBEV vaccinees had WV, but not NS1 antibodies, enabling efficient discrimination of infection/vaccination.
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| 9. |
- Almén, Edgar, 1943-, et al.
(författare)
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Kursvärderingssystemets delar och aktörer
- 2004
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Ingår i: Kursvärdering för studentinflytande och kvalitetsutveckling. En antologi med exempel från elva lärosäten. - Stockholm : Högskoleverket. ; , s. 105-116
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Bokkapitel (populärvet., debatt m.m.)
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| 10. |
- Elfving, Karin, et al.
(författare)
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Dissemination of Spotted Fever Rickettsia Agents in Europe by Migrating Birds
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Migratory birds are known to play a role as long-distance vectors for many microorganisms. To investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in Sweden. A total of 1127 Ixodes spp. ticks were removed from these birds and the extracted DNA from 957 of them was available for analyses. The DNA was assayed for detection of Rickettsia spp. using real-time PCR, followed by DNA sequencing for species identification. Rickettsia spp. organisms were detected in 108 (11.3%) of the ticks. Rickettsia helvetica, a spotted fever rickettsia associated with human infections, was predominant among the PCR-positive samples. In 9 (0.8%) of the ticks, the partial sequences of 17kDa and ompB genes showed the greatest similarity to Rickettsia monacensis, an etiologic agent of Mediterranean spotted fever-like illness, previously described in southern Europe as well as to the Rickettsia sp. IrITA3 strain. For 15 (1.4%) of the ticks, the 17kDa, ompB, gltA and ompA genes showed the greatest similarity to Rickettsia sp. strain Davousti, Rickettsia japonica and Rickettsia heilongjiangensis, all closely phylogenetically related, the former previously found in Amblyomma tholloni ticks in Africa and previously not detected in Ixodes spp. ticks. The infestation prevalence of ticks infected with rickettsial organisms was four times higher among ground foraging birds than among other bird species, but the two groups were equally competent in transmitting Rickettsia species. The birds did not seem to serve as reservoir hosts for Rickettsia spp., but in one case it seems likely that the bird was rickettsiemic and that the ticks had acquired the bacteria from the blood of the bird. In conclusion, migratory passerine birds host epidemiologically important vector ticks and Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents and their diseases.
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