| 1. |
- Blomgren, Eric, et al.
(författare)
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Pest occurrence of Aedes rossicus close to the Arctic Circle in northern Sweden
- 2018
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Ingår i: Journal of Vector Ecology. - : Society for Vector Ecology. - 1081-1710 .- 1948-7134. ; 43:1, s. 36-43
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Tidskriftsartikel (refereegranskat)abstract
- Major nuisance species are found among the floodwater mosquitoes and snow-pool mosquitoes, with the former being the main reason for mosquito control in most areas. Nuisance species vary with the area, and previous reports from northern areas conclude that the nuisance is most often caused by snow-pool mosquitoes. We investigated the mosquito fauna and abundances of host-seeking females using CDC traps baited with carbon dioxide, in overtornea city near the Arctic Circle in northern Sweden, after earlier complaints about massive mosquito nuisance. The abundance of host-seeking female mosquitoes was high in 2014, with a maximum of similar to 15,400 individuals per CDC trap night, of which 89% was the floodwater mosquito Aedes rossicus. Surprisingly, the main nuisance species was a floodwater mosquito, occurring at the northernmost location it has ever been recorded in Sweden. Our report is probably the first documentation of such large numbers of Aedes rossicus in any locality and probably the first documentation of a severe floodwater mosquito nuisance near the Arctic Circle. Given the historical data on river discharge in the area, the nuisance is recurrent. We conclude that in northern localities, as well as in more southern localities, production of floodwater mosquitoes is a natural component of the floodplain fauna of rivers with a fluctuating water flow regime. Also, the floodwater mosquitoes Aedes sticticus and Aedes vexans were found north of their formerly known distribution in Sweden.
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| 2. |
- Hesson, Jenny C., 1980-, et al.
(författare)
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First report on human-biting Culex pipiens in Sweden
- 2016
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Ingår i: Parasites & Vectors. - : Springer Science and Business Media LLC. - 1756-3305. ; 9
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Culex mosquitoes are vectors of several bird-hosted arboviruses that cause outbreaks in Europe, such as Sindbis virus and West Nile virus. Recently, the human-biting form of Culex pipiens, Cx. pipiens biotype molestus, was found causing big nuisance in a housing cooperative in Gothenburg in southern Sweden, confirmed by molecular identification. This is the first report of human-biting Culex in Scandinavia, signalling increased risk of arbovirus infection in northern Europe.
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| 3. |
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| 4. |
- Lundström, Jan O, et al.
(författare)
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Sindbis virus polyarthritis outbreak signalled by virus prevalence in the mosquito vectors
- 2019
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Ingår i: PLoS Neglected Tropical Diseases. - : Public Library of Science (PLoS). - 1935-2727 .- 1935-2735. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- Polyarthritis and rash caused by Sindbis virus (SINV), was first recognised in northern Europe about 50 years ago and is known as Ockelbo disease in Sweden and Pogosta disease in Finland. This mosquito-borne virus occurs mainly in tropical and sub-tropical countries, and in northern Europe it is suggested to cause regularly reoccurring outbreaks. Here a seven-year cycle of SINV outbreaks has been referred to in scientific papers, although the hypothesis is based solely on reported human cases. In the search for a more objective outbreak signal, we evaluated mosquito abundance and SINV prevalence in vector mosquitoes from an endemic area in central Sweden. Vector mosquitoes collected in the River Dalalven floodplains during the years before, during, and after the hypothesised 2002 outbreak year were assayed for virus on cell culture. Obtained isolates were partially sequenced, and the nucleotide sequences analysed using Bayesian maximum clade credibility and median joining network analysis. Only one SINV strain was recovered in 2001, and 4 strains in 2003, while 15 strains were recovered in 2002 with significantly increased infection rates in both the enzootic and the bridge-vectors. In 2002, the Maximum Likelihood Estimated infection rates were 10.0/1000 in the enzootic vectors Culex torrentium/pipiens, and 0.62/1000 in the bridge-vector Aedes cinereus, compared to 4.9/1000 and 0.0/1000 in 2001 and 0.0/1000 and 0.32/1000 in 2003 Sequence analysis showed that all isolates belonged to the SINV genotype I (SINV-I). The genetic analysis revealed local maintenance of four SINV-I clades in the River Dalalven floodplains over the years. Our findings suggest that increased SINV-I prevalence in vector mosquitoes constitutes the most valuable outbreak marker for further scrutinising the hypothesized seven-year cycle of SINV-I outbreaks and the mechanisms behind.
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| 5. |
- McMenamin, Martina, et al.
(författare)
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WHO Global Situational Alert System : a mixed methods multistage approach to identify country-level COVID-19 alerts
- 2023
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Ingår i: BMJ Global Health. - 2059-7908. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- Background Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched. Methods The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of 'High' or above were added to an operational watchlist and assistance was deployed as needed. Results Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%-67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available. Conclusions The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators.
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| 6. |
- Schafer, Martina L., et al.
(författare)
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Detection of temporary flooded areas with potential floodwater mosquito production using imaging radar
- 2012
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Ingår i: International Journal of Remote Sensing. - : Informa UK Limited. - 0143-1161 .- 1366-5901. ; 33:6, s. 1943-1953
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Tidskriftsartikel (refereegranskat)abstract
- Temporarily flooded areas can produce enormous numbers of floodwater mosquitoes, causing tremendous nuisance to people living in the vicinity. The aim of this study is to develop a remote-sensing method for detecting temporary flooded areas that can produce floodwater mosquitoes. For this objective, synthetic aperture radar (SAR) imagery from the European Remote Sensing satellite (ERS-2) and the Environmental Satellite (Envisat) are chosen. The images cover both flooded and dry periods around Lake Farnebofjarden, located in the lowlands of the River Dalalven, central Sweden, during the vegetation season between 2000 and 2006. Unsupervised classification and principal component analysis (PCA) are tested as methods for detecting floodwater mosquito production sites. In the unsupervised classification experiment, four types of images are tested. The classification of a synthetic colour image gives the best result with an overall accuracy of 85.7% and a kappa value of 0.7, as well as a 46% detection rate of field-mapped flooded areas. PCA is performed on a data set of 16 time series radar images. The resulting principal component (PC) bands provide information about flooding probability as well as vegetation structures. Regular flooding increases the probability for an area to provide breeding sites for floodwater mosquitoes. Thus, this approach will be very useful in estimating the risk of floodwater mosquito establishment.
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| 7. |
- Schafer, Martina L., et al.
(författare)
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The present distribution and predicted geographic expansion of the floodwater mosquito Aedes sticticus in Sweden
- 2009
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Ingår i: Journal of Vector Ecology. - : Society for Vector Ecology. - 1081-1710 .- 1948-7134. ; 34:1, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- The mass emergence of floodwater mosquitoes, in particular Aedes sticticus and Aedes vexans, causes substantial nuisance and reduces life quality for inhabitants of infested areas and can have a negative impact on the socio-economic conditions of a region. We compared the previous, present, and predicted geographic distribution of Ae. sticticus in Sweden. Previous records from the literature until 1990 list the species in three out of 21 Swedish counties. Beginning in 1998, studies show that the present distribution of the species covers 11 counties, with highest abundances in an east-west belt in Central Sweden. Using climate data from the present and predicted climate scenarios, the expected distribution of Ae. sticticus in 2020, 2050, and 2080 could be modelled using GIS. As variables, mean temperatures and cumulative precipitation between May and August and degree slope were chosen. The predicted geographic distribution of Ae. sticticus will continue to increase and include 20 out of 21 Swedish counties. The expected temperature rise will increase the suitable area towards the northern part of Sweden by 2050. Some non-suitable areas can be found along the south-east coast due to insufficient amount of precipitation in 2050 and 2080. Modelling the expected distribution of a species using predicted climate change scenarios provides a valuable tool for risk assessments and early-warning systems that is easily applied to different species and scenarios. Journal of Vector Ecology 34 (1): 141-147. 2009.
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| 8. |
- Östman, Örjan, et al.
(författare)
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Lower abundance of flood water mosquito larvae in managed wet meadows in the lower Dalalven floodplains, Sweden
- 2015
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Ingår i: Wetlands Ecology and Management. - : Springer Science and Business Media LLC. - 0923-4861 .- 1572-9834. ; 23:2, s. 257-267
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the effect of vegetation management on mosquito abundance on the floodplains of the River Dalalven, central Sweden, we studied abundance of floodwater mosquito larvae (mainly Aedes sticticus) using a paired design, comparing flooded wet meadows that were mowed or grazed by cattle to those that were unmanaged. Two floods occurred during the study year (2012), the first in conjunction with the spring flood in May and the second after heavy rainfall in July. We used the standard mosquito dipper to estimate mosquito larval abundance along transects from the shore towards permanent water on each meadow. The number of mosquito larvae was on average lower in each managed wet meadow compared to the corresponding unmanaged meadow, both in May (71 % reduction, SD = 28 %) and in July (35 % reduction, SD = 79 %). However, there was substantial variation in the difference between managed and unmanaged meadows among pairs. We measured water depth, temperature, estimated proportion of open water surface, soil nutrient levels and micro-topology. Some of the variation in larval abundance could be explained by differences in local conditions. Mosquito larval abundance increased with nutrient levels and occurrence of tussocks, and decreased with water depth and percentage open water surface, especially among unmanaged wetlands. This study suggests that mowing or grazing may reduce the abundance of floodwater mosquito larvae in flooded wet meadows. In addition, vegetation management seem to have the greatest effect on mosquito larval abundance in nutrient-rich wet meadows where tussocks are abundant.
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