| 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. |
- Latorre-Margalef, Neus, et al.
(författare)
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Effects of influenza A virus infection on migrating mallard ducks
- 2009
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 276:1659, s. 1029-1036
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Tidskriftsartikel (refereegranskat)abstract
- The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002-2007, we collected faecal samples (n = 10 918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales.
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| 3. |
- Axelsson Olsson, Diana, et al.
(författare)
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Acanthamoeba-Campylobacter coculture as a novel method for enrichment of Campylobacter species
- 2007
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 73:21, s. 6864-6869
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 10(4) CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.
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| 4. |
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| 7. |
- Fick, Jerker, et al.
(författare)
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Antiviral Oseltamivir is not removed or degraded in normal sewage water treatment : Implications for development of resistance by influenza A virus
- 2007
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 2:10, s. e986-
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Tidskriftsartikel (refereegranskat)abstract
- Oseltamivir is the main antiviral for treatment and prevention of pandemic influenza. The increase in oseltamivir resistance reported recently has therefore sparked a debate on how to use oseltamivir in non pandemic influenza and the risks associated with wide spread use during a pandemic. Several questions have been asked about the fate of oseltamivir in the sewage treatment plants and in the environment. We have assessed the fate of oseltamivir and discuss the implications of environmental residues of oseltamivir regarding the occurrence of resistance. A series of batch experiments that simulated normal sewage treatment with oseltamivir present was conducted and the UV-spectra of oseltamivir were recorded. Findings: Our experiments show that the active moiety of oseltamivir is not removed in normal sewage water treatments and is not degraded substantially by UV light radiation, and that the active substance is released in waste water leaving the plant. Our conclusion is that a ubiquitous use of oseltamivir may result in selection pressures in the environment that favor development of drug-resistance.
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| 8. |
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| 9. |
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| 10. |
- Haemig, Paul D., et al.
(författare)
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Barn Swallows (Hirundo rustica) Test Negative for Salmonella
- 2008
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert. - 1530-3667 .- 1557-7759. ; 8:4, s. 451-453
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Tidskriftsartikel (refereegranskat)abstract
- Farmers around the world have been urged to eliminate barn swallows (Hirundo rustica) from their buildings, based on the unproven assumption that these birds amplify and spread Salmonella to livestock, humans, and stored food. However, we tested over 500 barn swallows in Sweden and found no evidence that they carry Salmonella. Our results cast doubt on the hypothesis that barn swallows are competent reservoirs of Salmonella and suggest that their role, if any, is limited to being accidental hosts of the bacterium.
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| 11. |
- Haemig, Paul D., et al.
(författare)
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Dynamic table-visiting behavior of birds at outdoor restaurants and cafes
- 2021
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Ingår i: Ethology. - : John Wiley & Sons. - 0179-1613 .- 1439-0310. ; 127:7, s. 505-516
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Tidskriftsartikel (refereegranskat)abstract
- Fear of humans and its effect on animal behavior is increasingly being recognized as an important structuring force in ecological landscapes, with consequences for ecological interactions and communities. When aggressive, physically dominant species are displaced by anthropogenic disturbance, physically weaker species exploit competitor and predator downtimes to forage in previously risky places. Birds feeding at outdoor restaurants and cafes in association with humans are exposed to fluctuating levels of perceived danger caused by frequently changing densities of human diners. Consequently, birds must make decisions about which dining tables to visit based on trade-offs between foraging gain and perceived danger from avian competitors and humans. We tested the hypothesis that interspecific differences in response to perceived danger, combined with varying densities of human diners, dynamically alter which bird species predominates at dining tables. We found that house sparrows (Passer domesticus) tolerated higher human diner-densities than larger-sized, more physically dominant Eurasian jackdaws (Coloeus monedula). Sparrows were usually the first birds to visit diner-occupied tables and spent more time there than jackdaws. However, at diner-abandoned tables, this pattern changed: During low diner-densities at surrounding tables, jackdaws were usually the predominant species in first visits and minutes spent visiting, while at high diner-densities sparrows usually predominated. Moreover, along a gradient of increasing human diner-density, sparrows gradually replaced jackdaws as the predominant species in first visits and time at abandoned tables. However, at diner-occupied tables, once a sparrow chose which table to visit, factors other than diner-density influenced its choice of where to forage there (table-top or ground). To our knowledge, our research is the first scientific study of table-visiting behavior by birds at outdoor restaurants and cafes, and the first to reveal interspecific differences in table-visiting behavior by birds there.
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| 12. |
- Haemig, Paul D, et al.
(författare)
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Ecology and phylogeny of birds foraging at outdoor restaurants in Sweden
- 2015
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Ingår i: Biodiversity Data Journal. - : Pensoft Publishers. - 1314-2836 .- 1314-2828. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Birds frequently visit the outdoor serving areas of restaurants to feed on scraps of food and leftovers. Although this feeding association between humans and birds is widespread and could have significant effects, both positive and negative, for all taxa involved, the authors know of no published studies that have investigated restaurant bird communities. To lay the foundation for future research, the authors conducted a basic study of birds at 80 outdoor restaurants in Sweden, identifying which species and taxonomic clades of birds visited the restaurants and comparing restaurant birds in urban and rural environments. New information: Thirteen species of birds visited the outdoor restaurants. Eight of these species were predominant, i.e. accounting for 51% or more of bird presence (sum of minutes of all individual birds) at one or more restaurants. Every restaurant studied had a predominant species, but species often differed from each other in frequency of predominance in different landscapes. No endangered species were seen visiting restaurants. However, three farmland bird species (House Sparrow Passer domesticus, White Wagtail Motacilla alba, Eurasian Tree Sparrow Passer montanus), whose numbers are reported to be declining in the countryside, were predominant at the majority of restaurants in rural areas, suggesting that rural restaurants might be able to contribute to the conservation of these species. The thirteen species of restaurant-visiting birds belonged to five monophyletic clades. Ninety percent of all restaurants had, as their predominant species, birds from either Clade A (Passeridae, Motacillidae, Fringillidae) or Clade C (Corvidae). Statistical testing revealed that Clade A and Clade C were distributed differently in environments along the urban-rural gradient. At all spatial scales measured, birds of Clade C were predominant at the majority of restaurants in urban areas, while birds of Clade A were the predominant clade at the majority of restaurants in rural areas. The authors use this evidence, and observations of birds foraging in association with other primates, to hypothesize that the outdoor serving areas of modern restaurants may be helping to preserve and nurture ancient human-bird symbioses that have been part of human ecology since antiquity.
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| 13. |
- 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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| 14. |
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| 15. |
- Hernandez, Jorge, et al.
(författare)
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Enteropathogenic Escherichia coli (EPEC) in Antarctic fur seals Arctocephalus gazella
- 2007
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Ingår i: Polar Biology. - : Springer Science and Business Media LLC. - 0722-4060 .- 1432-2056. ; 30:10, s. 1227-1229
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Tidskriftsartikel (refereegranskat)abstract
- Rectal swabs were collected from Antarctic fur seal pups Arctocephalus gazella at Cape Shirreff, South Shetland Islands, and analyzed for the presence of anthropogenic pathogens. Two of the 33 pups tested positive for enteropathogenic Escherichia coli (EPEC). These samples are the first records of EPEC in Antarctic wildlife and suggest that more needs to be done to protect the Antarctic fauna from exotic anthropogenic pathogens.
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| 16. |
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| 17. |
- Thegerström, Johanna, et al.
(författare)
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Mycobacterium avium lymphadenopathy among children, Sweden
- 2008
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 14:4, s. 661-663
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Tidskriftsartikel (refereegranskat)abstract
- We studied Mycobacterium avium lymphadenopathy in 183 Swedish children (<7 years of age) from 1998 through 2003. Seasonal variation in the frequency of the disease, with a peak in October and a low point in April, suggests cyclic environmental factors. We also found a higher incidence of the disease in children who live close to water.
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| 18. |
- Wahlgren, J., et al.
(författare)
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Gene segment reassortment between American and Asian lineages of avian influenza virus from waterfowl in the Beringia area
- 2008
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 8:6, s. 783-90
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Tidskriftsartikel (refereegranskat)abstract
- Since prehistoric times, the Bering Strait area (Beringia) has served as an avenue of dispersal between the Old and the New Worlds. On a field expedition to this area, we collected fecal samples from dabbling ducks, geese, shorebirds, and gulls on the Chukchi Peninsula, Siberia, and Pt. Barrow, Alaska, and characterized the subtypes of avian influenza virus present in them. Four of 202 samples (2%) from Alaska were positive for influenza A virus RNA in two independent polymerase chain reaction (PCR)-based screening assays, while all shorebird samples from the Chukchi Peninsula were negative. Subtypes H3N8 and H6N1 were recorded once, while subtype H8N4 was found in two samples. Full-length sequences were obtained from the three unique isolates, and phylogenetic analysis with representative sequences for the Eurasian and North American lineages of influenza A virus showed that one HA gene clustered with the Eurasian rather than the North American lineage. However, the closest relative to this sequence was a North American isolate from Delaware described in 2002, indicating that a H6 spillover from Asia has established itself in North America.
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