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Wallensten, Anders
Publications (10 of 12) Show all publications
Karlsson, M., Wallensten, A., Lundkvist, A., Olsen, B. & Brytting, M. (2007). A real-time PCR assay for the monitoring of influenza a virus in wild birds. Journal of Virological Methods, 144(1-2), 27-31
Open this publication in new window or tab >>A real-time PCR assay for the monitoring of influenza a virus in wild birds
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2007 (English)In: Journal of Virological Methods, ISSN 0166-0934, E-ISSN 1879-0984, Vol. 144, no 1-2, p. 27-31Article in journal (Refereed) Published
Abstract [en]

A screening system including a new real-time PCR assay for the monitoring of influenza A virus in wild birds was developed. The real-time PCR assay uses SYBR green chemistry and the primers are targeting the matrix gene of influenza A virus. The performance of the assay was compared with two other assays, one assay also using SYBR green chemistry and one assay using TaqMan chemistry, i.e. a specific probe. A total of 45 fecal bird samples were analysed for influenza A virus in three different PCR reactions. Overall, 26 samples were positive in at least one of the three real-time PCR assays. Of the 26 samples, 18 were positive by all three reactions. Eight samples were found positive exclusively by the two SYBR green reactions, six of which were detected by both SYBR green reactions. Of the 26 positive samples, 15 samples were verified as positive either by virus isolation or influenza A M2-gene PCR. The results showed that the two SYBR green systems had a higher performance regarding the detection of influenza A as compared to the PCR reaction using a specific probe. © 2007 Elsevier B.V. All rights reserved.

Keywords
Avian, Influenza, Real-time PCR, SYBR green, TaqMan
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-48800 (URN)10.1016/j.jviromet.2007.03.013 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Fick, J., Lindberg, R., Tysklind, M., Haemig, P., Waldenstrom, J., Wallensten, A. & Olsen, B. (2007). Antiviral oseltamivir is not removed or degraded in normal sewage water treatment: Implications for development of resistance by influenza A virus. PLoS ONE, 2(10)
Open this publication in new window or tab >>Antiviral oseltamivir is not removed or degraded in normal sewage water treatment: Implications for development of resistance by influenza A virus
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2007 (English)In: PLoS ONE, ISSN 1932-6203, Vol. 2, no 10Article in journal (Refereed) Published
Abstract [en]

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. © 2007 Fick et al.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-48322 (URN)10.1371/journal.pone.0000986 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2011-01-11
Wallensten, A. (2007). Influenza virus in wild birds and mammals other than man. Microbiological Ecology in Health and Disease, 19(2), 122-139
Open this publication in new window or tab >>Influenza virus in wild birds and mammals other than man
2007 (English)In: Microbiological Ecology in Health and Disease, ISSN 0891-060X, E-ISSN 1651-2235, Vol. 19, no 2, p. 122-139Article, review/survey (Refereed) Published
Abstract [en]

Influenza virus is an RNA virus that exists as different types and subtypes. Influenza A virus strains are known to cause disease in several bird and mammalian species. Wild birds are believed to constitute the natural reservoir for influenza A virus. Influenza A virus has the ability to change through antigenic drift and recombination allowing for the emergence of new strains and subtype combinations. In man influenza A virus causes yearly seasonal epidemics and, at irregular intervals, pandemic outbreaks have had a devastating impact on mankind. For example, the Spanish influenza pandemic of 1918 is thought to have killed more than 50 million people. Influenza A virus is an important cause of disease in poultry, where virus strains of the H5 and H7 subtypes may change into forms that are highly pathogenic. These virus strains may transmit directly to man and multiple other species. This has been the case in the ongoing outbreak that started in South-east Asia in 2003. All known subtypes of influenza A virus have been isolated from wild birds living in aquatic environments, mainly dabbling ducks. This review focuses on what is known about the pathogenicity and spread of influenza A virus in species other than man, with particular emphasis on the wild bird reservoir. © 2007 Taylor & Francis.

Keywords
Avian influenza, Domestic birds, Ducks, Influenza A virus, Mammals, Wild birds
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-49366 (URN)10.1080/08910600701406786 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Munster, V., Baas, C., Lexmond, P., Waldenstrom, J., Wallensten, A., Fransson, T., . . . Fouchier, R. (2007). Spatial, temporal, and species variation in prevalence of influenza a viruses in wild migratory birds. PLoS Pathogens, 3(5), 0630-0638
Open this publication in new window or tab >>Spatial, temporal, and species variation in prevalence of influenza a viruses in wild migratory birds
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2007 (English)In: PLoS Pathogens, ISSN 1553-7366, Vol. 3, no 5, p. 0630-0638Article in journal (Refereed) Published
Abstract [en]

Although extensive data exist on avian influenza in wild birds in North America, limited information is available from elsewhere, including Europe. Here, molecular diagnostic tools were employed for high-throughput surveillance of migratory birds, as an alternative to classical labor-intensive methods of virus isolation in eggs. This study included 36,809 samples from 323 bird species belonging to 18 orders, of which only 25 species of three orders were positive for influenza A virus. Information on species, locations, and timing is provided for all samples tested. Seven previously unknown host species for avian influenza virus were identified: barnacle goose, bean goose, brent goose, pink-footed goose, bewick's swan, common gull, and guillemot. Dabbling ducks were more frequently infected than other ducks and Anseriformes, this distinction was probably related to bird behavior rather than population sizes. Waders did not appear to play a role in the epidemiology of avian influenza in Europe, in contrast to the Americas. The high virus prevalence in ducks in Europe in spring as compared with North America could explain the differences in virus-host ecology between these continents. Most influenza A virus subtypes were detected in ducks, but H13 and H16 subtypes were detected primarily in gulls. Viruses of subtype H6 were more promiscuous in host range than other subtypes. Temporal and spatial variation in influenza virus prevalence in wild birds was observed, with influenza A virus prevalence varying by sampling location, this is probably related to migration patterns from northeast to southwest and a higher prevalence farther north along the flyways. We discuss the ecology and epidemiology of avian influenza A virus in wild birds in relation to host ecology and compare our results with published studies. These data are useful for designing new surveillance programs and are particularly relevant due to increased interest in avian influenza in wild birds. © 2007 Munster et al.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-49532 (URN)10.1371/journal.ppat.0030061 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2011-01-11
Wallensten, A., Munster, V. J., Fransson, T., Haemig, P. D., Karlsson, M., Lundkvist, Å., . . . Fouchier, R. A. M. (2007). Surveillance of Influenza A Virus in Migratory Waterfowl in Northern Europe. Emerging Infectious Diseases, 13(3), 404-411
Open this publication in new window or tab >>Surveillance of Influenza A Virus in Migratory Waterfowl in Northern Europe
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2007 (English)In: Emerging Infectious Diseases, Vol. 13, no 3, p. 404-411Article in journal (Refereed) Published
Abstract [en]

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.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-14102 (URN)
Available from: 2006-10-27 Created: 2006-10-27
Olsen, B., Munster, V. J., Wallensten, A., Waldenström, J., Osterhaus, A. D. M. & Fouchier, R. A. .. (2006). Global patterns of influenza A virus in wild birds. Science, 312(5772), 384-388
Open this publication in new window or tab >>Global patterns of influenza A virus in wild birds
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2006 (English)In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 312, no 5772, p. 384-388Article in journal (Refereed) Published
Abstract [en]

The outbreak of highly pathogenic avian influenza of the H5N1 subtype in Asia, which has subsequently spread to Russia, the Middle East, Europe, and Africa, has put increased focus on the role of wild birds in the persistence of influenza viruses. The ecology, epidemiology, genetics, and evolution of pathogens cannot be fully understood without taking into account the ecology of their hosts. Here, we review our current knowledge on global patterns of influenza virus infections in wild birds, discuss these patterns in the context of host ecology and in particular birds' behavior, and identify some important gaps in our current knowledge.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-14103 (URN)10.1126/science.1122438 (DOI)
Available from: 2006-10-27 Created: 2006-10-27 Last updated: 2017-12-13
Wallensten, A., Munster, V., Karlsson, M., Lundkvist, A., Brytting, M., Stervander, M., . . . Olsen, B. (2006). High prevalence of influenza A virus in ducks caught during spring migration through Sweden. Vaccine, 24(44-46), 6734-6735
Open this publication in new window or tab >>High prevalence of influenza A virus in ducks caught during spring migration through Sweden
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2006 (English)In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 24, no 44-46, p. 6734-6735Article in journal (Refereed) Published
Abstract [en]

As part of our ongoing screening of wild birds in Northern Europe, 358 mallards (Anas platyrhynchos) and 203 shelducks (Tadorna tadorna) were caught in southern Sweden during the spring 2003. Faecal samples were analyzed by real time RT-PCR for the presence of influenza A virus. In contrast to what has been found in North American studies, Eurasian spring migrating ducks passing through Sweden had a relatively high prevalence of influenza A virus. © 2006 Elsevier Ltd. All rights reserved.

Keywords
Avian influenza A virus, Prevalence, Wild birds
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-50072 (URN)10.1016/j.vaccine.2006.05.057 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Wallensten, A. (2006). Influenza A virus in wild birds. (Doctoral dissertation). : Institutionen för molekylär och klinisk medicin
Open this publication in new window or tab >>Influenza A virus in wild birds
2006 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Influenza virus is a RNA virus that exists as different types and subtypes. Influenza A virus strains are known to cause disease in several bird and mammalian species. Wild birds are believed to constitute the natural reservoir for influenza A virus.

In humans, influenza A virus causes yearly seasonal influenza epidemics of respiratory disease resulting in high morbidity and severe economic consequences. Due to the virus’ ability to change its antigenic properties by mutation, yearly vaccination is required for protection from the disease.

There are many different subtypes of influenza virus which are characterized according to two surface structures - the hemagglutinin and neuraminidase proteins - , for example; H5N1. These subtypes have the ability to recombine, and thereby creating new variant combinations. If a subtype that the living population of humans has not encountered before starts to spread among humans, it can result in a pandemic. Pandemic outbreaks have occurred at irregular intervals throughout history and have had a devastating impact on mankind. For example the Spanish influenza pandemic of 1918 is thought to have killed more than 50 million people.

Influenza A virus is also an important cause of disease in poultry where virus strains of some subtypes may change into forms that are highly pathogenic. These virus strains may transmit directly to man and multiple other species. This has been the case in the ongoing outbreak that started in South East Asia in 2003. All known subtypes of influenza A virus have been isolated from wild birds living in aquatic environments, mainly dabbling ducks. These species are considered to be the reservoir for influenza A virus. The virus causes sub clinical gastrointestinal infection in ducks. High amounts of virus are excreted in the feces and spread via the fecal-oral route through water where it can persist for a prolonged time.

There are still many unknowns about the ecology of influenza virus in the wild bird reservoir. This thesis includes five articles where data are presented that add new knowledge on this subject. We add proof that wild ducks are indeed the host for most influenza A virus subtypes by presenting data from a meta-analysis on all published screening data from wild birds and by presenting data from a four year screening of migratory ducks that were caught and sampled at Ottenby Bird Observatory. Our investigations have shown that the prevalence of influenza virus in the wild duck population of western Eurasia shows temporal differences in comparison to the results found in studies in North America. The prevalence in western Eurasian ducks is high during the period August to December and also rises in the spring. These findings are of importance for the understanding of how influenza virus is perpetuated in nature. During the course of the study only low pathogenic subtypes were isolated. Of concern is the high frequency of isolation of virus strains of the H5 and H7 subtypes that are prone to change into highly pathogenic variants in poultry. Many of the strains isolated in our study are similar to the ones that have caused influenza outbreaks in poultry in Europe during the last seven years. This indicates that wild bird surveillance for influenza A virus can be of major value as a sentinel system to prevent outbreaks in domestic poultry.

Studies on Black-headed Gulls (Larus ridibundus) revealed a previously unknown subtype, H16. This finding widened the spectra of known influenza A virus subtypes in nature.

Influenza A virus was also isolated in samples from Guillemots (Uria aalge) in the Baltic Sea. This was the first time influenza A virus was isolated from this species in Europe. The isolated virus strains contained a mix of genes, some of which must have been derived from influenza A virus strains present in the North American bird population. This finding proves that limited exchanges between the virus strains present on the American and the Eurasian continents exist, which is of concern for evaluating the risk of spread of highly pathogenic virus strains by wild birds to the Americas.

Abstract [sv]

Influensavirus är RNA virus och indelas i olika typer och subtyper. Influensa A virus orsakar sjukdom hos ett flertal fågel- och däggdjursarter. Vilda fåglar anses utgöra den viktigaste reservoaren för influensa A virus.

Hos människa orsakar influensa A virus årliga epidemier av luftvägssjukdom med hög sjuklighet och stora ekonomiska konsekvenser för samhället. Eftersom frekventa mutationer orsakar ändringar i virusets ytstrukturer krävs årlig vaccination med nytt anpassat vaccin för att ge skydd mot sjukdom.

Det finns många olika subtyper av influensa A virus. Dessa karaktäriseras med två av virusets ytstrukturer; hemagglutinin och neuraminidas, vilket till exempel skrivs H5N1. Virus av olika subtyper kan rekombinera och på så sätt skapa nya varianter. Om en subtyp som tidigare ej cirkulerat bland världens befolkning orsakar ett utbrott kan detta leda till en världsomfattande epidemi, en så kallad pandemi. Pandemier har drabbat mänskligheten med viss regelbundenhet genom historien och haft förödande konsekvenser. Till exempel orsakade pandemin ”Spanska sjukan” under åren 1918-1920 mer än 50 miljoner dödsfall.

Influensa A virus orsakar också förödande utbrott i fjäderfäbesättningar. Virus av vissa subtyper kan mutera till högpatogena varianter och orsaka så kallad högpatogen aviär influensa. Dessa högpatogena varianter kan även överföras till och orsaka sjukdom hos människa och andra djur vilket varit fallet under det pågående utbrott av H5N1 som startade i sydöstra Asien 2003. Alla kända subtyper av influensa A virus har isolerats i material från vilda fåglar vilka lever i vattenmiljö, framförallt från änder. Dessa arter anses därför utgöra influensavirusets reservoar i naturen. Hos änder orsakar viruset framförallt en subklinisk infektion i gastrointestinalkanalen och sprids genom faekal-oral överföring via vatten i vilket viruset kan förbli aktivt en längre tid.

Det finns fortfarande många obesvarade frågor angående influensa A virus ekologi bland vilda fåglar. I denna avhandling presenteras fem artiklar som tillför ny kunskap inom detta område. I avhandlingen styrks bevisen för att vilda änder utgör virusets reservoar i naturen dels genom en metaanalys av samtliga publicerade data rörande fynd av influensa A virus hos vilda fåglar, dels med hjälp av data från fyra års provtagning från flyttande vilda änder vid Ottenby fågelstation. Resultaten påvisar temporala skillnader i influensvirusets prevalens i den västeuroasiatiska andpopulationen jämfört med den nordamerikanska. Prevalensen i den västeuroasiatiska andpopulationen är hög under perioden augusti till december och i viss mån även under våren. Dessa fynd talar för att influensavirus kontinuerligt cirkulerar i andpopulationen.

Under studien av förekomsten av influensa A virus hos änder isolerades enbart olika lågpatogena subtyper. Subtyperna H5 och H7 var vanligt förekommande. Dessa subtyper är benägna att utvecklas till högpatogena varianter om de sprids till fjäderfäbesättningar med svåra konsekvenser som följd. Genom studier av virus släktskap visas att de virus vi isolerat från vilda änder är snarlika de som orsakat utbrott bland fjäderfä i Europa under de senaste sju åren. Detta styrker värdet av att övervaka förekomsten av influensavirus hos vilda fåglar för att på så sätt förhindra utbrott av sjukdom bland fjäderfä.

Undersökning av prover från skrattmås (Larus ridibundus) ledde fram till upptäckten av en helt ny subtyp av influensavirus; H16. Därmed utvidgades spektret av kända subtyper i naturen.

Influensa A virus isolerades från sillgrisslor (Uria aalge) i Östersjön vilket inte tidigare gjorts hos denna art i Europa. Dessa virus innehöll gener från både nordamerikanska och euroasiatiska fågelpopulationers virus. Det visar att det finns ett utbyte av virus mellan fågelpopulationerna på de skilda kontinenterna.

Place, publisher, year, edition, pages
Institutionen för molekylär och klinisk medicin, 2006
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 955
Series
Keywords
Influenza A virus, Wild Birds, Ducks, Prevalence, Ecology
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:liu:diva-7643 (URN)91-85523-15-1 (ISBN)
Public defence
2006-09-29, B 135, Högskolan i Kalmar, Kalmar, 09:00 (English)
Opponent
Supervisors
Note
On the day of the defence data the status on article IV was Submitted and the title was "Multi-year surveillance of influenza virus type A in migratory waterfowl in northern Europe".Available from: 2006-10-27 Created: 2006-10-27 Last updated: 2018-01-13
Wallensten, A., Munster, V., Osterhaus, A., Waldenstrom, J., Bonnedahl, J., Broman, T., . . . Olsen, B. (2006). Mounting evidence for the presence of influenza A virus in the avifauna of the Antarctic region. Antarctic Science, 18(3), 353-356
Open this publication in new window or tab >>Mounting evidence for the presence of influenza A virus in the avifauna of the Antarctic region
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2006 (English)In: Antarctic Science, ISSN 0954-1020, E-ISSN 1365-2079, Vol. 18, no 3, p. 353-356Article in journal (Refereed) Published
Abstract [en]

Penguin blood samples collected at Bird Island, sub-Antarctic South Georgia, and faecal samples taken from penguins at several localities along the Antarctic Peninsula were analysed in order to investigate if influenza A virus is present in penguin populations in the South Atlantic Antarctic region. Serology was performed on the blood samples while the faecal samples were screened by a RT-PCR method directed at the matrix protein gene for determining the presence of influenza A virus. All faecal samples were negative by PCR, but the blood samples gave serologic indications that influenza A virus is present amongst these penguin species, confirming previous studies, although the virus has still not been isolated from any bird in the Antarctic region. © Antarctic Science Ltd.

Keywords
Avian influenza, RT-PCR, Serology, Sub-Antarctica
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-50155 (URN)10.1017/S095410200600040X (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Fouchier, R. A. M., Munster, V. J., Wallensten, A., Bestebroer, T. M., Herfst, S., Smith, D., . . . Osterhaus, A. D. M. (2005). Characterization of a novel influenza A virus hemagglutinin subtype (H16) obtained from Black-headed Gulls. Journal of Virology, 79(5), 2814-2822
Open this publication in new window or tab >>Characterization of a novel influenza A virus hemagglutinin subtype (H16) obtained from Black-headed Gulls
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2005 (English)In: Journal of Virology, ISSN 0022-538X, E-ISSN 1098-5514, Vol. 79, no 5, p. 2814-2822Article in journal (Refereed) Published
Abstract [en]

In wild aquatic birds and poultry around the world, influenzaA viruses carrying 15 antigenic subtypes of hemagglutinin (HA)and 9 antigenic subtypes of neuraminidase (NA) have been described.Here we describe a previously unidentified antigenic subtypeof HA (H16), detected in viruses circulating in black-headedgulls in Sweden. In agreement with established criteria forthe definition of antigenic subtypes, hemagglutination inhibitionassays and immunodiffusion assays failed to detect specificreactivity between H16 and the previously described subtypesH1 to H15. Genetically, H16 HA was found to be distantly relatedto H13 HA, a subtype also detected exclusively in shorebirds,and the amino acid composition of the putative receptor-bindingsite of H13 and H16 HAs was found to be distinct from that inHA subtypes circulating in ducks and geese. The H16 virusescontained NA genes that were similar to those of other Eurasianshorebirds but genetically distinct from N3 genes detected inother birds and geographical locations. The European gull viruseswere further distinguishable from other influenza A virusesbased on their PB2, NP, and NS genes. Gaining information onthe full spectrum of avian influenza A viruses and creatingreagents for their detection and identification will remainan important task for influenza surveillance, outbreak control,and animal and public health. We propose that sequence analysesof HA and NA genes of influenza A viruses be used for the rapididentification of existing and novel HA and NA subtypes.

Place, publisher, year, edition, pages
ASM International, 2005
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-14099 (URN)10.1128/JVI.79.5.2814-2822.2005 (DOI)
Available from: 2006-10-27 Created: 2006-10-27 Last updated: 2017-12-13Bibliographically approved
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