Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Infectious diseases - how may climate change influence epidemiology? • Ann Albihn, • National Veterinary Institute, Uppsala • www.sva.se Albihn, Rossby Centre Day 2013, May 7, SMHI, Norrköping The influence of CC on infectious diseases is well documented Klimat- och sårbarhetsutredningen 2005-2007 HÄLSOEFFEKTER AV EN KLIMATFÖRÄNDRING I SVERIGE En nationell utvärdering av hälsokonsekvenser hos människa och djur. Risker, anpassningsbehov och kostnader En rapport utarbetad för Klimat- och sårbarhetsutredningen SOU 2007:60 Bilaga B34 Schmallenberg virus affect ruminants • A surprisingly quick spread of VBD • Transmission from mother to foetus • Cows may deliver dead or malformed offspring • In the end of 2011 in Germany, France, Netherlands,... • In 2012 further spread also to Swe • Swedish survey of farm based milk containers in May 2012 only 1 pos., in Nov 72 % of 723 pos • Virus detected also in • midges (Culicoides spp.) • aborted lambs and calves • wildlife Zoonotic diseases may infect both humans and animals • 70% of all human infections • 14 milj humans/year die • More difficult to control than ”human only diseases” Infectious diseases are spread by.... • Water • Vector animals • Feed, soil • Contact • animal – animal • animal – human • Air What kind of diseases? • Endemic diseases • • Salmonella, Cryptosporidia, TBE Exotic diseases • RVF, WNF, Schmallenberg virus Ecosystem changes influence infectious diseases Diseases that are transmitted by the environment or by wild animals or use these as vectors or reservoirs •Epidemiology, geographical distribution, seasonality and prevalence may be affected. •Biodiversity decline •Damage for wildlife populations Vectors transmit diseases between individuals and species •Arthropod vectors - flies, mosquitoes, sandflies, ticks, midges... •Highly sensitive to climatic conditions as temperature and humidity •Distribution of vectors will shift particularly at their latitudinal and altitudinal limits Reservoir or host animals www.vpe.slu.se •Length of the vegetation period - Exposure period prolonged •Heat stress -Changed behavior -Immuno-suppressed H. Fogelfors 2008. Institutionen för växtproduktionsekologi Secondary effects of CC may contribute to an increased risk for infectious diseases 1961-90 ~2085A2 temp > 5oC (Fogelfors et al.,2008) Waterborne infections and CC Increased risk for contamination of water, soil and crop • Flooding or irrigation with contaminated water • Increased transportation of surface water and pathogens from e.g. grassing land • Sewage treatment plants has to low capacity to treat water from e.g. heavy rain or instant snow melting • Increased water temperatures is favourable for some pathogens VTEC-disease in Halland 2005 • Serious gastrointestinal disease as may cause deaths • > 100 diseased humans • On field lettuce crop • Irrigated just before harvest and packing • Heavy rainfall and surface runoff from grassing land • Contaminated river • VTEC isolated from cattle, lettuce and humans but not from the river Some arthropod vectors travel by the wind over long distances Geografic location Population Individual Temperature Life cycle Reprod. rate metabolism Biting rate Vector competence Active season Exposure period A. Albihn, 2010 Population density Moisture Vegetation Predators Host animal Disease reservoir Intermediate host Dead-end-hosts Pathogen Presence Serotype Incubation time Asian tiger mosquito (Aedes albopictus) • A “multi-competent” vector • Likes long-distance travelling in used tires in plants • Is easily detected on arrival (beautiful and aggressive) Distribution of the Asian tiger mosquito Photo: Eric Blomgren Originated i south-east Asia Distributed world-wide during the last 40 years Stegomyia albopicta / Asian tiger mosquito Infection landscapes, 2011 Distribution of the Asian tiger mosquito and the global transportation system Eric Blomgren, SVA The Common Tick - Ixodes ricinus Changed distribution to higher latitudes and in central Europe also to higher altitudes A higher population density of ticks is experienced Vector for e.g. •Borrelia/Lyme disease •Babesios •Anaplasmos •Rickettsia •Tick-borne encephalitis (TBE) Borreliosis/Lyme diseases • • • • Tick-borne (Ixodes spp.) Temp., humidity, vegetation Rodents are reservoir species Deer, humans and others are mostly ”dead end host” West Nile fever Reservoar: Birds Vector: Mosquitos Culex & Aedes West Nile virus Diagnosed in New York 1999 1999 West Nile virus 2000 West Nile virus 2001 West Nile virus 2002 West Nile virus 2003 West Nile virus 2009 Conclusions 1 • CC cause changes in the environment and in ecosystems • Complex and dynamic interaction between CC, ecosystems,vectors, pathogens, animals and humans • Changes awaited in geographical distribution, seasonality, prevalence of VBD • Lessons learned in other regions must be adapted to local conditions • Necessary to pool cross-border efforts to control VBD Conclusion 2 For endemic infections For exotic infections e.g. VTEC, salmonella, eg. Schmallenberg, WNF, blutongue, CC influence mainly due to increases surface CC influence mainly due run-off and flooding to influence on vectorand reservoir animals. These animals are in large dependent on temperature, precipitation, and vegetation