Lindahl, Johanna F.

CGSpace

Vector-borne diseases in a changing world Case studies of Japanese encephalitis virus and East African arboviruses  Kansas State University August 21 2014 Johanna Lindahl How to squeeze as much as possible into a presentation: 1. International Livestock Research Institute i. What does ILRI do? ii. What do I do for ILRI? 2. Introduction: EIDs, vectors and why we have a problem 3. Japanese Encephalitis Virus in Viet Nam i. Background JEV ii. Studies and results 4. Rift Valley fever virus in Kenya i. Background RVF  ii. Studies and results (so far) 5. Dynamic drivers of disease in Africa   International Livestock Research Institute Consultative Group for International Agricultural Research 2 Departments: Integrated sciences • Food safety and zoonoses Biosciences Nairobi Main campus Nairobi Second campus Addis Ababa CGIAR Research Program  Agriculture for Nutrition  and Health (A4NH) Agriculture  for Improved Nutrition & Health 12 CGIAR centers      IFPRI ILRI BIOVERSITY CIAT CIMMYT CIP ICARDA ICRAF ICRISAT IITA IWMI WORLD FISH 1. Leveraging value chains for nutrition 2. Biofortification of staple crops: Harvest + 3. Agricultural associated diseases 4. Evaluating nutrition outcomes in programs 4 Themes 1. Food Safety 2. Emerging infectious disease  3. Neglected zoonoses  Agriculture associated disease CGIAR Research Program  Livestock and fish- More meat, milk and fish for and by the poor My main projects 1. DDDAC i. RVF  ii. Cross-sectional socio-economic 2. Aflatoxins i. Aflatoxin risk assessment Kenya ii. More aflatoxin stuff (Uganda, Vietnam, India, Senegal, etc) 3. Dairy in India i. Hygiene project  ii. Tuberculosis, brucellosis and antibiotic resistance 4. Upcoming  i. Vector and water associated diseases in SEA   An introduction to disease emergence and anthropogenic influences • Humans are affecting every part of this planet – Directly or indirectly 2 billion hidden hunger          The world today 7 billion people      One billion hungry 1.7 billion overweight/obese Livestock is important • 24 billion livestock After rice, second most important source of food 19 billion in developing countries 1 billion poor people depend on livestock 600 million in South Asia 300 million in Sub-Saharan Africa 25% urban  There is a business case for one health • Zoonoses sicken 2.4 billion people, kill 2.2 million people and affect more than 1 in 7 livestock each year • Cost $9 billion in lost productivity; $25 billion in animal mortality; and$50 billion in human health Infectious diseases- historically important • In 1918-1920 Spanish flu:  • 50- 100 million humans • Late 19th century Rinderpest:  • Death of 2/3 of Maasai population in Tanzania and Kenya • Early 19th century Potato blight:  • 25% of Irish population starved or migrated  • 1967: "…war against infectious diseases has been won“  • US Surgeon General William H. Steward    FAO/G.R. Thomson HIV, TB, malaria Other infectious Mat//peri/nutritional Cardiovascular diseases Cancers Other NCD   Road traffic accidents Other unintentional Intentional injuries 0 5 10 15 20 25 30 2004 2015 2030 2004 2015 2030 2004 2015 2030 Deaths (millions) High-income countries Middle-income countries Low-income countries Mortality: global projection, 2004-2030 US Surgeon General William H. Steward was wrong Disease emergence?  • Which diseases? • EID twice as likely to be zoonotic than non-zoonotic (zoonotic viruses and protozoa had highest proportion) • Quick mutations- typically ssRNA • Where? • rapid intensification, increasing interactions between animals, humans and ecosystems, often rapidly changing habits and practices     Livestock      Wildlife Humans Ecosystem LH WL WH X Disease transmission Spillover event WNV WNV Malaria Malaria Malaria Dengue Dengue Dengue Dengue Yellow fever Yellow fever TBE TBE RSSE Borrelia Borrelia RSSE JEV JEV MVE Ross River SLEV VEE, EEE, WEE VEE Bluetongue Bluetongue African horse sickness African swine fever African swine fever Chikungunya Chikungunya JEV Babesia Babesia Anaplasma, Chikungunya Sleeping sickness Chaga’s disease RVF, WNV Chikungunya Climate & climate changes Globalisation Urbanization Land-use changes Why are vector-borne diseases emerging? k=   Probability that a vector feeding on an infected host gets infected. Pf =  Probability that a vector survives from one meal to the next. Pe=  Probability that a vector survives the Extrinsic incubation period, EIP Q=  Probability that a vector feeds from the right host – blood index for the host.  HBr=  Host biting rate, the number of vectors feeding from an animal per day.  v=   Probability of pathogens becoming infectious in the vector  C=   Vector capacity     C= HBr Qvk Pe/(1- Pf)  Vector capacity and competence Japanese Encephalitis Virus- risks with urban agriculture Infectious disease driver: urbanization Is urbanization important? Why is it a driver of disease? • 7 billion people • 50% urban inhabitants – continuous urbanisation • It involves approximately 800 million people and produces 15-20 % of the food in the world    Urban inhabitants need food • Large problems to supply from rural areas • Difficulties with cold chain    Johanna Lindahl                                           Swedish University of Agricultural Science The benefits and problems • Local markets with living and dead animals • Possibility to use urban wastes and waste water • Lacking sanitation     The benefits and problems Pathogens in the urban agriculture • Food-borne pathogens • Zoonotic animal diseases • Vector-borne diseases  Japanese Encephalitis Virus • Flavivirus, + ssRNA • Known to be a rural disease   C prM E NS1 NS2A NS2B NS3 NS4A NS4B NS5 Non structural proteins Genotypes distribution and spread  1,2,3,4,5 1,2 1,2,3 3 1,3 A Flavivirus • Culicidae, genus Culex – Culex pseudovishnui – Culex tritaeniorhyncus – Culex gelidus – Culex fuscocephala – Culex annulirostris – Culex quinquefasciatus …and an Arbovirus Disease in humans and horses • Often asymptomatic  • Incubation period 6-10    days • Fever, headache and meningitis • Acute flaccid paralysis • Coma, death   JEV and reproduction- pigs • SMEDI: Stillbirth, Mummification, Embryonal death, infertility • Middle third of pregnancy most affected • Immunocompetence after 65-70 days • Boars: orchitis, aspermia • Can be experimentally venerally transmitted Geographic spread  Population density (FAO stat estimates) •3 billion live in endemic areas  •50 000 cases per year  •Case fatality 30%   Our project in Vietnam • 84 million inhabitants • 1 600 km from North to South • Two delta regions – Red river delta in the north – Mekong delta in the south • A cooperation with the Can Tho university     Ninh Kieu district-Can Tho city • Around 4800 pigs on 288 pig farms – <17 pigs per farm – 1-2 sows • No poultry reported • Not many paddy fields Ninh kieu district, ”Can Tho city” Mosquito collections Johanna Lindahl Collected mosquitoes • Culex tritaeniorhynchus (36%) • Culex gelidus (24%)  • Culex quinquefasciatus (15%) Johanna Lindahl Pigs and mosquitoes Graphs showing the mosquitoes collected in households with and without pigs in Ninh Kieu district, Can Tho city, Vietnam.  Collections made close to humans are shown with thin boxes and collections close to pigs are shown with thick boxes.  A; total number of mosquitoes, B; Culex tritaeniorhynchus C; Culex gelidus D; Culex quinquefasciatus.  Circles depict outliers > 1.5 x the interquartile range and stars extreme outliers > 3 x the interquartile range. Serum from urban pigs • Competitive ELISA • All seropositive Johanna Lindahl Conclusions • The urban Ninh Kieu district  is densely populated with extensive pig keeping • Most mosquitoes at urban households are potential vectors • Pig keeping increase the number of vectors  JEV- infected mosquitoes Johanna Lindahl Household with JEV-positive  mosquito pool close to pigs Household with pigs,  no positive pools Household without pigs,  no positive pools Genotypes Johanna Lindahl  M18370.1| JaOArS982 U14163.1| SA14  U47032.1|  p3 AY585242.1|  K87P39 GQ902063.1|  KPP82-39-214CT AF075723.1|  GP78 AY508813.1|  JaOH0566 AF098735.1|  HVI AF098737.1|  TL AF069076.1| JaGAr 01  AF254452.1|  CH1392  AF254453.1|  T1P1  AF080251.1| Vellore P20778 EF571853.1| Nakayama Household D fall Household T fall Household D spring Household S nr 2 L48961.1| Beijing-1 L78128.1|  Ling Household I Spring Household S nr 1 GQ902061.1|  B-1381-85 Household X rural GQ902058.1|  B-0860/82 GQ902059.1|  1070/82  GQ902060.1| 3KP''U''CV569 JF499790.1|  TC2009-1 GQ902062.1| 4790-85 JF499789.1|  YL2009-4 AB051292.1| JEV AB241119.1|  JEV/sw /Mie/41/2002 AY316157.1|  KV1899 AF045551.2|  K94P05 AF217620.1|FU  HQ223286.1|  WTP-70-22  AY184212.1| JKT6468  HM596272.1| Muar |JF915894.1|  XZ093491868582685343376355484829192733323034484236342416392743990.01III I II IV V JEV infection rate 7885 mosquitoes, 352 mosquito pools, 7 positive  Johanna Lindahl Positive pool 9 Cx. tritaeniorhynchus 39 Cx. tritaeniorhynchus 25 Cx. tritaeniorhynchus 30 Cx. quinquefasciatus 50 unsorted 50 unsorted 50 unsorted Minimum infection rate per 1000 mosquitoes All mosquitoes 0.89 Females  (including unidentified mosquitoes) 0.98 Cx. tritaeniorhynchus 1.59 Cx. quinquefasciatus 1.27 Conclusions • Important with high sensitivity to circumvent inhibition in the PCR • Both genotype I and III can circulate within the same city • One per thousand mosquitoes can be infected in an urban area    Infectious disease driver:  Land use changes Rift valley fever- Risks with irrigation RVF • Bunyaviridae, phlebovirus • High mortality, abortions in ruminants • Hemorrhagic fever, encephalitis in humans • Arbovirus- but also directly transmitted   Why irrigation? • More and more range lands in Africa are being converted to crop lands through irrigation to alleviate food insecurity  • Results: major trade-offs in ecosystem services   More food produced (provisioning services) at the expense of biodiversity and regulatory services (disease, flooding, erosion)       Anthropogenic action:  Increased irrigation Effect on ecosystem: Creates more larval habitats Vector consequence: More infected vectors Epidemiologic consequence: More individuals exposed   Increased disease   Most drivers are desired- and not constantly leading to disease Hypothesis • Irrigation in an arid and semi-arid area increases the risk for RVF • But other diseases can also be affected by this… • … and the doctors don’t know if it is RVF     Study site with stagnant water in irrigation canals – source of water for the locals but also breeding grounds for mosquitoes  Solving that problem • Including possible differential diagnoses: – Leptospira, Q-fever, malaria, WNV, Dengue, Chikungunya, Crimean-Congo hemorrhagic fever, Brucella     Pastoralists in the study site Components • Cross-sectional – Humans – Livestock – Mosquitoes  – Wildlife – Ticks • Longitudinal – Human febrile cases – Livestock- shoats – Mosquitoes  •The study site: – Tana River and Garissa counties, northeastern Kenya    !.!.BuraHola0 10 20 30 405Kilometers´LegendSettlementsIrrigation Schemespermanentmixedtemporary!. TownsStudy BlockTana River CountyTana RiverOther RiversRiverrine ForestsMosquitoes trapped – relative abundance and species distribution 0.000.100.200.300.40RVF WNV DengueIrrigateed areaNon-irrigated areaDisease Seroprevalence  Samples screened – 481 samples have been screened so far  – Questionnaires administered to 430 households  Serological tests  – WNV and Dengue sero-prevalence apparently higher than that for RVF though confirmatory are yet to be done       Relative seroprevalence of RVF, WNV and Dengue Risk factor analysis - findings For WNV and Dengue model:  I.  Males have a higher risk of exposure  than females II.  Farmers have a higher risk compared to  pastoralists   For RVF model:  I  Males have a higher risk of exposure  than females  • Build capacity on differential diagnosis of febrile illnesses in the local health centres. Currently, most cases are treated as: – Malaria – Brucellosis – Typhoid  Intervention points  00.10.20.30.40.50.6Proportion Communities’ perceptions on diseases that manifest similar signs as malaria – limited knowledge on arboviruses  DDDAC Case study: Zambia/ Zimbabwe • Trypanosomiasis/tse tse • Land use changes – Protected area – Area where livestock has been increasing – Former large-scale farms with low biodiversity   Case study: Ghana • Henipa virus/ bats • Urban –rural migration • Livelihoods, poverty, ecology and the association with disease – How do humans interact with bats and what perceptions do they have of the risks – Protected/sacred area – Urban area   Case study: Sierra Leone • Lassa fever/ multimammate rats • Land use changes and rodent ecology – Urban-rural – Irrigation and precipitation – Human-rat interaction and risk perceptions   The perfect model?  Ecosystem health Human health Animal health Not the end…. ….but the beginning Open to questions Open to discussion Come visit us Come visit us 

Vector-borne diseases in a changing world: Case studies of Japanese encephalitis virus and East African arboviruses

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Vector-borne diseases in a changing world: Case studies of Japanese encephalitis virus and East African arboviruses

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