Role of climate change in epidemiology of infectious diseases Delia Grace Component Leader: Agriculture Associated Disease CGIAR Research Program on Agriculture for Nutrition and Health Field Epidemiology and Laboratory Training Programme in Kenya, 24 October 2012 Invited lecture FELTPK Residents during the “One Health Week The Field Epidemiology and Laboratory Training Programme (FELTPK) in Kenya is a two-year postgraduate competency based training program in applied epidemiology and public health laboratory management. It was established in April 2004 to enable frontline public health professionals acquire the latest knowledge and skills that address global threats to public health, using training-through-service approach. The program collaborates closely with the United States Centers for Disease Control and Prevention (CDC). Upon completion of all requirements, FELTPK graduates are awarded degrees in a Master of Science (Msc) in Applied Epidemiology or Msc in Laboratory Management and Epidemiology from Jomo Kenyatta University of Agriculture and Technology (JKUAT). Other key collaborating partners include Kenya Medical Research Institute (KEMRI), Ministry of Medical Services and Ministry of Public Health and Sanitation, Ministry of Livestock Development, World Health Organization (WHO), World Bank and the African Field Epidemiology Network (AFENET). Following the need to strengthen "One Health" initiatives in Kenya, FELTPK enrolled four (4) veterinary officers from the Ministry of Livestock Development this academic year. This was followed by designing a one health module that is to be delivered to the cohort 9 residents which constitutes a class of 18 residents. The following lecture “Role of Climate Change in Epidemiology of Infectious was requested by Dr Samuel Amwayi. International Livestock Research Institute 700 full time staff-1000 total 100 scientists & researchers 54 from 22 developing countries more than 30 scientific disciplines 2012 budget USD 60 million ILRI works with a range of research & development partners across 7 CGIAR research programs a member of the CGIAR Consortium, ILRI conducts livestock, food and environmental research to help alleviate poverty and improve food security, health & nutrition, while protecting the natural resource base.  Mali Nigeria Mozambique Kenya Ethiopia India China Laos Vietnam Thailand Overview Ecohealth/ One Health Our changing planet Warmer, wetter, weirder Implications for Africa and Kenya Role of agriculture in climate change Climate and infectious disease How does climate affect infectious disease? Climate sensitive infectious diseases Vector-borne disease Flood-associated disease Food-borne disease Climate sensitive non-infectious disease Implications for field epidemiologists Conclusions Human health Human health „One Medicine“ Ecosystems Societies Economies Peace Institutions “Syndrome approach” Agroecosystem Animal health Veterinary Public Health Ecosystem Approach to Health Gaia Hypothesis One world – one health One Health is the collaborative effort of multiple disciplines to attain optimal health for people, animals, and our environment. Ecohealth is systemic, participatory approaches to understanding and promoting health and well-being in the context of social and ecological interactions (Waltner-Toews D (2009), Can. Vet. J., 50(5): 519–521.). Key concept Key definitions Climate = average weather in time & place (IPCC) Climate change = Statistically significant variations in mean state of the climate or of its variability persisting for decades Climate scenario = a plausible representation of future climate based on climatological relationships Extreme weather event = often, rarer than the 10th or 90th percentile Greenhouse effect = greenhouse gases absorb infra-red radiation effectively trapping heat near the planet surface. Water vapour, CO2, nitrous oxide, methane and ozone are the most important Global warming = average increase in the temperature of the near the earth’s surface IPCC = Intergovernmental Panel on Climate Change= leading international body for assessment of climate change, established by UNEP and WMO in 1988 Key Resources: IPCC reports First assessment report 1990 – several paragraphs on health Second assessment report 1995 – chapter on potential health risks Third assessment report 2001 – chapter on human health potential impacts via: Thermal stress (heat waves and cold spells) Extreme events and disasters Air pollution Infectious diseases Fourth assessment report 2007 – review of health impacts. Evidence suggests climate change has: Altered seasonal distribution of some allergenic pollen Increased heat wave related deaths Altered distribution of some vectors (mosquito, sand fly) Climate influences malaria, dengue, TBD, cholera and some diarrhoeal disease Climate skeptics? Consensus 97-98% of scientists most active in the field believe global warming is occurring 90% believe mostly due to human activity Caveats Planet has been warmer in the past Role of geo-engineering in mitigation unknown Our Changing Planet: Warmer, wetter, weirder “Virtually certain” Over most land areas Warmer, and fewer cold days and nights. Warmer, and more frequent hot days and nights “Very Likely” Over most areas Warm spells / heat waves. Heavy precipitation events. Generally (3/4 land area) wetter; some areas (1/4) drier. “Likely” Area affected by droughts increases. Intense tropical cyclone activity increases. Increased incidence of extreme high sea level. Source: IPCC Climate Change 2007: The Physical Science Basis: Summary for Policymakers National Production Mixed rainfed temperate Mixed rainfed humid Mixed rainfed arid 2030 2050 2030 2050 2030 2050 2030 2050 Burundi 9 9 14 18 -2 -9 - - Kenya 15 18 33 46 -5 -10 -1 -8 Rwanda 11 15 13 19 5 4 1 3 Tanzania -3 -8 7 9 -2 -6 -5 -11 Uganda -2 -9 5 3 -5 -13 -1 -6 There may be winners as well as losers … Simulated percentage pasture production changes to 2030 and 2050, by country and system Mean of 4 combinations of GCM and emissions scenarios Thornton et al. (2010) Winners Losers Climate change in drylands SAHARA Temp: +3.6 C Rain: -6% Drought yrs:↑ WEST AFRICA Temp: +3.3 C Rain: +2% Flood yrs: +22% CENTRAL ASIA Temp: +3.7 C Rain: -3% Drought yrs: +12% EAST AFRICA Temp: +3.2 C Rain: +7% Flood yrs: +30% Drought yrs: +1% SOUTHERN ASIA Temp: +3.3 C Rain: +11% Flood yrs: +39% Drought yrs: +3% Source: IPPC working group 1, 2007 Livestock:9- 18% anthropogenic emissions 80% agricultural emissions Contributors to climate change Overview Ecohealth/ One Health Our changing planet Warmer, wetter, weirder Implications for Africa and Kenya Role of agriculture in climate change Climate and infectious disease How does climate affect infectious disease? Climate sensitive infectious diseases Vector-borne disease Flood-associated disease Food-borne disease Climate sensitive non-infectious disease Implications for field epidemiologists Conclusions Warmer, wetter, wider variation → sicker? Warmer Wetter / (drier) Wider variation D ↑ growth rate ↓ generation time ↑ ↓ survival ↑ season ↑ activity ↑ ↓ Survival in air ↑ Faecal-oral transmission ↑ Movement in water Post disaster disease Endemic instability Spread/shrinkage I Wildfires Change farming systems Air Pollution (O3, PM, GHG) Population movements Nuisance Plants Increase in biomass More intense air movement Change trade patterns Group work: What important diseases in Kenya may be climate sensitive Conceptualising CSD Vector-borne disease Malaria, dengue, WNV, RVF, TBE, Lyme, leishmaniasis, trypanosomosis, schistosomiasis, onchocerciasis Shifting distribution of vectors Higher temperatures affect vectorial capacity and feeding frequency Drought & heavy rain leads to population surges Water associated Cholera, cryptosporidiosis, leptospirosis Disaster and lack of sanitation Flooding and run-off Higher water temperature Food borne Salmonella, E. coli, Campy, Listeria Lack of sanitation Air borne Meningitis, Q fever (FMD) Higher RH allows survival Dust Soil associated Anthrax Clostridial disease Temperature, RH and soil moisture affect spore germination Heavy rainfall stirs up dormant spores Rodent borne Hanta virus; Lasa fever virus Multistage parasites Fascioliasis Conditions favour intermediate hosts Source: Climate Change and Human Health – Risks and Reponses. Summary (WHO, 2003) WHO conceptual framework HOW CLIMATE AFFECTS INFECTIOUS DISEASES OF LIVESTOCK AND PEOPLE (Vector-borne, parasitic,, air-borne, soil-borne, water-borne, food borne) Seasonal (within year) Short-term (1-5 years) Medium-term (5-15 years) Long-term (15-40 years) Environment Vegetation Land cover Relative humidity Surface water Soil Ambient temperature Animal populations, as definitive, intermediate and amplifier hosts Domestic livestock Wildlife Companion animals Human populations as definitive and aberrant hosts, and transporters of fomites Animal owners Rural dwellers Consumers of animal foods Vectors Arthropod and other invertebrate vectors of infectious agents More extreme events Raising sea levels Increased temperature, increased precipitation Regional shifts in climate envelopes * Annual human deaths early 21st century All infectious 18,000,000 Diarrhoea (50% zoonotic) 3,000,000 Road traffic 1,200,000 Leptospirosis 123,000 & pig/dairy production Cysticercosis 50,000 & pig production Extreme weather related 20,000 Predicted climate change 150,000 Malaria 1,000,000 Dengue 20,000 Sleeping sickness 50,000 & exclusion farming & production Leishmaniasis 47,000 & companion animal Q fever 3,000 & sheep, goat, dairy production, emerging Lyme disease 2,000 & emerging West Nile fever 100 & equine losses, emerging Rift valley fever 45 & sheep production, trade, emerging Emerging disease ???? Drivers of change GNDP Malaysia: climate and malaria 1967-1971: MEP 1982: Vector-borne Diseases Control Program- Policy, program & strategy development 2003: National Drug Resistance Surveillance Program 1961: Pilot Malaria Eradication Project 2006: National Treatment Review Committee: ACT 1990-92: Field trial on insecticide treated bednet (ITN) 1993: Nationwide Use of ITN 2004: Renewed studies on simian malaria 1972-1981: Anti-Malaria Program 0 50000 300000 1961 1970 1980 1990 2000 2005 Number of Cases Temperature 25 30 Overview Ecohealth/ One Health Our changing planet Warmer, wetter, weirder Implications for Africa and Kenya Role of agriculture in climate change Climate and infectious disease How does climate affect infectious disease? Climate sensitive infectious diseases Vector-borne disease Flood-associated disease Food-borne disease Climate sensitive non-infectious disease Implications for field epidemiologists Conclusions Vector-borne diseases Malaria Arboviral diseases transmitted by mosquitoes, midges or biting flies RVF Yellow Fever WNV Dengue Japanese encephalitis Ticks and tick-borne diseases Lyme disease Tick borne encephalitis Tsetse-transmitted trypanosomosis Chagas disease Onchocerciasis Flood-borne diseases Water-borne disease Major risk is contaminaiton of drinking water Water-borne epidemic Leptospirosis Vector-borne disease Malaria Dengue West Nile virus Rift Valley fever Risk posed by corpses Most agents do not surrvie in corpses (HIV is an exception up to 6 days) Routine handling of corpses puts at risk of TB, bloodborne viruses, gastro-intestinal illness Other risks Drowning, injurty, trauma Hypothermia Psycho socail distess Response Chlorination Early malaria diganosis Vaccination high risk groups Health education Long term Disaster preparedness Food-borne diseases Campylobacteriosis, salmonellosis, Salmonella Typhimurium infections and Salmonella Enteritidis positiviely associated with temperature 2-5 wks earlier (Lake et al., 2009) Air temperature: Campylobacteriosis and salmonellosis Water temperature: campylobacteriosis and non-cholera vibrio infections Precipitation frequency: cryptosporidiosis followed by campylobacteriosis; Precipitation events: cryptosporidiosis followed by non-cholera vibrio Listeria sp. was not associated with temperature thresholds, extreme precipitation events, or temperature limits (ECDC, 2012). Emerging disease Of 1500 human infectious diseases, 58-65% zoonotic, Around 150 to 200 EID75% of EID zoonotic One new disease emerges every 7 months Source (Nature, 2004, 430:242-249) Malaria vector in Africa A= current B- D: different climate scenarios CLIMEX model West Africa becomes less suitable vectors shift east & south Tonnang et al, 2010, Malaria journal Distribution of A. arabiensis HAT in Africa A= current geographical range suitable for T. b. rhodesience B= A2 climate change scenario 2055 SEIR model and IPCC data Range increases by 10%; considerable shifts – foci in Ethiopia disappear Moore et al 2012; J. R. Soc Interface Anthrax in Kazakhstan A= current scenario B= A2 scenario (drastic) C= B2 scenario (milder) IPCC & historical anthrax datasets; GARP model Joyner et al, 2010, PLOS 1 LOW <0.25 m DALY or no data MODERATE 0.25 to 1 m DALY HIGH 1 to 12 m DALY Very HIGH >12 m Daly LOW MODERATE HIGH VERY HIGH Malaria RVF Meningitis Cholera Diarrhoea, Respiratory Leishmaniaiss Jap. Enceph, Denge, RVF, West Nile, Yellow fever, Lyme Worms ECF, Ectoparasites Worms, tryps HIV, Childhood illness TB, schistosomiasis STD Trachoma, onchocerciasis Filiarisis, sleeping sickness Dermatophilosisresp. complex Heartwater Anthrax, blackleg Health burden Climate sensitivity Which CSD are most important to the poverty/ls nexus: the big five Animal disease Ticks and TBD Arbovirus: RVF, JE Internal parasites Trypanosomosis Culicoides transmitted virus – BT, AHS Zoonotic disease Diarrhoea Arbovirus: Dengue, YF, JE Schistosomiasis Sleeping sickness Tuberculosis Human disease Malaria Diarrhoea Respiratory Arbovirus Worms Overview Ecohealth/ One Health Our changing planet Warmer, wetter, weirder Implications for Africa and Kenya Role of agriculture in climate change Climate and infectious disease How does climate affect infectious disease? Climate sensitive infectious diseases Vector-borne disease Flood-associated disease Food-borne disease Climate sensitive non-infectious disease Implications for field epidemiologists Conclusions Implications for epidemiologists Non infectious disease Extreme heat, extreme events Disease dynamics Shifts, increase, decrease Emergence Human adaptation People movement Irrigation More and different livestock Different ways to manage risk: from cows to camels Northern Kenya: reduction in cattle numbers (10%) and increase of camels (78%) Lower mortality, more milk = more food and income security Courtesy Mario Herrero, ILRI But Coxiella burnetti : 31% Brucellosis: 5% Trypanosoma: 8% Orf/pox: 35% (Deem et al., 2012) 0º 20º -20º 0º 20º 40º An example of climate-induced livelihood transitions Areas where cropping of an indicator cereal may become unviable between now and 2050 and where farmers may have to rely more on livestock as a livelihood strategy Jones & Thornton (2008) Overview Ecohealth/ One Health Our changing planet Warmer, wetter, weirder Implications for Africa and Kenya Role of agriculture in climate change Climate and infectious disease How does climate affect infectious disease? Climate sensitive infectious diseases Vector-borne disease Flood-associated disease Food-borne disease Climate sensitive non-infectious disease Implications for field epidemiologists Conclusions Sea level rise (future) worse global nutrition failing governance Impaired public health milieu for catastrophic emerging diseases, e.g. multi-drug –resistant TB, artemisinin-resistant malaria, HIV, others Large-scale population dislocation Climate change Rising food prices High energy costs Dependence on fossil fuel, declining in quantity, quality and accessibility Increased use of crops for fuel conflict Butler, in press (2012) * Less climate change Improved governance Stable food prices Clean abundant energy technologies, especially solar Less conflict Better global education and communication, slower population growth, fairer global society, new ways to measure progress, new ways of thinking, less food waste, meat consumption “contracts and converges” Improved public health Butler, in press (2012) * Further reading courtesy of Jibrin Idris Manu Baede A.P.M., Ahlonsou E., Ding Y., Schimel Bolin B., and Pollonais S (-) The Climate System: an Overview ANTHONY MCMICHAEL ., ANDREW GITHEKO., R. Akhtar., R. Carcavallo., D. Gubler A. Haines., R.S. Kovats., P. Martens ., J. Patz ., A. Sasaki Human Health Anthony J McMichael Jonathan Patz and R Sari Kovats (1998). Impacts of global environmental change on future health and health care in tropical countries. British Medial Bulletin;54 (No. 2): 475-488 A.J. McMichael., D.H. Campbell-Lendrum., C.F. Corvalán ( 2003) Climate change and human health Risks And Responses Van den Bossche & Coetzer, 2008, Climate change and animal health in AfricaRev. sci. tech. Off. int. Epiz., 2008, 27 (2), 551-562 WHO, Flooding and communicable diseases http://www.ipcc.ch/ http://www.who.int/topics/climate/en/ * * Climate and health Definition Climate varies from place to place, depending on latitude, distance to the sea, vegetation, presence or absence of mountains or other geographical factors. It varies also in time; from season to season, year to year, decade to decade or on much longer time-scales, such as the Ice Ages Climate change refers to statistically significant variations of the mean state of the climate or of its variability, typically persisting for decades or longer * * DEFINITION The climate system is an interactive system consisting of the atmosphere, hydrosphere, cryosphere, land surface and the biosphere The system is influenced by various external forcing mechanisms; the Sun and human activities A balance is maintained between incoming solar radiation and the outgoing radiation emitted by the climate system. Climate change refers to any significant change in measures of climate, such as temperature, precipitation, wind, and other weather patterns, that lasts for decades or longer. (CDC, climate change Website) * * Greenhouse gases Greenhouse gases absorb infrared radiation, emitted by the Earth’s surface, the atmosphere and clouds The net result is an upward transfer of infrared radiation from warmer levels near the Earth’s surface to colder levels at higher altitudes. The natural greenhouse effect is part of the energy balance of the Earth Clouds also play an important role in the Earth’s energy balance and in particular in the natural greenhouse effect. * * Weather Weather is the fluctuating state of the atmosphere around us, characterized by the temperature, wind, precipitation, clouds and other weather elements. * * Human activities Combustion of fossil fuels , biomass burning, produce greenhouse gases and aerosols Chlorofluorocarbons (CFCs) and other chlorine and bromine compounds has an impact on the radiative forcing and has led to the depletion of the stratospheric ozone layer. Land-use change, Urbanization, human forestry, agricultural practices Affect the physical and biological properties of the Earth’s surface. Change the radiative forcing and have a potential impact on regional and global climate * * IPCC The Intergovernmental Panel on Climate Change (IPCC) : International body for the assessment of climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization Provide view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts. It reviews and assesses the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climate change. It does not conduct any research nor does it monitor climate related data or parameters. * * IPCC working group The IPCC has three Working Groups and a Task Force Working Group I : Assesses the scientific aspects of the climate system and climate change. Working Group II: Addresses the vulnerability of socioeconomic and natural systems to climate change, the resultant negative and positive impacts of climate change and the options for adaptations to lessen the impacts. Working Group III: Assesses options for limiting greenhouse gas emissions and otherwise mitigating climate change. The Task Force on National Greenhouse Gas Inventories defines and disseminates standardized methods for countries to calculate and report GHG emissions. * * control Preventive: anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects For the benefit of present and future generations of humankind on the basis of equity Equitably meet developmental and environmental needs of present and future generations References 1. A.J. McMichael., D.H. Campbell-Lendrum., C.F. Corvalán., K.L. Ebi., A.K. Githeko., J.D. Scheraga., A. Woodward (2003). Climate change and human health : Risks And Responses WHO, GENEVA 2. A.P.M. Baede ., E. Ahlonsou., Y. Ding., D. Schimel., B. Bolin, S. Pollonais (-). The Climate System: an Overview * * * * * * Establishment CGIAR * * * * Butler CD. Infectious disease emergence and global change: systemic thinking in a shrinking world. Infectious Diseases of Poverty * Butler CD. Infectious disease emergence and global change: systemic thinking in a shrinking world. Infectious Diseases of Poverty *