climate change &animal health by dr. v.k.gupta, senior scientist, division of medicine,...
TRANSCRIPT
Climate Change: “ Change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere which is in addition to natural climate variability observed over comparable time periods.” (UNFCCC,)
Climate:“Climate is defined as the "average weather" or statistical description in terms of the mean and variability of temperature, precipitation, humidity and wind. Climate in a wider sense is the state, including a statistical description, of the climate system”. (IPCC,)
Gases which absorb IR radiation are termed collectively as "greenhouse gases".
Infrared radiation from greenhouse gases in the atmosphere is emitted in all directions, including back to the earth's surface.It is this re-emission to the earth's surface that maintains a higher temperature on our planet than what would be possible without the atmosphere.
N2O from agriculture & others
Global atmospheric concentrations of greenhouse gases have increased markedly as a result of human activities, with an increase of 70% in 1970-2004
CO2 from fossil fuel & other sources
CH4 from agriculture, waste & energy
CO2 from deforestation, decay & peat
F-gases
60
50
40
30
20
10
01970 1980 1990 2000 2004
GtC
O2-e q
/yr
Global Anthropogenic GHG Emission
Observed changesObserved changes
Global average sea level
Northern hemispheresnow cover
Global average temperature
Impact
Melting of Glaciers
Vegetation
Temperature
storms / sea level rise
Humans
Volcanic eruption / earth quakes
Decrease in food & freshwater
(IPCC., 2007)
Animals
Climate change
Impact on animal health
Direct impact:
1.Impact on physiological and adaptation machenisms
2. Disease extention Emergence and Reemergence
Indirect impact:Feed Security
Changes in climate affects the quality and quantity of forage produced (Topp and Doyle, 1996)
As a consequence, productivity of dairy animals could be altered (Baker et al., 1993)
Heat stress
Thermo neutral zone varies from 15-25oC for crossbred cattle and buffaloes and 15-28oC for Sahiwal cattle
Heat stress is simply defined as the point where the animals cannot dissipate an adequate quantity of heat to maintain body thermal balance
(Singh and Upadhyay., 2008, 2009)
Increased maintenance energy requirement Animals will activate mechanisms to dissipate the excess heat and maintain body temperature (maintenance energy increase by 20-30%)
Dry matter intake (DMI) Decreases in animals subjected to heat stress (10 to 20%) (Singh et al.,2008)
Feed nutrient utilization Loss of sodium and potassium , associated with heat stress due to increased sweating rate
Reproductive performance Heat stress has also been reported to decrease reproductive performance in dairy animals.
(Upadhyay et al., 2009)
Animal growth
Growth gradients and growth constants indicate that climate change/global warming will negatively impact animal’s growth
Puberty will be prolonged due to rise in temperature
Time to attain puberty was observed to prolong from 5 to 17 days due to decline in growth rate at high temperatures
(Upadhyay et al., 2008).
Milk production Decrease in milk production in cattle/buffaloes under heat
stress (range from 10 to >25% ) (Upadhyay etal.,2009).
Temperature: Climate change is expected to increase average temperatures as well as the number and intensity of heat waves
Acclimation
Less feed intake Decrease of calorigenic harmones(catecholamines, GH etc)
Negative energy balance
Alteration in glucose & lipid metabolism & liver function
Less lactose
Reduced milk yield
Less NEFA/EFA
Oxidative stress
Less Immunoglobulins
Metabolic diseases
Infection, mastits,calf mortality
(Nardone et al., 2010)
Feed securityClimate change have serious implication on feed security resulting in Malnutrition
Excess or Scarcity of Water resulting from draught, floods, heavy rains can affect production
A new range of pests and diseases will affect most cropand forage species with effects on the quantity and quality of livestock feeds
Rising sea levels Coastal flooding of agricultural land due to sea levels rise leading to decreased yield of crops
New and emerging challenges in the field of livestock diseases
Disease Distribution to new regions (e.g Bluetongue)
Prevalent Disease e.g. parasitic gastroenteritis may become more widespread
Impact on Diseases
over 30 diseases have appeared that are new to medicine, since1975
Of equal concern is the resurgence of old diseases,such as malaria and cholera ( WHO, 2005)
Climate change affect the incidence of VBDs through its effect on
geographic distribution, population density, prevalence of infection by pathogens and the pathogen load in individual hosts and vectors
Vector-borne Disease
Climate change : Increase range or abundance of animal reservoirs and/or arthropod vectors
(e.g., Lyme, Schistosomiasis) Enhance transmission
(e.g., West Nile virus and other arboviruses)Increase importation of vectors or pathogens
(e.g., Dengue, Chikungunya, West Nile virus)Increase animal disease risk and potential human risk
(e.g., African trypanosomiasis)
Mosquitoes Borne DiseasesTrypanosomiasis, Malaria, Dengue, Chikungunia, Yellow fever, Filaria are some of most climate sensitive diseases in which there is a direct correlation with temperature and rainfall
Pest Borne DiseasesLyme ,Plague, Mediterranean spotted fever and west Nile fever
Rodent-borne diseasesLeptospirosis, are commonly reported in the after-math of flooding
Lyme disease is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia spread by blacklegged tick bites. The number of reported cases of Lyme disease has doubled during 1992-2006
Lyme disease
West Nile virus
Climate change may lengthen survival periods of WNV-competent Anopheles mosquitoes and possibly allow infected hosts (birds) to change their geographic range.
LeishmaniasisThe current environment is conducive to Phlebotomus sandfly survival for several months. The risk of contracting leishmaniasis may become high.
Mediterranean spotted fever
Abundant and widespread distribution of the tick as well as the high prevalence of dogs infected with Rickettsia conorii. Disease transmission is highest during warmer months
Schistosomiasis
Schistosoma transmission, the competent snail population may be infected, and the risk of transmission is high
Temperature change from 1960s to 1990s
0.6-1.2oC
1.2-1.8oC
Temperature Changes:1960s to 1990s
0.6-1.2oC
1.2-1.8oC
Climate change and water borne disease
Disasters. Lack of sanitation. More flooding and run-off. Disasters. Lack of sanitation. More flooding and run-off. Higher water temperature improving survival. Increase water Higher water temperature improving survival. Increase water bodiesbodies
Heavy rainfall, even without flooding, may increase rates of diarrheal disease as sewage systems overflow
Increases in soil run-off may contaminate water sources , Haemonchosis, cryptosporidiosis and Haemonchosis, cryptosporidiosis and Giaradiasis…Giaradiasis…eg. Salmonella , cholera
Effect of cl imate change on air quality
Climate Change also change patterns of air movement and pollution, causing expanded or changed patterns of exposure and resulting health effects
Higher RH allows survival, Increased air movement , Dust and Higher RH allows survival, Increased air movement , Dust and pollution exacerbating respiratory diseasepollution exacerbating respiratory disease
Climate change therefore influence pollutant concentrations, which in turn may affect health especially cardiorespiratory
IPCC expects all parts of the planet to experience more heat exposure in the future (IPCC , 2007) Dehydration increases the concentration of calcium and other compounds in the urine, which facilitates the formation of kidney stones
Cardiovascular Disease and StrokeCardiovascular disease appear to be modified by weather and climate. Ozone is also associated with acute myocardial infarction
(Cramer and Forrest , 2006)
Combate the change? Global and National Intiatives Global, regional or national efforts Sustainable Development andGreen Techology Reduce GHG emissions Follow guidelines- IPCC, UNEP, OIE, WHO Kyoto Protocol Carbon Trading and Clean Development Machenism
Efforts From Our Sector Development of disease and draught resistant breeds by genetic
approach Change in management practices of animal production to reduce
GHG emission Improved nutritional management schemes Thorough review of livestock production system in India A national policy on mitigation of climate change should give more
emphasis on livestock sector Proper risk management mechanisms and preparedness for CC
Conclusion Livestock animals are potential victims and causes of CC
It contributes 18% of total anthropogenic GHG emissions
Climate change will badly affect the animal health and production directly or indirectly if not checked
Climate change affects host ,vector and pathogens to change disease dynamics of VBD
Management practices should be changed to adapt with changing climate
References
1. Mass-Coma et al, Climate change effects on trematodiasis, with emphasis on zoonotic fascioliasis and schistosomiasis. Veterinary Parasitology 163(2009) 264-280.
2. Nardone et al, Effects of climate change on animal production and sustainability of livestock systems. Livestock science 130(2010) 57-69
3. Thornton et al,The impacts of climate change on livestock and livestock systems in developing countries: A review of what we know and what we need to know. Agricultural systems 101(2009) 113-127
4. Gubler et al, Resurgent vector-borne diseases as a global health problem. Emerging infectious disease4(1998) 442-450
5. Githeko et al, Climate change vector borne diseases: a regional analysis. Bull.WHO 78(2000)1136-1147
6. Patz et al. Effect of environmental change on emerging parasitic diseases. International journal of parasitology 30(2000)1395-1405
7. IPCC (Inter Governmental Panel on Climate Change:AR4).2007.The Inter governmental Panel on Climate Change 4th assesment report. www.ipcc.ch/
8. Baylis et al, The effects of climate change on infectious diseases of animals. Report for the Foresight Project on Detection of Infectious disease.2006 UK 35pp
9. Sutherst, Implications of global change and climate variability for vector!borne diseases] generic approaches to impact assessments. International Journal for Parasitology 28(1998) 935-945
10. De La Rocque et al, 2008. Climate change: effects on animal disease systems and implications for surveillance and control. In: De La Rocque, S., Hendrickx, G., Morand, S. (Eds.), Climate Change: Impact on the Epidemiology and Control of Animal Diseases. World Organization for Animal Health (OIE), Paris. Sci. Tech. Rev. 27 (2), 309–317