Dr Meena Final Tropacon Parasitology ppt

Parasites

1. BIOFIRE FILMARRAY DR. MEENA MISHRA PROFESSOR & HEAD, DEPARTMENT OF MICROBIOLOGY, AIIMS, NAGPUR EFFECT OF CLIMATE CHANGE ON PARASITE EPIDEMIOLOGY DR. MEENA MISHRA PROFESSOR & HEAD, DEPARTMENT OF MICROBIOLOGY, AIIMS, NAGPUR TROPACON 18/09/2025

2. BRIEF OUTLINE REVIEW ON CLIMATE CHANGE IMPACT ON PARASITIC DISEASES INCIDENCE AND PREVALENCE PARASITES AFFECTED BY CLIMATE CHANGE ACTIONS TO BE TAKEN TO CONTROL

3. INTRODUCTION Climate : connections between the different elements of the climate system, e.g atmosphere, oceans and landform C limate change – significant impact on the environment and affect millions of human health worldwide a ffects health through a variety of factors, including long-term changes in temperature and precipitation patterns, as well as the extreme weather events such as heat waves, hurricanes, flash floods, deteriorating air quality, rising sea levels in low-lying coastal areas, besides complex effects on food production systems and water resources

4. INTRODUCTION WHO reported that climate change and global warming are two of humanity's most pressing issues in the twenty-first century, affecting practically globally The term "global warming" implies the increase in average worldwide temperatures rec- orded in recent decades, in terms of frequency and intensity.

5. global warming Green- house effect due to increased the CO 2 emissions widespread deforestation Climate change impacts parasitic diseases via complex mechanisms, reshaping interactions between parasites and their hosts, disrupting ecosystems, and amplifying health inequities. relation between parasitosis and climate change, emphasizing its intensified effects on them, and vectorborne diseases, also emphasizing the crucial necessity for aggressive public health meas- ures to stop these risky hazards.

6. Each environmental change, whether occurring as a natural phenomenon or through human intervention, changes the ecological balance and context within which disease hosts or vectors and parasites breed, develop, and transmit zoonotic parasitic diseases

7. ENVIRONMENTAL CHANGES AFFECTING TRANSMISSION OF ZOONOTIC PARASITIC DISEASES

8. ENVIRONMENTAL CHANGES AFFECTING TRANSMISSION OF ZOONOTIC PARASITIC DISEASES

9. Potential range of effects of climate on disease transmitted to man through other hosts Increase in precipitation Increased rain increases quality and quantity of larval habitat and vector population size Excess rain can eliminate habitat by flooding Increased humidity increases vector survival Persistent flooding may increase potential snail habitats downstream Decrease in precipitation Increase in container-breeding mosquitoes because of increased water storage Increased abundance for vectors that breed indried -up river beds Prolonged droughts could reduce or eliminate snail populations

10. Potential range of effects of climate on disease transmitted to man through other hosts Increases in temperature: Effects- Decreased survival (e.g., Culex tarsalis ) Change in susceptibility to some pathogens;seasonal effects Increased feeding rate to combat dehydration,therefore increased vector-human contact Sea-level rise Coastal flooding affects vector abundance for mosquitoes that breed in brackish water (e.g., Anopheles subpictus and Anopheles sundaicus malaria vectors in Asia)

11. Table 1 Potential range of effects of climate on disease transmitted to man through other hosts. Adapted from McMichael and his coauthors in 2001 [19]. Climate Factor Intermediate host Pathogen Vertebrate host and rodents Increases in temperature Decreased survival (e.g., Culex tarsalis ) Change in susceptibility to some pathogens;seasonal effects Increased feeding rate to combat dehydration,therefore increased vector-human contact Increased rates of extrinsicincubation in vector Extended transmission season Expanded distribution – Warmer winters favor rodent survival Decreases in precipitation Increase in container-breeding mosquitoes because of increased water storage Increased abundance for vectors that breed indried -up river beds Prolonged droughts could reduce or eliminate snail populations – No effect Decreased food availability can reduce populations Rodents may be more likely to move into housing areas, increasing human contact

12. Table 1 Potential range of effects of climate on disease transmitted to man through other hosts. Adapted from McMichael and his coauthors in 2001 [19]. Climate Factor Intermediate host Pathogen Vertebrate host and rodents Increases in precipitation Increased rain increases quality and quantityof larval habitat and vector population size Excess rain can eliminate habitat by flooding Increased humidity increases vector survival Persistent flooding may increase potential snailhabitats downstream Little evidence of direct effects Some data on humidity effecton malarial parasite development in anopheline mosquito host – Increased food availability and population size Increase in precipitation extremes – Heavy rainfall events can synchronize vector host-seeking and virus transmission – No effect – Risk of contamination of flood waters/runoff with pathogens from rodents or their excrement (e.g., Leptospira from rat urine) Sea-level rise – Coastal flooding affects vector abundance for mosquitoes that breed in brackish water (e.g., Anopheles subpictus and Anopheles sundaicus malaria vectors in Asia) – No effect – No effect

13. Potential range of effects of climate on disease transmitted to man through other hosts Increases in temperature

14. CLIMATE CHANGE I ncrease in temperature -facilitate the development of arthropod vectors that carry many parasitic organisms and the parasites themselves. A warm climate also increases the range of reservoir hosts, vector abundance, biting rates and overall survival, and parasitic transmission rates of vectors such as mosquitoes, ticks, and tsetse flies E mergence and reemergence of parasitic diseases are very concerning

15. EPIDEMIOLOGY C limate change - increased flooding, the breakdown of sanitation systems increased salinity, more vector growth, and more water- and food-borne diseases, which ultimately impact on human health modify the transmission patterns of vector-borne diseases. Increases intemperature due to climate change provide a better breeding environment for vectors The geographical distribution of leishmaniasis includes 88 countries and almost 350 million people live in these areas where the disease has been considered as one of the most severe problems of public health Kala-azar is found in about88 tropical and sub-tropical countries with approximately 350 million people living in affected areasand at risk of infection. About 5,00,000 cases occur annually. More than 90% of the world’s VLcases are in India, Bangladesh, Nepal, Sudan, and Brazil, affecting largely the socially marginalizedand the poorest communities

16. VECTOR-BORNE PARASITIC DISEASES INSECTS Mosquito prevalence is highly dependent on precipitation levels that promote mosquito breeding sites and appropriate temperatures for survivability e.g sudden increase in malaria cases was highly associated with temperature, rainfall, relative humidity, and multivariate Southern Oscillation Index. an influx of sub clinically infected immigrants or travellers from endemic regions to be bitten by local mosquitoes and aid the spread of malaria into new regions

17. Erica E Short  quoted that An ecological niche model created to scout the potential distribution of lymphatic filariasis in Africa revealed that depending on the severity of future climate change, the number of people at risk of infection could increase from 543 to 804 million to an astounding 1.65 to 1.86 billion as soon as 2050 triatomine bugs known to transmit Chagas disease - has more recently occurred autochthonously, most likely due to increasing temperature, immigration, and global travel.

18. the preponderance of sand flies, an insect vector for leishmaniasis the expansion of suitable habitat for sand fly vectors, further increasing the risk of leishmaniasis in areas currently not endemic - massive movement of people from endemic areas to nonendemic regions of the world and international travel, this threshold should be crossed way earlier than predicted.

19. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTOR DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION IMPLICATIONS Mosquito Malaria, lymphatic filariasis associated with temperature, rainfall, relative humidity sand flies ( Phlebotomus argentipus ) Leishmaniasis expansion of suitable habitat, endemic - massive movement of people from endemic areas to nonendemic regions of the world and international travel triatomine bugs Chagas disease - has more recently occurred autochthonously, most likely due to increasing temperature, immigration, and global travel. Ticks babesiosi increased rainfall may aid mushroom growth in Poland, promoting mushroom harvests after rainy weeks when ticks are also more active, thus putting the harvesters at greater risk of being bitten Snails for  Fasciola  and  Schistosoma  parasites dependent on water velocity, rainfall, and temperature; climate change will cause water stress in some areas which could increase freshwater snail populations and disease incidence Protozoa Giardiasis, cryptosporidiosis, amebiasis, and toxoplasmosis Animal fertilizers, as well as human biosolids used as fertilizers, have the potential to contain parasitic cysts and oocysts. Heavy rainfall events, which may increase in frequency and intensity due to climate change, will more often wash fertilizers into local waterway

20. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTOR/ PATHOGEN DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION IMPLICATIONS Mosquito Malaria L ymphatic filariasis Associated with temperature, rainfall, relative humidity Sand flies ( Phlebotomus argentipus ) Leishmaniasis Expansion of suitable habitat, endemic - massive movement of people from endemic areas to nonendemic regions of the world and international travel Increased incidence in previously unaffected regions

21. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTOR/ PATHOGEN DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION IMPLICATIONS Triatomine bugs- Trypanosoma cruzi Chagas disease Has more recently occurred autochthonously, most likely due to increasing temperature, immigration, and global travel. Increased temperature: I ncrease their population density and increase the chances of spreading disease Higher rainfall creates more breeding sites, increasing vector populations Tsetse fly Trypanosoma brucei Human African trypanosomiasis Habitat fragmentation, although creating conditions leading to higher populations of older flies, still increases the rate of infection and risk of disease

22. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTOR/ PATHOGEN DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION IMPLICATIONS Ticks Babesia Babesiosis Increased rainfall may aid mushroom growth in Poland, promoting mushroom harvests after rainy weeks when ticks are also more active, thus putting the harvesters at greater risk of being bitten Predicted that tick populations will expand further in upcoming decades due to direct climatic factors and changing movement/ migration of wild host species such as birds, deer, and the white-footed mouse

23. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTOR/ PATHOGEN DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION IMPLICATIONS Snails -I ntermediate hosts Fasciola  and  Schistosoma   Fascioliasis  and  Schistosomiasis   Dependent on water velocity, rainfall, and temperature; Climate change will cause water stress in some areas which could increase freshwater snail populations and disease incidence Climate change - threat to changing water velocity and temperature, human activities major factors favoring increased snail populations New areas are likely to become endemic with warming temperatures Protozoa- Giardia, Cryptosporidium, Entamoeba, Toxoplasma Giardiasis, cryptosporidiosis, amebiasis, and toxoplasmosis Animal fertilizers, as well as human biosolids used as fertilizers, have the potential to contain parasitic cysts and oocysts. Heavy rainfall events, which may increase in frequency and intensity due to climate change, will more often wash fertilizers into local waterway

24. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTOR/ PATHOGEN DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION IMPLICATIONS A lumbricoides and  T trichuria Ascariasis & Trichuriasis Higher temperatures - faster larvae development and development within eggs for hookworms, which ultimately decreases their time to infectivity-could prevent desiccation of eggs/larvae thus allowing greater survival rates of these parasites Echinococcus granulosus no arthropod vectors Echinococcosis Warmer climate will definitely assist to perpetuate those stages.

25. VECTOR-BORNE PARASITIC DISEASES INSECTS VECTORPATHOGEN DISEASE ASSOCIATED CLIMATE CHANGE ASSOCIATION Ticks babesiosis

26. IMPACT OF CLIMATE CHANGE……..

27. MALARIA Vector : Anopheles mosquitoes. Parasite : Plasmodium spp. Climate Impact : Increased temperatures shorten the extrinsic incubation period (EIP) of the parasite, leading to faster transmission cycles. Higher rainfall creates more breeding sites, increasing vector populations.

28. LEISHMANIASIS Parasite : Leishmania spp. Vector : Female sandflies (Phlebotomus argentipus ) Climate Effects : 1. directly, by the effect of temperature on parasite development and vector competence 2. indirectly, by the effect of temperature and other environmental variables on the range and abundance of the sandfly species that act as vectors 3. indirectly, through socio-economic changes that affect the amount of human contact with the transmission cycles Implications : Increased incidence in previously unaffected regions.

29. Conclusion Summary : Climate change is a significant driver of the changing epidemiology of parasitic diseases in India. Call to Action : Urgent need for interdisciplinary approaches combining climate science, epidemiology, and public health to mitigate impacts.

30. TRYPANOSOMIASIS

31. CRYPTOSPORIDIOSIS

32. GIARDIASIS

33. Shistosomiasis (Bilharzia) TREMATODE Parasite : Schistosoma spp. Transmission : Contact with freshwater habitats. Climate Impact : Warmer temperatures enhance snail intermediate host development. Altered water levels and flow patterns affect snail habitats. Concern : Potential spread to new areas due to changing hydrological conditions.

34. SOIL-TRANSMITTED HELMINTHIASES Helminths such as hookworms,  Ascaris lumbricoides , and  Trichuris trichuria  are present in soils before infecting a host, and certain soil components may be fundamentally altered by a changing climate Higher temperatures -faster larvae development and development within eggs for hookworms, which ultimately decreases their time to infectivity I ncreased humidity levels increase larval survival in soil, especially for hookworms as their larvae are at a greater risk of desiccation compared with other helminth species

35. TISSUE NEMATODES - FILARIASIS

36. TISSUE NEMATODES -ONCHOCERCIASIS (RIVER BLINDNESS)

37. TISSUE NEMATODES-LOIASIS

38. FASCIOLIASIS

39. BABESIOSIS

40. ECHINOCOCCUS Echinococcosis is a disease caused by  Echinococcus granulosus , with a life cycle requiring no arthropod vectors. However, this parasite does not have a specific intermediate host, rather it uses a variety of organisms such as the fox, cat, and dog. 81  Unfortunately, this parasite has been able to use the raccoon dog as a definitive host, allowing it to expand its geographical range, thus further expanding the range of  Echinococcus  as well. 81  Even without a host, some parasites can survive in resistant, dormant stages until a suitable host is found, and a warmer climate will definitely assist to perpetuate those stages

41. COPING WITH THE FUTURE The continued disturbance of natural ecosystems by destructive changes in land use, especially deforestation, and poor husbanding of natural resources has modified the distribution and behaviour of parasites, their hosts and vectors. Improved surveillance and monitoring is needed so as to detect changes resulting from global climate and ecological change, both for identification of immediately required action and to serve as the basis for developing predictive models insight into associations among ecological factors, entomological, genetic and behavioural characte ri stics of vectors and parasites, and human behaviour that are associated with disease transmission

42. WAY AHEAD…… Multidisciplinary co-operation among workers in public health, ecology, and the social and physical sciences - to develop comprehensive risk assessment to aid local, national & international governments and decision makers

43. Research gaps on climate change and parasitic diseases Changes in transmission patterns of parasitic diseases are a likely major consequence of climate change. There are both direct and indirect implications of climate change on the scope and distribution of parasitic organisms and their associated vectors and host species More information about the underlying complex causal relationships is needed. Also, it is crucial to apply such information to the prediction of future impacts, using more complete, better validated, integrated models.

44. Climate-Health Data Integration EpiClim Dataset : A comprehensive dataset linking climate variables with disease incidence across India. Applications : Predicting disease outbreaks. Informing public health interventions. Guiding resource allocation

45. Adaptation and Mitigation Strategies Surveillance : Enhanced monitoring of vector populations and disease incidence. Control Measures : Use of insecticide-treated nets, indoor spraying, and environmental management. Public Awareness : Community education on preventing mosquito breeding and disease transmission. Policy Recommendations : Integration of climate change considerations into national health policies.

46. Conclusion Summary : Climate change is a significant driver of the changing epidemiology of parasitic diseases in India. Call to Action : Urgent need for interdisciplinary approaches combining climate science, epidemiology, and public health to mitigate impacts.

47. If you don’t have time to do it right, when will you have time to do it over again??? Albert Einstein

48. MAHAMICROCON 23/08/2025 DR MEENA MISHRA PROFESSOR & HEAD, DEPARTMENT OF MICROBIOLOGY, ALL INDIA INSTITUTE OF MEDICAL SCIENCES, NAGPUR GLOBAL TRENDS IN ANTIMICROBIAL RESISTANCE AMONGST GRAM POSITIVE & GRAM NEGATIVE ORGANISMS

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50. MAN VERSUS MICROBES….. 14/09/25

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