1. The significance of Medical Parasitology

2. Prevalent infections worldwide Significant morbidity & mortality Significant impact on economic & social development Increased mobility of individuals & populations Drug resistance, climate change & opportunistic infections

3. Global estimates of parasitic diseases and disease burden (Topley & Wilson, 2005)

4. Definitions of parasitism Concept of metabolic dependence (Smyth) (nutrition, developmental stimuli, control of maturation) Genetic complementation Population dynamic approach (Crofton)- lethal level, overdispersion, reproductive rate

5. Morphological adaptations Biochemical changes Specialized mechanisms for entry Complex life cycles and transmission opportunities Mechanisms for immune evasion Impact on host versus impact of host Parasitic adaptations

7. Important parasitic groups Microparasites (Protists) –Kinetoplastida –Ciliophora –Apicomplexa Macroparasites (Helminths, Arthropods) –Platyhelminthes –Nematoda –Arthropoda

8. Important issues associated with parasites of human importance Life cycle and transmission Pathology and symptomatology Epidemiology, human behaviour and at risk groups Medical history Diagnostic difficulties Prevention and control

9. Approach to the patient Full history required particularly travel history Symptoms may be subtle and change over time (repeated history taking) General history also important - occupation, hobby and leisure activities, diet, medication Clinical exam

10. Life cycle and routes of transmission Diverse routes of transmission which relate to human behaviour and risk factors e.g. Toxoplasma gondii Diverse routes of transmission with implications for parasite survival and pathogenicity e.g. Strongloides stercoralis

11. Toxoplasma Life cycle

12. Strongyloides life cycle

13. Symptomatology and pathology 1 Parasites often provoke nonspecific and diverse symptoms –e.g. Toxocariasis in children Microparasites often provoke more acute disease compared to the chronicity of macroparasites –e.g. Plasmodium falciparum versus Strongyloides stercoralis

14. Symptomatology and pathology 2 Differential pathology Immunocompromised versus Immunocompetent hosts e.g. Toxoplasma gondii & Cryptosporidium parvum

15. Epidemiology Changes in human behaviour –Migration and International travel –Exotic foods –Pet ownership (including exotic pets) –Intensification of agricultural practices At risk groups –Age, Occupation, Immune status, Pregnancy, Organ transplantation

16. Diagnostic dilemmas Different diagnostic tests for different patient groups –Toxoplasma gondii Need for repeat diagnostic testing – Giardia intestinalis Need for improved sensitivity of diagnostic methods –Strongyloides stercoralis & Taenia solium

17. Prevention and control

18. Dracunculus medinensis : guinea worm

19. Prevalence of important Microparasites Malaria : 500 million (annual deaths 2.2 to 2.5 million) Giardiasis : 200 million American Trypanosomiasis : 16-18 million (annual deaths 60,000) Leishmaniasis : 12-13 million Amoebiasis : 500 million

20. Prevalence of important Macroparasites Cestodiasis : 70 million Schistosomiasis : 200 million (annual deaths 500,000 to 1 million) Lymphatic filariasis : 78.6-90 million Onchocerciasis : 17.5 million Ascariasis : 1.3 billion Hookworm : 1 billion Strongyloidiasis : 80-100 million

21. The Big Three and Neglected tropical diseases (NTDC) Three vector-borne protists: Leishmaniasis, African Trypanosomiasis & Chagas disease Three bacterial infections: trachoma, leprosy and Buruli ulcer Seven helminth infections: hookworm, ascariasis, trichuriasis, lymphatic filariasis, onchocerciasis, guinea worm & schistosomiasis Cysticercosis, food-borne trematodiasis & some other parasitic infections could be included From Hotez et al, 2006, PLoS Medicine

22. UNITING TO COMBAT NEGLECTED TROPICAL DISEASES 30 January 2012, London: 13 pharmaceutical companies, the U.S., U.K. and U.A.E governments, the Bill & Melinda Gates Foundation, the World Bank etc new, coordinated push to accelerate progress toward eliminating or controlling 10 NTDs by the end of the decade

23. Implications of co-infections

24. A. The proportion of individuals with Plasmodium spp. over time B. The log odds of individuals being infected with Plasmodium spp. over time

25. Rare diseases Echinococcus multilocularis : alveolar echinococcosis (AE) Emerging diseases Challenges

26. Toxoplasmosis Malaria Schistosomiasis Neurocysticercosis Lymphatic filariasis

27. Texts Topley and Wilson’s Microbiology and Microbial infections Parasitology (2005). Eds Cox, F.E.G., Wakelin, D., Gillespie, S.H and D.D. Despommier. 10th Edition. Hodder Arnold. Peters, W. and Pasvol, G. (2007). Tropical Medicine and Parasitology. Mosby 6th edition.

28. Clinical Parasitology: a practical approach E. A. Zeibig Expected Date of Publication 13 May 2012 ISBN 9781416060444