1. Intro
Medical parasitology: the study and medical implications of parasites that infect humans.
Molecular parasitology: the study of the molecular biology of parasites.
A parasite: a living organism that acquires some of its basic nutritional requirements through its intimate contact with another living organism. Parasites may be simple unicellular protozoa or complex multicellular metazoa.
Eukaryote: a cell with a well-defined chromosome in a membrane-bound nucleus. All parasitic organisms are eukaryotes.
Protozoa: unicellular organisms, e.g. Plasmodium (malaria), trypanosomas, Leishmania.
Metazoa: multicellular organisms, e.g. helminths (worms) and arthropods (ticks, lice).
An endoparasite: a parasite that lives within another living organism – e.g. malaria, Leishmania, Giardia, Trypanosoma, helminths
An ectoparasite: a parasite that lives on the external surface of another living organism – e.g. lice, ticks
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2. Intro
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3. 3

4. Intro
Host: the organism in, or on, which the parasite lives and causes harm (or acts as a reservoir)
Definitive host: the organism in which the adult or sexually mature stage of the parasite lives.
Intermediate host: the organism in which the parasite lives during a period of its development only.
Zoonosis: a parasitic disease in which an animal is normally the host - but which also infects man.
Vector: a living carrier (e.g.an arthropod) that transports a pathogenic organism from an infected to a non-infected host. A typical example is the female Anopheles mosquito that transmits malaria
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5. Intro
Although parasitic infections occur globally, the majority occur in tropical regions, where there is poverty, poor sanitation and personal hygiene
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6. Intro Med Mol Para Parasite Diseases No. people infected Deaths/yr
Plasmodium
malaria
273 million
1.12 million
Soil transmitted helminths:
Roundworm (Ascaris)
Whipworm (Trichuris)
Hookworm (Ancylostoma and Necator)
Pnemonitis, intestinal obstruction
Bloody diarrhoea, rectal prolapse
Coughing, wheezing, abdominal pain and anaemia
2 billion
200,000
Schistosoma
Renal tract and intestinal disease
200 million
15,000
Filariae
Lymphatic filariasis and elephantiasis
120 million
Not fatal but 40 million disfigured or incapacitated
Trypanasoma cruzi
Chagas disease (cardiovascular)
13 million
44,000
African trypanosomes
African sleeping sickness
0.3 – 0.5 million
68,000
Leishamania
Cutaneous, mucocutaneous and visceral leishmaniasis
12 million; 2 million new cases/yr
100,000
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7. Intro
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8. Intro
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9. Intro
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10. Intro
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11. Why do we study parasites?
Intro
Why do we study parasites?
Parasites provide unique examples of biological phenomena not found in free-living organisms.
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12. Why do we study parasites?
Intro
Why do we study parasites?
Parasites provide unique examples of biological phenomena not found in free-living organisms.
Medical Importance
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13. Why do we study parasites?
Intro
Why do we study parasites?
Parasites provide unique examples of biological phenomena not found in free-living organisms.
Medical Importance
Veterinary Importance
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14. Why do we study parasites?
Intro
Why do we study parasites?
Parasites provide unique examples of biological phenomena not found in free-living organisms.
Medical Importance ********
Veterinary Importance
Economic Importance********
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15. Intro
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16. Elephantiasis

17. Intro
Lymphatic filariasis, commonly known as elephantiasis, is a neglected tropical disease. Infection occurs when filarial parasites are transmitted to humans through mosquitoes. When a mosquito with infective stage larvae bites a person, the parasites are deposited on the person's skin from where they enter the body. The larvae then migrate to the lymphatic vessels where they develop into adult worms in the human lymphatic system.
Wuchereria bancrofti, which is responsible for 90% of the cases
Brugia malayi, which causes most of the remainder of the cases
Adult worms lodge in the lymphatic system and disrupt the immune system. They live for 6-8 years and, during their life time, produce millions of microfilariae (small larvae) that circulate in the blood.
Lymphatic filariasis is transmitted by different types of mosquitoes for example by the Culex mosquito, widespread across urban and semi-urban areas; Anopheles mainly in rural areas, and Aedes, mainly in endemic islands in the Pacific
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18. Intro
African trypanosomiasis, also known as "sleeping sickness," is caused by microscopic parasites of the species Trypanosoma brucei. It is transmitted by the tsetse fly (Glossina species), which is found only in rural Africa.
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19. Intro
Chagas disease is named after the Brazilian physician Carlos Chagas, who discovered the disease in It is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors (triatomines) and is found only in the Americas (mainly, in rural areas of Latin America where poverty is widespread). Chagas disease (T. cruzi infection) is also referred to as American trypanosomiasis.
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20. Importation of Parasites from Tropics to the U.S.
Intro
Importation of Parasites from Tropics to the U.S.
Movement of persons from all areas of the world have introduced parasitic diseases into the U.S.
Numerous cases of malaria are brought back by vacationers from the tropics.
Service personnel are often employed in areas endemic with many parasites.
Many immigrants have brought their parasites with them.
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