Parasites and Disease

·         Parasites: usually do not kill hosts; benefit at the expense of another species

o   Obligate: spend at least part of life as parasite

o   Facultative: not normally parasitic but may become so

o   Reservoir host:

o   Incidental host:

o   Endoparasite: inside body

o   Ectoparasite: outside body

·         Parasites cause disease: observable condition

o   Zoonoses: animal diseases

·         Parasites are adapted to specific hosts:

o   Ex: mites and mammal hosts

 

·         Microparasites (bacteria, viruses, fungi, protists=microscopic)

o   Trypanosoma

 

o   Theileria

 

 

o   Babesia

 

 

o   Leishmania

 

 

o   Giardia

 

 

o   Plasmodium

 

 

 

·         Macroparasites (worms, arthropods)

o   Trematodes: Visceral and blood flukes

§  Fasciola

 

§  Paragonimus

 

 

§  Schistosoma

 

o   Cestodes: Tapeworms

§  Diphyllobothrium latum

 

§  Taenia

 

 

§  Echinococcus

 

o   Nematodes: Roundworms

§  Trichuris

 

§  Capillaria

 

 

§  Trichinella

 

§  Necator americanus

 

 

§  Ascaris

 

§  Toxocara canis

 

 

o   Arthropods: ticks, fleas, mites, flies, mosquitoes, lice

 

 

·         Some relevant zoonoses

o   Plague

 

 

o   Lyme Disease

 

 

 

o   Rocky Mountain Spotted Fever

 

 

o   Tularemia

 

 

 

o   Rabies

 

 

o   Hemorrhagic Fever

 

 

 

o   Spongiform encephalopathy

 

 

·         Case Study: Lawsonia intracellularis