Diagnosis:
Blood-borne parasites transmitted by vectors
• In 2010, more than 200 million cases of malaria occurred worldwide, and about 650,000 people died, most (91%) in the African region. Only Anopheles mosquitoes support the sporogenic development of Plasmodium species, and the female mosquito can remain infective for life (see table).
• The Anopheles gambiae mosquito has a predominant role in transmitting Plasmodium falciparum.
• Little is known about the prevalence of Babesia in malaria-endemic countries, where misidentification as Plasmodium probably occurs. In Europe, most reported cases of babesiosis are due to B. divergens and occur in splenectomized patients. In the United States, B. microti is the agent most frequently identified (Northeast and Midwest) and it can occur in nonsplenectomized individuals.
• The World Health Organization estimates the worldwide prevalence of leishmaniasis to be about 12 million cases, with an annual mortality of about 60,000 individuals.
• Hard- and soft-bodied ticks are ectoparasites, distinguished by the presence or absence of a dorsal plate that covers the insect’s surface. Dermacentor (dog tick) has white markings on the dorsal plate, and Ixodes (deer tick) does not.
Vector-Borne Parasites
| Parasite |
Disease |
Vector |
Endemic areas |
| Babesia microti |
Babesiosis |
Ixodes scapularis
(black-legged, hard-bodied tick)
(deer tick) |
Northeast and upper Midwest United States |
| Leishmania |
Leishmaniasis
(cutaneous, mucocutaneous, and visceral) |
Phlebotomus and Lutzomyia
(female sand flies) |
Afro-Eurasia (Phlebotomus)
Western hemisphere (Lutzomyia) |
| Plasmodium species |
Malaria |
Female Anopheles mosquitoes |
Tropical and subtropical regions, including sub-Saharan Africa, Asia, Mexico, and Central and South America |
| Trypanosoma cruzi |
Chagas’ disease
American trypanosomiasis |
Triatoma infestans
Rhodnius prolixus
Triatomine, kissing or reduviid bugs |
Mexico and South and Central America |
Trypanosoma brucei gambiense
Trypanosoma brucei rhodesiense |
African trypanosomiasis
(sleeping sickness) |
Glossina vectors
(tsetse flies) |
T. brucei gambiense: Western Africa
T. brucei rhodesiense: Eastern Africa |
