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The
Bite of a Malaria Mosquito
Malaria is transmitted when a female Anopheles mosquito takes a blood meal.
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This female Anopheles freeborni mosquito is taking a blood
meal. She is pumping blood from her human prey through her “labrum” (seen
as a straight red line between the mosquito’s head and the human’s
skin). She is near the end of the blood meal. Her belly (“abdomen”)
is now distended with blood, and she even spills out some liquid (drop
at the rear tip of the abdomen) to make room for more blood!
During blood meals taken on persons infected with malaria parasites,
the mosquitoes pick up sexual parasite forms (“gametocytes”).
After 10-18 days of further development, infective parasite forms (“sporozoites”)
are found in the mosquito’s salivary glands. When the mosquito
takes another blood meal, the parasites are inoculated into another
person.
 See
also: Life
cycle of malaria
Female mosquitoes take blood meals because these meals provide them
with the proteins needed for making eggs.
More: Anopheles
mosquitoes
Anopheles freeborni is found in the western United States.
It was one of the principal mosquito species transmitting malaria (“vector”)
in the United States before the disease was eradicated in 1951. (The
other principal vector was An. quadrimaculatus.) The continued
presence of both An. freeborni and An. quadrimaculatus means
that there is a constant risk
that malaria could be reintroduced in the United States. Travelers visiting
malaria-endemic countries should take precautions against malaria, to
avoid contracting (and bringing back to the United States) a potentially
fatal disease. Health-care providers should be alert to the possibility
of malaria, to ensure that patients with the disease are diagnosed
and treated rapidly, before parasites are spread into the community
through the bites of local Anopheles.
Page last modified : May
26, 2004
Content source: Division of Parasitic Diseases
National Center for Zoonotic, Vector-Borne, and Enteric Diseases (ZVED)
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