When you're bitten by a
malaria-infected mosquito, the parasites that cause
malaria are released into your blood and infect your liver cells. The parasite
reproduces in the liver cells, which then burst open. This allows thousands of new
parasites to enter the bloodstream and infect red blood cells. The parasites
reproduce again in the blood cells, kill the blood cells, and then move to
other uninfected blood cells.
After the early stages,
life-threatening complications may develop rapidly with P. falciparum and P. knowlesi. If the infected person is not treated, serious complications or death can occur.
There has already been considerable progress in preventing some causes of encephalitis.
The elimination of smallpox and vaccines against mumps, measles, and rubella has reduced the incidence of encephalitis, especially in children.
Vaccines have been developed for people who travel to high-risk areas as well.
Other ways to prevent it are to avoid viruses that can lead to the disease (like herpes) and to protect yourself against mosquito and tick bites.
But you may recover in a week to a
month (or longer) after being infected with P. vivax,
P. malariae, or P. ovale, even without treatment.
Malaria can be a very serious disease for a
pregnant woman and her developing fetus, for people without a spleen, and for
young children. Medicine choices are limited for a pregnant woman or a
child. Infection with P. falciparum can lead to death
for a pregnant woman and her fetus. For these reasons, a pregnant woman should
not travel to an area where she could get P. falciparum
malaria. Visit the CDC website (www.cdc.gov/malaria/travelers/index.html) to find
out whether malaria is a problem in the country where you will be traveling.
Malaria caused by
P. falciparum may come back (recur) at irregular
intervals for up to 2 years if treatment is not complete.
caused by P. vivax and P. ovale
may recur at irregular intervals for up to 3 to 4 years, but medicine can prevent relapses.
can remain in the blood of an infected person for more than 30 years, usually
without causing any symptoms.