Things you need to know about malaria
Things you need to know about malaria
What is malaria?
Malaria is a serious, sometimes fatal, disease caused by a
parasite. There are four kinds of malaria that can infect humans:
Plasmodium falciparum, P. vivax, P. ovale, and P. malariae.
Where does malaria occur?
Malaria occurs in over 100 countries and territories. More
than 40 percent of the people in the world are at risk. Large
areas of Central and South America, Hispaniola (Haiti and the
Dominican Republic), Africa, the Indian subcontinent, Southeast
Asia, the Middle East, and Oceania are considered malaria-risk
areas (an area of the world that has malaria).
How common is malaria?
The World Health Organization estimates that yearly 300-500
million cases of malaria occur and more than 1 million people die
of malaria.
How do you get malaria?
Humans get malaria from the bite of a malaria-infected
mosquito. When a mosquito bites an infected person, it ingests
microscopic malaria parasites found in the person's blood.
The malaria parasite must grow in the mosquito for a week or
more before infection can be passed to another person. If, after
a week, the mosquito then bites another person, the parasites go
from the mosquito's mouth into the person's blood. The parasites
then travel to the person's liver, enter the liver's cells, grow
and multiply. During this time when the parasites are in the
liver, the person has not yet felt sick. The parasites leave the
liver and enter red blood cells; this may take as little as eight
days or as many as several months.
Once inside the red blood cells, the parasites grow and
multiply. The red blood cells burst, freeing the parasites to
attack other red blood cells. Toxins from the parasite are also
released into the blood, making the person feel sick. If a
mosquito bites this person while the parasites are in his or her
blood, it will ingest the tiny parasites. After a week or more,
the mosquito can infect another person.
Each year in the United States, a few cases of malaria result
from blood transfusions, are passed from mother to fetus during
pregnancy, or are transmitted by locally infected mosquitoes.
What are the signs and symptoms of malaria?
Symptoms of malaria include fever and flu-like illness,
including shaking chills, headache, muscle aches, and tiredness.
Nausea, vomiting, and diarrhea may also occur. Malaria may cause
anemia and jaundice (yellow coloring of the skin and eyes)
because of the loss of red blood cells. Infection with one type
of malaria, Plasmodium falciparum, if not promptly treated, may
cause kidney failure, seizures, mental confusion, coma, and
death.
How soon will a person feel sick after being bitten by an
infected mosquito?
For most people, symptoms begin 10 days to four weeks after
infection, although a person may feel ill as early as eight days
or up to a year later.
Two kinds of malaria, P. vivax and P. ovale, can relapse; some
parasites can rest in the liver for several months up to four
years after a person is bitten by an infected mosquito. When
these parasites come out of hibernation and begin invading red
blood cells, the person will become sick.
How is malaria diagnosed?
Malaria is diagnosed by looking for the parasites in a drop of
blood. Blood will be put onto a microscope slide and stained so
that the parasites will be visible under a microscope.
Any traveler who becomes ill with a fever or flu-like illness
while traveling and up to a year after returning home should
immediately seek professional medical care. You should tell your
health care provider that you have been traveling in a malaria-
risk area.
Who is at risk for malaria?
Persons living in, and travelers to, any area of the world
where malaria is transmitted may become infected.
What is the treatment for malaria?
Malaria can be cured with prescription drugs. The type of
drugs and length of treatment depend on which kind of malaria is
diagnosed, where the patient was infected, the age of the
patient, and how severely ill the patient was at start of
treatment.
How can malaria and other travel-related illnesses be
prevented?
* Visit your health care provider four to six weeks before
foreign travel for any necessary vaccinations and a prescription
for an antimalarial drug.
* Take your antimalarial drug exactly on schedule without missing
doses.
* Prevent mosquito and other insect bites. Use insect repellent
on exposed skin and flying insect spray in the room where you
sleep.
* Wear long pants and long-sleeved shirts, especially from dusk
to dawn. This is the time when mosquitoes that spread malaria
bite.
Sleep under a mosquito bednet that has been dipped in
permethrin insecticide if you are not living in screened or air-
conditioned housing.
-- www.cdc.gov