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.
occurs in over 100 countries and territories. More than 40
percent of the people in the world are at risk. The World
Health Organisation estimates that yearly 300-500 million
cases of malaria occur and more than 1 million people die
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. A few cases of malaria
result from blood transfusions, are passed from mother to
foetus during pregnancy, or are transmitted by locally infected
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 diarrhoea may also occur. Malaria may cause
anaemia and jaundice (yellow colouring 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,
soon will a person feel sick after being bitten by an infected
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 one 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.
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.
traveller who becomes ill with a fever or flu-like illness
while travelling and up to one year after returning home should
immediately seek professional medical care. You should tell
your health care provider that you have been travelling in
a malaria-risk area. (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).
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
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
* Prevent mosquito and other insect bites. Use DEET 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
* Sleep under a mosquito bednet that has been dipped in permethrin
insecticide if you are not living in screened or air-conditioned
CDC Travellers' Health