Malaria
What is it?
Malaria is a serious, parasitic infection that
is spread by the bite of certain mosquitoes. A
parasite is an organism that survives by living
inside a larger organism, called a host.
Who gets it?
Anyone living in or traveling to an area of the
world where malaria is more commonly transmitted
can get this disease. It is more common in
tropical climates, such as Central and South
America, Haiti and the Dominican Republic, Africa,
the Indian subcontinent, Southeast Asia, the
Middle East, and Oceania. Malaria is considered
“endemic” to these regions, which means it is
native to, or naturally occurring, in these areas.
While small outbreaks sometimes occur within the
United States, malaria is not a serious problem
here.
What causes it?
Malaria is spread in three ways. The most
common is by the bite of an infected female
Anopheles mosquito. However, malaria can also be
spread through a transfusion of infected blood or
by sharing a needle with an infected person. There
are four different species of parasites that cause
malaria. They are the Plasmodium falciparum (which
is the most fatal), P. vivax, P. malariae, and P.
ovale. When an infected mosquito bites a person,
the parasites enter the bloodstream and travel to
the liver. They multiply in the liver, then travel
back into the blood, where they continue to grow
and multiply so quickly that they clog blood
vessels and rupture blood cells. When the red
blood cells burst, the parasites are released and
then attack other red blood cells. Malaria is not
contagious, which means one person cannot pass it
directly to another. However, if a mosquito that
is not infected bites an infected person, it picks
up the malaria parasites. Animals can also get
malaria, but animal malaria cannot spread to
humans, and human malaria cannot spread to
animals.
What are the symptoms?
It takes anywhere from eight days to several
months for the parasites to multiply in the liver,
then enter the bloodstream. The most dangerous
parasite, falciparum, usually takes between 8 and
12 days. While the parasites are in the liver, the
person does not feel sick. However, once they
enter the bloodstream, symptoms begin. At first,
the person may have flu-like symptoms, including
low fever, chills, fever, headache, body aches,
nausea, vomiting, and a general feeling of
illness. The chills and fever are referred to as
“malaria ague.” Symptoms usually follow a cycle of
uncontrollable shivering, then high fever, then
intense sweating, which brings down the fever. The
patient is by this time exhausted and sleeps.
Then, the cycle of chills, fever, and sweats
begins again and continues to occur sometimes
every other day, or every third day. This may go
on for anywhere between a week and a month. There
is a chronic form of malaria where symptoms
reoccur as much as 50 years after the first
infection. Untreated malaria can cause jaundice,
which is a yellow coloring of the skin and eyes,
and anemia. Falciparum malaria causes more severe
symptoms because it destroys so many red blood
cells so quickly that they block the blood vessels
in major organs, such as the kidneys. Falciparum
malaria can also affect brain function. When this
occurs, symptoms include a high fever (at least
104 deg. F), severe headache, confusion, delirium,
and drowsiness, and can result in coma and
convulsions. Falciparum malaria also causes an
enlarged spleen, as well as kidney and liver
failure. Malaria during pregnancy can result in
premature birth, miscarriage, or stillbirth.
People who live in areas where malaria is common
can get the disease repeatedly and never fully
recover.
How is it diagnosed?
Your doctor will take a complete medical
history so he or she can assess your risk factors
for malaria. It is important to tell your doctor
if you have been traveling in an area where
malaria is endemic, even as long ago as one year.
He or she will also perform a complete physical
examination, looking specifically for symptoms
such as chills, fever, and an enlarged spleen. If
your doctor thinks you may have malaria, he or she
will take a blood sample to be tested in a
laboratory. The parasite that causes malaria can
be seen on a blood smear under a microscope. The
malaria parasite multiplies over time, so you may
need to give more than one blood sample to make
the diagnosis. Because falciparum malaria must be
treated immediately or it can be fatal, you should
insist upon a malaria blood test if you have
flu-like symptoms and have recently traveled to a
high risk area.
What is the treatment?
Malaria can be cured if treated while in its
early stages. Treatment depends upon the type of
malaria you have. Falciparum malaria is considered
a medical emergency and the patient is admitted to
the hospital for treatment with the antimalarial
drugs chloroquine or quinine, often intravenously,
combined with tetracyline, an antibiotic. In some
countries where malaria is common, the parasite
has become resistant to quinine, so different
combinations and doses of medication may need to
be given. The patient may also need kidney
dialysis, blood transfusions, oxygen therapy, and
intravenous (IV) fluids, depending upon the
severity of symptoms. Other types of malaria are
treated successfully with chloroquine, which is
taken by mouth. The length of time anti-malaria
drugs must be taken depends upon the type of
malaria, the age of the patient, and how severe
the symptoms are. Even with drug treatment,
malaria symptoms can recur if the parasite remains
in the liver. Patients who have recovered from the
P. vivax or P. ovale strains of malaria can take a
drug called primaquine to prevent reoccurences of
the disease.
Self-care tips
There are ways to protect yourself if you are
traveling to a country that is known to have a
high population of malaria-carrying mosquitoes.
You can avoid mosquito bites by using a mosquito
repellent spray or lotion on your body and clothes
and staying in well-screened areas, especially
after dark. Your sleeping area should have
repellant-treated mosquito netting over the bed.
When outdoors, wear clothing that covers your
entire body. Avoid leaving any containers of
standing water outside where mosquitoes can breed.
If you know you will be traveling in an area where
malaria is common, see your doctor first. You can
take antimalarial drugs before leaving the United
States, then continue to take these drugs for
approximately four weeks after returning home. You
should still follow all the precautions listed
above for avoiding mosquito bites. See a
healthcare professional immediately if you have
been in an area endemic to malaria and you have
any flu-like illness with fever.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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