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Malaria

Malaria is a parasitic disease commonly caused by four different species of Plasmodium: P. falciparum, P. vivax, P. ovale, and P. malaria. The Anopheles mosquito is responsible for the spread of this parasite.

Malaria is seen in over 100 countries worldwide and anywhere from 20 - 30,000 travelers contract the disease annually.

Depending on which species you are infected with, the illness can range from mild fever to severe debility and if untreated result in death if infected with P. falciparum.

Where does it occur?

While malaria is reported in over 100 countries in the world, the greatest risk of acquiring it is from Africa, India, Vietnam, Sri-Lanka, Brazil, Columbia and the Solomon Islands. Map

How is it transmitted?

Malaria is transmitted by the bite of the Anopheles mosquito, which tend to bite more at night.

Is it contagious from person to person?

It is not contagious from person to person.

What is the risk for travelers?

There is a significant risk for travelers to high risk countries especially during the rainy season when mosquito populations are at the highest concentration. Staying in rural areas, accommodations that are without screens and engaging in outdoor activities at night also increase the risk of contracting malaria.

How soon after exposure will one develop symptoms?

One can develop symptoms as early as one week after arriving in a malaria zone or up to 3 months after leaving the area. Very rarely mild cases with P. malaria species can occur years later.

Are there any lab tests to diagnose the illness?

Malaria parasites are visible under the microscope when thick and thin smears of blood are examined in the lab. If the initial blood smears are negative and symptoms continue, the test may have to be repeated every 6 – 12 hours to make a diagnosis.

Rapid diagnostic tests have become available (BinaxNOW), but have issues of false negative results.

 

Is there any treatment?

Depending on the species of Plasmodium that is involved and the pattern of drug resistance, your physician can choose from one of the following antibiotics: Chloroquine, Quinine derivative, Mefloquine, Doxycycline, Artemether -Lumefantrine or Atovaquone-proguanil. Supportive measures of fluid replacement etc are also vital.

In severe cases antibiotics will have to be given intravenously and blood exchange transfusions performed.

If infected with P.vivax or P. ovale species, after initial treatment an additional antibiotic (Primaquine) treatment to kill parasites harbored in the liver needs to be initiated.

What are the sign and symptoms?

Symptoms include fever, chills, sweats, muscle pain, headache, nausea, vomiting and sometimes diarrhea. The symptoms can wax and wane every few hours or every 1 or 2 days. In severe cases one sees progression to shortness of breath, confusion, lethargy, seizures and general collapse. If untreated or treated too late (> 24 hours with P. falciparum) one can die from malaria.

The risk of complicated illness is greatest in young children (<12 years), elderly (>65 years) and pregnant females. Malaria during pregnancy increases the risk of miscarriage, stillbirth, neonatal death and maternal death.

What preventive measures can be taken?

There is no single ‘magic bullet’ malaria prevention strategy. A combination of appropriate antibiotic and insect safety measures are most effective. However no combination of strategies are 100% effective.

Insect safety measure:

Avoid nighttime outdoor activities

Stay in accommodations with screened windows and doors

Wear long sleeve shirts, pants and socks

Apply insect repellant containing DEET on exposed skin and clothing

Use permethrin impregnated fine mesh mosquito nets

Use mosquito repellant coil in your room

Please see our section on insect safety for more details

 Anti-malaria medications:

 Chloroquine sensitive country              Chloroquine

Chlorquine resistant country                 Mefloquine

                                                          Atovaquone-proguanil

                                                          Doxycycline

Mefloquine resistant country                 Atovaquoone-proguanil

                                                          Doxycycline

 

For specific anti-malaria medication recommendations for the country

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