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Malaria

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View the Malaria PDF Infographic

The Disease
Malaria is a serious disease caused by Plasmodium (a parasite). It is a medical emergency, treatable, and largely preventable.

It is important to determine whether the area you visit has malaria. If it does, it is imperative you know how to protect yourself, what the symptoms are, and what to do if symptoms develop.

Risk to travellers
Malaria generally occurs in tropical and subtropical areas where humidity and rainfall levels are high. This includes large areas of Central and South America, Africa, Asia (including the Indian Subcontinent, Southeast Asia and the Middle East) and the South Pacific. The risk is less at altitudes above 1,500 metres/ 4,921 feet. However, depending on weather conditions like temperature and humidity, the risk can occur at altitudes as high as 3,000 metres/ 9,843 feet.

In some countries, the risk is nationwide. In others, the risk is limited to specific areas.

Transmission
Malaria is spread to humans via the bite of an infected mosquito. The parasite lives in the female Anopheles mosquito, which usually bites at night (from dusk until dawn). Malaria cannot move from person to person, except from a mother to her baby during pregnancy or via a blood transfusion using infected blood.

Symptoms
Symptoms can develop in a week to ten days after being bitten by an infected mosquito. Alternatively, it could take several months to a year for symptoms to appear. This is why it is important to notify your doctor of your travel history whenever you develop 'flu like' symptoms, for up to a year after visiting a malarial area.

Early malaria symptoms are flu like, such as fever, sweats/chills, head/body aches, nausea, vomiting, generally feeling tired and unwell, diarrhoea and jaundice. Later symptoms include abnormal behaviour, impaired consciousness, seizures, severe anaemia, dark urine, little or no urine, bleeding, extreme weakness, difficulty in breathing and shock, unconsciousness or coma.

Malaria is a medical emergency. If not promptly treated, malaria can affect vital organs like the brain, blood, kidneys and lungs.

In general, some groups are at a higher risk of contracting malaria and developing severe illness such as children below five years, pregnant women, people with weakened immune systems, non-immune migrants and travellers.

Diagnosis
The diagnosis is suspected based on symptoms and history of having been in a malarial area. It must be confirmed by a blood test. Insist on being repeatedly tested for malaria if you have symptoms even if the initial test was negative. Malaria tests are not 100% accurate and occasionally may need to be repeated.

Treatment
Malaria needs to be treated urgently. Prompt treatment with effective antimalarial medication is life-saving. Severe or potentially severe cases require hospitalization. Mild cases can be treated as outpatients. Travellers from non-malarial areas are more susceptible to infection, and developing severe illness.

There are several medications which can be used. Artemisinin–based combination therapies (ACTs) are the most effective medications for treating malaria. (See the International SOS travel advice article Artemisinin, Chinese herbal treatment for malaria for more detail)

Travellers who are likely to be more than 24-hours away from reliable medical care are often recommended to carry "Emergency Standby Treatment" (EST). Treatment is started when symptoms consistent with malaria infection develop, while seeking appropriate diagnosis and treatment.

Prevention
Although a vaccine is being evaluated in sub-Saharan Africa, currently there is no vaccine commercially available. Prevention is through preventing mosquito bites, and the use of preventive medication (“chemoprophylaxis”).

Prevent mosquito bites:

  • When outdoors, wear clothing that covers most of your body (long sleeves, long pants, socks and covered shoes).
  • Consider treating clothing with an insecticide. These are available as both soaks and sprays, and usually last through several washings. Always follow the manufacturer's instructions.
  • Use an effective insect repellent that contains DEET, Picaridin, PMD, or IR3535. In general, the higher the concentration of the active ingredient in a product, the longer it lasts and hence the more effective it is. Reapply after swimming or excessive sweating.
  • Stay away from mosquito breeding areas, such as stagnant water. Avoid using perfumes and wash off sweat as both attract mosquitoes.
  • Consider using a bed net impregnated with insecticides.
  • Ensure windows are covered with fly-wire. Use "knock-down" insect spray to kill mosquitoes in your room.
  • Choose air-conditioned, well-screened accommodation, if possible.

(For more information see the article "preventing mosquito bites" in the "Travel Advice" dropdown on International SOS Country Guides.)

Chemoprophylaxis: A number of different medications are available. The medication recommended will depend on the country and area of travel, as well as an individual's health profile.

When used appropriately, chemoprophylaxis is highly effective in preventing malaria, but no medication is 100% effective. Therefore, measures to prevent mosquito bites must always be used when in a malarial area, even if taking chemoprophylaxis.

People who do develop malaria while taking preventive medication are much less likely to have severe or fatal malaria. Note that although extremely useful in treating malaria, neither artemisinin nor its derivative drugs (such as artemether, artether, artesunate, artelinic acid) have been adequately proven to protect patients from contracting the disease. Thus they are not recommended as prophylaxis against malaria.

Medication resistance and “Super malaria”

Malaria resistance to one or more medications (multi-drug resistance) is an increasing problem.

In most areas, malaria is resistant to the medication chloroquine. In several countries in Asia, the parasite is also resistant to mefloquine (China, Cambodia, Laos, Myanmar, Thailand and Vietnam).

Resistance to the most effective treatment drug, artemisinin, is spreading geographically and is now confirmed in five countries in the Greater Mekong area (Cambodia, Laos, Myanmar, Thailand and Vietnam). The problem is growing partly due to the use of artemisinin alone ("monotherapy"). Authorities advise that artemisinin should never be used as a single therapy in the treatment of malaria, but only as a combined medication (ACT), to reduce the risk of further resistance. The World Health Organization has urged national authorities to stop the production and sale of oral artemisinin-based monotherapies.

A strain of malaria which is resistant to artemisinin and a drug it is combined with, piperaquine, has been dubbed “super malaria”. It was first found in Cambodia in 2008, and is now present in Thailand, Laos and Vietnam*.

*Spread of a single multidrug resistant malaria parasite lineage (PfPailin) to Vietnam Imwong, Mallika et al. The Lancet Infectious Diseases , Volume 17 , Issue 10 , 1022 - 1023

Frequently Asked Questions on Malaria Resistance and "Super malaria"
(PDF File)
CDC Malaria information
WHO Malaria information
WHO addresses drug resistance in malaria (32-page PDF file)

 
 
 
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