Malaria
Malaria is a serious and sometimes fatal tropical disease. Four kinds of malaria parasites can infect humans: Plasmodium falciparum, P. vivax, P. ovale, and P. malariae; infection with P. falciparum, if not promptly and correctly treated, can be fatal in as little as one or two days.
Competent advice from an up-to-date source of information, such as the tropical diseases department of a major hospital, is essential.
Transmission
According to the CDC, Malaria is transmitted in large areas of Central and South America, the island of Hispaniola (includes Haiti and the Dominican Republic), Africa, Asia (including the Indian subcontinent, Southeast Asia and the Middle East), Eastern Europe, and the South Pacific.
In general, the risk of contracting malaria is higher in rural areas and lower in urban areas. Often there is also a correlation to the mosquito population, with the rainy season creating stagnant pools of water where mosquitoes can breed.
Symptoms
Symptoms usually include shaking chills, high fevers, and flu-like illness. No vaccine is currently available to travellers. Methods of prevention includes avoiding mosquito bites, and preventative drugs (prophylaxis); some drugs are not effective for all areas. Malaria symptoms sometimes take several months to appear, so in the event of any fever within 12 months of travelling in a risk area, contact a doctor and specify where you've been in the last year. Diagnosis is by blood test. Self-test kits are highly unreliable.
Prophylaxis
Anti-malarial drugs are highly effective in preventing malaria. As with all drugs, anti-malarials may cause side-effects, and their effectiveness may be compromised by various factors (eg parasite resistance); a specialist doctor should be consulted beforehand. Pregnant women should be especially careful, as some anti-malarials must not be taken during pregnancy, and malaria during pregnancy is usually more severe and is always considered to be a serious emergency. As with most prophylaxis, anti-malarials are not 100% effective; however studies have shown that when taken as directed, the most common drugs (eg doxycycline, Malarone) are ~98%~99% effective. All anti-malarials must be taken for an additional period of time (which varies from drug to drug) after leaving the risk area.
The most common anti-malarials include:
- Doxycycline is highly effective and can be very inexpensive. Possible disadvantages include increased sun sensitivity (sunburning easier), and nausea and stomach pain; some sources caution that it may reduce the effectiveness of birth control pills.
- Lariam (mefloquine) is highly effective, has a simple weekly dose and can be taken for extended periods. It does have a number of contra-indications and must be prescribed by a doctor, and has also been known to have very rare but severe neurological side effects. Your doctor may advise that you start using it several weeks before leaving, in order to check for possible side effects.
- Malarone (atovaquone + proguanil) is highly effective, has a very low incidence of side effects, and only needs to be taken for one week after leaving the risk area; however it is expensive.
- Chloroquine (Daramal / Nivaquine / Promal) in combination with proguanil (Paludrine) may sometimes be recommended, and is generally well tolerated. Problems include people having difficulty adhering to the prescribed regime due to its complexity, and widespread resistance.
See also