Difference between revisions of "Malaria"
Revision as of 09:08, 26 October 2007
This article is a travel topic
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.
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), and a few areas of 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 of malaria mimic common flu, with an infected person suffering fever, headache, and vomiting usually within 10 to 15 days after the mosquito bite. This means that you may become sick when you're already back at home, so be aware of that.
Malaria is life-threatening, and requires immediate treatment. No vaccine is currently available, but methods of prevention include avoiding mosquito bites and preventative drugs (prophylaxis). Note that some drugs are not effective for all areas. If a person who has visited a malaria risk zone contracts a fever within one year, their physician should be informed of the possibility of malaria. Less serious forms (such as P. vivax) can mimic symptoms of the flu. Physicians who rarely, if ever, examine malaria patients may need to be reminded of this fact. The standard laboratory test for malaria is a thick and thin blood smear on a glass slide viewed under the microscope. Self-test kits are highly unreliable.
Any malaria prophylaxis must be taken before, during, and (especially) after traveling to a malaria-risk zone. 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 (e.g. resistance); a specialist doctor should be consulted beforehand. Seldom will malaria be the sole health concern, and the physician will need to assess all the health risks the traveler will face. Most often a general practitioner cannot prescribe medications or give vaccinations for third-world travel.
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 (e.g. doxycycline, Malarone) are ~98%~99% effective. The choice of a malaria prophylaxis should be made carefully with one's physician, taking into account drug resistance in the traveler's destination; possible side effects, interactions, and contraindications; and finally the preferred frequency per dose (daily, weekly, etc.)
Even before considering prophylactic medications, there are important anti-insect measures that should be used. Avoiding mosquito bites (i.e. using DEET, screens, and proper bed netting) when mosquitoes are obviously present is important as well. For those sensitive to DEET, or dislike its smell, repellents containing Picaridin (e.g. Cutter Advanced) are available in limited areas. This has been shown to be as effective as DEET, and has almost no odor.
The most common anti-malarials include:
There has been some debate recently over whether pre-travel malaria prophylaxis is being started early enough. For example, mefloquine is normally taken one week prior to travel. Some feel this is inadequate if the person is unfortunate enough to be exposed to malaria shortly upon arrival. Those who have concerns may wish to discuss with their physician the option of doubling the time period (not the dosage) that their malaria prophylaxis will be taken prior to travel. In addition to providing better protection, there will be more time to switch to another anti-malaria medication, if necessary.
Aspirin must never be taken as an antipyretic (fever reducer) when malaria or dengue fever is a possibility. (Continuing daily low-dose 81 mg aspirin therapy during and after third-world travel should be discussed with your physician.) Acetaminophen (paracetamol) and ibuprofen are considered safe alternatives provided all of their precautions are observed. Malaria, dengue fever, and typhoid fever all tend to have somewhat similar symptoms at first and should not be self-diagnosed.
Travel to rural areas always involves more potential exposure to malaria than in the larger cities. (This is in contrast to dengue fever where cities present the greater risk.) For example, the capital cities of the Philippines, Thailand and Sri Lanka are essentially malaria-free. However, malaria is present in many other places (especially rural areas) of these countries. By contrast, in West Africa, Ghana and Nigeria have malaria throughout the entire country. However, the risk will always be lower in the larger cities. Travelers should never assume that their choice of malaria prophylaxis is available in the country that they will be visiting. Many third-world countries stock only chloroquine and possibly doxycycline. Quinine might also be available, but is not recommended as a prophylactic anti-malarial.
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