Malaria is transmitted by the bite of Anopheles infected with Plasmodium. There are four kinds of Plasmodium for human infection: Plasmodium vivax, Plasmodium falciparum, Plasmodium ovale and Plasmodium malariae, among which the infection of Plasmodium falciparum is life-threatening if treatment is delayed.

Typical symptoms are intermittent chills, fever, sweating, and may also include headache, back pain, muscle pain, nausea, vomiting, dysentery and cough. Severe cases can lead to splenomegaly, jaundice, shock, liver and kidney failure, pulmonary edema, acute encephalopathy and coma.

Malaria endemic areas

Malaria is still rampant throughout the world, with 219 million cases each year and about 660,000 deaths, especially in Africa, Southeast Asia, Oceania and Central and South America and other tropical and subtropical regions. However, some metropolitan and tourist destinations are not all endemic areas because of the better public health environment. Detailed information can be obtained from the Centers for Disease Control website (http://www.cdc.gov.tw) for global information and latest outbreaks.

Avoid mosquito bites. The more times mosquitoes bite, the higher the chance of getting sick, and the more serious the symptoms of malaria may be.

Personal protection in areas at risk of malaria infection

• Avoid going out between dusk and dawn. When you go out at night, you should wear light-colored short-sleeved shirts and trousers. Mosquito-repellent ointments or liquids can be applied onto the exposed parts.
• Live in a house with screen doors and windows and good sanitation. Use a mosquito net when you sleep, and check it for holes and mosquitoes.

Mosquito repellent

• The WHO recommends the use of DEET to prevent Anopheles. Children over 2 months old and adults can choose mosquito repellents with DEET of ≦ 50% concentration, while infants under 2 months should use those with DEET of ≦ 10% concentration. Higher DEET levels can provide more lasting protection against mosquitoes.
• Anti-mosquito agents approved by the Environmental Protection Administration can be used on environment or clothing, while those approved by the Department of Health can be used on skin. They should be used according to the directions on the label, such as vertical spraying 15-20 cm away from skin or clothing, while DEET can be sprayed or applied to bare skin and clothing, but be careful not to apply mosquito repellent products to skin with wounds, inflammation or eczema.
• Current reports have reviewed all available data on DEET and human and animal neurotoxicity and conclude that "there is no evidence that DEET is a selective neurotoxic agent, no evidence that DEET poses any greater risk to children, and toxicity reports in medical literature reveal that there is no correlation with the age of the user." The American Academy of Pediatrics has also revised its recommendation to use DEET for children, suggesting that about 30% of DEET can be used for children.
• Take preventive malaria drugs and consult a physician about a month before you leave the country.