Malaria is a serious and sometimes fatal disease caused by a parasite that can infect a certain type of mosquito which feeds on humans. About 1,500 cases of malaria are diagnosed in the United States each year. Almost all are in travelers and immigrants returning from parts of the world where malaria transmission occurs, mainly sub-Saharan Africa and South Asia. All travelers who visit a country where malaria transmission occurs should take precautions against contracting malaria. First and second-generation immigrants are at very high risk of malaria infection because they may not realize that they have lost any partial protection that they had against malaria.
Malaria transmission occurs in many tropical and subtropical countries (see map). CDC has a list of all the places in the world (http://www.cdc.gov/malaria/travelers/country_table/a.html) where malaria transmission occurs and the malaria drugs that are recommended for use in each place. If you are traveling to parts of the world where malaria transmission occurs, you could be at risk for malaria.
More Information on Insect Repellents
If you will not be staying in well-screened or air-conditioned rooms, take additional precautions, such as sleeping under an insecticide-treated bed net (mosquito netting). Bed nets sprayed with the insecticide permethrin are most effective. In the United States, you can buy permethrin as a spray or liquid to treat clothes and bed nets and you can also purchase bed nets that have already been treated with permethrin.
Some antimalarial drugs can be started the day before travel and so last-minute travelers can still benefit from a visit to the student health center or their health-care provider before traveling. Fill your prescription before you travel rather than at your destination because buying medications in a foreign country can be risky. The medication may be contaminated or counterfeit and therefore will not protect you from malaria.
All medicines may have some side effects. Minor side effects such as nausea, occasional vomiting, or diarrhea usually do not require stopping the antimalarial drug. If you have side effects that are too uncomfortable, see a health-care provider; other antimalarial drugs are available.