Malaria–Great Exuma, Bahamas, May-June 2006

Malaria in humans is caused by four distinct protozoan species of the genus Plasmodium (P. falciparum, P. vivax, P. ovale, and P. malariae). These parasites are transmitted by the bite of an infective female Anopheles mosquito. In the Caribbean region, malaria has been eliminated from all islands except Hispaniola, the island consisting of Haiti and the Dominican Republic. Elimination of malaria elsewhere resulted from a combination of integrated control measures, socioeconomic development, and close public health surveillance. However, even Caribbean islands where malaria is no longer endemic remain at constant risk for reintroduction of the disease because of their tropical climate, presence of competent malaria vectors, and proximity to other countries where malaria is endemic. This susceptibility was underscored by the recent outbreak of malaria on the island of Great Exuma in the Bahamas; during May-June 2006, a total of 19 malaria cases were identified. Four of the cases, in travelers from North America and Europe, are described in this report; such cases of imported malaria can signal the presence of a malaria problem in the country visited and thus assist local health authorities in their investigations. On September 19, after 3 months with no report of new cases, CDC rescinded its previous recommendation that U.S.-based travelers take preventive doses of the antimalarial drug chloroquine before, during, and after travel to Great Exuma.