Transmission of malaria in resort areas–Dominican Republic, 2004

Malaria is caused by any of four Plasmodium parasites carried by Anopheles mosquitoes and usually is transmitted by the bite of an infective female Anopheles. In rural areas of the Dominican Republic, P. falciparum malaria is endemic, with the highest risk in the far western region of the country, and prophylactic medication with chloroquine is recommended for incoming travelers. Conversely, urban and resort areas in the Dominican Republic have been considered nonmalarious, and prophylactic medication has not been recommended for persons traveling to these areas. However, since November 2004, CDC has received reports of three malaria cases in U.S. travelers returning from areas in La Altagracia and Duarte provinces previously considered nonmalarious. An additional 14 cases of malaria in La Altagracia Province, in the far eastern region of the country, have been reported in European and Canadian travelers. This report describes three of these 17 malaria cases and summarizes the overall investigation, which led to expansion of CDC recommendations for chloroquine prophylaxis to include all of La Altagracia and Duarte provinces.