Included in the week 16 communicable disease threats report issued by the European Centre for Disease Prevention and Control (ECDC) on April 18 are the first chikungunya case counts from the Dominican Republic. The DR has reported 17 confirmed and 767 suspected cases of the mosquito borne disease. The number of confirmed and suspected cases for the entire Caribbean outbreak increased nearly 20 percent in the week, to 29,760.
The French-speaking islands of Martinique and Guadeloupe continue to be the most seriously affected by chikungunya. Martinique is reporting 1,473 confirmed cases and an astonishing 16,000 suspected cases, along with two deaths. Guadeloupe has seen 1,261 confirmed and 4,710 suspected chikungunya cases, with one death.
The French side of the island of St. Martin has reported three chikungunya deaths. There have been 793 confirmed cases and 2,980 suspected cases. Chikungunya was first detected in the Western Hemisphere on French St. Martin in early Dec. 2013.
The spread of chikungunya on the South American mainland continues to be slow but steady. French Guyana reported 46 confirmed cases, an increase of four from last week. Unlike several of the French islands, Guyana is not reporting suspected cases to the ECDC.
The British and Dutch islands that have reported chikungunya cases reported no new cases this week. Based upon the reporting history since Jan., it appears that these smaller governments are making less frequent reports to the ECDC. Timely testing is an issue for these islands, with patient specimens being sent to other islands such as Trinidad for processing.
The Dominican Republic began investigating an outbreak of illnesses with chikungunya symptoms in mid-March. On April 4, the Health Minister, Dr. Freddy Hidalgo Núñez, announced that testing done by the Centers for Disease Control in Atlanta had confirmed chikungunya was present. Today's data represents the first official case counts after that announcement.
Chikungunya is carried by the Yellow Fever mosquito, Aedes aegypti. The mosquito is common throughout tropical and sub-tropical North and South America. The University of Florida, in its presentation on Ae. aegypti, notes that the species has been found in at least 23 U.S. states.
The Yellow Fever mosquito is highly adapted to feeding off humans. It is an aggressive day biter, and will bite indoors as well as outdoors. The species breeds in containers with rainwater in them such as empty cans, gutters, unattended pet bowls and bird baths.