Health officials in the Dominican Republic say the mosquito-borne chikungunya virus has spread widely since making its first appearance in the country. (Associated Press)

Caribbean health experts warned last week that they “cannot stop” a rapidly spreading mosquito-borne virus that has infected thousands and is associated with six deaths in the region.

The alert came as the Dominican Republic’s health ministry became the 15th Caribbean nation to confirm cases of the chikungunya virus and Haiti announced it was awaiting confirmation on whether the disease had arrived on its shores.

So far, the World Health Organization has documented more than 4,000 confirmed cases in the Caribbean, with the French territories the hardest hit, and more than 31,000 suspected cases. The developments come as the Caribbean prepares for the summer travel season, when hundreds of thousands of tourists usually flock to the region.

“At first I thought we could stop it. I have since revised that thinking, given the way it is spreading. We cannot stop it,” said James Hospedales, the executive director of the Caribbean Public Health Agency. The Trinidad-based organization was awaiting the arrival of 17 specimens from Haiti for testing. “All we can hope to do is slow it down,” Hospedales said.

More commonly found in Asia and Africa, chikungunya was first detected in the Caribbean in December in St. Martin.

A baby boy sleeps under a cloth to keep away flies and mosquitos. (Harish Tyagi/EPA)

Last week, the U.S. Centers for Disease Control and Prevention warned that several Caribbean countries and territories had reported cases of chikungunya. The alerts — categorized as Level 1, the least urgent on CDC’s scale — advised travelers to take precautions, including using repellant and permethrin-treated clothing.

The virus is transmitted by the same Aedes aegypti mosquito that transmits dengue, a much more dangerous disease that the Caribbean region has struggled to control for years.

But unlike dengue fever, the newly arrived disease isn’t usually life-threatening, experts say. However, children younger than 1, people older than 65 with diabetes and hypertension, and individuals who are chronically ill are at high risk for serious complications including death, said Leticia Linn, a regional spokeswoman with the WHO/Pan American Health Organization.

But the tourist-dependent Caribbean nations aren’t the only ones under threat. Because the A. aegypti mosquito is prevalent throughout the hemisphere, South and Central America and the United States are also at risk for an outbreak.

The CDC said it has been documenting an increase in returning U.S. travelers infected with the painful viral disease since 2006, when the large global expansion of the disease started to occur.

“We expect to see more chikungunya-infected travelers coming from the Caribbean as the virus spreads in the region and more people are exposed,” CDC spokeswoman Donda Hansen said.

She added that the agency is working with state health departments to help them better detect the virus, which causes a severe fever and joint pains.