On Tuesday Federal officials stated that outbreak of dengue in key West was feared in Florida. It was stated post a survey of Key West residents which found that about five per cent of people were either infected or exposed to the virus.

There were no reported cases of dengue in the U. S. since 1946 and no outbreak in Florida since 1934 except a handful of isolated cases along the Texas-Mexico border.

Dr. Harold Margolis, chief of the dengue branch at the Centers for Disease Control and Prevention, said, "We're concerned that if dengue gains a foothold in Key West, it will travel to other Southern cities where the mosquito that transmits dengue is present, like Miami.”

A suspected dengue fever case was reported by a physician in New York who then had notified the Monroe County (Fla.) Health Department in last September. This resident had traveled to only Key West.

Two dengue infections in Key West residents in the next two weeks were identified and they had not traveled elsewhere. There were about 27 cases identified by the end of the year.

Out of 240 blood samples collected by researchers from CDC and the Florida health department from households in Key West, it was found that dengue virus showed itself in about five per cent pf people.

"These people had not traveled outside of Florida, so we need to determine if these cases are an isolated occurrence or if dengue has once again become endemic in the continental United States," Margolis said.