Officials say tourists shouldn't fear outbreak of tropical disease.
Dengue fever has hit the Florida Keys.
The Centers for Disease Control and Prevention and the Florida Health Department launched a study after three dengue cases surfaced in Key West last August.
They were the first locally acquired cases reported in the Florida in four decades.
Officials say 39 residents and visitors have actually come down with the mosquito-borne disease.
Dengue fever is a flu-like illness spread by the bite of an type of infected mosquito that is common urban mosquito in the U.S. and Caribbean.
It is also known as breakbone fever because of the intense joint pain suffered in extreme cases.
National news about the recent cases here prompted concerned calls.
Local officials say they're working hard to make sure tourists know it's still safe to visit the Keys.
"There were 27 cases last year and we have 17 cases this year so you can see it's not an epidemic by any means," explains Bob Eadie of the Monroe County Health Department.
An aggressive mosquito control campaign has been launched to help combat the spread of the disease.