Health officials: 7 new cases of West Nile virus in Miami

Thirty three Miami-Dade County residents have now been infected with the West Nile virus, health officials said.

On Thursday the county’s Florida Department of Health said seven additional residents have contracted the mosquito-borne illness from local transmission.

The county’s first two cases of the virus were detected in May. Both cases were local residents.

On Aug. 4 in nearby Broward County, officials announced the county’s first West Nile virus case since 2012, the Miami Herald reported. And in Monroe County, officials are dealing with an outbreak of 26 cases of Dengue fever. It’s the first outbreak of the mosquito-borne illness there in a decade.

The health department said West Nile virus is the leading cause of mosquito-borne disease in the United States. There are no vaccines to prevent it or medications to treat it.

About 1 in 5 of those infected develop a fever or other symptoms, and fewer than 1% develop a serious or fatal illness. Symptoms typically appear within two to 14 days after an infected bite.