MIAMI, Fla. - Miami-Dade County health officials have confirmed four more local cases of West Nile virus, bringing the county total to 18 residents.
The Miami Herald reports the county's mosquito-control chief said last week that this summer's resurgence of West Nile probably reflects the heavy rains that cause mosquito populations to explode. More mosquitoes mean more mosquito bites, increasing the odds of infection.
The county is under a mosquito-borne-illness alert. 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.
Miami-Dade's first two cases of West Nile virus were detected in May.
On June 11, health officials reported two more cases of the virus. On June 25, 10 more residents were confirmed to have the virus.