For the second time in May 2020, The Florida Department of Health in Miami-Dade County has reported an additional human case of West Nile virus (WNV) local transmission infection in a Miami-Dade resident.

Miami-Dade County map
Image/David Benbennick

WNV is the leading cause of mosquito-borne disease in the continental United States.  It is most commonly spread to people by the bite of an infected mosquito. There are no vaccines to prevent or medications to treat WNV in people.

Most people infected with West Nile virus do not feel sick. About 1 in 5 people who are infected develop a fever and other symptoms such as headache, pain, and fatigue.  People with mild illness typically recover within about a week with symptomatic treatment. Less than one-percent of infected people develop a serious, sometimes fatal, illness. Symptoms typically appear between two and 14 days after the bite of an infected mosquito. People over the age of 60 and individuals with weakened immune systems are at an increased risk for severe disease.

DOH-Miami-Dade continues to advise the public to remain diligent in their personal mosquito protection efforts by remembering to “Drain and Cover.

DRAIN standing water to stop mosquitoes from multiplying.

  • Drain water from garbage cans, house gutters, buckets, pool covers, coolers, toys, flower pots or any other containers where sprinkler or rain water has collected.
  • Discard old tires, drums, bottles, cans, pots and pans, broken appliances and other items that aren’t being used.
  • Empty and clean birdbaths and pet’s water bowls at least once or twice a week
  • Protect boats and vehicles from rain with tarps that don’t accumulate water.
  • Maintain swimming pools in good condition and appropriately chlorinated. Empty plastic swimming pools when not in use.

COVER skin with clothing or repellent.

  • Clothing – Wear shoes, socks, and long pants and long-sleeves. This type of protection may be necessary for people who must work in areas where mosquitoes are present.
  • Repellent – Apply mosquito repellent to bare skin and clothing.
    • Always use repellents according to the label. Repellents with DEET, picaridin, oil of lemon eucalyptus, para-menthane-diol, and IR3535 are effective.
    • Use mosquito netting to protect children younger than 2 months old.

DEET: Safe for humans when used according to manufacturer instructions, according to University of Florida study

Tips on Repellent Use

  • Always read label directions carefully for the approved usage before you apply a repellent. Some repellents are not suitable for children.
  • Products with concentrations of up to 30 percent DEET (N, N-diethyl-m-toluamide) are generally recommended. Other U.S. Environmental Protection Agency-approved repellents contain picaridin, oil of lemon eucalyptus, para-menthane-diol, or IR3535. These products are generally available at local pharmacies. Look for active ingredients to be listed on the product label.
  • Apply insect repellent to exposed skin, or onto clothing, but not under clothing.
  • In protecting children, read label instructions to be sure the repellent is age-appropriate. According to the Centers for Disease Control and Prevention (CDC), mosquito repellents containing oil of lemon eucalyptus should not be used on children under the age of three years. DEET is not recommended on children younger than two months old.
  • Avoid applying repellents to the hands of children. Adults should apply repellent first to their own hands and then transfer it to the child’s skin and clothing.
  • If additional protection is necessary, apply a permethrin repellent directly to your clothing. Again, always follow the manufacturer’s directions.

COVER doors and windows with screens to keep mosquitoes out of your house.

  • Repair broken screening on windows, doors, porches, and patios.