Although more than eight in 10 adults know that avoiding mosquito bites is the best way to avoid West Nile virus and dengue fever, far fewer know how to select and correctly apply insect repellent, a new national survey shows. 

Nearly two-thirds say they try to prevent mosquito bites through methods such as wearing bug spray or long-sleeved shirts when outdoors, removing standing water from around the home, and maintaining window screens, according to an Annenberg Science and Public Health survey published yesterday.

But respondents were uncertain about how to use sunscreen and insect repellent together.

Only one-third of respondents knew that the Centers for Disease Control and Prevention (CDC) recommends applying sunscreen first, letting it dry, then applying bug spray, according to the survey of 1,904 adults, conducted August 4 to August 17. Only 18% know to choose insect repellent registered with the Environmental Protection Agency (EPA). And just 15% know not to apply mosquito repellent to skin under clothing. 

The survey found 53% know that insect repellent should not be used on babies younger than 2 months old.

Only 16% of adults worry that they or someone in their family will contract West Nile or dengue in the next three months.

EPA-registered insect repellents recommended

The CDC has reported 504 human infections with West Nile Virus as of September 8. There also have been 1,404 cases of dengue fever in people infected locally, rather than through travel.

The CDC recommends EPA-registered insect repellents with active ingredients such as DEET, picaridin, IR3535, oil of lemon eucalyptus, para-menthane-diol, or 2-undecanone. The CDC notes that concentrations above 50% DEET do not provide additional protection against mosquito bites.

The margin of sampling error for the survey is plus or minus 3.2 percentage points at the 95% confidence level.

• Today, citing a steep decline in cases, the US Food and Drug Administration (FDA) declared an end to the massive lettuce-related outbreak of Cyclospora but announced that its investigation will continue. “While the outbreak is over, FDA continues the outbreak investigation of Cyclospora infections linked to iceberg lettuce sourced from central Mexico and recalled by Taylor Farms de Mexico,” the agency said. Starting in July, 12,883 people in 21 states were sickened by the parasite, 570 were hospitalized, and two died. The contaminated lettuce was recalled on July 17, and the last date of symptom onset was August 17.
• The Florida Department of Health is investigating whether a woman in Hillsborough County died of dengue. Hillsborough, home to Tampa, is in the west-central part of Florida. Officials cited privacy concerns in declining to provide details of the death, which media reports said occurred in an 80-year-old woman. Last week, Florida Health logged 38 more locally acquired cases of the mosquito-borne illness, for a total of 111 infections in six counties. Another 109 travel-related dengue cases have been reported this year.
• The US Centers for Disease Control and Prevention (CDC) issued a Health Alert Network advisory yesterday about a nationwide increase in reported animal rabies cases and related exposures in people this summer. “CDC urges clinicians to conduct careful, evidence-based rabies risk assessments and follow current ACIP recommendations when post-exposure vaccination or treatment is indicated,” the alert said. The public should avoid contact with sick animals and wildlife and promptly seek medical care after bites or scratches, the CDC said.
• Today, the Global Polio Eradication Initiative (GPEI) reported 15 new polio cases in three countries. Afghanistan logged four cases of wild poliovirus type 1 (WPV1), the Democratic Republic of Congo documented five cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) cases, and Nigeria reported one cVDPV2 infection.