Mosquito Repellents

By: Michael Lam, MD, MPH

Mosquito repellent can protect from diseaseA recent study documented the efficacy of several products and devices to determine their mosquito repellent properties.

The New England Journal of Medicine (2002;347:13-18) recently published a study conducted by investigators from North Carolina and Florida. The study was based on four products that contained DEET, a repellent that contains IR3535, three wristbands containing repellent, and a moisturizer. Each had claims of repelling mosquitoes and many also claim to protect against infections from mosquitoes.

The results of the study showed that the products containing DEET offered the most protection. The amount of protection corresponds with the concentration of DEET. However, the rate of difference peaked at 50%, there was a minimal difference after that. The products that do not contain DEET lost their repellent properties after 20 minutes.

Although DEET had questions raised about its safety to users, study authors said that its safety profile after 60 years of use and more than 8 billion applications is remarkable. The reported adverse effects from users are generally due to gross over-usage.

No part of the world can avoid infections carried by mosquitoes; about 700 million mosquito-borne infections are transmitted to people annually. Among them, encephalitis and West Nile virus are two of the most common illnesses. The West Nile virus has spread to 27 states in the United States already.

As compared to the risks of infection, the risk of DEET-related adverse effects pales in comparison.

Mosquito repellent can protect from disease