Mosquito repellents for travellers

Abstract

#### The bottom line A pregnant woman visits you as her general practitioner (GP) because she and her children will be visiting a country with mosquito borne disease. You recommend using repellents to protect against mosquitoes, as well as vaccinations and other relevant disease prevention measures. She asks which repellents would be best. The key factors to consider when choosing a repellent are the active chemical ingredients and the strength (concentration (%) of active ingredient) because these influence the efficacy and duration of protection.1 2 There are four active ingredients with sufficient published scientific evidence to warrant recommendation. Repellents are useful in areas of low risk of mosquito borne disease to prevent nuisance biting (which may lead to problems such as allergies) and are essential in moderate to high risk areas (figure⇓) to prevent disease transmission (such as malaria and dengue fever) through bites. Repellents work on mosquitoes by directly stimulating avoidance behaviour or by blocking the mosquito’s receptors for attractive odours, not though toxicity.3 Areas of low, moderate, and high risk of mosquito borne disease worldwide