Mosquito repellents, effectiveness in preventing diseases and safety during pregnancy

Insect repellents are adjuvant treatment to prevent arthropod-borne diseases including malaria and arboviruses (e.g., yellow fever, dengue, chikungunya, zika fever, West Nile encephalitis and other diseases). At least two of these mosquito-transmitted infections (malaria and zika fever) have been associated with adverse pregnancy outcomes including gestation losses, low birthweight and an increased incidence of major birth defects. Symptoms and prognosis of malaria infections, particularly the disease caused by Plasmodium falciparum, are usually much worse in pregnant women. The safety and efficacy of the commercial mosquito repellent products, therefore, are of paramount public health importance. In this article efficacy and safety of synthetic (DEET, Picaridin, IR3535) and plant-based repellents (PMD: p-menthane 3,8-diol, a constituent of the oil of lemon eucalyptus, oil of citronella, Cympopogon nardus, and oil of andiroba, Carapa guianensis) were briefly reviewed with particular emphasis on the experimental and clinical evidence on their safety during pregnancy. Relevant studies were identified through a comprehensive search in MEDLINE and TOXLINE databases and the web. Recommendations for a safe use of repellents to prevent Anopheles sp (malaria) and Aedes sp (arboviruses) transmitted diseases during pregnancy are also made.