Study summary
Efficacy of four insect repellents against mosquito bites: a double-blind randomized placebo-controlled field study in Senegal
Uzzan B, et al.
Read the original paper- Study type
- Rct
- Year
- 2009
- Published in
- Fundamental & Clinical Pharmacology 23(5):589-594
- Evidence strength
- Definitive evidence
How it was tested
Double-blind randomized placebo-controlled field trial of four commercial repellents under intense malaria-vector biting pressure.
Summary
A double-blind field trial in two Senegalese villages, run at peak biting season, testing four real repellents against a look-alike placebo lotion under heavy wild-mosquito pressure: 20% picaridin, 20% and 50% PMD (the lemon-eucalyptus active), and 50% DEET. Volunteers applied a product to one bare lower leg and caught every mosquito that landed over an evening.
Key findings
All four repellents worked, and they worked about equally well. Mean bites per person per night were 1.25 for 50% DEET, 1.29 for 50% PMD, 1.43 for 20% picaridin, and 2.37 for 20% PMD, against 12.5 for the placebo, so every active cut biting by roughly 80 to 90%. The differences among the four were not statistically significant; 50% DEET was numerically best, with only a non-significant edge over 20% PMD. Protection held across the whole evening window, and about half the volunteers got zero bites while the rest still had around 90% protection.
Limitations
Biting was measured, not malaria itself, and the evening-only catch window makes the duration estimate coarse. Volunteers varied widely in how many mosquitoes they caught, application was done by a physician rather than self-applied, and the product rotation was not fully balanced.