Table 4 Main shortcomings of topical repellents

General

• Complete coverage of exposed skin is impossible

• No ‘proxy’-protection for nearby untreated skin or untreated persons

• Practical problems, e.g., abrasion, wash-off, etc

• Problem with simultaneous application of sunscreen

• Complete coverage of a community with repellent is unrealistic

• Reasons for non-use:

 ◦ tourists: sunscreen, long sleeves, hot and humid, sweat

 ◦ locals: unaffordable, unavailable, spoilage/deterioration, lack of storage facilities

• Current and future resistance to various technologies in wild mosquito populations

• Lack of user compliance in adequate and timeless reapplication

• Low residual character of current repellent technology

• Not always working

• ‘Natural’ repellents may still be toxic or their production environmentally questionable

DEET

• Unpleasant, oily, sticky

• Plasticises plastics and synthetic fabrics

• Guidelines for use [195]; not use under clothing, clean palms (esp. children) after application to avoid contact with eyes, mouth, or mucosa; after exposure, wash treated areas with soap and water; avoid inhaling aerosol; avoid spraying into eyes (own and others), especially contact-lens wearers

• Not recommended for children under 6 months and pregnant women