Objectives: To describe a malarial outbreak amongst a British military force deployed to Sierra Leone in May 2000.
Methods: A case-control study was conducted that investigated possible risk or protective factors affecting the population.
Results: All bite avoidance measures (use of insecticide-treated bed nets and insecticide-treated clothes and use of thermal fogging/knockdown insecticide sprays) offered some degree of protection, although only use of clothes and nets was significant at the 5% level. Use of 3 or 4 protection measures was significantly protective, as was the cumulative protective effect when using multiple protective measures.
Conclusion: Professionals giving travel advice must continue to advice travellers that they can significantly improve their levels of malarial protection by using multiple protection measures.