I got this information from an article published in the New England Journal of Medicine. The article focused on malaria prevention in short-term travellers ( up to 3 weeks) but I think the strategies can be used in other categories of visitors as well.
Use effective personal protection against mosquitoes
Anopheles mosquitoes bite between dusk and dawn
Wear long sleeves, long pants, and fully closed shoes with socks after dark. Tucking long pants into socks while trekking can prevent fatal snake bites.
Use permethrin-treated mosquito nets if accommodations are neither well screened nor air-conditioned.
Repellent containing 30-50% DEET should be applied to exposed skin every 4-6 hours. More frequent applications for agents containing lower concentrations of DEET. Agents containing 20% of higher concentrations of picaridin (KBR 3023) are similar to those containing DEET at the same concentration with regard to activity against anopheles mosquitoes.
Adhere to an antimalarial regimen
Take weekly medications on the same day each week. Sunday maybe easier to remember.
Take daily medications with the same meal each day.
Continue medications after the trip for recommended duration.
If side effects occur, contact a local physician or the physician who prescribed you the prophylactic drugs.
Remember that no chemoprophylactic regimen against malaria is 100% effective
Symptoms of malaria may be mild and may mimic influenza, gastroenteritis or other common infections. Fever during or after travel to a malaria endemic area should raise the suspicion.
Early treatment is effective. Delay of treatment in non-immune individuals can be fatal. Seek prompt medical attention.
If fever develops within 3 months after travel a physician should be informed of the recent travel so appropriate tests can be done.
If you treat yourself for fever and fever persists see a local physician or seek prompt medical attention.
Have travel insurance cover before travel.
Freedman 2008, Malaria Prevention in Short-Term Travelers, N Engl J Med 359 (6);603-612.