The best prevention is personal protection against the mosquito. Malaria mosquitoes generally bite after dark, wear long sleeves and trousers in the afternoon and evening; stay in-doors if possible. Use insect repellent on exposed skin.
You are advised to visit your general practice surgery or a travel medicine clinic at least 6 weeks before you travel. However, it is never too late to seek advice.
If you have a medical condition, you are advised to discuss the suitability of the trip before you book.