You can get it in India, South East Asia, and South America, but 90% of the world's cases occur in Sub-Saharan Africa. Mosquitoes come out when the sun isn't at its height, first thing in the morning and last thing in the evening. They're attracted by body odours, by darker colours and by perfumes -hair spray, after shave, deodorant, things like that. Wear light colours and cover up exposed areas when the mosquitoes are buzzing around. Use good insect repellent, with at least 30-50% DEET.

How can you avoid upset stomachs on holidays?

Irish people forget when they go overseas that the Irish climate and Irish food is actually very healthy. And we're used to our own food. When you get overseas, you think you should try all the local foods but that's crazy. Your head may want you to try something, but your stomach may not. We normally give people a prescription for something like Motilium, which will settle down the stomach. So travelling with something like that in your handbag isn't a bad idea.

Dr Graham Fry is a member of the Tropical Medical Bureau, www. tmb. ie