The online guide to... Tropical diseases

THE INTERNET, some people think, is like a colossal library, housing the absolute cream of the world's knowledge. It's not. It's more like a very very big pub. For every eruditely argued and painstakingly compiled site, there's another five ragged, dysfunctional and even dangerous alternatives.

I mention all this by way of warning: don't take the information you find at face value. Take travellers' health web pages. You won't find somebody insisting that paracetamol is a sure-fire method for blitzing typhoid. But use these sites as a starting point for your research, rather than an excuse not to visit the doctor. The following pages all come via recognised institutions, however, and should give you some reliable background.

Travel Health Consultation has a basic checklist covering issues ranging from water purification to Aids advice. It's informal, and includes some anecdotes which, aside from anything else, will reassure you that whatever could happen to you has already happened to somebody else. And they probably survived.

If you have a really healthy appetite for knowledge, then the World Health Organisation's health pages are probably more for you. They will tell you, for example, that there are some 300-500 million malaria sufferers annually, of which 1.5 to 2.7 million die; and that African countries account for about 90 per cent of all incidents of the disease.

The Centre for Disease Control's pages has an up-to-date list of recent worldwide disease outbreaks, including material about the recent Avian Flu scare in Hong Kong. It tends to be pitched more at medical professionals than lay-people, but then what is the Internet about if not to stretch us occasionally?

l travelhealth.com - Travel Health Information service. An excellent place to start. l www.who.ch/home/map-ht.html - The World Health Organisation's index of disease sites.

l www.cdc.gov/travel/travel.html- The Centre for Disease Control travellers' health page.