While travellers often worry about serious diseases such as hepatitis, cholera and malaria, studies show that the risk of catching a virulent disease during a one-month stay in a developing country is remarkably small - around 0.4 per cent for viral hepatitis and 0.03 per cent for typhoid fever (J Infect Dis, 1987; 156: 84-91; Bull WHO, 1990; 68: 313-22).
In contrast, the risk of diarrhoea is about 50 per cent (Rev Infect Dis, 1990; 12: S73-9), and it's these common problems - diarrhoea, colds, headaches and insect bites - that most often plague the unprepared traveller.
Around one in five passengers develops a cold within a week of flying (JAMA, 2002; 288: 483-6). The recirculating dry air on aircraft weakens immunity, resulting in respiratory and ear infections as well as headaches, allergies, dizziness, and irritation and inflammation of the eyes, skin and nose. The viruses that cause colds/flu don't respond to antibiotic treatment.
* stay hydrated, inside and out. Drink lots of water to ward off colds, and prevent travel headache, stress and fatigue. Keep a water spray with you and spritz yourself throughout the flight.
* take Echinacea (300-900 mg/day) to support immune function (Econ Med Plant Res, 1991; 5: 253-321; Can Pharm J, 1991; 124: 572-6) and control viral, bacterial and fungal infections (Therapiewoche, 1986; 36: 3352; Aust J Med Herb, 1992; 4: 104-11).
* eat well. If your holiday is a junk-food fest, your health will suffer.
* take your vitamins. Vitamin C is vital for the immune system, and can inhibit viruses and bacteria (Proc Natl Acad Sci USA, 1990; 87: 7245-9). Vitamin A, another antioxidant, can kill disease-causing viruses (Antimicrob Agents Chemother, 1980; 17: 1034-7). Vitamins E and B-complex, selenium and zinc are also necessary for proper immune function.
Instead of DEET- or permethrin-containing pesticides, opt for essential oils.
* Citronella and eucalyptus have a strong smell that interferes with mosquitoes' sense of direction and taste, making it difficult for them to find a host. Frequent reapplications of essential oil-containing sprays or lotions are essential.
* Neem oil mixed with coconut oil kept users completely mosquito-bite-free in one study (J Am Mosq Control Assoc, 1993; 9: 359-60).
Wearing light colours (J Econ Entomol, 1947; 40: 326-7), long-sleeved shirts and pants also helps. In areas of high infestation, use very fine-mesh mosquito nets.
Traveller's tummy is usually acquired by ingesting faeces-contaminated food and/ or water. Scrupulous attention to hygiene will lower your risk of diarrhoea.
* Don't drink from the water supply unless you're sure of its purity. This also applies to water for ice cubes and cleaning your teeth. Water from sealed bottles is usually safe, as are hot tea and coffee, fizzy drinks, beer and wine.
* Take care with local cheeses and ice cream, and boil unpasteurised milk.
* Cook meat thoroughly and eat while hot. Avoid leftovers and food that has been standing or exposed to flies.
* Fish and shellfish may be hazardous even when well cooked. If there is any doubt, avoid eating it.
* Eat only cooked vegetables and avoid salads. Peel all fruit, including tomatoes.
If you do get diarrhoea, stay hydrated. Consider packing rehydration remedies (such as Diarolyte) before you go.
Need a vaccination?
If you're going to a country where vaccinations are only recommended, consider homoeopathy. Constitutional remedies and nosodes (made from disease material) can be a prophylaxis against worrisome diseases such as cholera, hepatitis, malaria, smallpox, polio and typhus.