Waqaruddin Ahmed  ( PMRC Research Centre, Jinnah Postgraduate Medical Centre, Karachi. )

Many health hazards to travellers, visiting areas of the world not familiar to them, can be avoided by simple precautions and preventive measures recommended by WHO.
Certain stresses such as crowding, disturbed pattern of sleep and wakefulness cycles, dis­ruption of usual eating and drinking patterns over long periods may lower resistance to disease which can lead to nausea, indigestion, fatigue or insomnia. It can be prevented by simply taking care not to become overtired. Simple drugs such as aspirin for aches and pains and sleep inducing drugs to get over time difference and regulate sleep pattern may be helpful.
Evironmental changes like heat and cold can be directly or indirectly responsible for some diseases. Excessive heat and humidity may lead to heat exhaustion, heat stroke or hyperthermia. Deimatophytes such as tinea pedes or athletes foot are often exacerbated by warm and humid condi­tions Ultravoilet rays or the sun can cause sunburn especially in the light-skinned persons. Excessive cold may affect inadequately clad and, particularly, the elderly persons and can lead to hypothermia and frost-bite of exposed parts. These hazards can be prevented by avoiding excessive cold, heat and humidity even without allowing time to acclimatize.
Breathing and swallowing dust as a result of travelling on unpaved roads or in arid areas may be followed by nausea or malaise and cause in­creased susceptibility to upper respiratory tract infections. High altitudes may initially lead to insomnia and cause distress to patients with cardiac and pulmonary diseases.
Fresh water streams, canals, lakes in tropical areas may be infested with larvae that penetrate the skin, causing Schistosomiasis. Fatal prihary amebic meningoencephalitis may occur following swimming in warm dirty pools. Water showers and some airconditioning systems, especially in hotels, may transmit pneumonic illness due to Regionalla, which can be prevented by chlorination of hotel water supplies. Food and drinks are the common sources for the transmis­sion of cholera, amoebic and badillary dysentries,
Giardiasis, guinea-worm and other helminthic infections, viral hepatitis A, epidemic hepatitis non-A non-B, typhoid and paratyphoid fevers and other salmonellosis. At certain seasons, various species of even well cooked fish and shellfish contain poisonous biotoxins. To avoid these hazards, closer attention to personal hygiene should be paid, e.g., hand washing with soap and water, eating and drinking only safe foods and liquids. Unpasteurized milk should be boiled before drinking. Unless the purity of drinking water is confirmed it should be boiled or chlorinated. Intestopan or Imodium for stomach upsets commonly caused by changes in food and water can be helpful.





Travellers are at special risk of contracting sexually transmitted diseases, being outside their normal environment and in close proximity with the persons who have high incidence of such diseases. Sexual contact has been shown to be the main mode of transmission for human immuno­deficiency virus (H.I.V.) the causative agent of AIDS. The risk of infection with these diseases is increased by having multiple sexual-partners, either homosexual or heterosexual. Person-to-person transmission often occurs from apparently healthy persons who are capable of transmitting infections. There is no effective vaccine or treat­ment for AIDS.
“The risk of AIDS and other sexually transmitted infections can be avoided by the un­married through abstinence and, by the married, by confining sexual relationship to lawfully married spouse and within the limits laid down by religion. All religions forbid extra-marital sex and homosexuality and, in Islam, transgressions carry heavy penalties’
Many arthopodes transmit communicable diseases such as Malaria, Yellow fever, Dengue and Dengue haemorrhagic fever, Viral encephalitides, Filariasis, Onchocerciaris, Leishmaniasis, Tryp­nosomiasis, Plague, Tungiasis, Typhus and relapsing fever. These can be prevented by wearing appropriate clothing and footwear.
Animal associated diseases include rabies, haemorrhagic fevers and anthrax. They can be prevented by avoiding contact of domestic dogs and cats with wild animals, avoiding contact with rodents and use of adequately treated leather goods. Biting and stinging fish, corals and jelly­fish may all provide hazards to the bather. Poisonous - snakes are hazards in many areas.

1. Vaccination Certificate Requirements and Health Advice for International Travel. W.H.O. , Geneva,1987.