Mountaineering in the tropics

摘要

Mountaineers face several specific health problems when travelling to tropical countries. They are therefore recommended to seek advice from an expert on tropical medicine at least two months before departure.Depending on the country of destination, season of the year and expected activity, the following vaccines should be considered: hepatitis A and B, Japanese encephalitis, measles, meningococcal meningitis, poliomyelitis, rabies, rubella, tetanus/diphtheria, typhoid fever and yellow fever. Cholera and smallpox vaccines are neither required nor recommended. All malaria vaccines are still under investigation. Prevention of malaria relies on a) avoiding mosquito bites and b) chemoprophylaxis from a week before departure until four weeks after return. Where the risk of malaria is low, chemoprophylaxis can be dispensed off or done with chloroquine alone. Where the risk is high (Amazonian basin, tropical Africa, Indian Subcontinent, South East Asia and Melanesia), the preferred drugs are mefloquine, doxycycline, chloroquine/proguanil, dapsone/pyrimethamine, atovaquone/proguanil and primaquine. Mountaineers travelling to isolated areas of malarious countries should carry anti-malarial drugs for self-treatment in case they develop fever or any other suspicious symptom and a diagnosis of malaria cannot be confirmed or ruled out (presumptive treatment). The preferred drugs for this purpose are halofantrine, mefloquine (if not taken for chemoprophylaxis), sulfadoxine/pyrimethamine, quinine (alone or associated with doxycycline), atovaquone/proguanil and lumefantrine/artemether. In tropical countries, many diseases are transmitted by the faecal-oral route. Water should be disinfected and food should be "boiled, peeled by oneself or rejected". Most cases of traveller's diarrhoea are caused by enterotoxigenic Escherichia coli, but diarrhoea can also be due to many other bacteria, viruses, protozoa and intestinal irritants. Hydration is always crucial. Clinical decisions in the field can be made depending on the presence of fever and blood in faeces. Animals can inflict dangerous bites and, in most countries, can also transmit rabies. In endemic countries, bites from mammals (except possibly those caused by rodents or lagomorphs) should be considered potentially rabid. In addition to the local treatment of the wound, a rabies immunisation should be started at once. If an expedition member becomes i!l after travelling to the tropics (irrespective of the months or years lapsed), he should inform his doctor to avoid delay in diagnosis or treatment.