Although anthrax is most uncommon in travelers, certain handi¬crafts may be contaminated and should be avoided.
Dr. Arnold F. Kaufmann is Chief of Bacterial Zoonoses Activity, Centers for Disease Control, Atlanta, Georgia, USA, and specializes in public health control of anthrax and other infections acquired from animals.
Anthrax is a lethal bacterial disease of livestock that is occasionally transmitted to humans. A disease of considerable historic signifi¬cance, anthrax occurs or has occurred in virtually every country of the world. It is currently a minor public health problem, even in developing countries, due to the wide use of animal anthrax vaccines. Lapses in local control programmes, however, can have serious consequences such as the recent epidemic of almost 10 000 human cases in Zimbabwe. The most frequent victims of this disease are persons closely associated with raising livestock or working in industries processing animal bones, hair, and hides.
How it is spread
Anthrax is caused by Bacillus anthracis, a bacterium normally present in various types of soil. The anthrax bacillus has a cyclic pattern of replication, growing rapidly when environmental conditions are optimal and then forming spores to survive adverse periods.
These spores are resistant to disinfectants and can remain viable for many years. Animals become infected by grazing on soils where the anthrax bacillus is in its active growth phase.
Human anthrax results not from contact with the soil but from handling the tissues of infected animals.
When an animal dies of anthrax, the important control measure is either to bury or to burn the carcass. Poverty or failure to recognize the cause of death, however, frequently leads animal owners in developing countries to salvage anything of value.
The meat may be eaten, and by-products such as bones, skin, and hair sold or used. Anthrax spore contamination of these by-products, which may be made into handicrafts or exported for industrial processing, can become a hazard to people far away.
Forms of anthrax
Human anthrax has three forms, namely cutaneous (skin), gastrointestinal, and inhalation forms, and these directly reflect the route of the infection.
Cutaneous anthrax, the most common, results when the anthrax bacillus is introduced beneath the skin e.g. by a puncture, abrasion, or through a pre-existing break in the skin while handling contaminated materials. A red, raised area develops at the site of the infection—rather like an insect bite—and characteristically progresses to a large blister Anally becoming an ulcer covered with a dark scab. This form of the disease is diagnosed easily and can be treated effectively with common antibiotics such as penicillin and tetracycline.
Gastrointestinal anthrax results from eating raw or undercooked meat from infected animals, and causes severe abdominal symptoms.
Inhalation anthrax is almost exclusively an occupational respiratory disease, associated with the industrial processing of goat hair from western Asia. These two forms of the disease are difficult to diagnose and are often fatal; however, both are so rare as to be a negligible risk.
Summary of advice for travelers
- Although cutaneous anthrax may cause severe illness, the disease is only weakly contagious and presents little risk to the average traveler. Only one travel-associated case has occurred in a US citizen in the past forty years. This patient acquired her infection from a goat-skin handicraft purchased in Haiti.
- Subsequent studies revealed that Haitian handicrafts incorporating dried or poorly tanned goat skins were commonly contaminated with anthrax spores. As a result, rugs, drums, and other handicrafts containing goat skin with attached hair (the spores are found in the hair) are not permitted to be brought into the USA. Another case, not in a traveler, was traced to a coarse goat-hair yarn produced in Pakistan.
- Travellers should not buy any item made of coarse goat hair or goatskin with attached hair in any poor country.
- General commonsense precautions of eating only well-cooked meat and avoiding unnecessary handling of dead animals also apply. Otherwise, no special precautions or immunizations are necessary.