Prevention of Hepatitis Requires Preparation

Traveling to developing countries carries with it the risk of acquiring hepatitis, but the danger can be minimized by observing some simple rules and, for certain travelers, by getting vaccinated.

A report published this year in a leading medical journal referred to hepatitis as “a major cause of morbidity to travelers to developing countries.” According to the article, for every 1,000 unprotected travelers to these regions, the estimated incidence of hepatitis varies from 3 to 20 cases for each month of stay.

But hepatitis actually is several illnesses--each one caused by a different virus and requiring a different means of prevention.

While several types are present in the United States, it is in the developing world that all types of the disease exist, usually in a much higher percentage of the population.

Of highest risk to travelers is type A hepatitis, which usually is acquired from contaminated water or ice or shellfish raised in sewage-contaminated water. Another cause is fruits and vegetables that may have been handled by people who have not washed their hands.

Other factors that affect risk include living conditions (the more rugged or rural they are, the higher the risk) and incidence of the disease in the country being visited.

Nevertheless, according to the Centers for Disease Control in Atlanta, many cases of travel-related hepatitis A occur in travelers who stay in tourist accommodations and eat standard types of foods.

“We (now) feel that all travelers going to developing countries, including Mexico, must consider the risk of getting type A hepatitis even if they don’t go off the beaten track,” said Dr. Miriam Alter, a CDC expert.

The CDC lists the areas of highest incidence for hepatitis A as being North and sub-Saharan Africa, Central America and the Caribbean, tropical South America and most of Asia. Travelers to Europe, Australia and New Zealand are not seen as being at greater risk than they would be at home.

Hepatitis A virus in water can be killed by boiling it for one minute. Adequate chlorination will also kill the virus. Cooked food is safe, unless it is handled after cooking by someone who is contaminated.

Although a vaccine now being developed may be available in Europe next year, the CDC still is recommending that travelers to developing countries protect themselves from hepatitis A by receiving a single dose of immune globulin before leaving home. The shot contains antibodies protective against the virus.

For travelers who go frequently to high-risk countries, many doctors now recommend that the traveler have a blood test which determines whether he or she is already immune to hepatitis A. Because they already have natural protection, those who test positive for the antibodies--about one-half of the U.S. population--can avoid the expense as well as the pain thatsometimes follows a globulin shot.

A second kind of hepatitis is called type B. It is transmitted primarily by blood transfusions, homosexual or heterosexual intercourse and by unsterilized needles used for acupuncture, tattooing, consuming illegal drugs or for medical purposes.

In the developing world, hepatitis B is one of the most important infectious diseases. The chronic form kills about 40 million people a year worldwide. The 200 to 300 million people who carry the B virus are the principal reservoir for contaminating others.

A vaccine that protects against hepatitis B now exists. For travelers, the CDC says the vaccine should be considered primarily for people who plan to remain six months or longer in high-risk regions and be in daily contact with local residents, or who are apt to have sexual contact with local people or receive medical care in the country. The vaccine is not considered to be of risk to pregnant women or their fetuses.

The highest risk areas are all of Africa; Southeast Asia, including China, Korea, Indonesia and the Philippines; the Middle East except Israel; the South and Western Pacific Islands; the interior Amazon Basin, and Haiti and the Dominican Republic. Moderate risk countries include south-central and southwest Asia, Israel, Japan, Eastern and Southern Europe and the Soviet Union, and most of Central and South America.

Until recently, a third type of hepatitis was known as non-A, non-B. However, recent research indicates that this type is actually at least three different viruses. They can be transmitted either by food and water or by blood, depending on which of the three is contracted.

The blood-borne form is called hepatitis C. The CDC does not classify this as offering serious problems for travelers unless they are exposed to blood. But a second kind, called hepatitis E, which can be acquired in food or water, can be a risk, the agency says. Epidemics of this newly discovered type have occurred recently in the southern part of the Soviet Union, Pakistan, India, Burma, Indonesia, North Africa and rural areas of Mexico.

All types of hepatitis have similar symptoms, which may include headache, nausea and possibly vomiting, decreased appetite, fatigue, yellow tinge to the eyes and skin, fever and abdominal pain.

Travelers who go on adventure trips unescorted by properly informed guides are the most vulnerable to acquiring hepatitis, as well as typhoid fever, malaria, diarrhea and several other rarer tropical illnesses. The best protection is to eat only well-cooked food, drink only boiled or bottled beverages, and avoid sex with local people and contact with blood.