Preventing Turista and Other Travelers' Ailments : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

Giardiasis, a parasitic disease, most common in the Soviet Union, Mexico, western South America, South and Southeast Asia, and the Middle East, is also increasing in North America, particularly among mountain hikers who drink untreated water from streams contaminated with feces from infected animals such as beavers.

Giardiasis can range from a mild intestinal discomfort that disappears in a few days to a severe debilitating disease. Its symptoms include the sudden onset of explosive diarrhea and foul-smelling gas. Giardiasis can be treated with metronidazole (Flagyl), quinacrine (Atabrine), or furazolidone (Furoxone). Quinacrine can cure 90 percent of the disease's victims, Wolfe says, but can cause nausea, headaches and diarrhea in children and, rarely, toxic psychosis in adults, FDA's Maxwell says.

In several cases, vaccination can prevent diseases travelers may be exposed to. FDA approved an oral vaccine for typhoid in 1989 that has significantly fewer side effects than the injectable vaccines previously used. Typhoid is caused by the bacterial organism Salmonella typhi, usually transmitted through contaminated food or water. Rare in the United States, most of the 400 to 500 typhoid cases a year reported in this country have been contracted abroad, usually in less developed areas where sanitation is poor. Immunization is therefore recommended, but only for travelers going to areas where the disease is common.

Yellow fever, still endemic through much of tropical Africa and South America, is easily preventable by vaccination, as is meningitis. The cholera vaccine, on the other hand, is only about 50 percent effective. As a result, the World Health Organization advises against its use. Three countries — Pakistan, Sudan and Pitcairn Island (best remembered as where mutineers from the British ship Bounty hid out 200 years ago) — still require it for entrance, however. Fortunately, few tourists are likely to get cholera.

There is also a vaccine for hepatitis B, which can be transmitted sexually, by blood transfusions, and by intravenous drug use. For hepatitis A, experts recommend immunization with immune globulin for travelers going to rural areas with poor sanitation. Hepatitis E, which is transmitted similarly to hepatitis A, has caused epidemics in Africa, Asia and, most recently, Mexico. It is not known whether gamma globulin can prevent it. Polio immunizations should also be brought up-to-date since the disease has recently resurged in Israel and parts of Africa and Mexico.

Finally, a word about acquired immune deficiency syndrome. AIDS, which is transmitted the same ways as hepatitis B, is now widespread throughout much of the world, but especially in sub-Saharan Africa and Brazil. In Africa, it is commonly spread through heterosexual contact, often with prostitutes. The only sure way to avoid the sexual transmission of AIDS is to abstain from sexual contact. Otherwise, safe sex practices, including the use of a latex condom, are advised. (See "Latex Condoms Lessen Risks of STDs" in the September FDA Consumer.)

For tourists wanting to learn more about travelers' illnesses, the Centers for Disease Control publishes an annual "Health Information for International Travel." Copies are available for $5 from the U.S. Government Printing Office by writing the Superintendent of Documents, Washington, D.C. 20402.

CDC also maintains a recorded telephone message system with general and geographic-specific information on travelers' diseases. The number is [phone]. Malaria and other disease-specific information can be obtained by calling [phone].

Drug for Sleeping Sickness

A new drug to treat African sleeping sickness has been approved by FDA.

There are two types of African sleeping sickness — the Gambian strain and the Rhodesian strain. Both are spread by the bite of the tsetse fly, which transmits the parasitic infection.

The newly approved drug, eflornithine hydrochloride, effectively treats the final, most serious stages of the Gambian strain of the illness. Studies have shown that, given intravenously, the drug inhibits the growth of the parasite.

African sleeping sickness is widespread in 36 central and west African countries, where 20,000 new cases are reported each year. There are usually fewer than 10 cases per year in the United States. These are mainly among travelers who were exposed to the disease in the endemic areas of Africa.

Bites from tsetse flies spread sleeping sickness similar to the way malaria is spread by mosquitoes. The first sign of infection from the Gambian strain is fever, followed by anemia and painful swelling of the lymph glands. Finally, the infection spreads to the central nervous system, causing extreme mental and physical lethargy, along with tremors, convulsions, and eventually coma and death.

The only alternatives to the newly approved drug for treating the final stages of infection are two drugs that contain arsenic. These drugs can be fatal or cause serious nervous system problems in up to 10 percent of patients.

The new drug does not appear to have these serious nervous system effects, but does have a potential for causing anemia and, sometimes, dangerous decreases in the numbers of white blood cells and platelets in the blood. As a result, the drug's labeling warns that the patient's blood cell count must be monitored twice a week.

Merrell Dow Pharmaceuticals of Cincinnati will market eflornithine hydrochloride under the brand name Ornidyl. FDA has designated Ornidyl an orphan drug. The federal orphan drug program provides incentives to companies to research and market products for very small patient populations.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.