Patients who are planning foreign travel often seek advice about immunizations and prevention of traveler's diarrhea and malaria. Medical Letter consultants summarized the current recommendations for these and other conditions, suggesting several new sources of complete medical information for travelers.
Medical Letter consultants generally do not recommend prophylaxis for traveler's diarrhea. Prophylactic prescriptive agents such as ciprofloxacin, levofloxacin, ofloxacin or norfloxacin can cause photosensitivity, and over-the-counter bismuth subsalicylate is less effective than an antibiotic. Rather, they suggest treatment only for severe or persistent symptoms. Loperamide hydrochloride, along with a single dose of ciprofloxacin, levofloxacin or ofloxacin, usually provides symptomatic relief in adults in less than 24 hours. Trimethoprim-sulfamethoxazole is safe for use in children. Oral rehydration salts (available in packets) help maintain fluid balance, particularly in young children and the elderly.
Specific recommendations for immunizations were listed by disease type, including cholera, hepatitis A and B, influenza, measles, meningitis, polio, typhoid, yellow fever and malaria. The parenteral vaccine for cholera is not recommended because of its limited effectiveness and association with adverse reactions. Travelers going anywhere outside the United States, Canada, Western Europe, Japan, Australia or New Zealand are encouraged to obtain a hepatitis A vaccination. However, only persons at “high risk” and those who may require medical or dental care in endemic areas require vaccination for hepatitis B. Vaccination against influenza is recommended for all persons at high risk of complications and for those traveling to the tropics or to the Southern Hemisphere between April and September.
Persons born after 1956 who have not received two doses of measles vaccine and have no history of infection or evidence of immunity should receive a single dose of measles or, preferably, measles-mumps-rubella (MMR) vaccine before traveling. Meningococcal vaccine is recommended for persons traveling to areas in which epidemics are occurring. Travelers to tropical or developing countries who have not previously been immunized should complete a primary polio series of inactivated polio vaccine. Typhoid vaccine is recommended for travelers going outside usual tourist routes in Latin America, Africa and Asia. The vaccine for yellow fever is recommended for administration at least 10 days before travel to endemic areas. Generally, patients who are pregnant or immunocompromised should not receive live virus vaccines, such as measles, oral polio and yellow fever.
Prophylaxis for malaria includes a dose of 300 mg base of chloroquine once a week in areas with chloroquine-sensitive malaria. In areas of chloroquine-resistant malaria, 250 mg of mefloquine once a week is the drug of choice, except in the Thai-Cambodian and Thai-Myanmar border areas and western Cambodia, where mefloquine resistance is common. In these areas, doxycycline is an alternative treatment for persons older than 8 years of age who are not pregnant. Additional recommendations for malaria prophylaxis in adults and children were published in the January 2, 1998, edition of The Medical Letter.
editor's note: A CD-ROM for travelers that includes the most current recommendations from the Centers for Disease Control and Prevention (CDC) and the World Health Organization, along with maps, addresses of American embassies and a travel report that can be customized with vaccination recommendations is available for purchase from The Medical Letter (telephone: 800-211-2769). Travel advice is also available directly from the CDC at this Web address: www.cdc.gov and this telephone number: 888-232-3228.—b.a.