Travelers' diarrhea is the most common travel-related ailment. The cornerstone of prevention is food and water precautions, as outlined below. All travelers should bring along an antibiotic and an antidiarrheal drug to be started promptly if significant diarrhea occurs, defined as three or more loose stools in an 8-hour period or five or more loose stools in a 24-hour period, especially if associated with nausea, vomiting, cramps, fever or blood in the stool. A quinolone antibiotic is usually prescribed: either ciprofloxacin (Cipro)(PDF) 500 mg twice daily or levofloxacin (Levaquin) (PDF) 500 mg once daily for a total of three days. Quinolones are generally well-tolerated, but occasionally cause sun sensitivity and should not be given to children, pregnant women, or anyone with a history of quinolone allergy. Alternative regimens include a three day course of rifaximin (Xifaxan) 200 mg three times daily or azithromycin (Zithromax) 500 mg once daily. Rifaximin should not be used by those with fever or bloody stools and is not approved for pregnant women or those under age 12. Azithromycin should be avoided in those allergic to erythromycin or related antibiotics. An antidiarrheal drug such as loperamide (Imodium) or diphenoxylate (Lomotil) should be taken as needed to slow the frequency of stools, but not enough to stop the bowel movements completely. Diphenoxylate (Lomotil) and loperamide (Imodium) should not be given to children under age two.

Most cases of travelers' diarrhea are mild and do not require either antibiotics or antidiarrheal drugs. Adequate fluid intake is essential.

If diarrhea is severe or bloody, or if fever occurs with shaking chills, or if abdominal pain becomes marked, or if diarrhea persists for more than 72 hours, medical attention should be sought.

Though effective, antibiotics are not recommended prophylactically (i.e. to prevent diarrhea before it occurs) because of the risk of adverse effects, though this approach may be warranted in special situations, such as immunocompromised travelers.

The following are the recommended vaccinations for Kuala Lumpur:

Hepatitis A vaccine is recommended for all travelers over one year of age. It should be given at least two weeks (preferably four weeks or more) before departure. A booster should be given 6-12 months later to confer long-term immunity. Two vaccines are currently available in the United States: VAQTA (Merck and Co., Inc.) (PDF) and Havrix (GlaxoSmithKline) (PDF). Both are well-tolerated. Side-effects, which are generally mild, may include soreness at the injection site, headache, and malaise.

Older adults, immunocompromised persons, and those with chronic liver disease or other chronic medical conditions who have less than two weeks before departure should receive a single intramuscular dose of immune globulin (0.02 mL/kg) at a separate anatomic injection site in addition to the initial dose of vaccine. Travelers who are less than one year of age or allergic to a vaccine component should receive a single intramuscular dose of immune globulin (see hepatitis A for dosage) in the place of vaccine.

Typhoid vaccine is recommended for travelers who may eat or drink outside major restaurants and hotels. It is generally given in an oral form (Vivotif Berna) consisting of four capsules taken on alternate days until completed. The capsules should be kept refrigerated and taken with cool liquid. Side-effects are uncommon and may include abdominal discomfort, nausea, rash or hives. The alternative is an injectable polysaccharide vaccine (Typhim Vi; Aventis Pasteur Inc.) (PDF), given as a single dose. Adverse reactions, which are uncommon, may include discomfort at the injection site, fever and headache. The oral vaccine is approved for travelers at least six years old, whereas the injectable vaccine is approved for those over age two. There are no data concerning the safety of typhoid vaccine during pregnancy. The injectable vaccine (Typhim Vi) is probably preferable to the oral vaccine in pregnant and immunocompromised travelers.

Tetanus-diphtheria vaccine is recommended for all travelers who have not received a tetanus-diphtheria immunization within the last 10 years.

Measles-mumps-rubella vaccine: two doses are recommended (if not previously given) for all travelers born after 1956, unless blood tests show immunity. Many adults born after 1956 and before 1970 received only one vaccination against measles, mumps, and rubella as children and should be given a second dose before travel. MMR vaccine should not be given to pregnant or severely immunocompromised individuals.

Yellow fever vaccine is required for all travelers over one year of age arriving from a yellow-fever-infected country in Africa or the Americas, but is not recommended or required otherwise. Yellow fever vaccine (YF-VAX; Aventis Pasteur Inc.) (PDF) must be administered at an approved yellow fever vaccination center, which will give each vaccinee a fully validated International Certificate of Vaccination. Yellow fever vaccine should not in general be given to those who are younger than nine months of age, pregnant, immunocompromised, or allergic to eggs. It should also not be given to those with a history of thymus disease or thymectomy.

An outbreak of viral myocarditis (inflammation of the heart muscle), apparently caused by enterovirus 71, was reported from Sarawak, Malaysia in the spring of 1997, resulting in 29 deaths. Enterovirus 71 is responsible for epidemics of hand, foot and mouth disease, characterized by fever in association with a rash or small blisters on the palms and soles and in the mouth. A small percentage of those infected develop more serious complications, such as myocarditis and infections of the central nervous system. Children less than three years old are most susceptible. The virus is transmitted by exposure to fecal material from infected individuals. The key to prevention is good personal hygiene and scrupulous hand-washing, especially after defecation and before handling food. No outbreaks of myocarditis have been reported since that time.

An outbreak of encephalitis caused by a previously unrecognized paramyxovirus, now called Nipah virus, was reported in March and April of 1999 in the states of Perak and Negri Sembilan. Infection appeared to be related to exposure to infected pigs and was limited to those closely associated with pig farms. There was no evidence of human-to-human transmission and no evidence of any risk associated with eating cooked pork. The outbreak was controlled by mass slaughter of pigs and personal protective measures. No cases have been reported since that time.

Dengue fever, a flu-like illness sometimes complicated by hemorrhage or shock, is highly prevalent throughout Malaysia. Dengue is transmitted by Aedes mosquitoes, which bite primarily in the daytime and favor densely populated areas, though they also inhabit rural environments. The prevalence is greatest in densely populated, highly developed areas, particularly the states of Federal Territory Kuala Lumpur, Selangor, Johor, Pahang, and Penang. Peak transmission is from May through August, though the disease occurs year-round. The incidence of dengue fever has been increasing in recent years. In 1997, a total of 19,544 cases of dengue fever were reported, the highest on record at that time. Of these, 806 (4%) were complicated by dengue hemorrhagic fever, and 50 cases resulted in death. Figures were similar for 1998. Fewer cases were reported in 1999 and 2000. See the World Health Organization for details. No vaccine is available at this time. Insect protection measures are strongly advised, as outlined below.

HIV (human immunodeficiency virus) infection is reported, but travelers are not at risk unless they have unprotected sexual contacts or receive injections or blood transfusions.

Other infections include

• Hepatitis E (transmitted by contaminated food or water)
• Leptospirosis (animal reservoir includes rats, cattle, buffalo, and pigs)

Do not drink tap water unless it has been boiled, filtered, or chemically disinfected. Do not drink unbottled beverages or drinks with ice. Do not eat fruits or vegetables unless they have been peeled or cooked. Avoid cooked foods that are no longer piping hot. Cooked foods that have been left at room temperature are particularly hazardous. Avoid unpasteurized milk and any products that might have been made from unpasteurized milk, such as ice cream. Avoid food and beverages obtained from street vendors. Do not eat raw or undercooked meat or fish. Some types of fish may contain poisonous biotoxins even when cooked. Barracuda in particular should never be eaten. Other fish that may contain toxins include red snapper, grouper, amberjack, sea bass, and a large number of tropical reef fish.

All travelers should bring along an antibiotic and an antidiarrheal drug to be started promptly if significant diarrhea occurs, defined as three or more loose stools in an 8-hour period or five or more loose stools in a 24-hour period, especially if accompanied by nausea, vomiting, cramps, fever or blood in the stool. Antibiotics which have been shown to be effective include ciprofloxacin (Cipro), levofloxacin (Levaquin), rifaximin (Xifaxan), or azithromycin (Zithromax). Either loperamide (Imodium) or diphenoxylate (Lomotil) should be taken in addition to the antibiotic to reduce diarrhea and prevent dehydration.

If diarrhea is severe or bloody, or if fever occurs with shaking chills, or if abdominal pain becomes marked, or if diarrhea persists for more than 72 hours, medical attention should be sought.

Wear long sleeves, long pants, hats and shoes (rather than sandals). Apply insect repellents containing 25-50% DEET (N,N-diethyl-3-methylbenzamide) or 20% picaridin (Bayrepel) to exposed skin (but not to the eyes, mouth, or open wounds). DEET may also be applied to clothing. Products with a lower concentration of either repellent need to be repplied more frequently. Products with a higher concentration of DEET carry an increased risk of neurologic toxicity, especially in children, without any additional benefit. Do not use either DEET or picaridin on children less than two years of age. For additional protection, apply permethrin-containing compounds to clothing, shoes, and bed nets. Permethrin-treated clothing appears to have little toxicity. Don't sleep with the window open unless there is a screen. If sleeping outdoors or in an accomodation that allows entry of mosquitoes, use a bed net, preferably impregnated with insect repellent, with edges tucked in under the mattress. The mesh size should be less than 1.5 mm. If the sleeping area is not otherwise protected, use a mosquito coil, which fills the room with insecticide through the night.

Air pollution is a significant health problem in Malaysia. Among the causes are vehicle emissions, industrial pollution, deforestation, and forest fires. Pollutants of greatest concern include benzene, sulfur dioxide, nitrogen oxides, ozone, and particulate matter. At times, Kuala Lumpur has had the worst air quality in Asia, including benzene levels as high as 37 ppm. Benzene is a known carcinogen. Short-term exposure to high concentrations may cause depression of the central nervous system, whereas long-term exposure to lower levels may affect the bone marrow and the reproductive system.

Travelers with respiratory or cardiac conditions and those who are elderly or extremely young are at greatest risk for complications from air pollution, which may include cough, difficulty breathing, wheezing, or chest pain. The risk may be minimized by staying indoors, avoiding outdoor exercise, and drinking plenty of fluids.

Bring adequate supplies of all medications in their original containers, clearly labeled. Carry a signed, dated letter from the primary physician describing all medical conditions and listing all medications, including generic names. If carrying syringes or needles, be sure to carry a physician's letter documenting their medical necessity.Pack all medications in hand luggage. Carry a duplicate supply in the checked luggage. If you wear glasses or contacts, bring an extra pair. If you have significant allergies or chronic medical problems, wear a medical alert bracelet.

Make sure your health insurance covers you for medical expenses abroad. If not, supplemental insurance for overseas coverage, including possible evacuation, should be seriously considered. If illness occurs while abroad, medical expenses including evacuation may run to tens of thousands of dollars. For a list of travel insurance and air ambulance companies, go to Medical Information for Americans Traveling Abroad on the U.S. State Department website. Bring your insurance card, claim forms, and any other relevant insurance documents. Before departure, determine whether your insurance plan will make payments directly to providers or reimburse you later for overseas health expenditures. The Medicare and Medicaid programs do not pay for medical services outside the United States.

Pack a personal medical kit, customized for your trip (see description). Take appropriate measures to prevent motion sickness and jet lag, discussed elsewhere. On long flights, be sure to walk around the cabin, contract your leg muscles periodically, and drink plenty of fluids to prevent blood clots in the legs. For those at high risk for blood clots, consider wearing compression stockings.

Avoid contact with stray dogs and other animals. If an animal bites or scratches you, clean the wound with large amounts of soap and water and contact local health authorities immediately. Wear sun block regularly when needed. Use condoms for all sexual encounters. Ride only in motor vehicles with seat belts. Do not ride on motorcycles.

For an on-line list of hospitals in Malaysia, go to the Malaysian Medical Association website.

Medical facilities and services are adequate in the larger cities where Western-trained doctors can be found. The U.S. Embassy can also provide a list of English-speaking doctors and hospitals upon request. Psychological and psychiatric medical and counseling services are limited. Serious medical problems requiring hospitalization and/or medical evacuation to the United States can cost thousands of dollars or more. Doctors and hospitals often expect immediate cash payment for health services although major credit cards are acceptable.

Before you leave, make sure you have the names and contact information for physicians, clinics, and hospitals where you can obtain emergency medical care if needed.

All children should be up-to-date on routine childhood immunizations, as recommended by the American Academy of Pediatrics. Children who are 12 months or older should receive a total of 2 doses of MMR (measles-mumps-rubella) vaccine, separated by at least 28 days, before international travel. Children between the ages of 6 and 11 months should be given a single dose of measles vaccine. MMR vaccine may be given if measles vaccine is not available, though immunization against mumps and rubella is not necessary before age one unless visiting a country where an outbreak is in progress. Children less than one year of age may also need to receive other immunizations ahead of schedule (see the accelerated immunization schedule).

When traveling with young children, be particularly careful about what you allow them to eat and drink (see food and water precautions), because diarrhea can be especially dangerous in this age group and because the vaccines for hepatitis A and typhoid fever, which are transmitted by contaminated food and water, are not approved for children under age two. Baby foods and cows' milk may not be available in developing nations. Only commercially bottled milk with a printed expiration date should be used. Young children should be kept well-hydrated and protected from the sun at all times.

Be sure to pack a medical kit when traveling with children. In addition to the items listed for adults, bring along plenty of disposable diapers, cream for diaper rash, oral replacement salts, and appropriate antibiotics for common childhood infections, such as middle ear infections.

International travel should be avoided by pregnant women with underlying medical conditions, such as diabetes or high blood pressure, or a history of complications during previous pregnancies, such as miscarriage or premature labor. For pregnant women in good health, the second trimester (18–24 weeks) is probably the safest time to go abroad and the third trimester the least safe, since it's far better not to have to deliver in a foreign country.

Before departure, make sure you have the names and contact information for physicians, clinics, and hospitals where you can obtain emergency obstetric care if necessary. In general, pregnant women should avoid traveling to countries which do not have modern facilities for the management of premature labor and other complications of pregnancy.

Strict attention to food and water precautions is especially important for the pregnant traveler because some infections, such as listeriosis, have grave consequences for the developing fetus. Additionally, many of the medications used to treat travelers' diarrhea may not be given during pregnancy. Quinolone antibiotics, such as ciprofloxacin (Cipro) and levofloxacin (Levaquin), should not be given because of concern they might interfere with fetal joint development. Data are limited concerning trimethoprim-sulfamethoxazole, but the drug should probably be avoided during pregnancy, especially the first trimester. Options for treating travelers' diarrhea in pregnant women include azithromycin and third-generation cephalosporins. For symptomatic relief, the combination of kaolin and pectin (Kaopectate; Donnagel) appears to be safe, but loperamide (Imodium) should be used only when necessary. Adequate fluid intake is essential.

Helpful maps are available in the University of Texas Perry-Castaneda Map Collection and the United Nations map library. If you have the name of the town or city you'll be visiting and need to know which state or province it's in, you might find your answer in the Getty Thesaurus of Geographic Names.

American citizens living in or visiting Malaysia are encouraged to register at the U.S. embassy in Kuala Lumpur either online, or in person at the consular section, and to obtain updated information on travel and security within the country. The U.S. embassy is located at 376 Jalan Tun Razak 50400, Kuala Lumpur. The local mailing address is P.O. Box No. 10035, 50700 Kuala Lumpur. The U.S. embassy telephone (60-3) 2168-5000, is available 24 hours per day for emergencies such as arrests, serious illness/injury, or death of Americans, (after business hours, please press 1 at the recording). The American Citizen Services telephone number is (60-3) 2168-4997/4979, and the Consular section fax number is (60-3) 2148-5801. The general fax number for the U.S. Embassy is (60-3) 2142-2207. The U.S. Embassy's web site is http://malaysia.usembassy.gov/; and the Consular section's e-mail is: klconsular@state.gov.