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 vaccinations are recommended for Micronesia.

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 all travelers, with the exception of short-term visitors who restrict their meals to major restaurants and hotels, such as business travelers. 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.

Hepatitis B vaccine is recommended for travelers who will have intimate contact with local residents or potentially need blood transfusions or injections while abroad, especially if visiting for more than six months. It is also recommended for all health care personnel. Two vaccines are currently licensed in the United States: Recombivax HB (Merck and Co., Inc.) (PDF) and Engerix-B (GlaxoSmithKline) (PDF). A full series consists of three intramuscular doses given at 0, 1 and 6 months. Engerix-B is also approved for administration at 0, 1, 2, and 12 months, which may be appropriate for travelers departing in less than 6 months. Side-effects are generally mild and may include discomfort at the injection site and low-grade fever. Severe allergic reactions (anaphylaxis) occur rarely.

Rabies vaccine is recommended only for those at high risk for animal bites, such as veterinarians and animal handlers, and for long-term travelers who may have contact with animals and may not have access to medical care. A complete preexposure series consists of three doses of vaccine injected into the deltoid muscle on days 0, 7, and 21 or 28. Side-effects may include pain at the injection site, headache, nausea, abdominal pain, muscle aches, dizziness, or allergic reactions.

Any animal bite or scratch should be thoroughly cleaned with large amounts of soap and water and local health authorities should be contacted immediately for possible post-exposure treatment, whether or not the person has been immunized against rabies.

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.

Polio vaccine is not recommended for any adult traveler who completed the recommended childhood immunizations. In October 2000, the World Health Organization certified that polio had been eradicated from the Western Pacific region.

Cholera vaccine is not generally recommended, despite the recent outbreak on Pohnpei island (see below), because most travelers are at low risk for infection. The only cholera vaccine approved for use in the United States has low efficacy and a high incidence of adverse reactions, and is no longer being manufactured or sold. Two oral vaccines have recently been developed but are not yet approved in the United States (see cholera). These vaccines, where available, may be considered for high-risk individuals, such as relief workers or health professionals.

An outbreak of hepatitis A was reported from Chuuk in August 2008, believed to be caused by by heavy rains that resulted in the overflow of raw sewage and contamination of the municipal water supply (see ProMED-mail, August 7, 2008). All travelers to Micronesia should be immunized against hepatitis A, as above.

A small outbreak of dengue fever, a flu-like illness which may be complicated by hemorrhage or shock, was reported from Yap in October 2007. Dengue fever is transmitted by Aedes mosquitoes, which bite primarily in the daytime and favor densely populated areas, though they also inhabit rural environments. No vaccine is available at this time. The cornerstone of prevention is insect protection measures, as outlined below.

An outbreak of Zika virus infections was reported in June 2007 from Micronesia, resulting in 99 confirmed and 54 probable cases. Most of the cases occurred on Yap Island, but a small number were reported from the neighboring islands of Ulithi, Fais, Earpik, Woleai, and Ifalik. In retrospect, the outbreak probably began in April. As of July, the outbreak appeared to be subsiding. No hospitalizations or deaths have been reported to date. Zika is a mosquito-borne virus similar to dengue. Most cases are mild and last 4-7 days. In the Yap outbreak, the main symptoms were rash, conjunctivitis ("pink-eye"), and joint pains. Not all patients had a fever. Other symptoms included pains behind the eyes, muscle aches, swelling of the lower extremities, lymphadenopathy (swollen glands), and diarrhea. For further information, go to the CDC website and ProMED-mail (July 2 and 13 and August 7, 2007). There is no treatment or vaccine. Insect protection measures, as below, are strongly recommended for travelers to Micronesia.

A cholera outbreak was reported from Pohnpei island in April 2000, resulting in more than 3000 cases, including 20 deaths. See the World Health Organization for details. Cholera is not being reported from Micronesia at this time.

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.

For further information on health issues in Micronesia, go to the World Health Organization - Western Pacific Region.

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.

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.

Medical care is extremely limited. Essential supplies and medicines may be lacking. There are hospitals on each of the four major islands, but they are poorly equipped. There are only two decompression chambers in Micronesia (in Yap and Chuuk); staffing and availability may not be reliable. Most doctors and hospitals will expect payment in cash, regardless of whether you have travel health insurance. Serious medical problems will require air evacuation to a country with state-of-the-art medical facilities.

Micronesia has some of the most spectacular scuba diving in the world. We hope all divers enjoy a safe diving vacation here. However, dive accidents do occur in FSM waters. Since October 1998, eight divers have been evacuated due to diving accidents. As medical evacuation flights (MEDEVAC) are very expensive (up to $25,000) when a diver pays personally, the U.S. Embassy encourages divers to obtain MEDEVAC insurance prior to arriving in the FSM. MEDEVAC insurance is good protection for the thousands of dollars divers have invested in travel and diving packages to visit Micronesia and provides the best coverage/care should an accident occur.

MEDEVAC insurance provides 24 hour access by telephone to medical doctors in the U.S. and other countries who are familiar with diving accidents and who can arrange for private air evacuation 24 hours a day. You can sign up for this insurance by e-mail from your home prior to your dive trip. If you arrive in the FSM without dive insurance, we urge you to get on the internet in the FSM and sign up from here. Be sure to give your dive operator your MEDEVAC insurance number to have on file. American citizens living in the FSM can have their MEDEVAC insurance number put on file at the U.S. Embassy.

Many insurance companies provide MEDEVAC insurance.

An organization specializing in medical advice and assistance (including MEDEVAC) for divers is Divers Alert Network (DAN) MEDEVAC insurance.

Phone:1-800-446-2671; 1-919-684-2948; Fax 919-490-6630. E-mail: dan@DiversAlertNetwork.org

$35 will provide a year of MEDEVAC coverage for worldwide diving!

If you decline to obtain MEDEVAC insurance you should know that, if you should be in a diving accident, the dive operator will take you to the closest hospital to be treated with oxygen, if it is available. You should be aware that hospitals in the four states of the FSM are poorly equipped and may not have oxygen available. Depending on the severity of the diving accident, the one commercial air carrier that provides service to all four states in the FSM (Continental Airlines) may not be able to pressurize its cabin low enough to transport a patient with a severe case of the bends. Continental Airlines flies to Guam only four days a week from the states of the FSM. With MEDEVAC insurance, private aircraft are available 24 hours a day to fly you medical assistance/recompression chamber.

While diving experiences in the FSM are among the best in the world, diving safety in the FSM can be very poor. Many dive operators in the FSM do not have portable oxygen equipment on dive boats or in their offices. Many operators do not provide extra tanks at safety stops. Divers should question dive operators to determine if they have appropriate equipment to deal with diving accidents.

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.

Americans living in or visiting the Federated States of Micronesia are encouraged to register at the Consular Section of the U.S. Embassy in Kolonia and obtain updated information on travel and security within Micronesia. The U.S. Embassy in Kolonia is located on Kasalehlie Street (the main downtown street). The mailing address is P.O. Box 1286, Pohnpei, Federated States of Micronesia 96941. The telephone number is (691) 320-2187. The fax number is (691) 320-2186. The U.S. Embassy's website can be accessed at either http://kolonia.usembassy.gov or http://micronesia.usembassy.gov.

For information on safety and security, go to the U.S. Department of State, United Kingdom Foreign and Commonwealth Office, Foreign Affairs Canada, and the Australian Department of Foreign Affairs and Trade.