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 trimethoprim-sulfamethoxazole one double-strength tablet twice daily or azithromycin (Zithromax) 500 mg twice daily.Trimethoprim-sulfamethoxazole should not be given to pregnant women or those with a history of sulfa allergy. 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.

Malaria in El Salvador: prophylaxis is recommended for rural areas of the departments of Santa Ana, Ahuachapan, and La Union. The greatest risk occurs in Santa Ana province, due to migration from Guatemala. The drug of choice is chloroquine, taken once weekly in a dosage of 500 mg, starting one-to-two weeks before arrival and continuing through the trip and for four weeks after departure from rural areas. Chloroquine may cause mild adverse reactions, including gastrointestinal disturbance, headache, dizziness, blurred vision, and itching, but severe reactions are uncommon. Insect protection measures are advised, as below.

The following are the recommended vaccinations for El Salvador.

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. 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 all travelers if not previously vaccinated. 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 for travelers spending a lot of time outdoors, for travelers at high risk for animal bites, such as veterinarians and animal handlers, for long-term travelers and expatriates, and for travelers involved in any activities that might bring them into direct contact with bats. Children are considered at higher risk because they tend to play with animals, may receive more severe bites, or may not report bites. In El Salvador, most cases of rabies are related to dog bites. 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.

Yellow fever vaccine is required for all travelers over six months 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. The vaccine should not in general be given to anyone who is younger than nine months old, pregnant, immunocompromised, or allergic to eggs (since the vaccine is produced in chick embryos).

Cholera vaccine is not generally recommended, even though cholera is reported, because most travelers are at low risk for infection. Two oral vaccines have recently been developed: Orochol (Mutacol), licensed in Canada and Australia, and Dukoral, licensed in Canada, Australia, and the European Union. These vaccines, where available, are recommended only for high-risk individuals, such as relief workers, health professionals, and those traveling to remote areas where cholera epidemics are occurring and there is limited access to medical care. The only cholera vaccine approved for use in the United States is no longer manufactured or sold, due to low efficacy and frequent side-effects.

Polio vaccine is not recommended for any adult traveler who completed the recommended childhood immunizations. Polio has been eradicated from the Americas, except for a small outbreak of vaccine-related poliomyelitis in the Dominican Republic and Haiti in late 2000.

An outbreak of histoplasmosis was reported in February-March 2008 among three mission groups from Pennsylvania and Virginia that had traveled separately to El Salvador to renovate a church. A total of 20 cases were identified. Symptoms included fatigue, fever, headache, dry cough, and chest pain. Histoplasmosis is caused by Histoplasma capsulatum, a soil-based fungus transmitted by inhalation. Those who reported sweeping, cleaning, or digging outdoors appeared to be at greatest risk. The infection is not transmitted from person to person. For further information, go to MMWR.

Cases of dengue fever, a flu-like illness which may be complicated by hemorrhage or shock, are reported annually from El Salvador. More than 6500 cases were reported nationwide in the first eleven months of 2009, including 11 deaths. 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. Insect protection measures are strongly advised, as outlined below.

In July 2007, a preventative dengue alert was issued for the capital, San Vicente; La Paz, in the central part of the country; La Libertad, in the south; and Santa Ana, in the east, because of an observed increase in the number of cases. By December, a total of 12,360 cases had been reported for the year, with no fatalities. For dengue statistics for the year 2006, go to the Ministerio de Salud website. A major dengue outbreak was reported from El Salvador in the spring of 2002, chiefly affecting children between the ages of five and nine. More than 2000 cases were reported, including 156 cases of dengue hemorrhagic fever and six deaths. The departments of San Salvador, Santa Ana, Cabanas and Cuscatlan were most affected. See the Pan-American Health Organization and the World Health Organization for further information.

• Venezuelan equine encephalitis (transmitted by mosquitoes)
• Chagas disease (American trypanosomiasis) (rural areas)
• Visceral and cutaneous leishmaniasis (chiefly rural areas, especially in the department of San Vicente)
• Tick-borne relapsing fever
• Brucellosis (the chief animal source is infected cattle)
• Paragonimiasis (rare)

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 disease statistics and updates on recent outbreaks, go to Vigilancia Epidemiologica (in Spanish) on the Ministerio de Salud Publica website. For in-depth public health information, go to the Pan-American Health Organization.

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, including ceviche. 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). For rural and forested areas, boots are preferable, with pants tucked in, to prevent tick bites. Apply insect repellents containing 25-35% DEET (N,Ndiethylmetatoluamide) to clothing and exposed skin (but not to the eyes, mouth, or open wounds). For children between 2 and 12 years of age, use preparations containing no more than 10% DEET and apply sparingly. Do not use DEET-containing compounds on children less than two years of age. Preparations containing a higher concentration of DEET carry an increased risk of neurologic toxicity, especially in children. For additional protection, apply permethrin-containing repellents 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. In rural or forested areas, perform a thorough tick check at the end of each day with the assistance of a friend or a full-length mirror. Ticks should be removed with tweezers, grasping the tick by the head. Many tick-borne illnesses can be prevented by prompt tick removal.

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 ambulance in El Salvador, call Priority Ambulance at 503-2264-7911. Response times may be slow due to the heavy traffic in San Salvador, so transportation by private vehicle is preferable when possible.

>Medical care is extremely limited. Many physicians are well-trained, often in the United States, but ambulances and hospitals may lack critical supplies and the quality of the support staff is variable. In general, private hospitals are superior to the public facilities. For emergencies, many travelers go to the Hospital Centro de Emergencias, which offers a 24-hour emergency room and a broad range of specialty services (Colonia Médica, Diagonal Dr. Luis E. Vasquez, No 250, San Salvador; tel. 2530-3333, 2226-0003 2225-9303, 2225-4651 and 2225-4651; website http://www.centroemergencias.com/). The medical advisor to the U.S. Embassy is Dr. Renato Matamoros (Escalon Office tel. 263-6898 and 264-19-54; Calle Padres Aguilar #612, Clinica Ortopedas Asociados, Col. Escalon; Esperanza Office tel. 226-3040/5111; Edificio Diagonal, 2a Diagonal 2nd Floor #202; Urb. La Esperanza, front of Hosp. Diagnostico; radio 226-4087; beeper 243-2000; unidad 224; home tel. 263-0789). For an online list of other physicians, dentists, laboratories and hospitals in El Salvador, go to the U.S. Embassy website at http://elsalvador.usembassy.gov/consular/english/acs/doctorslist.html. Most hospitals accept credit cards for hospital services, but physicians will generally 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.

Medical supplies may be limited in El Salvador, including medications. Medicines may have a different brand name and be more expensive than in the United States.

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 (see the U.S. Embassy website).

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).

The recommendations for malaria prophylaxis are the same for young children as for adults, except that the dosage of chloroquine is lower. DEET-containing insect repellents are not advised for children under age two, so it's especially important to keep children in this age group well-covered to protect them from mosquito bites.

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 (see the U.S. Embassy website). 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.

As a rule, pregnant women should avoid visiting areas where malaria occurs. Malaria may cause life-threatening illness in both the mother and the unborn child. None of the currently available prophylactic medications is 100% effective. If travel to malarious areas is unavoidable, chloroquine must be taken once a week and insect protection measures must be strictly followed at all times. The recommendations for DEET-containing insect repellents are the same for pregnant women as for other adults.

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 El Salvador are encouraged to register at the Consular Section of the U.S. Embassy in San Salvador and obtain updated information on travel and security in El Salvador and neighboring countries.

The Consular Section of the U.S. Embassy in El Salvador is located at Final Boulevard Santa Elena Sur, Urbanizacion Santa Elena, Antiguo Cuscatlan, La Libertad, telephone 011-503-278-4444. The Embassy's web site can be accessed at http://elsalvador.usembassy.gov. The Consular Section is open for U.S. citizen services from 8:15 a.m. to 11:30 a.m. weekdays, excluding U.S. and Salvadoran holidays.

For any questions concerning U.S. visas for either temporary travel to or permanent residence in the U.S., please contact our regional U.S. Visa Information Center. From El Salvador, the Visa Information Center may be reached by calling 900-6011 or by purchasing a VISAS-USA calling card from any place that sells Telefonica phone cards. Calling instructions are on the back of the card. Calls using the 900 number cost approximately two dollars and 15 cents per minute and will be charged to the caller's telephone bill. The Telefonica phone card costs 15 dollars and permits a seven-minute call. From the U.S., the Visa Information Center can be contacted by dialing 818-755-8425 and charging the call to a Visa or MasterCard credit card.

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.