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 Croatia:

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 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 only for those at high risk for animal bites, such as veterinarians and animal handlers, for long-term travelers living in areas with a high risk of exposure, and for travelers involved in any activities that might bring them into direct contact with bats. 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.

Influenza vaccine is recommended for all travelers during flu season, which runs from November through April. Influenza vaccine may cause soreness at the injection site, low-grade fevers, malaise, and muscle aches. Severe reactions are rare. Influenza vaccine should not be given to pregnant women during the first trimester or those allergic to eggs.

Tick-borne encephalitis vaccine may be considered for long-term travelers who expect to be visiting rural or forested areas in the spring or summer. In Croatia, tick-borne encephalitis is prevalent throughout rural and forested areas, except along the coast. Most cases occur in the northern part of the country, between the rivers Sava and Drava (see Eurosurveillance). Two vaccines have been developed: TicoVac, also known as FSME Immun (Baxter AG), which is manufactured in Austria, and Encepur (Chiron Behring), which is made in Germany. The vaccines are approved for use in a number of European countries, but not the United States. A full series consists of three doses over a one-year period, which is not practical for most travelers, though limited data indicate that Encepur may be given in an accelerated schedule for faster immunity. Tick precautions, as discussed below, are strongly advised.

A measles outbreak was reported from Zagreb and Slavonski Brod from April to June, 2008, causing 49 cases (see Eurosurveillance). All travelers born after 1956 should make sure they have had either two documented MMR or measles immunizations or a blood test showing measles immunity. Those born before 1957 are presumed to be immune. Although measles immunization is usually begun at age 12 months, children between the ages of 6 and 11 months should be given an initial dose of measles or MMR vaccine before traveling to Croatia.

An outbreak of hemorrhagic fever with renal syndrome was reported in May 2002, involving more than 100 people and causing at least one death. Outbreaks of hemorrhagic fever with renal syndrome occur periodically in Croatia, typically caused by either Puumala virus or Dobrava-Belgrade virus. The disease is acquired by exposure to rodent excreta, often by the aerosol route. Most travelers are at low risk for infection. For further information, go to ProMED-mail (May 22, 2002) and the Lancet Infectious Diseases (July 2002).

Two outbreaks of trichinellosis were reported from East Croatia in February 2003. Both were associated with the consumption of domestic pigs. For further information, go to ProMED-mail (March 24, 2003). A prior outbreak was reported from Istria in November 2002 (see ProMED-mail; November 5, 2002). In Croatia, cases of trichinellosis may be related to consumption of either pork or horsemeat.

Brucellosis is occasionally reported. Sheep and pigs are the most common sources of infection.

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.

Tap water is generally safe to drink in major cities, but water quality is variable in rural areas. If in doubt, do not drink tap water unless it has been boiled, filtered, or chemically disinfected. 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 red snapper, grouper, amberjack, and sea bass.

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.

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.

If you come from an EU country which has signed the Health Care Convention with Croatia, your health expenses in Croatia will be covered if you bring along form E111.

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 Croatia, call 94.

Health facilities in Croatia are generally of good quality, but are not well-funded. In Zagreb, the main facility is the KBC Hospital (locations at Kispaticeva 12, Zagreb; tel. 238-8888; and Salata 4, Zagreb; tel. 455-2333; website www.kbc-zagreb.hr; includes Women's Health Clinic, Petrova 13, tel. 460-4646; Orthopedic Institute, Bozidareviceva 11; tel. 236-2330; and Clinic for Dental Medicine, Gunduliceva 5; tel. 480-2111). The primary trauma hospital is Traumatoligija (Draskoviceva 19, Zagreb; tel. 461-0011, 469-7000). In Rijeka, medical care for travelers is provided by the Travel Clinic (Nebojsa Nikolic MD, Riva Boduli 1, 51000 Rijeka; tel. 385-51-213605; email travel-medicina@ri.htnet.hr). For a list of other physicians, dentists, and hospitals in Croatia, go to the U.S. Embassy website. Most doctors and hospitals will expect payment in cash, regardless of whether you have travel health insurance. Life-threatening medical problems will require air evacuation to a country with state-of-the-art medical facilities.

Most private pharmacies are well-supplied, though not all medications available in North America and Western Europe are obtainable in Croatia. In the cities and larger towns, the pharmacies take turns staying open after hours.

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.

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. 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.

U.S. citizens are encouraged to register online at https://travelregistration.state.gov and obtain updated information on travel and security in Croatia from the Consular Section of the U.S. Embassy in Zagreb on 2 Thomas Jefferson Street, 10010 Zagreb, tel.: (385)(1) 661-2300. This location is in the southern outskirts of Zagreb toward the airport. On weekend, holidays and after hours, an embassy duty officer can be reached at tel.: (385)(1) 661-2400 or (385)(91) 455-2247. Further information on travel to Croatia is also located on the Embassy web site at http://www.usembassy.hr.

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.