Illnesses from Food and Water

Cholera

Cholera is an acute bacterial intestinal infection usually caused by consuming contaminated water or food. The infection is extremely rare and is most often mild and self-limited in otherwise healthy travelers. Severe cases begin with sudden onset of frequent watery stools (vomiting may also occur) and progress to dehydration, shock, and coma. Cholera is concentrated in areas that are infrequently visited by typical tourists.

Prevention: The primary prevention of cholera is observance of food and beverage precautions and hand-hygiene (frequent, thorough handwashing) measures. Maintenance of such personal hygiene is essentially 100% effective for prevention in usual travel situations. Thus, cholera vaccines, including those that have been available in many countries for many years, are not to be considered as one of the routine travel vaccines. The main risk populations who should consider vaccination are aid, refugee, and health care workers likely to have direct contact with bodily fluids in proximity to displaced populations, especially in crowded camps or impoverished areas. Travelers who follow usual tourist itineraries with standard accommodations and who observe food-safety recommendations while in countries reporting cholera have almost no risk.

Hepatitis A

Hepatitis A is a viral infection of the liver acquired though the consumption of fecally-contaminated foods or through contact with infected persons via the fecal-oral route (including oral or anal sex). Hepatitis A infection, which occurs worldwide, is one of the most common diseases for which travelers are at risk, especially in developing countries; risk is less for those traveling exclusively to developed countries. Symptoms most commonly appear 25 to 50 days following exposure and include nausea, loss of appetite, stomach pain (just under the rib cage, on the right side of the body), weakness, fatigue, fever, dark urine, and jaundice (yellow skin and eyes). Illness can range from a mild, influenza-like ailment lasting 1 to 2 weeks to severe illness lasting several months.

Prevention: Practice good personal hygiene and observe strict food and water precautions. Hepatitis A vaccination provides long-lasting immunity following 2 doses (a single dose any time before departure followed by a second dose 6 months later). A combined hepatitis A-hepatitis B vaccine is also available.

Travelers' Diarrhea

Travelers' diarrhea (TD) is a major concern for travelers, especially those heading to developing countries. TD results from ingesting contaminated food or water. The majority of TD is caused by bacteria (e.g., E. coli), but can also be caused by protozoa (e.g., Giardia) or a virus (e.g., rotavirus). TD occurs in up to 70% of travelers going to developing countries. Episodes typically last 3 to 4 days on average, but some cases can persist for weeks.

Destination is an important risk factor for TD. Developing countries in Africa, Latin America, Asia, and the Middle East are considered high-risk areas for acquiring TD, whereas southern Europe and a few Caribbean islands are considered intermediate risk. Australia, Canada, northern Europe, New Zealand, the U.S., and several of the Caribbean islands are considered low risk.

Prevention: Practice good personal hygiene and observe strict food and water precautions. A vaccine (Dukoral) that has been shown to be effective against a few of the many types of diarrhea is available in Canada and elsewhere (not in the U.S.). However, despite prevention strategies, TD still occurs. Therefore, it is important to learn how to recognize and manage TD if it occurs.

Symptoms

Bacterial diarrhea has an abrupt onset of uncomfortable diarrhea. Fever, nausea, or vomiting may occur. "Abrupt onset" generally means that the traveler is aware of the exact time of day the illness began, and the symptoms are quite bothersome from the beginning. Travelers who experience an abrupt onset of uncomfortable diarrhea can be reasonably confident that the cause is bacterial; to shorten the illness they can self-treat with loperamide (Imodium AD is one brand). An antibiotic may be prescribed by a health care provider prior to the trip for self-treatment if the diarrhea is very severe and does not respond to loperamide.

In contrast, protozoal diarrhea begins gradually (with loose stools occurring in distinct episodes during the day, gradually becoming more bothersome) and is associated with fatigue. Diarrhea might occur after the first few weeks of travel, and persons with protozoal infections often do not seek medical care for weeks due to the generally mild nature of the symptoms. Drugs such as metronidazole or tinidazole (Tindamax) are usually prescribed for protozoal diarrhea, but, in general, travelers should not carry these drugs for self-treatment. A proper diagnosis should be made and the drugs administered under medical supervision.

Treating Bacterial TD

Travelers are often in areas where prompt, effective medical care is unavailable. Therefore, it is often more practical to self-treat bacterial diarrhea with antibiotics that have been prescribed and purchased prior to leaving for the trip. Travelers who do bring medication should make sure that written information on symptoms, precautions, correct dosage and scheduling is included. Many drug treatments for diarrhea should not be used by pregnant women, and some that are recommended for adults can cause complications for children.

Nonantibiotic Methods

Antimotility drugs such as loperamide (Imodium) may be useful on a temporary basis to slow bowel movements and reduce frequency of stools. Dosing of over-the-counter loperamide should not exceed 8 mg/day. Consult a health care provider about the advantages and disadvantages of use.

Some people take bismuth subsalicylate (Pepto-Bismol) preventively to reduce their risk of travelers' diarrhea. It should be used this way only if recommended by a health care provider and only for less than 3 weeks. Side effects include darkening of the tongue and stools and, occasionally, nausea, constipation, or ringing in the ears. It should not be used by children younger than 12 years, pregnant or nursing women, persons who have an aspirin allergy or are taking aspirin, persons who have renal insufficiency or gout, or persons taking anticoagulants, probenecid, or methotrexate. (Use with caution in older children and teens with a viral infection.)

Antibiotics

For treatment of suspected severe bacterial diarrhea, azithromycin is preferred and is the only choice for children and pregnant women. Quinolone antibiotics (ciprofloxacin and levofloxacin) are alternative antibiotics that are only effective at certain destinations and should not be used if diarrhea is accompanied by fever or blood. Rifaximin (Xifaxan) is an alternative when neither quinolones nor azithromycin can be used; rifaximin is approved for treatment of TD caused by E. coli in persons 12 years and older (only for use in persons who do not have fever or bloody stools).

Bacterial Diarrhea

Suggestions for Treatment

  • Travelers who have mild loose stools without other symptoms: An antibiotic is not recommended. Try bismuth subsalicylate or an antimotility drug if needed for travel but not for more than 48 hours.
  • Travelers who have moderately loose or frequent stools with cramps or nausea: An antibiotic is not recommended. Try bismuth subsalicylate or an antimotility drug if needed for travel but not for more than 48 hours.
  • Travelers who have diarrhea severe enough to completely restrict normal activities or diarrhea with bloody stools, dehydration, or high fever and chills: Take azithromycin. Antimotility drugs may be used (for a maximum of 48 hours) if there are no bloody stools. Seek medical help if symptoms do not rapidly improve.

Managing TD Symptoms

Travelers who have diarrhea will need to take measures to prevent dehydration, especially during prolonged episodes.

Adults can replace fluids and electrolytes (body salts) by eating salted crackers and drinking plenty of nonalcoholic, noncaffeinated beverages and soups. If there is any question about the purity of the water source, make sure all beverages and soups are prepared with purified water.

If signs of dehydration appear (dizziness, weakness, dry skin, sunken eyes, deep-yellow urine, reduction or lack of tears and urine), seek medical help immediately. Dehydration can quickly become serious for infants, children, and the elderly.

Travelers who begin to pass soft stools should try eating easy-to-digest foods such as bread, potatoes, tortillas, and rice. Eat lightly for a few days, and stay away from dairy products and foods that are spicy or greasy.

Infants must be given food and fluids throughout the course of any diarrheal episode and should be watched closely for signs of dehydration.

Oral rehydration solutions (ORS) may be helpful in replacing lost fluids. They were designed to decrease childhood mortality rates and are absorbed rapidly from the intestine. ORS packets are available in most developing countries. They should be reconstituted with boiled, bottled, or purified water.

Travelers should see a health care provider or travel medicine specialist if diarrhea does not improve after a few days; if fever, shaking chills, severe fluid loss, or blood or mucus in the stools develop; if a rash or hives develop while taking antibiotics.

Poliomyelitis (Polio)

Although best known as a cause of paralysis in infants and children, adults are also vulnerable to polio. Polio is usually spread via the fecal-oral route, by ingestion of water or food contaminated with the virus. After an incubation period of 6 to 20 days, the virus can cause fever, headache, sore throat, and vomiting. Most people recover at this point, but in some cases, the virus invades the central nervous system and results in paralysis. Polio continues to occur in Afghanistan, Nigeria, and Pakistan but is essentially eradicated almost everywhere else.

Prevention: Although food and beverage precautions may help reduce the risk of exposure to polio virus, vaccination is the only reliable protection against polio. Travelers should have received a complete series of injected polio vaccine during childhood. Additionally, a one-time adult booster dose may be recommended for some travelers going to risk countries or countries with temporary polio outbreaks.

Typhoid Fever

Typhoid fever is a bacterial infection of the digestive tract caused by Salmonella typhi or paratyphi. Prevalent in countries with warm climates and poor sanitary conditions, typhoid typically is spread via food and water contaminated with fecal matter or urine from an infected human carrier. Typhoid has an incubation period of 1 to 3 weeks. Symptoms include headache, fever, abdominal pain, and, sometimes, a rash. If untreated, it may progress to a more severe illness with ongoing high fevers, "pea-soup" diarrhea, disorientation, multiple organ involvement, and coma.

Prevention: Vaccination is available by injection and in oral form in some countries. The injection (1 dose) should be given at least 2 weeks before possible exposure, and the oral vaccine series (4 doses) should be completed at least 1 week before possible exposure for optimum protection. A health care provider may recommend vaccination if traveling in endemic areas or areas with a recent typhoid outbreak. Whether vaccinated or not, it is important to follow food and water precautions because the vaccine is only 60% to 70% effective in preventing illness.

See Additional Illnesses for less common illnesses that may be contracted from food and water.