Traveler’s diarrhea

Traveler’s diarrhea (TD) refers to a stomach and intestinal infection.

It is defined as the passage of unformed stool, while traveling.

Defined as diarrhea that develops while traveling abroad or shortly after returning from a developing country.

Approximately 8% of travelers to the developing world will require medical care during or after the trip, and more than 25% of those who seek medical care have gastrointestinal symptoms.

Usually a self-limited disease with a duration of less than 1 week.

About 90% of cases resolve within one week, and 98% within one month of onset of symptoms. Antbiotic’s are typically prescribed for moderate to severe cases.

Considered an acute illness, however can lead to chronic disease including reactive arthritis and postinfectious IBS.

Affects 20-50% of travelers.

Every year, the CDC reports that 30-70% of international travelers (an estimated 12 million people) develop diarrhea, usually within the first week of travel.

Symptoms typically occur suddenly and include diarrhea, abdominal cramps, flatus, fever, nausea, vomiting, and malaise, increased frequency, volume, and weight of stool,altered stool consistency

Caused primarily by exposure to a bacterial enteric pathogen: enterotoxigenic E. coli and enteroaggregated E.coli are the most common causative agents.

Prevention measures include: avoiding tap water, foods washed with water, ice, uncooked seafood and raw or undercooked meats.

Safe foods and beverages include: bottled beverages, well cooked foods and dry foods. Approximately 80% of cases caused by bacteria.

The GeoSentinel Surveillance Network found that significant pathogens isolated from patients included approximately 65% parasitic organisms, 31% bacterial organisms and 3% viral (Swaminathan A et al).

In the above study six organisms: Giardia, Campylobacter, and to Entameba histolytica, Shigella, Strongyloides, and salmonella species accounted for 70% of the gastrointestinal pathogens. Most common responsible organisms include enterotoxigenic E. Coli, Campylobacter and noncholera vibrios.

Antibiotics should be reserved for patients that develop diarrhea rather than treating with prophylactic antibiotics.

Efficacious agents include ciprofloxacin, and rifaximin.

Typically, a traveler experiences four to five loose or watery bowel movements each day.

Clinically, it may be accompanied by abdominal cramps, nausea, fever, bloating and malaise.

Appetite may decrease.

Bloody diarrhea may occur with TD.

About 35% of travelers to the developing world develop travelers diarrhea.

As many as 840 million cases worldwide of traveler’s diarrhea reported in developing countries each year.

The onset is usually within the first week of travel, but may occur at any time while traveling, and even after returning home.

The timing of onset depends on the incubation period of the infectious agent.

Bacterial related TD typically begins abruptly.

Cryptosporidium may incubate for seven days, and Giardia for 14 days or more, before symptoms develop.

Most recover within four days with little or no treatment.

In about 10% of patients symptoms persist for a week.

Then most common cause of Traveler’s diarrhea is E. coli.

Refers to Unformed stool while traveling, with fever, abdominal cramps.

Duration typically is < 5 days.

Causes are Often bacterial.

Prevention of travelers diarrhea:

Eating only properly prepared food,

drinking bottled water,

frequent hand washing

Treatment includes oral rehydration therapy, antibiotics, and loperamide.

Bacteria are responsible for more than half of cases of TD.

The bacteria enterotoxigenic Escherichia coli (ETEC) are typically the most common cause of TD, except in Southeast Asia, where Campylobacter is more prominent.

The most common causative agent isolated has been enterotoxigenic Escherichia coli (ETEC).

About 10% to 20% of cases are due to norovirus.

Protozoa such as Giardia may cause longer term travelers disease.

Protozoans such as Giardia lamblia, Cryptosporidium and Cyclospora cayetanensis can also cause diarrhea.

TD risk is greatest in the first two weeks of travel and among young adults.

Persons at particular high-risk include young adults, immunosuppressed persons, persons with inflammatory bowel disease or diabetes, and persons taking H2 blockers or antacids.

People affected are more often from the developed world.

The oral cholera vaccine, is of questionable use for traveler’s diarrhea.

Preventive antibiotics are generally discouraged.

Hospitalization is required in less than 3% of cases of TD.

TD affects 20 to 50% among of visitors the developing world.

TD is particularly common among people travelling to Asia, except for Japan and Singapore, the Middle East, Africa, Mexico, and Central and South America.

Moderate risk of TD occurs in Southern Europe, Russia, and China.

It has been linked to later irritable bowel syndrome and Guillain–Barré syndrome.

Agents involved:

E. coli, enterotoxigenic 20–75%

E. coli, enteroaggregative 0–20%

E. coli, enteroinvasive 0–6%

Shigella spp. 2–30%

Salmonella spp. 0–33%

Campylobacter jejuni 3–17%

Vibrio parahaemolyticus 0–31%

Aeromonas hydrophila 0–30%

Giardia lamblia 0–20%

Entamoeba histolytica 0–5%

Cryptosporidium spp. 0–20%

Cyclospora cayetanensis

Rotavirus 0–36%

Norovirus 0–10%

Bacterial G.I. bacteria cause about 80% of cases, while viruses and protozoans account for most of the rest.

E. coli is increasingly recognized agent, while Shigella spp. and Salmonella spp. are other common bacterial pathogens.

Campylobacter, Yersinia, Aeromonas, and Plesiomonas spp. are less frequently found as etiology Christmas agents.

Some bacteria release toxins which bind to the intestinal wall and cause diarrhea.

Other bacteria damage the intestines directly.

Viral agents are associated with less than 20% of adult cases of traveler’s diarrhea. but may be responsible for nearly 70% of cases in infants and children.

Diarrhea due to viral agents is unaffected by antibiotic therapy, but is usually self-limited.

Traveler’s diarrhea in hikers and campers,(wilderness diarrhea), may have different frequency of distribution of pathogens.

The primary source of infection is the ingestion of fecally contaminated food or water.

The destination of travel is most important determinant of risk.

High-risk destinations include: developing countries in Latin America, Africa, the Middle East, and Asia.

Among backpackers, additional risk factors include drinking untreated surface water and failure to maintain personal hygiene and clean cookware, and campsites often being primitive.

In about 20% of cases, the illness is severe enough to require bedrest, and in 10%, the illness duration exceeds one week.

It can be life threatening with serious bacillary dysentery, amoebic dysentery, and cholera infections.

Risk for TD increased in young adults, immunosuppressed persons, persons with inflammatory bowel disease or diabetes, and those taking H2 blockers or antacids.

Local residents may be immune to TD, while travelers often get diarrhea from eating and drinking the same foods and beverages.

Locals develop immunity with constant, and repeated exposure to pathogenic organisms.

Such immunity may take up to seven years to develop.

It is a sanitation failure, leading to bacterial contamination of drinking water and food.

Safe beverages include bottled water, bottled carbonated beverages, and water boiled.

Risks exist with tea, coffee, and other hot beverages that may be only heated, not boiled.

Bottled water should be opened in ones presence.

Ice should be avoided as it may not have been made with safe water.

Green salads should be avoided,because the lettuce and other uncooked ingredients are unlikely to have been washed with safe water.

Avoid eating raw fruits and vegetables unless known to be cleaned and peeled safely.

Cooked fresh and packaged foods are usually safe, while raw or undercooked meat and seafood should be avoided.

Unpasteurized milk, dairy products, mayonnaise, and pastry icing, foods and beverages purchased from street vendors and other establishments where unhygienic conditions may be present. associated with increased risk for TD.

Safe bottled water can be treated with boiling, filtering, chemical treatment, and ultraviolet light.

Boiling is by far the most effective of these methods, as it rapidly kills all active bacteria, viruses, and protozoa.

Most microorganisms are killed within seconds at water temperature above 130–160 °F

Filters can eliminate most bacteria and protozoa, but not viruses.

Chemical treatment with chlorine bleach, tincture of iodine, or commercial tablets have low-to-moderate effectiveness against protozoa such as Giardia, but work well against bacteria and viruses.

UV light is effective against both viruses and cellular organisms.

UV light, however only works in clear water.

Bismuth subsalicylate reduces rates of traveler’s diarrhea.

Antibiotics are not recommended for prevention of TD

Antibiotic therapy may outweigh risks, in immunocompromised travelers, chronic intestinal disorders, prior history of repeated disabling bouts of TD, or scenarios in which the onset of diarrhea might prove particularly troublesome.

Options for prophylactic treatment include: quinolone antibiotics, azithromycin, and trimethoprim/sulfamethoxazole, and rifaximin.

The value is probiotics is controversial.

Treatment- as most cases are mild and resolve in a few days without treatment.

With severe or protracted TD, it may result in dehydration and electrolyte imbalance, rehydration therapy.

If diarrhea becomes severe, defined as three or more loose stools in an eight-hour period, and associated with nausea, vomiting, abdominal cramps, fever, or blood in stools, medical treatment with antimicrobial therapy may be beneficial.

Antibiotic treatment shortens the duration and severity of TD.

The antibiotics recommended vary with the destination of travel.

Previously Trimethoprim–sulfamethoxazole and doxycycline were recommended, but because of high levels of resistance to these agents, they are no longer.

When given, antibiotics are typically given for three to five days, but single doses of azithromycin or levofloxacin have been used.

Rifaximin and rifamycin are approved for treatment of TD caused by ETEC.

If diarrhea persists despite therapy, travelers should be evaluated for bacterial strains resistant to the prescribed antibiotic, possible viral or parasitic infections, bacterial or amoebic dysentery, Giardia, helminths, or cholera.

Loperamide and diphenoxylate reduce the symptoms of diarrhea by slowing transit time in the gut.

If antimotility drugs stop bowel movements completely, they may delay expulsion of the causative organisms from the intestines.

Antimotility agents are avoided in patients with fever, bloody diarrhea, and possible inflammatory diarrhea.

Wilderness diarrhea, refers to diarrhea among backpackers, hikers, campers and other outdoor recreationalists in wilderness or backcountry situations, either at home or abroad.

Wilderness diarrhea is caused by the same fecal microorganisms as other forms of traveler’s diarrhea, usually bacterial or viral.