Nepal is a high-risk country for gastrointestinal illness. About a third of patients seen at CIWEC Hospital come in for diarrhea. Poor restaurant and food hygiene, and a lack of adequate sanitation infrastructure, are probably responsible for the high rates. Risk is higher from April to September than in the cooler months.
CIWEC Hospital has performed extensive research on diarrheal disease in travelers and expatriates, and the advice below is borne out by that research.
What causes diarrhea?
Bacterial infections cause most cases — about 70–75%. Typically there is an abrupt onset of uncomfortable diarrhea and cramps, often beginning in the middle of the night or early morning. Nausea, vomiting and fever can occur but aren't needed to make the diagnosis. Bacterial diarrhea can resolve on its own, but can last one to two weeks, causing dehydration, fatigue and lost time from work or holiday. Replacing lost fluids is very important. Antibiotic treatment can shorten the illness.
Viral infections cause 20–25% of acute diarrhea. Norovirus is the most common, followed by rotavirus and other viruses now being identified with molecular techniques. Onset is usually sudden and vomiting is common. Viral diarrhea doesn't need antibiotics — but it isn't easy to tell viral from bacterial diarrhea.
Parasitic infections cause about 5% of acute diarrhea in travelers.
- Giardia causes relatively low-grade, subacute to chronic diarrhea, with stomach rumbling, gas, cramping and three to five loose stools a day; sometimes a lot of watery diarrhea. Fever almost never occurs. Sulfurous-smelling burps and gas, sometimes seen with giardia, are just as common in bacterial infections, so they aren't a reliable sign.
- Cyclospora is a protozoan parasite that causes infections from May to August, mostly in June and July. It can start with abrupt diarrhea, sometimes with low-grade fever, nausea or vomiting, then follows a waxing and waning course with profound fatigue, loss of appetite and diarrhea that comes and goes. Untreated, it can last several weeks. There is a specific antibiotic treatment.
- Other parasites — such as Dientamoeba fragilis, Cryptosporidium and Entamoeba histolytica — can also cause diarrhea. In the local population, amoebic infection usually causes chronic diarrhea alternating with constipation, with fatigue and weight loss as it persists. Rarely it progresses to stools with mucus and blood: "amoebic dysentery".
Worms are intestinal parasites that almost never cause diarrhea, though they may cause mild abdominal pain. Hookworm can cause anemia. Worms are more common in children. Occasionally an adult roundworm, which looks like an earthworm, is passed in the stool — a source of great anxiety to parents.
Treating the symptoms
When diarrhea or vomiting occurs, replace fluid and electrolytes to prevent dehydration. This is easy with an oral rehydration salt mixed into a liter of boiled or mineral water — local brands include Nava Jeevan and Jeevan Jal. Other fluids can supplement it: flat Coca-Cola or Sprite, herbal tea, clear soup, Tang, Gatorade or weak tea. Avoid alcohol and heavily caffeinated drinks.
Encourage young children with diarrhea to drink often — they can become dehydrated quickly from seemingly small losses. Adults should drink three liters or more a day, depending on how much is lost.
Loperamide and other "bowel paralyzers" can give temporary relief from cramps and diarrhea, but don't shorten the illness or treat the cause. Take two tablets to start, then one after each loose stool (no more than four a day) until the diarrhea stops. If you have bloody diarrhea or fever, don't use loperamide unless you also take an antibiotic.
Water and food precautions
Assume all tap and ground water in Nepal is contaminated. Bottled water is reasonably safe. Water can be purified by bringing it to a boil, or by adding liquid iodine (Lugol's solution) at four to six drops per liter — it's safe to drink after 20–30 minutes; cold water takes longer than warm. Iodine tablets are also available. The taste and smell of iodine can be removed completely by adding a little vitamin C (about 50 mg) after the water is purified.
Some restaurants soak salad vegetables in iodine or other disinfectants, which makes them safe. Otherwise, avoid raw vegetables and fruit you can't peel.
You can't completely control what you eat, and however careful you are, you can still get ill. Take reasonable precautions, then relax and enjoy your food.
Stool examination at CIWEC
We pride ourselves on our stool microscopy. Every sample is examined two ways: a fresh sample is examined on a slide under the microscope, and a second portion is mixed with an equal volume of formalin-ether and centrifuged, which digests fecal material and makes parasites easier to see. Some parasites, such as giardia, aren't always found in a single test, so multiple tests — or treatment based on symptoms — may be needed.
A stool test guides treatment, but a negative result doesn't mean there's no problem.