Travelers' Diarrhea, "peel it, boil it, or forget it"

Every year, an estimated 10 million international travelers are affected by traveler's diarrhea (TD), a gastrointestinal disorder that causes loose stools and abdominal cramping. For Americans, the risk for developing TD is particularly high in the developing countries of Latin America, Africa, the Middle East, and in Asia.

What causes TD? TD is caused by consuming food or water that is contaminated with an infectious agent. Approximately 80% of the time, the source is a type of E. coli bacteria (enterotoxigenic), that produces toxins within the bowel. Other bacteria (Campylobacter, Salmonella, Shigella) as well as a variety of viruses (Hepatitis A, Norwalk Virus, Rotavirus), and parasites (Giardia, Cryptosporidium) are less common causative agents.

Are certain people at risk for developing TD? Travelers to areas of the world with substandard water purification or sanitary practices are at particular risk for the development of TD. Young adults, people taking certain medications including stomach acid-blockers (Prevacid, Prilosec, others) or immune-suppressants (prednisone, methotrexate, others), and people with certain diseases, such as diabetes or inflammatory bowel disease are at particular risk.

What are the symptoms of TD? Most people with TD have the sudden onset of diarrhea, passing 4 to 5 loose stools per day. This may be accompanied by abdominal cramps, nausea, vomiting, generalized weakness or discomfort, or low-grade fever.

How is TD treated? Traveler's diarrhea usually resolves on its own within 48 hours and is rarely life threatening. Drinking clear liquids or oral rehydration solutions to prevent dehydration and loss of electrolytes is usually all that is required. A rehydrating solution can be prepared by mixing together:

• 1/2 teaspoon salt
• 1/2 teaspoon baking soda
• 4 tablespoons sugar
• 1 liter safe drinking water

Taking antimotility agents (Imodium, Lomotil) can relieve TD-associated diarrhea and cramps, but they may also prolong the duration of the illness. Antibiotics can shorten a course of diarrhea and discomfort, but taking them is generally unnecessary. However, when symptoms warrant, such as with the development of bloody diarrhea, high fever, or severe cramps, antibiotics belonging to the fluoroquinolone group ( Cipro, Norfloxacin) have been shown to be effective.

Can medications prevent TD? Certain antibiotics have been shown to be effective at preventing travelers' diarrhea, however, the CDC does not generally recommend that they be used. The reasons for this include the relatively benign nature of TD, the possibility of adverse effects from taking an antibiotic, and the risk of the development of antibiotic-resistant organisms. Bismuth subsalicylate preparations, such as Pepto Bismol, taken as 1 oz of liquid or two 262.5-mg tablets four times daily can reduce the risk of becoming infected with the common bacteria that cause TD. This medication is not recommended for children, pregnant women, or people who are allergic to aspirin.

How else can TD be prevented?The risk of developing TD can be greatly reduced with attention to the following measures:

• Tap water and dairy products, particularly those that are unpasteurized, are some of the most likely sources of contamination associated with the development of TD. When travelling in high risk countries it is safer to drink bottled water, pasteurized milk, hot tea or coffee, or canned or bottled drinks.
• Avoid eating raw fruits and vegetables unless washed (with purified water) and peeled by yourself. It is best to avoid eating salads and fruits or vegetables that cannot be peeled, such as grapes and berries.
• Avoid eating raw or undercooked meats or seafood.
• Avoid purchasing food or drinks from street vendors or from sources where the sanitation is suspect.
• Unsterilized water, either from tap, well or ground sources, must be purified by boiling, filtering, or treating with iodine or chlorine. The Centers for Disease Control (CDC), advises that water should be brought to a rolling boil for at least 1 minute. At altitudes greater than 6,500 feet (2000 meters), boiling time should increase to around 3-5 minutes. Several manufacturers, including Katadyn, Sawyer, and MSR, offer portable filtration systems that are effective in removing bacteria and parasites. When shopping for a filter, make sure that it has a pore size no larger than 0.1 microns. Recognize also that most "backpacking" filters will not remove viruses unless their microfilter has an extremely small pore size (0.01 microns) or has a disinfecting stage (usually incorporating iodine). Water disinfecting tablets containing iodine (Potable Aqua) or chlorine (MSR Aquatabs) are also effective when used as directed.

Other sources of contamination that people may not think about while travelling include getting water in the mouth while showering, rinsing with tap water after tooth brushing (use bottle or filtered water instead), and drinking beverages chilled with ice made from tap water. Medical attention should be sought for severe or persistent symptoms of TD to determine the exact cause and proper treatment.

Probiotics and Antibiotic-Associated Diarrhea

Antibiotics, used in the treatment of bacterial infections, are one of the most commonly prescribed medications in the world. A common side effect when taking antibiotics is antibiotic-associated diarrhea (AAD). This occurs in up to 25% of people taking antibiotics.

Why do antibiotics cause gastrointestinal problems? In addition to killing bacteria that cause illness, antibiotics also kill the beneficial bacteria that inhabit the bowel. A decrease in these good bacteria may lead to digestive problems, such as diarrhea, gas, and cramping. Another adverse effect from a reduction in good bacteria is that harmful bacteria are allowed to multiply and take their place. One of the most serious of these harmful bacterial is called Clostridium difficile. Overgrowth of these particular bacteria has been responsible for numerous hospitalizations and even deaths.

What are probiotics? Probiotics are live bacteria that are the same or similar to the good bacteria that live in the human body. They occur naturally in such foods as yogurt, buttermilk, and fermented foods, such as sauerkraut. Probiotics are also available as nutritional supplements. When ingested, probiotics take up residence in the intestines and are thought to provide a number of health benefits.

How do probiotics help to prevent AAD? A number of studies have demonstrated that probiotics, in particular products containing Lactobacillus, are effective in preventing AAD. They have specifically been shown to reduce the risk of developing Clostridium-associated diarrhea by up to 64%. They also appear to be helpful in reducing the incidence of other antibiotic-related side effects, such as gas and cramping. Probiotics are thought to work by replacing the beneficial bacteria that were killed during antibiotic treatment. It is conceivable that probiotics may one day be routinely coupled with a prescription for an antibiotic.

Where are probiotics obtained? Probiotics are considered to be dietary supplements and their sale is not under the regulation of the U.S. Food and Drug Administration (FDA). Probiotic manufacturers are responsible for seeing that they contain the purported types and amounts of bacteria, are safe, and achieve their advertised claims. Probiotics are marketed primarily as oral products such as capsules and in yogurt cultures and are sold in most grocery and health food stores. Activa yogurt, Nature's Bounty Extra Strength Probiotic Acidophilus, Truebiotics by One-a-day, and Naked Juice Probiotics are a few of the commercial preparations of probiotics available.

Do probiotics have other uses? In addition to preventing AAD, probiotics are also used in the treatment or prevention of other medical conditions such as recurrent urinary tract infections, irritable bowel syndrome and yeast infections. Since probiotic bacteria are already a normal part of the human flora, they are generally considered to be safe with very few side effects. People with an impaired immune system or who are severely debilitated, however, are advised to avoid taking them.

What's so bad about sugary drinks?

Sugar-sweetened beverages (SSBs) are those that contain added caloric sweeteners such as sucrose, high-fructose corn syrup, or fruit-juice concentrates. They include soft drinks, fruit drinks, sports drinks, sweetened iced tea, and lemonade. Findings from multiple scientific studies show a positive association between greater intakes of sugar sweetened beverages and weight gain in both children and adults. They may also increase risk of developing Type 2 diabetes mellitus and cardiovascular disease.

And the problem doesn't lie with SSBs alone. Quick, can you tell which has more sugar, a glass of cranberry juice or a cup of coffee with 2 packets of sugar? If you guessed the coffee, you'd be wrong since the cranberry juice has over 5 times as much sugar! The amount of sugar reported in 12 ounces of other popular drinks may surprise you too. In some cases, the beverages listed below are sweetened with added sugars, in other instances, as with orange juice, the beverage is naturally high in sugar:

• Coca-Cola® Classic---10 teaspoons of sugar (146 calories)
  
• Minute Maid® Orange Juice---10 teaspoons of sugar (165 calories)
  
• POM Wonderful® 100% Pomegranate Juice---14 teaspoons of sugar (240 calories)
  
• Sunny D® Tangy Original Style---10 teaspoons or sugar (180 calories)
  
• Welch's® 100% Grape Juice---15 teaspoons of sugar (255 calories)
  
• Red Bull®---10 teaspoons of sugar (165 calories)

What is the significance of all this? As mentioned previously, there is a strong relationship between the consumption of sugary drinks and the development of obesity, type 2 diabetes, and heart disease. Let's look at the connection between sugary drinks and these conditions further.

Obesity: The rising consumption of SSBs in the U.S. is a major contributor to the obesity epidemic. These beverages add calories to the diet without providing a significant amount of nutrients. Drinking a single sugar-sweetened soft drink per day could add up to 55,000 calories over the course of a year. If this added caloric load is not accompanied by an equal amount of energy expenditure through activity or exercise, it does little but contribute to weight gain. At approximately 100 calories burned per mile of walking, this would mean that you would have to walk an additional 550 miles over the course of a year to prevent these calories from being converted to fat.

Diabetes: Several studies have shown that SSBs contribute to the development of type 2 diabetes. The reason for this is not due to sugar itself, but rather to the weight gain from excessive calories in these drinks. A study involving over 90,000 female nurses found that drinking one or more servings a day of sugar-sweetened beverages resulting in a doubling of the likelihood for developing Type 2 diabetes.

Heart Disease:: Obesity and diabetes are well known risk factors for the development of heart disease. Since sugary drinks can contribute to the development of both of these, it stands to reason that heart disease risk would increase also. In fact, a study that followed over 40,000 men over 20 years found that those who drank one can of a sugary beverage per day had a 20% higher risk of having a heart attack or dying from a heart attack than men who rarely consumed sugary drinks. A similar association between the consumption of SSBs and heart disease was noted in the study of female nurses mentioned previously. In addition to the excess calories from sugar drinks, there is also concern that the high glycemic load and inflammatory factors associated with these beverages may contribute to the higher risk of heart disease.

The good news is that studies have also demonstrated that reducing sugary drink consumption can lead to better weight control among those who are overweight. By addressing obesity, the risks for developing diabetes and heart disease will go down also. While meeting constitutional opposition, efforts to reduce "supersizing" of soft drinks in New York State is an attempt to decrease the number of empty calories from SSBs. New labeling practices indicating the amount of exercise necessary to "burn" excess calories from sugary drinks is another way to encourage healthier beverage choices.