Food and Water Precautions

Food and Water Precautions

In tropical and developing areas of the world, illness associated with contaminated water and food is common. Diseases such as traveler's diarrhea, cholera, Hepatitis A and typhoid fever can often be prevented by proper precautions with the food and water you eat and drink. All water and food in these countries needs to be considered contaminated until treated. Extra care should also be taken by properly washing hands after use of the bathroom and before eating. In many of these countries it is safest to use packaged towelettes for washing hands. Always use them before eating!

FOOD

In general, if food is cooked and served to you hot, you can consider it safe to eat. This goes for meats, fish, vegetables, rice, noodles, etc. Shellfish which are served raw or steamed should be avoided as they may carry hepatitis or typhoid. Fruits and vegetables which are not cooked could pose a health risk. They should be eaten raw only if they have a thick, intact skin that can be peeled at the table. ( e.g. oranges, bananas, pineapple and melons). Lettuce is a particular problem as it is very difficult to disinfect, so salads should be avoided. Lettuce, scallions, and such uncooked vegetables may sneak onto the plate as garnish and must be avoided.. The main problem with these foods is the water used to clean them. In order to make produce safe to eat raw, it must be soaked in bleach and water for 1/2 hour before use. No restaurant will do this for you, so unless you are preparing raw vegetables yourself, they are very risky to eat. Dairy products can also pose health risks. Avoid any unpasturized dairy products like milk, soft cheese, yogurt, ice cream and cream sauces. Canned milk and powdered milk reconstituted with water of known purity are safe. Infants should be fed these products or formula. At lower altitudes milk can be pasteurized by heating it to boiling, then leaving it in a thermos for two hours.

WATER

There are several ways to ensure safe water. In order of effectiveness they are:

1) boiling

2) bottled or canned drinks

3) treatment with iodine tablets

4) treatment with chlorine liquid

5) use of an adequate water filtering device

Boiling: To effectively kill diarrhea and disease-causing organisms, water should be brought to a vigorous boil and should be safe after 10 minutes of boiling.

Bottled Water: Bottled water is only safe to drink if it has been processed after being placed in the bottle. The seal should be intact. Commercially processed water is recommended. If it is carbonated, it is usually safe. Canned juices and carbonated soft drinks are also safe.

Iodine: Iodine tablets (Potable Aqua or Globuline) are available at backpacking stores and are adequate for treating water. The manufacturer's instructions for purification of water should be followed carefully.

Iodine Crystals (Polar Pure) are available to dissolve in water. Once dissolved, the solution is used to treat water. Again, it is important that manufacturer’s instructions are followed when using this product.

Tincture of Iodine 2% is also effective and is available at drug stores. You should use 5 drops of iodine per quart (or liter) of clear water. If the water is very cold or cloudy, the amount of iodine should be doubled. Let the water stand for two hours before use. If the water is very cloudy or cold, it may need to stand for several hours before use.

Chlorine: Chlorine tablets (Halazone) are not as effective as iodine and they disintegrate easily, therefore we do not recommend them. Liquid chlorine (laundry bleach) may be used if it has no other active ingredients (only sodium hypochlorite). Read the label to find the percentage of chlorine available (usually 4-6%). For 1% available chlorine use 10 drops per quart (or liter) of clear water. For 4-6% use 2 drops per quart (or liter) of clear water. For 7-10% use I drop per quart (or liter) of clear water. If the percentage of available chlorine is unknown, use 10 drops per quart of clear water. When cloudy or very cold water is being treated, double the amount of chlorine. The chlorine taste may be lessened by pouring water from one clean container to another, or by dissolving vitamin C tablets in the water only after the water has been properly treated.

Water Treatment Devices: The more expensive brands of commercial water filers (I.E. Katadyne, First Need) are effective in filtering bacteria, giardia, and amoebic cysts from water, as well as making the water appear more potable. Viral contaminants cannot be filtered, but there is some evidence that viruses may be inactivated by some brands of filter that use iodine resin. If there is any question about the purity of filtered water, it should also be treated with iodine.

Common Mistakes:

· Using ice (which is rarely made from treated water).

· It is safer to drink directly from a bottle or can than a questionable container (e.g., a glass that was not adequately washed in soap and water). Water on the outside of cans and bottles may be contaminated, so they should be dried before opening and pouring, and surfaces of such containers that will come in contact with the mouth should be wiped clean. Use of wrapped disposable straws may help avoid contamination.

· Brushing teeth can also transmit contaminants from water, so treated or safe water should be used.

Shirley Tainter, R.N., CEN Nurse Manager

University of Washington Medical Center

1959 NE Pacific St Box 356123

Seattle, WA 98195

(206) 598-4888