Untreated Water and the Traveling Sailor

By Domenic A. Sammarco, R.Ph., EMT

Most sailors already know the hazards of drinking untreated water. But were you aware that Giardia lamblia, the same parasite that causes illness among unsuspecting sailors, commonly causes trouble in more civilized locales-like your backyard pool or local day care center?

"The number of Giardia illnesses caused by drinking unfiltered water in the wild is actually smaller than you might expect," says Bela Matyas, MD, who monitors disease outbreaks for the Massachusetts Department of Public Health. "Most cases occur closer to home."

Recent outbreaks have been linked to public swimming pools. While chlorine kills the parasite, it takes about 15 minutes, and in that time live Giardia can reach the digestive tract of someone who inadvertently swallows contaminated pool water. Day care centers are culprits, too. Giardiasis, the disease caused by Giardia, can be spread by infected children as well as by caregivers who do not wash up thoroughly after changing dirty diapers.

Unlike with foodborne illness, where symptoms usually begin within a day or two of eating the offending food, symptoms of giardiasis usually set in about a week after ingesting Giardia cysts (the parasite in its immature, or resting stage). They include prolonged "greasy" diarrhea, gas, stomach cramps, fatigue, and weight loss. Some people may not experience symptoms at all but could still transmit the parasite to others. The disease usually runs its course in a week or two, although in some cases it drags on for months.

According to the Centers for Disease Control and Prevention, drinking untreated water on a camping trip, or at sea, and swimming in contaminated water are only some of the common ways to contract giardiasis. International travelers and sailors who drink untreated municipal water can also pick up the bug. Even in the U.S., 20 million people drink unfiltered city water that comes from streams or rivers, although Michael Beach, PhD, of the CDC's Division of Parasitic Diseases, notes that giardiasis outbreaks from city water have been rare. And most of them have been due not to the absence of filters but to malfunctions in city water treatment plants, such as temporary drops in adequate chlorine levels.

Avoiding the Bug

Despite the potential hazards, your summer fun, whether swimming, sailing, or traveling abroad, is not laden with Giardia risk-if you take the right precautions.

Massachusetts's Dr. Matyas says to make sure the swimming pool you frequent is properly maintained and to avoid pools that appear unclean. Poor pool maintenance can lead to insufficient levels of chlorine needed to kill Giardia.

The CDC's Dr. Beach adds that "if your child is sick with diarrhea or has recently had diarrhea [stools can contain Giardia for a while following a bout of the runs], don't take the youngster in the pool. Kids with a case of diarrhea or who otherwise have an urge for a bowel movement that they might not be able to control shouldn't be swimming with other people. Parents need to be responsible in helping to prevent the spread of infection."

"Hand washing also goes a long way," says Dr. Beach-after using the bathroom or changing diapers and before preparing foods. If you go hiking or camping or sailing, pack a water filter (available at most outdoor goods stores) or purify untreated water by bringing it to a rolling boil for a full minute. Summer travelers abroad should also exercise caution, especially in areas where hygiene and sanitation practices are poor. If you suspect the local water supply might be tainted, stick to beverages made with boiled water, such as coffee and tea, and canned and bottled drinks (skip the ice). And avoid raw produce that can't be peeled first.

In situations where giardiasis is suspected despite precautions taken, physicians will want to consider having a stool sample examined for parasites in a lab. Treatment after diagnosis usually consists of taking a drug known as metronidazole (Flagyl).

Consult us at WWW.MARINEMEDICAL.COM for specific destination information, as to what to and which precaution to take. Again the best defense to traveler illness is a knowledgeable offense armed with the best medical plan or protocol.


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