Risky Trips: Hiking, backpacking and camping, thanks to intestinal parasites that populate backcountry streams and lakes. The Center for Disease Control and Prevention reports that the number of cases spikes in the summer months.
Vital Signs: No matter how clean that burbling brook appears, don’t take even a small sip—or you’ll risk ingesting the microscopic Giardia lamblia. These intestinal parasites, once hatched in your gut, will cause the Beaver Fever infection, also called giardiasis, an affliction responsible for abdominal pain, bloating and—you guessed it— diarrhea. More than 20,000 cases are confirmed each year, says Jonathan S. Yoder, an epidemiologist at CDC, but estimates say that over a million reports go undocumented. To avoid setting up residence in your bathroom—the infection can last from a few days to weeks—follow good sanitation practices. If you must drink the water, always boil it first, and hygiene is especially important. “Stick to old fashioned soap and water since it physically removes the parasite” adds Yoder. “Hand sanitizers may be effective for bacteria and viruses, but these parasites are more likely to resist disinfection.”