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Cryptosporidiosis is an infection caused by the parasite, Cryptosporidium, often called crypto. It is spread by direct contact with infected people or animals or exposure to fecal contamination of water, soil, food, or the hands of contaminated individuals. The parasite has an outer shell which means it can survive outside of the body for long periods of time, plus the shell protects it from chlorine disinfection, making it difficult to eradicate. Crypto outbreaks occur around the world, but are more common in low income areas with poorer water treatment and food sanitation. However, outbreaks of crypto from contaminated drinking water occurred in Texas in 1984 and Milwaukee in 1993. More recently, large-scale outbreaks have been linked to recreational water activities and childcare centers.

As it usually causes an infection of the small intestine, the most common symptoms of crypto are watery diarrhea, abdominal pain and cramps, fever, nausea, vomiting, and dehydration. Some people have no symptoms. Those with compromised immune systems such as people with HIV/AIDS, immunosuppression from cancer chemotherapy and other medications, or malnutrition may have more severe symptoms up to and including death. It may take up to two weeks after infection for symptoms to appear. Symptoms typically last one to two weeks but may last up to 30 days. Most people with healthy immune systems usually recover on their own with rest and hydration. A new antiparasitic drug, nitazoxanide, recently approved by the FDA, is available for use in those with severe symptoms and/or compromised immune systems. Prevention of infection is achieved by frequent hand washing with soap and water. Alcohol-based hand sanitizers and chlorine-based disinfectants are not effective at killing the parasite because of its outer shell.

Those at the highest risk for crypto include international travelers, children, workers in childcare facilities, older adults, and people with compromised immune systems. Travelers, especially those traveling to poorer areas, should avoid eating raw fruits and vegetables, drinking tap water or ice made from tap water, consuming unpasteurized dairy products, and eating food from street vendors. Also, do not swallow water when in lakes, pools, rivers, and hot tubs. Because crypto can survive in saltwater, this includes oceans. Toys and other surfaces in childcare facilities should be cleaned regularly with soap and water, especially during outbreaks. Children with diarrhea should not swim, and if you have diarrhea, do not swim for at least two weeks after symptoms subside. Specialized filters that remove Cryptosporidium are available online or in retail stores for preparation of drinking water.

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By Peter Galvin, MD

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