Only some of these infections lead to serious disease. Crypto causes diarrhea, nausea, vomiting, and stomach cramps. In people with healthy immune systems, these symptoms do not last more than about a week. But crypto may continue for a long time if the immune system is damaged. This usually happens with T-cell counts below 300.
Diarrhea can interfere with the absorption of nutrients.
Several diseases cause similar problems. There is no medication that prevents crypto. The best protection is cleanliness. Avoid contact with human or animal wastes. Wash your hands after using the bathroom, gardening, handling dirty laundry or animals, or changing diapers.