Cryptosporidium

Cryptosporidium

Cryptosporidium is a single-celled parasite that causes an intestinal illness known as cryptosporidiosis and spreads when its tough oocysts are swallowed. These oocysts are small and especially hardy, allowing them to survive in lakes, pools, and municipal water if treatment is insufficient. Infection can occur after swallowing even a tiny amount of contaminated water, which makes recreational water and untreated sources risky. Symptoms commonly include watery diarrhea, stomach pain, nausea, and sometimes fever, and they usually begin a few days after exposure. For most healthy people the illness is self-limiting, but it can be severe and long-lasting in infants, the elderly, and people with weakened immune systems. Cryptosporidium is more resistant to ordinary chlorine disinfection than many other germs, so effective removal often requires fine filtration, ultraviolet light, ozone, or boiling. Preventing infection relies on treating drinking water properly, avoiding swallowing recreational water, and practicing careful hygiene. Because it can survive common disinfectant levels and spread easily, this parasite is an important concern for public health and for anyone handling or using untreated surface water.