San Diego County public health officials are investigating four cases of cryptosporidiosis, a highly contagious parasite known for causing prolonged watery diarrhea, linked to the swimming pools at the Gaylord Pacific Resort and Convention Center in Chula Vista. The agency is warning individuals who swam in the resort's pools between July 24 and August 15 that they may have been exposed.

The sprawling 4.25-acre pool complex at the 1,600-room property, which cost $1.3 billion to construct and was partially funded by taxpayer dollars, is the focus of the investigation. Cryptosporidiosis, often called "crypto," is notoriously resistant to chlorine and can survive for extended periods in water.

The county has not specified whether pool maintenance was a factor in the outbreak. Representatives for Gaylord Pacific did not immediately respond to requests for comment.

The Gaylord Pacific is a popular destination for tourists and local families, with day passes to its water park-style pools starting at $12.50. These passes are frequently sold out.

Cryptosporidiosis is a common parasitic infection in the United States, affecting an estimated 800,000 people annually. Symptoms typically emerge days after exposure and can last from one to two weeks. The parasite spreads through contaminated water, food, soil, or surfaces contaminated with infected fecal matter. While most individuals with healthy immune systems recover, it is crucial to avoid swimming while infected, as individuals can continue to shed the parasite even after symptoms subside.