San Diego County health officials are investigating four cases involving people who visited the resort's waterpark and say anyone who entered its swimming pools between July 24 and August 15 may have been exposed, prompting Gaylord Pacific to send an “Important Health Department Notice” to guests this week. The warning, dated September 2, was sent to Gaylord guests and day-pass pool users after the County's Public Health Services began its investigation.
Gaylord Pacific sent an email to guests Thursday titled “Important Health Department Notice,” telling recipients that the County Health Department had asked the resort to distribute information connected to its investigation of reported Cryptosporidium infections.“The San Diego County Health Department has asked us to share the attached information in connection with its recent investigation into reported cases of Cryptosporidium infection,” the Gaylord message states, adding that guest safety and wellbeing is the resort's “top priority.”
The attached notice from San Diego County Public Health Services is considerably more specific.
“The County of San Diego Public Health Services is investigating four cases of Cryptosporidiosis (Crypto), that developed in individuals after they visited the waterpark swimming pools at the Gaylord Pacific Resort,” the notice states.
County officials stop short of saying the resort's pools have been conclusively established as the source of the infections. The notice instead describes a potential exposure and says other people who entered the pools during the roughly three-week period identified by investigators “may have been exposed to Cryptosporidium.”
That distinction is important. The four infected people all visited Gaylord Pacific's waterpark pools, according to the County, but the notice does not say investigators have determined how the parasite entered the water, whether all four cases were acquired at the resort, whether environmental testing detected Cryptosporidium in any pool, or whether a single infected swimmer or another source was responsible.
The timing nevertheless creates an unwelcome public-health problem for one of Southern California's newest and most heavily promoted destination resorts.
Gaylord Pacific opened on Chula Vista's bayfront in May 2025 after years of planning and approximately $1.3 billion in development costs. The massive property includes 1,600 rooms, hundreds of thousands of square feet of convention space and a major outdoor water complex marketed as one of the resort's signature attractions.
Cryptosporidium, commonly called “Crypto,” is a microscopic parasite that causes the gastrointestinal disease cryptosporidiosis. Its most common symptom is frequent, watery diarrhea, although patients can also experience stomach cramps, nausea, vomiting, fever, weight loss and dehydration. Symptoms generally begin between two and 10 days after infection, with an average onset of about seven days.
For otherwise healthy people, the illness is often self-limiting. But people with weakened immune systems can experience much more serious, prolonged and potentially life-threatening complications, according to the Centers for Disease Control and Prevention.
What makes Crypto particularly troublesome at swimming pools is its resistance to ordinary chlorine levels.
San Diego County specifically noted that the parasite can survive in aquatic environments and spread among swimmers even when pools and water features are being properly operated and recommended chlorine levels are consistently maintained.
The CDC says the same thing in even starker terms: while chlorine kills many common pool germs relatively quickly, Cryptosporidium can remain alive in properly chlorinated water for days. Under standard test conditions involving one part per million of free chlorine, the CDC estimates it can take approximately 10.6 days to inactivate Crypto.
That resistance is one reason Cryptosporidium has become particularly associated with recreational-water illnesses. CDC guidance says Crypto causes more than half of reported waterborne disease outbreaks associated with treated recreational venues including pools, hot tubs and splash pads.
The parasite spreads when microscopic amounts of infected fecal material contaminate water and that water is swallowed by another person. Even small amounts can be enough to cause infection, and swimmers who are infected can continue shedding the parasite after their symptoms have resolved.
The County's notice says the most common symptom is watery diarrhea and that symptoms typically last one to two weeks, although some infected people may never develop symptoms.
Anyone who visited Gaylord Pacific's pools during the July 24-August 15 exposure window and subsequently developed severe, persistent or worsening symptoms is being advised to contact a healthcare provider. The County also directed people seeking assistance locating medical care to call 211.
There are several important unanswered questions surrounding the episode.
The County notice does not identify the ages of the four infected individuals, when each became ill, whether any were hospitalized, whether they were members of the same party, how many days each spent at the property or whether investigators have identified any epidemiological connection among them beyond visiting Gaylord's waterpark pools.
It also does not say when the first case was reported to health officials, when Gaylord Pacific was initially notified, whether any pools were temporarily closed or hyperchlorinated, whether additional water treatment was ordered, or whether the resort's waterpark remains fully operational.
Perhaps most notably for guests who used the resort during the exposure period, the notice is dated September 2, meaning the public notification arrived more than two weeks after the last date in the County's identified potential-exposure window.
SanDiegoVille has reached out to Gaylord Pacific and San Diego County seeking additional information about the investigation, including when the resort first learned of the cases, whether any swimming areas were closed or treated, whether environmental testing has been conducted, whether additional suspected cases are under investigation and whether County officials believe there is any continuing risk to guests.
The health warning lands during an unusually eventful week for Gaylord Pacific. Just one day before the County's notice was dated, Voice of San Diego published an investigation examining the public financing behind the $1.3 billion resort and reporting that the cost of repaying hundreds of millions of dollars in bonds used to help finance the development is expected to exceed earlier projections. Chula Vista officials subsequently said they intend to seek clarifications and corrections to portions of that report.
The health investigation is unrelated to those financial issues, but together they put the year-old mega-resort under an unusual amount of scrutiny at the same moment Chula Vista officials continue promoting Gaylord Pacific as the centerpiece of the city's long-awaited bayfront transformation.
For now, County health officials have identified four cases and a specific exposure window, but they have not declared that Gaylord Pacific caused an outbreak or that its pools are presently unsafe. What they have done is unusual enough: formally notify people who swam at one of Southern California's newest resort waterparks that they may have been exposed to a chlorine-resistant intestinal parasite capable of causing days or weeks of severe gastrointestinal illness.
SanDiegoVille will update this story as additional information becomes available from the County and Gaylord Pacific.
Originally published on September 3, 2026.