The cryptosporidiosis outbreak last summer in Lawrence might have been slowed if health authorities had alerted the community sooner, a new federal report suggests.
The report also shows that as many as 600 people may have been infected, about five times more than previously reported.
"The speed of diffusion of an outbreak like the one (in Lawrence) requires prompt and swift actions," said the report from the federal Centers for Disease Control. The report was made public Friday by the Kansas Department of Health and Environment.
Alerting the public sooner and intervening more quickly "in similar outbreaks may prove advantageous" in preventing the spread of disease, the report's authors wrote.
But Douglas County and state authorities Friday said they took the correct action during the outbreak based on what they knew at the time.
"Keep in mind that cryptosporidium is a fairly new disease," said KDHE spokeswoman Sharon Watson. "It's fairly easy to look back and see how things may have been done differently once you have all the information."
She added: "There is no standard in place that says, if you have a cryptosporidiosis case in the community, you do A, B, C."
The first cases of the diarrhea-inducing parasite in Lawrence were diagnosed in July. Among the initial victims was at least one member of the Kansas University swim team.
The Lawrence-Douglas County Health Department came under fierce criticism because it didn't alert the broader public about the parasite until late August, when authorities closed swimming pools after 11 cases had been confirmed. The parasite is easily spread in pools and at day-care centers.
Eventually, 96 cases were confirmed in northeast Kansas -- 89 in Douglas County, the vast majority of those in Lawrence -- and more than 600 other probable, but unconfirmed, cases identified by community surveys. Only the confirmed cases were reported during the outbreak.
Many of those cases were connected to Lawrence pools and day-care centers.
The source of the outbreak was not determined, CDC officials wrote, but the genotype of the parasite found in stool samples is found only in human-to-human contact, not the animal-to-human contact that often starts a cryptosporidium outbreak.
CDC's investigators suggested that in future cryptosporidium cases, the community be alerted immediately:
- When multiple, apparently unrelated cases are reported.
- When diagnosis is confirmed of cryptosporidiosis in any patient who has been in a swimming pool during the infection period.
Either condition would have resulted in a public announcement weeks earlier than late August had the protocols been in place.
"We were working with limited data at the time, making decisions as data came in," Watson said. "Not everything pointed to a specific source at the time."
Authorities said at the time they waited to alert the public because they weren't sure the cases were related. Lawrence-Douglas County Health Department Director Kay Kent said Friday her department followed "traditional" methods in waiting to make the announcement.
"I think the (CDC) report basically does say that there might be some difference in the future than what might be traditionally done," Kent said. "This is the first time the CDC has put that in writing, and I think that will be extremely helpful in the future."
And she pointed out that the Health Department followed many other recommendations in the CDC report during the outbreak.
- "Hyperchlorination" of pools linked to cryptosporidium.
- Increased public education to discourage swimmers from entering pools until two weeks after a bout of diarrhea.
- Waiting three weeks after the last laboratory-confirmed case before declaring the outbreak over.
Kent said she was proud of how her department handled the outbreak.
"I think really," she said, "the whole working together with local, state and federal worked very well."