More than 200 people in July were sickened by a
recreational water illness outbreak at a Pennsylvania
university swimming pool that appears to have multiple
Visitors to the Graham Natatorium Pool at West Chester
University in West Chester, Pa., reported cases of
diarrhea, nausea and vomiting shortly after swimming. Early
test samples revealednorovirus traced back to the
pool, causing the facility to be shut down immediately on
July 10. Since then,cryptosporidium and one case
ofgiardia also have been identified in stool
The Chester County Health Department issued a health
alert requiring all pool managers in the county to treat
their pools forcrypto by superchlorinating and
backwashing. It also requires the managers to ask bathers
and staff, before entering the pool, if they had any
symptoms of diarrhea or vomiting within the past two weeks.
In addition, all swimmers must shower before entering, and
any unusual illnesses must be reported.
The health department is awaiting reports from
investigations and private providers, said Betsy Walls,
bureau director for personal health services. She?s
already given the go-ahead for the pool to be reopened, but
none of its staffers have been released to return to
This outbreak is similar to others seen across the
country, said Alison Osinski, Ph.D., president of Aquatic
Consulting Services in San Diego. ?Having a
secondary water treatment, a good UV treatment, would
probably kill off [the disease] before it infects too many
people,? she noted.
It can take nearly a week for chlorine to
destroycrypto;giardia takes at least 24
hours. Norovirus, usually found in hotels and cruise ships,
can be contained within an hour by chlorine.