- NEW YORK (Reuters Health) -- The bacterium E. coli O157:H7 was responsible
for a higher number of outbreaks of waterborne disease in swimmers during
1995-1996 compared with previous years, according to the Centers for Disease
Control and Prevention (CDC).
- The potentially life-threatening bacterium,
commonly associated with disease outbreaks due to consumption of undercooked
meat, can also cause illness when found in recreational pools or lakes.
- In 1995 and 1996, there were 37 reported
US outbreaks of illness associated with swimming in pools, lakes or other
bodies of water. A total of 9,129 people became ill and six died. All six
deaths were caused by amebic meningoencephalitis " a rare disease
associated with Naegleria infections.
- The number of outbreaks caused by bacteria
increased from four in past years to 10, with 6 outbreaks linked to O157:H7.
One of these outbreaks was caused by inadequate chlorination of a pool,
and five cases were associated with contaminated lakes.
- The number of outbreaks associated with
gastroenteritis, or diarrheal illness, was greater in 1995-1996 than in
previous years " 22 compared with 13 to 14 per year in 1989 to 1994.
While the number of outbreaks due to parasites decreased from 10 to 7,
two outbreaks caused by the parasite Cryptosporidium caused illness in
more than 8,000 people.
- Five of the six outbreaks associated
with Cryptosporidium occurred in pools, which contain chlorine levels inadequate
to kill the oocysts of the parasite, which spread the disease. Pool filtration
systems that contain sand or other material may also not remove the oocysts,
which can be accidentally swallowed while swimming.
- "Prevention efforts have focuses
on providing adequate bathroom facilities, including diaper-changing areas,
at recreational areas and on limiting the numbers of swimmers per unit
area,'' according to the CDC. "An additional important measure, although
difficult to enforce, is to prevent persons (especially young, nontoilet-trained
children) from entering recreational water if they are either experiencing
or convalescing from a diarrheal illness.''
- SOURCE: CDC Surveillance Summaries 1998;47:SS-5.