A statewide outbreak of cryptosporidiosis in New South Wales associated with swimming at public pools.
From December 1997 to April 1998, 1060 laboratory-confirmed cryptosporidiosis cases were reported in New South Wales, Australia. In a case-control study, compared with 200 controls, the 100 cases were younger (mean age 42 versus 71 years; P < 0.0001), more likely to report swimming at a public pool (59% versus 38%; adjusted OR and 95% CI = 27; 1.4-5.1) and swimming in a dam, river or lake (OR = 48; 1.1-20.3) but less likely to report drinking bottled water (OR = 0.4; 0.2-0.9). In subgroup analyses, in rural areas illness was associated mainly with contact with another person with diarrhoea, and in urban areas illness was associated with swimming in a public pool. Cryptosporidium oocysts were more commonly detected in pools to which at least two notified cases had swum (P = 004). Outbreaks of cryptosporidiosis can be prolonged, involve multiple pools and be difficult to control.
Puech
M C
MC
Department of Public Health and Community Medicine, Westmead Hospital, NSW, Australia.
McAnulty
J M
JM
Lesjak
M
M
Shaw
N
N
Heron
L
L
Watson
J M
JM
D000293:Adolescent; D017677:Age Distribution; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000209:etiology / Q000469:parasitology / Q000517:prevention & control / Q000635:transmission; D004196:Disease Outbreaks / Q000517:prevention & control / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D011159:Population Surveillance; D012307:Risk Factors; D012423:Rural Health / Q000706:statistics & numerical data; D012621:Seasons; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D013550:Swimming / Q000706:statistics & numerical data*; D013551:Swimming Pools / Q000706:statistics & numerical data*; D014504:Urban Health / Q000706:statistics & numerical data; D014867:Water / Q000469:parasitology*
D014867:Water