Enteric illness risks before and after water treatment improvements.
This study evaluated whether occurrence of acute gastrointestinal illnesses declined after filtration and ozonation were added to a previously unfiltered, chlorinated high-quality surface water source in a northwest United States city. Enteric and other illnesses were recorded for two 6-month periods for control and intervention sites in the same city. During phase 1, chlorinated, unfiltered drinking water for both sites was obtained from protected watersheds. During phase 2, the intervention site received chlorinated, filtered and ozonated drinking water. The water was not altered in the control site. No overall differences were found in the risk of any of the illnesses after the new water treatment plant was completed. There was a significantly increased risk of diarrhoea and highly credible gastrointestinal illness in participants with three or more episodes of the same type of illness during phase 1.
Frost
Floyd J
FJ
Lovelace Clinic Foundation, 2309 Renard Pl. SE, Suite 103, 87106, Albuquerque NM 87106, USA.
Tollestrup
Kristine
K
Roberts
Melissa
M
Kunde
Twila R
TR
Craun
Gunther F
GF
Harter
Lucy
L
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000517:prevention & control; D003458:Cryptosporidium; D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D004755:Enterobacteriaceae; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D005872:Giardia; D005873:Giardiasis / Q000453:epidemiology / Q000517:prevention & control; D054879:Halogenation; D006801:Humans; D007109:Immunity; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D010083:Oxidants, Photochemical; D010126:Ozone; D016012:Poisson Distribution; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D012499:Sanitation / Q000379:methods; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply; D055815:Young Adult
D010083:Oxidants, Photochemical; D010126:Ozone