Volume 5, Number 4—August 1999
Dispatch
Chlorine Disinfection of Recreational Water for Cryptosporidium parvum
Table 2
2 ppm |
10 ppm |
||||||
---|---|---|---|---|---|---|---|
Infectivity |
Infectivity |
||||||
Expt. | Days (min.) | Ctb value | 20ºC | 30ºC | Ctb value | 20ºC | 30ºC |
2 | (360) | 720 | 4/4 | 4/4 | 3,600 | 4/4 | 0/4 |
2 | (720) | 1,440 | 4/4 | 3/4 | 7,200 | 0/4 | 0/4 |
1 | 1 (1440) | 2,880 | 4/4c | 0/4 | 14,400 | 0/4 | 0/4 |
2 | 1 (1440) | 2,880 | 4/4 | 0/4 | 14,400 | 0/4 | 0/4 |
1 | 2 (2880) | 5,760 | 0/4 | 0/4 | 28,800 | 0/4 | 0/4 |
2 | 2 (2880) | 5,760 | 0/4 | 0/4 | 28,800 | 0/4 | 0/4 |
1 | 3 (4320) | 8,640 | 4/4 | 0/4 | 43,200 | 0/4 | 0/4 |
2 | 3 (4320) | 8,640 | 0/4 | 0/4 | 43,200 | 0/4 | 3/4 |
1 | 4 (5760) | 11,520 | 0/4 | 0/4 | 57,600 | 0/4 | 0/4 |
1 | 5 (7200) | 14,400 | 0/4 | 0/4 | 72,000 | 0/4 | 0/4 |
1 | 6 (8640) | 17,280 | 0/4 | 0/4 | 86,400 | 0/4 | 0/4 |
1 | 7 (10,080) | 20,160 | 0/4 | 0/4 | 100,800 | 0/4 | 0/4 |
aTreatments in which mice were found infected are shown in bold
bHypothetical Ct value calculated by assuming constant chlorine concentration.
cFraction represents number of mice showing developmental stages of C. parvum in the intestinal epithelium over the total number of mice inoculated, e.g., 4/4 indicates 4 mice were found infected out of 4 mice inoculated.
Page created: December 13, 2010
Page updated: December 13, 2010
Page reviewed: December 13, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.