TABLE 4.
Waterborne outbreaks and cases associated with drinking water by water system type, 1971 to 2006
| Water type | No. (%) of: |
|
|---|---|---|
| Outbreaks | Cases of illness | |
| Community systems | 338 (43.3) | 518,091b (89.8) |
| Noncommunity systems | 342 (43.8) | 55,601 (9.6) |
| Individual systems | 82 (10.5) | 1,176 (0.2) |
| Bottled water | 11 (1.4) | 505 (<0.1) |
| Bulk water purchase | 1 (0.1) | 103 (<0.1) |
| Mixed systemsa | 3 (0.4) | 1,565 (0.3) |
| System not identified | 3 (0.4) | 53 (<0.1) |
| Total | 780 (100) | 577,094 (100) |
a
One outbreak of 20 cases (community and individual systems), one outbreak of 95 cases (individual system and bottled water), and one outbreak of 1,450 cases (noncommunity and individual systems).
b
Includes 403,000 cases from a single cryptosporidiosis outbreak in Milwaukee, WI.