Volume 25, Number 11—November 2019
Research
Comparison of Whole-Genome Sequences of Legionella pneumophila in Tap Water and in Clinical Strains, Flint, Michigan, USA, 2016
Table 1
Water sample source | March 2016 |
June 2016 |
August 2016 |
||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
No. buildings or samples | No. (%) positive | No. isolates analyzed | No. buildings or samples | No. (%) positive | No. isolates analyzed | No. buildings or samples | No. (%) positive | No. isolates analyzed | |||
Flint residences | 5 | 0 | 32† | 2 (6) | 10‡ | 2 (20) | |||||
Hot (flushed) | 5 | 0 | 0 | 62 | 2 (3) | 3 | 14 | 1 (7) | 1 | ||
Hot (stagnant) | NS | 62 | 2 (3) | 4 | NS | ||||||
Cold (flushed) | NS | 61 | 1 (2) | 2 | NS | ||||||
Cold (stagnant) | 5 | 0 | 0 | 61 | 1 (2) | 4 | 11 | 4 (36) | 1 | ||
Water heater drain valve | NS | 62 | 1 (2) | 5 | NS | ||||||
Shower (hot and
cold) |
NS |
62 |
1 (2) |
2 |
3 |
1 (33) |
1 |
||||
Hospitals | 1 | 1 (100) | NS | NS | |||||||
Hot (flushed) | 19 | 16 (84) | 56 | NS | NS | ||||||
Cold (stagnant) |
19 |
6 (32) |
14 |
NS |
NS |
||||||
Buildings receiving DWSD water | 4 | 0 | NS | 8 | 0 | ||||||
Hot (flushed) | 4 | 0 | 0 | NS | 8 | 0 | 0 | ||||
Cold (stagnant) |
4 |
0 |
0 |
NS |
8 |
0 |
0 |
||||
Flint large buildings | 2 | 1 (50) | NS | NS | |||||||
Hot (flushed) | 5 | 0 | 0 | NS | NS | ||||||
Cold (stagnant) |
5 |
1 (20) |
1 |
NS |
NS |
||||||
Buildings receiving well water | 1 | 1 (100) | NS | NS | |||||||
Hot (flushed) | 4 | 4 (100) | 5§ | NS | NS | ||||||
Cold (stagnant) |
3 |
2 (67) |
4¶ |
NS |
NS |
||||||
Flint small businesses | 6 | 0 | NS | 8 | 0 | ||||||
Hot (flushed) | 6 | 0 | 0 | NS | 8 | 0 | 0 | ||||
Cold (stagnant) | 6 | 0 | 0 | NS | 8 | 0 | 0 |
*Positive samples indicate presumptive L. pneumophila identified by performing culture according to the method described in (12). Unless otherwise noted, identification as L. pneumophila was confirmed by using whole-genome sequencing. Boldface indicates total buildings sampled. Blank cells indicate that data were not reported when applicable samples were not collected. NS, no samples of this type were collected.
†1 of the 32 homes was also sampled in March 2016.
‡5 of the 10 homes were also sampled in March 2016; 1 of the 10 was sampled in June 2016 (but not in March 2016; samples from this house were positive on both dates).
§4 of 5 isolates were a non–L. pneumophila species, according to whole-genome sequencing.
¶4 of 4 isolates were a non–L. pneumophila species, according to whole-genome sequencing.