Enteric Bacterial Contamination of Public Restrooms

Here are the facts:

Study conducted by Denise I. Kennedy, Carlos E. Enriquez, Charles P. Gerba

Study identifies those sites in public restrooms where enteric bacteria are likely to occur. Forty-seven public restrooms were randomly selected and analyzed.

Approximately 31 sites were sampled in 20 male restrooms and 28 sites in 27 female restrooms.

Sinks, floors, toilet seats, and sanitary napkin disposals were the most contaminated sites based on occurrence.

Female restrooms were more contaminated at all sites overall than male restrooms.

Coliforms were isolated more than 50% of the time at three sites, i.e., floor in front of the toilet, drain of the sink basin, and the sanitary napkin disposal.

The sanitary napkin disposal was the site where E. coli was most commonly isolated (almost 29% of the time)

Conclusions

1. Overall, the most contaminated areas in public restrooms were the toilet, floor, sink and sanitary napkin disposal.
2. E. coli was most commonly isolated at the sanitary napkin disposal, drain in the sink basin, and inside the urinals.
3. Female restrooms were significantly more contaminated than male restrooms.
High traffic institutional restrooms were the most contaminated, followed by fast food restrooms and hospital public restrooms.
5. Coliform bacteria were isolated more than 50% of the time at three sites, i.e., floor in front of the toilet, drain of the sink basin, and the sanitary napkin disposal.
6. Coliforms or E. coli were isolated at least once on all sites sampled except the urinal flush handle and the top of the urinal.
7. Mops used to clean restroom floors contained coliform bacteria, but not E. coli.
8. Restrooms containing one stall and four stalls/urinals were the most contaminated.
9. Appearance was related to bacterial contamination for those judged poor and those judged excellent, good and acceptable.
10. Coliform bacteria could be detected on the paper towel trash bin door and paper towel lever.