Bacterial contamination in household and office building tap water

Water is a source of concern for disseminating the bacteria Legionella pneumophila and Mycobacterium avium, which cause lung disease (legionellosis and pulmonary nontuberculous mycobacterium disease, respectively). A new Journal of Applied Microbiology study has examined the presence of these microbes in tap water from residences and office buildings across the United States.

The occurrence of L. pneumophila and M. avium was largely sporadic. Office buildings were prone to microbial persistence independent of building age and square footage. Microbial persistence at residences was observed in those older than 40 years for L. pneumophila and was rarely observed for M. avium.

The investigators noted that the lack of consistent detections reduces the potential to cause an outbreak among a family or group of workers.

"Residences are often suspected to be the source of bacteria when a case of disease is reported, but this study shows that this may not be the case for a sporadic incidence," said lead author Dr. Maura Donohue, of the United States Environmental Protection Agency, in Cincinnati. "Data from this study can help public health officials pinpoint locations of disease transmission, inform decisions on detection or recovery of the causative agent, and improve public health protection."