Household Plumbing May Be Source of Bacteria for Sinusitis

Larry Hand

September 12, 2012

September 12, 2012 — People who suffer from chronic rhinosinusitis (CRS) even after being medically or surgically treated might be infected by nontuberculous mycobacteria (NTM) that are present in household plumbing, according to a study published online September 12 and in the October print issue of Emerging Infectious Diseases.

Wellington S. Tichenor, MD, from the Center for Allergy, Asthma and Sinusitis, New York City, and colleagues from the University of Texas Health Science Center, Tyler, Texas, and from Virginia Polytechnic Institute and State University, Blacksburg, Virginia, analyzed the records of 33 patients from Dr. Tichenor's practice who had been diagnosed with CRS and in whom NTM had been detected through endoscopically directed sinus cultures. The researchers took sample tests from the plumbing systems of 8 of the patients.

Of the 33 patients, 30 (91%) had undergone endoscopic sinus surgery perviously, and 31 (94%) were using nasal irrigation at the time of endoscopy. Of the 31 patients using nasal irrigation, 26 were using tap water for irrigation. Patient charts showed that 39 NTM isolates were recovered from the patients' sinuses.

For the 8 patients who consented to submitting household plumbing samples, the researchers provided instructions for the patients to collect 500-mL cold and hot water samples and to swab the insides of taps and showerheads, to collect samples that were then placed in tubes containing 2 mL tap water that had been sterilized by autoclaving at Virginia Polytechnical Institute and State University.

The 8 collaborating patients submitted a total of 80 samples for testing, including 43 water samples, 31 biofilm samples, and 6 samples from water filters. "NTM were isolated from water, biofilm, or filter samples from at least 1 sample from 5 (63%) of the 8 households sampled and from 35 (40%) of the 80 samples," the researchers write. "The frequency of NTM recovery from water (44%), biofilm (42%), and filter (50%) samples was not significantly different (p = 0.6065, Kruskal-Wallace test)."

The researchers performed pulsed-field gel electrophoresis (PFGE) tests to determine whether NTM from the household samples were related to the NTM from patients' sinuses, getting varied results among the patients, from "indistinguishable" to "closely related."

"Besides establishing NTM as a potential agent of CRS, our results strongly suggest that in 3 of the 8 CRS patients studied here, the household plumbing was the source of infection, on the basis of identity of rep-PCR fingerprints of patient and household isolates and their clonal relatedness as determined by PFGE," the researchers write.

They recommend that people with CRS have multiple cultures done over time because endoscopy might find NTM in only 1 of between 2 and 5 procedures.

"Unfortunately, the combination of insufficient experience and the absence of an established treatment protocol for CRS caused by NTM, prevent any meaningful review of treatment regimens for CRS caused by NTM," the researchers write.

They conclude, "The role of NTM in infectious disease processes is only starting to be recognized. This work documents that a proportion of patients with CRS could be infected with NTM and that sinus samples should be cultured for NTM. In addition, CRS patients should avoid sinus irrigation with tap water because tap water may contain NTM, and it may not be possible to remove it. Sterile saline should be used instead."

Work in the Mycobacteria/Nocardia Laboratory at the University of Texas Health Science Center was supported by the Carter Foundation.

Emerg Infect Dis. Published online September 12, 2012. Full text