Ocular Microbiology and Immunology Group
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2011 OMIG Abstract 16

Is polyhexamethylene biguanide (PHMB) an effective disinfectant for adenovirus?
E.G. Romanowski, K.A. Yates, K. O’Connor, F.S. Mah, R.M.Q. Shanks, R.P. Kowalski
The Charles T. Campbell Laboratory, UPMC Eye Center, Ophthalmology and Visual Sciences Research Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA

Purpose: Polyhexamethylene biguanide (PHMB) is a disinfectant used in swimming pools, hot tubs, and contact lens solutions. Swimming pools have been shown to act as vectors for the transmission of adenoviral (Ad) ocular infections. The goal of the current study was to determine whether PHMB is an effective disinfectant against common ocular Ad serotypes. 

Methods: The direct inactivating activity of PHMB was determined by incubating high titer stocks of the clinical isolates of Ad1, Ad2, Ad3, Ad4, Ad5, Ad7a, Ad8, Ad19, and Ad37 ATCC, with 50 and 20 PPM (μg/ml) (the recommended concentration range for PHMB use in swimming pools and hot tubs) and control media for 24h at room temperature (RT) (swimming pool) or 40^oC (the recommended maximum hot tub temperature). Standard plaque assays were performed on the reaction mixtures to determine the Ad titers after PHMB or control treatment. Ad titers were Log converted and Log₁₀ reductions in titers from the control were calculated. A one Log₁₀ reduction in Ad titer was considered to be an effective reduction.

Results: At RT, PHMB did not produce effective reductions in titers for any of the Ad serotypes tested at 50 or 20 PPM. At 40^oC, PHMB produced effective reductions in Ad titers at both 50 and 20 PPM for several, but not all, Ad serotypes.

Conclusions: PHMB, at concentrations used to disinfect swimming pools and hot tubs, was ineffective in reducing Ad titers at room temperature. The effectiveness of PHMB in reducing Ad titers increased when the temperature was raised to 40^oC, but its effectiveness did not cover all the Ad serotypes tested. PHMB does not appear to be an effective disinfectant against Ad in swimming pools and only moderately effective in hot tubs. Presumably, the concentrations of PHMB in contact lens solutions (1-5 PPM) would also be ineffective for the disinfection contact lenses contaminated with adenovirus.

Support: NIH Core Grant P30 EY008098, RPB, Eye & Ear Foundation

Disclosure: N

2011 Abstract List | < Previous | Next >