CHEMICAL DISINFECTION TO INTERRUPT TRANSFER OF RHINOVIRUS TYPE-14 FROM ENVIRONMENTAL SURFACES TO HANDS

Rhinoviruses can survive on environmental surfaces for several hours u nder ambient conditions. Hands can readily become contaminated after c ontact with such surfaces, and self-inoculation may lead to infection. Whereas hand washing is crucial in preventing the spread of rhinoviru s colds, proper disinfection of environmental surfaces may further red uce rhinovirus transmission. In this study, the capacities of Lysol Di sinfectant Spray (0.1% o-phenylphenol and 79% ethanol), a domestic ble ach (6% sodium hypochlorite diluted to give 800 ppm of free chlorine), a quaternary ammonium-based product (7.05% quaternary ammonium dilute d 1:128 in tap water), and a phenol-based product (14.7% phenol dilute d 1:256 in tap water) were compared in interrupting the transfer of rh inovirus type 14 from stainless steel disks to fingerpads of human vol unteers upon a 10-s contact at a pressure of 1 kg/cm2. Ten microliters of the virus, suspended in bovine mucin (5 mg/ml), was placed on each disk, and the inoculum was dried under ambient conditions; the input number on each disk ranged from 0.5 x 10(5) to 2.1 x 10(6) PFU. The dr ied virus was exposed to 20 mul of the test disinfectant. The Lysol sp ray was able to reduce virus infectivity by >99.99% after a contact of either 1 or 10 min, and no detectable virus was transferred to finger pads from Lysol-treated disks. The bleach (800 ppm of free chlorine) r educed the virus titer by 99.7% after a contact time of 10 min, and ag ain no virus was transferred from the disks treated with it. On the ot her hand, the quaternary ammonium and phenolic products were able to i nactivate only 14.7 and 62.3% of the virus on the disks, respectively; contact of fingerpads with disks treated separately with these produc ts resulted in the transfer of 8.4% +/- 3.6 and 3.3% +/- 1.9%, respect ively, of the infectious virus remaining on the disks after the disinf ectant was allowed to dry. Virus transfer from the control disks was 0 .58% +/- 0.35%. These findings suggest that care must be exercised in the selection of disinfectants if transfer of rhinoviruses from enviro nmental surfaces to human hands is to be interrupted efficiently.