STUDIES ON THE SURVIVAL OF AEROSOLIZED BOVINE ROTAVIRUS (UK) AND A MURINE ROTAVIRUS

The effect of relative humidity (RH) and temperature on the survival o f airborne bovine rotavirus UK isolate (BRV-UK) and a murine rotavirus (MRV) was studied. In any one experiment, the virus under test was su spended in tryptose phosphate broth (TPB) supplemented with uranine (p hysical tracer) and an antifoam, was aerosolized using a Collison nebu lizer into the rotating drum with the RH at either low (30 +/- 5%), me dium (50 + 5%) or high (80 +/- 5%) level at 20 +/- 1-degrees-C. Follow ing a 15-min period of viral aerosol stabilization, sequential samples of drum air were collected using an All-Glass Impinger (AGI) for 24 h post-aerosolization. Both of the rotavirus isolates were found to sur vive best at medium RH level and high RH was found least favorable for the survival of these aerosolized rotaviruses. The survival pattern o f aerosolized MRV was found to be the best when compared with survival pattern of all animal and human rotavirus isolates studies performed under aerosolized conditions in our laboratory. The findings of these experiments confirm and extend our previous reports on the survival of other animal and human aerosolized rotaviruses and emphasize the fact that air may be one of the vehicles for their dissemination and could explain why it is difficult to control nosocomial outbreaks of rotavi rus gastroenteritis and to keep animal colonies rotavirus-free.