Effect of temperature and relative humidity on the stability ofinfectious porcine reproductive and respiratory syndrome virus in aerosols
The objective of this experiment was to describe the stability of airborne infectious porcine reproductive and respiratory syndrome virus (PRRSV) as a function of temperature and relative humidity. A cloud of infectious PRRSV was aerosolized using 24-jet Collison nebulizer into a dynamic aerosoltoroid (DAT) maintained at a specific temperature and relative humidity. The PRRSV cloud within the DAT was sampled repeatedly over time using SKC BioSampler impingers and the total viral RNA (RT-PCR) and concentration of infectious PRRSV (TCID in the air samples was determined. As measured by quantitative RT-PCR, PRRSV RNA was stable under the conditions evaluated in this study. Thus, a comparison of viral RNA and Rhodamine B dye, a physical tracer, found no significant difference in the slopes of the lines. Titers of infectious virus were plotted by time and the half-life (1/2) of infectious PRRSV was calculated using linear regression analysis. An analysis of the results showed that aerosolized PRRSV was more stable at lower temperatures and/or lower relative humidity, but temperature had a greater effect on the 1/2 of PRRSV than relative humidity. Based on these results, an equation was derived to predict the 1/2 of infectious airborne PRRSV for any combination of environmental temperature and relative humidity.
This article is from Veterinary Research 38, no. 1 (2007): 81–93, doi:10.1051/vetres:2006044. Posted with permission.