title: Effect of temperature and relative humidity on the stability of infectious porcine reproductive and respiratory syndrome virus in aerosols.
abstract: 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 aerosol toroid (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 (TCID50) 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 (T1/2) 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 T1/2 of PRRSV than relative humidity. Based on these results, an equation was derived to predict the T1/2 of infectious airborne PRRSV for any combination of environmental temperature and relative humidity.
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011-1250, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Hermann
authors.forename: Steve
authors.initials: S
authors.lastname: Hoff
authors.forename: Claudia
authors.initials: C
authors.lastname: Muñoz-Zanzi
authors.forename: Kyoung-Jin
authors.initials: KJ
authors.lastname: Yoon
authors.forename: Michael
authors.initials: M
authors.lastname: Roof
authors.forename: Anna
authors.initials: A
authors.lastname: Burkhardt
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Zimmerman
mesh_terms: D000336:Aerosols; D006813:Humidity; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D012367:RNA, Viral / Q000032:analysis; D013696:Temperature; D013997:Time Factors
chemical_list: D000336:Aerosols; D012367:RNA, Viral