Stability of Porcine reproductive and respiratory syndrome virus at ambient temperatures.
The stability of Porcine reproductive and respiratory syndrome virus (PRRSV) was evaluated for temperatures appropriate to laboratory and field settings. Four North American (type 2) isolates (ATCC VR-2332, JA-142, MN-184, and Ingelvac(R) PRRS ATP vaccine virus) in cell culture medium (pH 7.5) were held at 1 of 4 temperatures (4, 10, 20, and 30 degrees C) and sampled over time. Samples were tested for infectious virus and total PRRSV RNA using median tissue culture infectious dose and quantitative reverse transcription polymerase chain reaction, respectively. The rate of loss of infectious virus was expressed in terms of the time required for virus concentration to decline by one half (i.e., half-life [T(1/2)]). Statistical analysis found that temperature, but not virus isolate, had a significant effect on T(1/2), and a single nonlinear regression model was derived to predict T(1/2) for temperatures between 0 and 50 degrees C: T(1/2) = 243.54 e((-0.109*TEMP)). In contrast to changes over time in the concentration of infectious virus, no change in the concentration of quantitative reverse transcription polymerase chain reaction-detectable PRRSV was detected at any temperature and contact time. This information will be of interest to persons working in laboratory or field situations in which the control of PRRSV is important.
Anna C
AC
Jacobs
Joseph R
JR
Hermann
Claudia
C
Muñoz-Zanzi
John R
JR
Prickett
Michael B
MB
Roof
Kyoung-Jin
KJ
Yoon
Veterinary Medical Research Institute (Building 1), College of Veterinary Medicine, 1802 University Blvd, Iowa State University, Ames, IA 50011-1240. jjzimm@iastate.edu
Jeffrey J
JJ
Zimmerman
D006358:Hot Temperature; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D012367:RNA, Viral; D013048:Specimen Handling / Q000662:veterinary
D012367:RNA, Viral