Survival of Pseudorabies Virus on Swabs Maintained under Standard Field Sample Shipping Conditions

Abstract

Pseudorabies virus survival was compared using three different types of applicator swabs in Eagle's minimum essential medium held under shipping conditions (packed with frozen gel packs) for up to 96 hours. Virus titer decay rates for dacron-tipped applicators were not statistically different from those of controls. Titer decay rates were statistically different from controls for cotton- and calcium alginate-tipped applicators. With the lowest input virus titer, virus was detectable up to 96, 72, or 24 hours after inoculation for dacron-, cotton-, and calcium alginate-tipped applicators, respectively. Dacron-tipped applicators were chosen to evaluate pseudorabies virus survival on tonsil swabs collected from experimentally challenged or contact control pigs to simulate field sampling and shipping conditions. Virus was still detectable in 20 of 24 swab samples after 72 hours in cell culture medium under shipping conditions.

References

Barnard

Fames

Richards

: 1986, Suitability of new Chlamydia transport medium for transport of herpes simplex virus. J Clin Microbiol 24:692–695.

Bettoli

Brewer

Oxtoby

: 1982, The role of temperature and swab materials in the recovery of herpes simplex virus from lesions. J Infect Dis 14:53–99.

Crane

Gutterman

Chapel

Lemer

: 1980, Incubation of swab materials with herpes simplex virus. J Infect Dis 141:531.

Hanson

Schipper

: 1976, Effects of swab materials on infectious bovine rhinotracheitis virus. Am J Vet Res 37:707–708.

Hill

Crandell

Kanitz

: 1977, Recommended minimum standards for diagnostic tests employed in the diagnosis of pseudorabies (Aujeszky's disease). Proc Annu Meet Am Assoc Vet Lab Diagn 20:375–390.

Iglesias

Pijoan

Molitor

: 1989, Interaction of pseudorabies with swine alveolar macrophages. Effects of cell functions. J Leuk Biol 45:410–415.

Kleinbaum

Kupper

: 1989, Comparing two straight-line regression models. In: Applied regression analysis and other multivariate methods, ed. Kleinbaum

Kupper

, pp. 95–112. Duxbury Press, Boston, MA.

Loula

: 1992, Field test of a pseudorabies vaccine for swine. Agri-practice 13:6–8.

Madeley

Lennette

Halonen

: 1988, Specimen collection and transport. In: Laboratory diagnosis of infectious diseases, principles and practice, ed. Lennette

Halonen

Murphe

, vol. 2, pp. 7–11. Springer-Verlag, New York, NY.

10.

McCaw

: 1993, Protection against pseudorabies virus infection by intranasal vaccination of newborn pigs. Am J Vet Res 54:527–533.

11.

Morrison

Thawley

: 1989, Serologic status of pseudorabies virus in growing-finishing pigs in quarantined herds. J Am Vet Med Assoc 195:1577–1579.

12.

SAS Institute: 1985, SASR language guide for personal computers, version 6 ed. SAS Institute, Cary, NC.

13.

van Oirschot

: 1987, Intranasal vaccination of pigs against Aujeszky's disease: comparison with one or two doses of attenuated vaccines in pigs with high maternal antibody titers. Res Vet Sci 42:12–16.

14.

Warford

Rekrut

Levy

Drill

: 1984, Sucrose phosphate glutamate for combined transport of Chlamydial and viral specimens. Am J Clin Pathol 81:762–764.