TY - JOUR AU - Freese, WR AU - Joo, HS TI - Cessation of porcine reproductive and respiratory syndrome (PRRS) virus spread in a commercial swine herd T2 - Journal of Swine Health and Production JF - Journal of Swine Health and Production J2 - JSHAP SN - 1537-209X DP - American Association of Swine Veterinarians PB - American Association of Swine Veterinarians DA - 1994/Jan// PY - 1994 VL - 2 M1 - 1 IS - 1 M2 - 13 SP - 13-15 UR - https://www.aasv.org/shap/abstracts/abstract.php?v2n1p13 L1 - https://www.aasv.org/shap/issues/v2n1/v2n1p13.pdf KW - swine KW - PRRS N2 - We report a case of porcine reproductive and respiratory syndrome (PRRS) virus infection that appeared to spontaneously stop spreading. We compared serologic profiles of this 250-sow farm (herd A) with those of another 300-sow farm (herd B), both with a previous history of PRRS. In November 1992, we collected serum samples from pigs of different age groups (from I week to 3 years old) from both herds. We tested PRRS virus antibody titers by an indirect-fluorescent antibody (IFA) method. IFA titers of >1:16 were detected in 20 of 129 pigs (15.5%) from herd A and 73 of 158 pigs (46.2%) from herd B. In April 1993, none of 30 pigs between 4-26 weeks of age from herd A were seropositive, while all 60 pigs of the same age group from herd B were seropositive. A group of IS gilts in herd A, introduced in January 1992 from a form showing no clinical signs of PRRS, remained seronegative. No PRRS virus was isolated in April 1993 from 30 serum samples from pigs 5-10 weeks old in herd A, while virus was isolated from 4 of 28 sera from pigs of a similar age in herd B. PRRS virus stopped spreading in herd A, while the infection is still endemic in herd B. ER -