In this study, the prevalence of porcine reproductive and respiratory syndrome virus (PRRSV) infection on swine farms in Japan was investigated. Out of 92 farrow-to-finish swine farms targeted in this study, 82.6% (76/92) were positive for PRRSV. The post-weaning mortality of the PRRSV-negative group was significantly lower than that of the PRRSV-positive group (negative: 3.9%, positive: 6.1%: P < 0.01). The average daily weight gain of the PRRSV-negative group was significantly higher than that of the PRRSV-positive group (negative: 638.8 g, positive: 585.1 g: P < 0.01). The Kanto region was significantly associated (P < 0.01) with PRRSV-positive status (odds ratio (OR) = 41.8, 95% confidence interval (CI) = 4.80-363.0). With respect to farm location, the presence of other pig farms within a 3-km radius were significantly associated (P < 0.05) with PRRSV-positive status (OR = 4.09, 95% CI = 1.07-15.70). Our findings suggest that PRRSV significantly worsens farm productivity. Regional collaboration is an important strategy required to control or eliminate PRRSV.
(Viral Disease and Epidemiology Research Division)
References:
Ishizeki S. et al (2014) Anim. Sci. J. 85:171-177
