Transmission of porcine reproductive and respiratory syndrome virus under field conditions during a putative increase in the fly population

Abstract

Indirect transmission of porcine reproductive and respiratory syndrome virus (PRRSV) is described, from an experimentally infected pig population to a group of negative controls housed 30 m apart. The episode appeared to involve an increase in PRRSV shedding and, concurrently, environmental changes favoring an increase in the fly population.