Zimmerman J J, Yoon K J, Pirtle E C, Wills R W, Sanderson T J, McGinley M J
Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames 50011, USA.
Vet Microbiol. 1997 Apr;55(1-4):329-36. doi: 10.1016/s0378-1135(96)01320-x.
Porcine reproductive and respiratory syndrome virus (PRRSV) is a recently recognized virus of swine. As a newly emerging virus, much of the basic information regarding PRRSV is in the process of discovery. We report three experiments with PRRSV in birds, and a fourth experiment to evaluate the infectivity and transmissibility of avian-derived PRRSV in swine. Experiment 1 compared the susceptibility of Muscovy ducks, Mallard ducks, guinea fowl, and chickens to PRRSV. Birds were exposed to PRRSV (ATCC VR-2402) in drinking water and virus isolation was attempted from feces collected from cages. Based on the duration of fecal shedding of the virus, this experiment showed that Mallard ducks were particularly susceptible to PRRSV. Experiment 2 was done in mallards to corroborate and augment the observations of experiment 1. Virus was isolated from pooled mallard feces up to 25 days post exposure (PE) and from the intestinal contents of 8 of 20 birds euthanized on day 38 PE. No gross or microscopic lesions were observed in ducks collected between 0 and 15 days PE. Experiment 3 evaluated the infectivity and transmissibility of mallard-derived PRRSV in mallards. A cage of mallards orally exposed to PRRSV shed the virus in feces. Exposure of a second cage of mallards to feces from the first cage resulted in fecal shedding of PRRSV by birds in cage two. In turn, exposure to feces from the second cage led to fecal shedding by mallards in a third cage. Experiment 4 assessed the infectivity and transmissibility of mallard-derived virus in swine. Pigs intranasally exposed to PRRSV isolaed from mallard feces in experiment 2 became viremic, seroconverted by ELISA, and transmitted the virus to sentinel swine. Collectively, these studies show that the possibility exists for avian species to be involved in the epidemiology of PRRSV. This is the first report of PRRSV infection in a species other than swine.
猪繁殖与呼吸综合征病毒（PRRSV）是一种最近才被认识的猪病毒。作为一种新出现的病毒，许多关于PRRSV的基本信息仍在探索过程中。我们报告了三项用PRRSV感染禽类的实验，以及第四项评估源自禽类的PRRSV在猪中的感染性和传播性的实验。实验1比较了番鸭、绿头鸭、珍珠鸡和鸡对PRRSV的易感性。让禽类通过饮用水接触PRRSV（美国典型培养物保藏中心VR - 2402），并尝试从笼子里收集的粪便中分离病毒。根据病毒粪便排出的持续时间，该实验表明绿头鸭对PRRSV特别易感。实验2在绿头鸭中进行，以证实和补充实验1的观察结果。在接触病毒后长达25天从合并的绿头鸭粪便中分离到病毒，在接触病毒后第38天对20只绿头鸭实施安乐死，其中8只的肠道内容物中分离到病毒。在接触病毒后0至15天收集的鸭子中未观察到肉眼可见或显微镜下的病变。实验3评估了源自绿头鸭的PRRSV在绿头鸭中的感染性和传播性。一组经口接触PRRSV的绿头鸭通过粪便排出病毒。让第二组绿头鸭接触第一组绿头鸭的粪便，导致第二组笼子里的禽类粪便中排出PRRSV。反过来，让第三组绿头鸭接触第二组笼子里的粪便，导致第三组笼子里的绿头鸭粪便中排出病毒。实验4评估了源自绿头鸭的病毒在猪中的感染性和传播性。在实验2中经鼻接触从绿头鸭粪便中分离的PRRSV的猪出现病毒血症，通过酶联免疫吸附测定法发生血清转化，并将病毒传播给哨兵猪。总体而言，这些研究表明禽类有可能参与PRRSV的流行病学。这是PRRSV在猪以外物种中感染的首次报告。
