Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia.
Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, Georgia.
Am J Trop Med Hyg. 2021 Oct 25;106(1):182-186. doi: 10.4269/ajtmh.21-0188.
Rift Valley fever phlebovirus (RVFV) is a mosquito-transmitted phlebovirus (Family: Phenuiviridae, Order: Bunyavirales) causing severe neonatal mortality and abortion primarily in domestic ruminants. The susceptibility of young domestic swine to RVFV and this species' role in geographic expansion and establishment of viral endemicity is unclear. Six commercially bred Landrace-cross piglets were inoculated subcutaneously with 105 plaque-forming units of RVFV ZH501 strain and two piglets received a sham inoculum. All animals were monitored for clinical signs, viremia, viral shedding, and antibody response for 14 days. Piglets did not develop evidence of clinical disease, become febrile, or experience decreased weight gain during the study period. A brief lymphopenia followed by progressive lymphocytosis was observed following inoculation in all piglets. Four piglets developed a brief viremia for 2 days post-inoculation and three of these had detectable virus in oronasal secretions three days post-inoculation. Primary inoculated piglets seroconverted and those that developed detectable viremias had the highest titers assessed by serum neutralization (1:64-1:256). Two viremic piglets had a lymphoplasmacytic encephalitis with glial nodules; RVFV was not detected by immunohistochemistry in these sections. While young piglets do not appear to readily develop clinical disease following RVFV infection, results suggest swine could be subclinically infected with RVFV.
裂谷热病毒（RVFV）是一种通过蚊子传播的黄病毒（科：Phenuiviridae，目：Bunyavirales），主要导致家养反刍动物的新生儿死亡和流产。幼猪对 RVFV 的易感性以及该物种在病毒地方性流行中的地理传播和建立中的作用尚不清楚。六头商业饲养的长白杂交仔猪通过皮下接种 RVFV ZH501 株 105 噬菌斑形成单位，两只仔猪接受假接种。所有动物均在 14 天内监测临床症状、病毒血症、病毒脱落和抗体反应。在研究期间，仔猪没有出现临床疾病、发热或体重下降的迹象。接种后，所有仔猪均出现短暂的淋巴细胞减少，随后逐渐出现淋巴细胞增多。四头仔猪在接种后 2 天内出现短暂的病毒血症，其中 3 头在接种后 3 天在口鼻分泌物中检测到病毒。原发性接种仔猪血清中和试验血清转化，且出现可检测病毒血症的仔猪血清中和试验滴度最高（1:64-1:256）。两只病毒血症仔猪出现淋巴浆细胞性脑炎和神经胶质结节；这些切片中通过免疫组织化学未检测到 RVFV。虽然幼猪在感染 RVFV 后似乎不容易出现临床疾病，但结果表明猪可能处于亚临床感染 RVFV 的状态。
