一项为期十二年的流行病学研究表明,羊痘疾病既广泛又地方性,主要在冬季和夏季波动。这项调查集中在11场爆发的羊痘上,涉及来自卡纳塔克邦六个地区的非迁徙羊群的889只动物,在印度南部半岛。其中,105只动物表现出提示羊痘的临床体征,比如身体上的病变,通过PCR检测确认了95例。羊痘的总体阳性率为10.68%(889只动物中有95只)。羊痘的发病率在1至2岁的动物中明显较高,在女性中更为普遍。受影响的动物表现出包括呼吸窘迫在内的症状,弱点,发烧,食欲不振,抑郁症,以及各种皮肤病变,从丘疹到麻点病变。白细胞总数显著增加,而血红蛋白水平,红细胞计数,和血细胞比容值显着下降。粗略检查,羊痘病变,从泡状到结节状,主要在身体的无毛区域发现。皮肤病变的显微镜检查显示广泛的变化,比如角化过度,角化不全,棘皮病,积水变性,上皮细胞坏死,以及特征性的胞浆内病毒包涵体。肺部表现为II型肺细胞增生和增生性细支气管炎,也有胞质内包涵体。通过PCR和随后的序列分析实现羊痘病毒的确认。全长P32和RPO30基因的系统发育分析表明与来自印度各地和邻国的羊痘分离株具有同源性,这表明印度羊痘病毒具有高度的谱系特异性,并且与宿主的起源相关。基于这些发现,建议实施同源疫苗接种策略,利用选择性宿主/病毒株增强易感动物的保护。
An epidemiological study spanning twelve years has revealed that
sheeppox disease is both widespread and endemic, predominantly surging during the winter and summer seasons. This investigation focused on
sheeppox across 11 field outbreaks, involving 889 animals from non-migratory flocks across six districts in Karnataka, in the southern peninsula of India. Among these, 105 animals exhibited clinical signs suggestive of
sheeppox, such as lesions on the body, and 95 cases were confirmed through PCR testing. The overall positivity rate for
sheeppox stood at 10.68% (95 out of 889 animals). The incidence of sheeppox was notably higher in animals aged between 1 and 2 years and was more prevalent in females. Affected animals displayed symptoms including respiratory distress, weakness, fever, loss of appetite, depression, and various skin lesions ranging from papular to pock lesions across their bodies. There was a significant increase in total leukocyte count, while hemoglobin levels, red blood cell counts, and hematocrit values significantly decreased. On gross examination, sheeppox lesions, varying from vesicular to nodular forms, were predominantly found on hairless areas of the body. Microscopic examination of skin lesions revealed extensive changes, such as hyperkeratosis, parakeratosis, acanthosis, hydropic degeneration, and necrosis of epithelial cells, along with characteristic intracytoplasmic viral inclusions. The lungs exhibited type-II pneumocyte hyperplasia and proliferative bronchiolitis, also with intracytoplasmic inclusions. Confirmation of the
sheeppox virus was achieved through PCR and subsequent sequence analysis. Phylogenetic analysis of the full-length P32 and RPO30 gene demonstrated homology with sheeppox isolates from various parts of India and neighboring countries, indicating that Indian sheeppox viruses are highly lineage-specific and correlate with the host of origin. Based on these findings, it is recommended to implement a homologous vaccination strategy, utilizing selective host/viral strains to enhance protection in susceptible animals.