MSc. Public Health Entomology Student, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry.
Unit of One Health, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry.
Vector Borne Zoonotic Dis. 2024 May;24(5):299-307. doi: 10.1089/vbz.2023.0069. Epub 2024 Jan 5.
Scrub typhus (ST) is detected in one-fourth of patients with acute febrile illnesses, confirming its nationwide re-emergence. The disease, if not diagnosed, can lead to multiple organ dysfunction and mortality. Being a vector-borne zoonotic disease, the molecular survey for pathogens in animal hosts is essential to predict the risk of its transmission to humans. Hence, this study aimed at identifying the effective animal tissue and molecular technique for zoonotic surveillance of ST infection in small animal hosts. Rodents/shrews were trapped from seventeen randomly selected villages in Puducherry between July and September, 2022. The presence of in ectoparasites and tissues including blood, lung, liver, spleen, kidney, heart, brain, and intestine retrieved from the animals was screened by nested PCR targeting 56 kDa, real-time PCR (qPCR) targeting 47 kDa and traD, and conventional PCR targeting groEL. The Weil-Felix test was carried out to detect antibodies against in rodent/shrew serum samples. Diagnostic accuracy measures of the molecular tests were calculated for each of the tissues by latent class modeling. detected in the rodents/shrews were identified to be Karp-like and Kawasaki-like strains. Upon statistical analysis, qPCR targeting 47 kDa exhibited the highest accuracy measures in most of the tissues analyzed, with perfect sensitivity and specificity of 100% and 97% for intestine and lung samples for the epidemiological surveillance, respectively. The study recommends qPCR targeting 47 kDa gene and analysis of intestine and lung along with blood for the zoonotic surveillance of ST infection.
恙虫病（ST）在四分之一的急性发热患者中被检测到，证实了其在全国范围内的再次出现。如果不进行诊断，该病可导致多器官功能障碍和死亡。作为一种媒介传播的人畜共患病，对动物宿主中的病原体进行分子调查对于预测其向人类传播的风险至关重要。因此，本研究旨在确定有效的动物组织和分子技术，用于小动物宿主中 ST 感染的人畜共患病监测。 2022 年 7 月至 9 月，从浦那十七个随机选定的村庄中捕获了啮齿动物/鼩鼱。通过针对 56kDa 的巢式 PCR、针对 47kDa 和 traD 的实时 PCR（qPCR）以及针对 groEL 的常规 PCR 筛选从动物中获得的外寄生虫和组织（包括血液、肺、肝、脾、肾、心、脑和肠）中是否存在。对啮齿动物/鼩鼱血清样本进行魏尔-菲利斯试验以检测针对 的抗体。通过潜在类别建模计算了针对每种组织的分子测试的诊断准确性度量。 在啮齿动物/鼩鼱中检测到的 被鉴定为 Karp 样和 Kawasaki 样株。通过统计分析，针对 47kDa 的 qPCR 在大多数分析的组织中表现出最高的准确性度量，针对肠和肺样本的敏感性和特异性分别为 100%和 97%，用于流行病学监测。 该研究建议针对 47kDa 基因进行 qPCR，并分析肠和肺以及血液，用于 ST 感染的人畜共患病监测。
