Lakshmi Ram Mohan Mylavarapu Venkata Naga, Dharma Teja Vijay, Sudhaharan Sukanya, Surya Subbalaxmi Malladi Venkata, Emmadi Rajkiran, Yadati Satyanarayana Raju, Modugu Nageswara Rao, Jyotsna Aparna
Department of Microbiology, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad, Telangana, India.
Department of General Medicine, Nizam's Institute of Medical Sciences, Punjagutta, Hyderabad, Telangana, India.
Iran J Microbiol. 2020 Jun;12(3):204-208.
Scrub typhus is re-emerging as an important cause of acute undifferentiated fever in the last decade from various parts of India. Complexity in performing the "gold standard" immunofluorescent assay and the unreliable nature of Weil Felix test often results in delayed or misdiagnosis in a majority of cases. The present study seeks to integrate the results of rapid diagnostic tests, clinical and laboratory features to aid the diagnosis and management of scrub typhus patients.
A total of 645 serum samples with suspected scrub typhus sent to the Department of Microbiology were included in the study. Scrub typhus was tested by rapid immunochromatographic test (SD Diagnostics) and IgM ELISA (Inbios International, USA). Clinical features, laboratory parameters and final outcome were analysed from the clinical records of positive patients.
Scrub typhus was diagnosed in 13.7% of patients and majority of them were observed in the month of August. 58.6% of scrub typhus patients presented with fever of one to two weeks duration. Eschar was documented in 13.7% of patients and 24% of patients gave a history of working outdoors or exposure to vegetation. All the patients responded to Doxycycline treatment and there was no mortality.
High index of suspicion for scrub typhus is necessary in febrile patients not responding to conventional antibiotics especially during outbreak situations. Rapid immunochromatographic tests with excellent specificity and acceptable sensitivity can be used as potential point of care tests for quick diagnosis of scrub typhus especially in delayed presentation.
在过去十年中，恙虫病在印度各地再度成为急性未分化型发热的重要病因。进行“金标准”免疫荧光检测存在复杂性，而外斐试验结果不可靠，这常常导致大多数病例的诊断延迟或误诊。本研究旨在整合快速诊断检测结果、临床及实验室特征，以辅助恙虫病患者的诊断与管理。
本研究纳入了共645份送至微生物学系的疑似恙虫病血清样本。采用快速免疫层析试验（SD诊断公司）和IgM酶联免疫吸附测定（美国英博生物科技公司）检测恙虫病。从阳性患者的临床记录中分析临床特征、实验室参数及最终结果。
13.7%的患者被诊断为恙虫病，其中大多数病例出现在8月份。58.6%的恙虫病患者发热持续一至两周。13.7%的患者有焦痂记录，24%的患者有户外工作或接触植被的病史。所有患者对多西环素治疗均有反应，无死亡病例。
对于对常规抗生素无反应的发热患者，尤其是在疫情暴发期间，必须对恙虫病保持高度怀疑。特异性高且灵敏度可接受的快速免疫层析试验可作为即时检测手段，用于快速诊断恙虫病，尤其是在就诊延迟的情况下。
