Sajith Anupama, Iyengar Varsha, Varamballi Prasad, Mukhopadhyay Chiranjay, Nittur Sudheesh
Manipal Academy of Higher Education, Manipal Institute of Virology, Manipal, India.
Ann Med. 2025 Dec;57(1):2523559. doi: 10.1080/07853890.2025.2523559. Epub 2025 Jun 26.
Chikungunya fever is a viral disease spread by Aedes mosquitoes, reported in over 110 countries. In India, it was first detected in Kolkata in 1963 and is now widespread. Diagnosis often relies on detecting anti-chikungunya IgM antibodies, but these may not be present during the acute phase as viremia can last up to 8 days, leading to underreporting. The present study aims to assess the diagnostic use of real-time RT-PCR for detecting chikungunya-specific nucleic acid in serum samples during the early stages of infection.
A retrospective cross-sectional study was conducted using archived samples collected as a part of 'the hospital-based Acute Febrile Illness (AFI) surveillance project'. AFI cases having fever ≤8 days and arthralgia without any aetiology between 2016 and 2018 from Karnataka, Kerala, and Tamil Nadu were included in the study. Samples were subjected to nucleic acid extraction followed by chikungunya real-time RT-PCR using a standardized in-house protocol. The samples that tested positive for Chikungunya by real-time RT-PCR were further tested for detecting anti-Chikungunya IgM antibodies using enzyme-linked immunosorbent assay. Demographic characterization of the cases was performed using SPSS version 20 and GraphPad Prism version 10.
Out of a total of 646 samples tested, 31 samples (4.79%) were positive by real-time RT-PCR for chikungunya virus, 20 of which had a Ct value of <30, indicating a relatively high viral load. Among the 31 serum samples tested for anti-Chikungunya IgM antibodies, only one showed a positive result. Demographic analysis showed that 67% of cases were male and 32% were female, respectively. Clinical data analysis showed that most of the cases presented with cough (87%), headache (80.6%), myalgia (77.4%), coryza (70.9%), vomiting (58%), and abdominal pain (38.7%).
The current study findings highlight the importance of screening patients with fever for up to 8 days and arthralgia for not only detecting IgM antibodies against chikungunya using ELISA but also for chikungunya virus-specific nucleic acid through real-time PCR/nucleic acid amplification techniques, or other methods. Not performing laboratory tests to screen for chikungunya-specific nucleic acid or antigen may result in underreporting of chikungunya cases, thereby impacting effective control measures and management of cases.
基孔肯雅热是一种由伊蚊传播的病毒性疾病，在110多个国家均有报道。1963年在印度加尔各答首次发现该病，如今已广泛传播。诊断通常依赖于检测抗基孔肯雅IgM抗体，但在急性期这些抗体可能不存在，因为病毒血症可持续长达8天，导致报告不足。本研究旨在评估实时逆转录聚合酶链反应（RT-PCR）在感染早期血清样本中检测基孔肯雅特异性核酸的诊断用途。
采用作为“基于医院的急性发热性疾病（AFI）监测项目”一部分收集的存档样本进行回顾性横断面研究。纳入2016年至2018年来自卡纳塔克邦、喀拉拉邦和泰米尔纳德邦的发热≤8天且无任何病因的关节痛的AFI病例。样本先进行核酸提取，然后使用标准化的内部方案进行基孔肯雅实时RT-PCR检测。通过实时RT-PCR检测为基孔肯雅阳性的样本，再使用酶联免疫吸附测定法检测抗基孔肯雅IgM抗体。使用SPSS 20版和GraphPad Prism 10版对病例进行人口统计学特征分析。
在总共检测的646个样本中，31个样本（4.79%）通过实时RT-PCR检测为基孔肯雅病毒阳性，其中20个样本的Ct值<30，表明病毒载量相对较高。在检测抗基孔肯雅IgM抗体的31份血清样本中，只有一份呈阳性结果。人口统计学分析显示，病例中男性占67%，女性占32%。临床数据分析显示，大多数病例表现为咳嗽（87%）、头痛（80.6%）、肌痛（77.4%）、鼻炎（70.9%）、呕吐（58%）和腹痛（38.7%）。
当前研究结果强调了对发热长达8天且有关节痛的患者进行筛查的重要性，这不仅有助于通过酶联免疫吸附测定法检测抗基孔肯雅IgM抗体，还能通过实时PCR/核酸扩增技术或其他方法检测基孔肯雅病毒特异性核酸。不进行实验室检测以筛查基孔肯雅特异性核酸或抗原可能导致基孔肯雅病例报告不足，从而影响病例的有效控制措施和管理。
