Joshi Rajnish, Mishra Pradyumna Kumar, Joshi Deepti, Santhosh S R, Parida M M, Desikan Prabha, Gangane Nitin, Kalantri S P, Reingold Arthur, Colford John M
Department of Medicine, All India Institute of Medical Sciences, Bhopal, India.
Clin Neurol Neurosurg. 2013 Sep;115(9):1753-61. doi: 10.1016/j.clineuro.2013.04.008. Epub 2013 May 1.
Acute encephalitis syndrome (AES) is a constellation of symptoms that includes fever and altered mental status. Most cases are attributed to viral encephalitis (VE), occurring either in outbreaks or sporadically. We conducted hospital-based surveillance for sporadic adult-AES in rural Central India in order to describe its incidence, spatial and temporal distribution, clinical profile, etiology and predictors of mortality.
All consecutive hospital admissions during the study period were screened to identify adult-AES cases and were followed until 30-days of hospitalization. We estimated incidence by administrative sub-division of residence and described the temporal distribution of cases. We performed viral diagnostic studies on cerebrospinal fluid (CSF) samples to determine the etiology of AES. The diagnostic tests included RT-PCR (for enteroviruses, HSV 1 and 2), conventional PCR (for flaviviruses), CSF IgM capture ELISA (for Japanese encephalitis virus, dengue, West Nile virus, Varicella zoster virus, measles, and mumps). We compared demographic and clinical variables across etiologic subtypes and estimated predictors of 30-day mortality.
A total of 183 AES cases were identified between January and October 2007, representing 2.38% of all admissions. The incidence of adult AES in the administrative subdivisions closest to the hospital was 16 per 100,000. Of the 183 cases, a non-viral etiology was confirmed in 31 (16.9%) and the remaining 152 were considered as VE suspects. Of the VE suspects, we could confirm a viral etiology in 31 cases: 17 (11.2%) enterovirus; 8 (5.2%) flavivirus; 3 (1.9%) Varicella zoster; 1 (0.6%) herpesvirus; and 2 (1.3%) mixed etiology); the etiology remained unknown in remaining 121 (79.6%) cases. 53 (36%) of the AES patients died; the case fatality proportion was similar in patients with a confirmed and unknown viral etiology (45.1 and 33.6% respectively). A requirement for assisted ventilation significantly increased mortality (HR 2.14 (95% CI 1.0-4.77)), while a high Glasgow coma score (HR 0.76 (95% CI 0.69-0.83)), and longer duration of hospitalization (HR 0.88 (95% CI 0.83-0.94)) were protective.
This study is the first description of the etiology of adult-AES in India, and provides a framework for future surveillance programs in India.
急性脑炎综合征（AES）是一组症状，包括发热和精神状态改变。大多数病例归因于病毒性脑炎（VE），可呈暴发或散发性发生。我们在印度中部农村地区开展了基于医院的散发性成人AES监测，以描述其发病率、时空分布、临床特征、病因及死亡预测因素。
对研究期间所有连续住院患者进行筛查以确定成人AES病例，并随访至住院30天。我们按居住行政分区估算发病率，并描述病例的时间分布。我们对脑脊液（CSF）样本进行病毒诊断研究以确定AES的病因。诊断检测包括逆转录聚合酶链反应（RT-PCR，用于检测肠道病毒、单纯疱疹病毒1型和2型）、常规聚合酶链反应（用于检测黄病毒）、脑脊液IgM捕获酶联免疫吸附测定（用于检测日本脑炎病毒、登革热病毒、西尼罗河病毒、水痘带状疱疹病毒、麻疹病毒和腮腺炎病毒）。我们比较了不同病因亚型的人口统计学和临床变量，并估算了30天死亡率的预测因素。
2007年1月至10月共确诊183例AES病例，占所有住院患者的2.38%。离医院最近的行政分区成人AES发病率为每10万人16例。在183例病例中，31例（16.9%）确诊为非病毒病因，其余152例被视为VE疑似病例。在VE疑似病例中，31例确诊为病毒病因：17例（11.2%）为肠道病毒；8例（5.2%）为黄病毒；3例（1.9%）为水痘带状疱疹病毒；1例（0.6%）为疱疹病毒；2例（1.3%）为混合病因；其余121例（79.6%）病因不明。53例（36%）AES患者死亡；确诊病毒病因和病因不明的患者病死率相似（分别为45.1%和33.6%）。需要辅助通气显著增加死亡率（风险比2.14（95%置信区间1.0 - 4.77）），而高格拉斯哥昏迷评分（风险比0.76（95%置信区间0.69 - 0.83））和较长住院时间（风险比0.88（95%置信区间0.83 - 0.94））具有保护作用。
本研究首次描述了印度成人AES的病因，并为印度未来的监测项目提供了框架。
