Centre for Infections, Health Protection Agency, London, UK.
Lancet Infect Dis. 2010 Dec;10(12):835-44. doi: 10.1016/S1473-3099(10)70222-X. Epub 2010 Oct 15.
Encephalitis has many causes, but for most patients the cause is unknown. We aimed to establish the cause and identify the clinical differences between causes in patients with encephalitis in England.
Patients of all ages and with symptoms suggestive of encephalitis were actively recruited for 2 years (staged start between October, 2005, and November, 2006) from 24 hospitals by clinical staff. Systematic laboratory testing included PCR and antibody assays for all commonly recognised causes of infectious encephalitis, investigation for less commonly recognised causes in immunocompromised patients, and testing for travel-related causes if indicated. We also tested for non-infectious causes for acute encephalitis including autoimmunity. A multidisciplinary expert team reviewed clinical presentation and hospital tests and directed further investigations. Patients were followed up for 6 months after discharge from hospital.
We identified 203 patients with encephalitis. Median age was 30 years (range 0-87). 86 patients (42%, 95% CI 35-49) had infectious causes, including 38 (19%, 14-25) herpes simplex virus, ten (5%, 2-9) varicella zoster virus, and ten (5%, 2-9) Mycobacterium tuberculosis; 75 (37%, 30-44) had unknown causes. 42 patients (21%, 15-27) had acute immune-mediated encephalitis. 24 patients (12%, 8-17) died, with higher case fatality for infections from M tuberculosis (three patients; 30%, 7-65) and varicella zoster virus (two patients; 20%, 2-56). The 16 patients with antibody-associated encephalitis had the worst outcome of all groups-nine (56%, 30-80) either died or had severe disabilities. Patients who died were more likely to be immunocompromised than were those who survived (OR = 3·44).
Early diagnosis of encephalitis is crucial to ensure that the right treatment is given on time. Extensive testing substantially reduced the proportion with unknown cause, but the proportion of cases with unknown cause was higher than that for any specific identified cause.
The Policy Research Programme, Department of Health, UK.
脑炎有很多病因，但大多数患者的病因不明。我们旨在确定病因并确定英国脑炎患者病因之间的临床差异。
在 24 家医院中，由临床工作人员在 2 年内（分期启动于 2005 年 10 月至 2006 年 11 月之间）对所有年龄段且有疑似脑炎症状的患者进行主动招募。系统实验室检测包括所有常见传染性脑炎病因的 PCR 和抗体检测、免疫功能低下患者中少见病因的调查以及有指征时进行与旅行相关病因的检测。我们还为急性脑炎的非感染性病因（包括自身免疫）进行了检测。一个多学科专家团队对临床表现和医院检测进行了回顾，并指导了进一步的检查。患者在出院后 6 个月进行随访。
我们共确定了 203 例脑炎患者。中位年龄为 30 岁（范围 0-87 岁）。86 例（42%，95%CI 35-49）患者有感染性病因，包括 38 例（19%，14-25）单纯疱疹病毒，10 例（5%，2-9）水痘-带状疱疹病毒，以及 10 例（5%，2-9）结核分枝杆菌；75 例（37%，30-44）病因不明。42 例（21%，15-27）患者为急性免疫介导性脑炎。24 例（12%，8-17）患者死亡，结核分枝杆菌（3 例；30%，7-65）和水痘-带状疱疹病毒（2 例；20%，2-56）感染者的病死率更高。16 例抗体相关性脑炎患者的预后最差，其中 9 例（56%，30-80）死亡或有严重残疾。死亡患者比存活患者更有可能免疫功能低下（OR=3.44）。
早期诊断脑炎对于确保及时给予正确的治疗至关重要。广泛的检测大大降低了病因不明的比例，但病因不明的比例高于任何特定的明确病因。
英国卫生部政策研究计划。
