MMWR Morb Mortal Wkly Rep. 2010 Mar 26;59(11):335-8.
Tick-borne encephalitis virus (TBEV) is the most common arbovirus transmitted by ticks in Europe. Approximately 10,000 cases of tick-borne encephalitis (TBE) are reported annually in Europe and Russia. Although TBE is endemic in parts of China, information regarding its incidence is limited. TBEV is closely related to Powassan virus (POWV), another tick-borne flavivirus that is a rare cause of encephalitis in North America and Russia; TBEV and POWV can cross-react in serologic tests. Before 2000, two cases of TBE in North American travelers to Europe were reported. State health officials or clinicians send specimens from patients with unexplained encephalitis to CDC as part of routine surveillance and diagnostic testing. CDC recently reviewed all 2000-2009 laboratory records to identify cases of TBE among U.S. travelers; the five cases identified are summarized in this report. All five cases had TBEV or POWV immunoglobulin M (IgM) antibodies in serum and were confirmed as acute TBE cases by plaque-reduction neutralization tests against both viruses. All four patients who had traveled to Europe or Russia had biphasic illnesses (a common feature of TBE) and made nearly complete recoveries. The fifth patient, the first reported case of TBE in a U.S. traveler to China, had a monophasic illness with severe encephalitis and neurologic sequelae. Health-care providers should be aware of TBE, should counsel travelers about measures to reduce exposure to tick bites, and should consider the diagnosis of TBE in travelers returning from TBE-endemic countries with meningitis or encephalitis.
蜱传脑炎病毒（TBEV）是欧洲最常见的蜱传虫媒病毒。欧洲和俄罗斯每年报告约 10000 例蜱传脑炎（TBE）病例。尽管 TBE 在中国部分地区流行，但有关其发病率的信息有限。TBEV 与 Powassan 病毒（POWV）密切相关，后者是另一种蜱传黄病毒，也是北美的罕见脑炎病因；TBEV 和 POWV 在血清学检测中可发生交叉反应。2000 年以前，曾报告过两例前往欧洲的北美人感染 TBE。州卫生官员或临床医生将来自不明原因脑炎患者的标本送往 CDC，作为常规监测和诊断检测的一部分。CDC 最近审查了所有 2000-2009 年的实验室记录，以确定美国旅行者中的 TBE 病例；本报告总结了在此期间发现的五例 TBE 病例。所有五例患者血清中均存在 TBEV 或 POWV 免疫球蛋白 M（IgM）抗体，且通过针对两种病毒的蚀斑减少中和试验均被确认为急性 TBE 病例。所有四名前往欧洲或俄罗斯的患者均有双相疾病（TBE 的常见特征），几乎完全康复。第五例是首例报告的前往中国的美国旅行者 TBE 病例，表现为单相疾病，伴有严重脑炎和神经后遗症。医疗保健提供者应意识到 TBE，应就减少接触蜱叮咬的措施对旅行者进行咨询，并应考虑从 TBE 流行国家返回的有脑膜炎或脑炎的旅行者的 TBE 诊断。
