新腸病毒Enterovirus D68 感染性強/致死率低

日本小児科学会　急性弛緩性麻痺や急性呼吸不全で実態調査協力呼びかけ

公開日時　2015/10/26 03:50日本小児科学会は10月23日、ポリオの麻痺に似た急性弛緩性麻痺症状を呈する急性弛緩性脊椎炎や、喘息のような症状を示す急性呼吸不全が小児に相次いでみられたことから、実態把握調査に協力するよう会員に呼びかけた。ポリオウイルス以外の感染症も考えられることから、感染症法に基づく積極的疫学調査の一環として国立感染症研究所が実態調査を行うことになり、厚労省が21日に自治体含む関係団体に協力依頼していた。 米国では昨年、エンテロウイルスD68（EV-D68）との関連が疑われる重い呼吸器症状を示す患者が1000例を超えて報告されている。同時期に急性弛緩性麻痺も120例報告され、一部からEV-D68を検出された。日本でも今年、似たような症例が報告されたとして、より広く調査することになった。小児科学会は、同様の症例を診察した会員は、最寄りの自治体（保健所）に連絡するよう求めている。 同学会が会員に宛てた文書によると、日本では今年８月末から９月をピークに、全国各地で喘息様症状を呈する下気道炎患者が急増し、中には急性呼吸不全症例も発生している。症例からはEV-D68が検出されたとの報告もある。ほぼ同時期に、急性弛緩性麻痺症状を呈する急性弛緩性脊髄炎症例も報告され、その症例からはEV-D68が検出されている。

Enterovirus D68 Appears More Virulent, Not More Lethal in Kids  Diana Swift  October 15, 2015 Enterovirus D68 (EV-D68) seems to be a more virulent pulmonary pathogen than rhinovirus or other enterovirus strains, researchers report in an article published online October 13 in the Canadian Medical Association Journal. A study led by Dominik Mertz, MD, an assistant professor in McMaster University's Division of Infectious Diseases in Hamilton, Ontario, Canada, found that pediatric patients with EV-D68 were more likely to present with respiratory distress, were slightly more likely to require hospitalization, and more frequently received magnesium sulfate or intravenous salbutamol than those with rhinovirus or non-EV-D68 infection. "However, they were not significantly more likely to require admission to the pediatric critical care unit or die," Dr Mertz and colleagues write. No EV-D68 transmissions occurred in hospital. The researchers evaluated consecutive children (mean age, 58 months; 32.2% female) presenting to the Hamilton Children's Hospital between August 1 and October 31, 2014, the year an EV-D68 outbreak in North America targeted children and teenagers. During that period, nasopharyngeal swabs positive for rhinovirus or enterovirus were automatically sent for EV-D68 testing. The authors compared the characteristics and outcomes in patients with EV-D68, and those with rhinovirus or non-EV-D68 enterovirus were compared in a matched cohort study. A total of 93 (31.3%) of 297 rhinovirus or enterovirus samples tested positive for EV-D68, and the team was able to compare 87 matched pairs between the two groups. Children with EV-D68 infection were three times more likely to have difficulty breathing (odds ratio [OR], 3.00; 95% confidence interval [CI], 1.47 - 6.14). They were also more often admitted to hospital (79.3% vs 65.5%), but not significantly so (adjusted OR, 2.29; 95% CI, 0.96 - 5.46). There was also no significant difference in admission to critical care or death among EV-D68-infected children vs those with rhinovirus or other enterovirus strains (adjusted OR, 1.47; 95% CI, 0.61 - 3.52). Rates of admission to the pediatric critical care unit were 23.0% (n = 20) for children with EV-D68 and 14.9% (n = 13) for those with non-EV-D68 infections. There were no deaths in the EV-D68 group, but there was one death in the non-EV-D68 group. Patients with EV-D68 infection were more likely to have a personal or family history of allergy. The OR for asthma/wheezing was 1.77, for eczema it was 1.70, for hay fever it was 1.22, and for a family history of allergy it was 2.25. As in this analysis, other studies have reported an association between respiratory EV-D68 and a history of asthma or atopy. "It seems reasonable to hypothesize that EV-D68 is a more virulent pulmonary pathogen to those with pre-existing atopic disease than other rhinoviruses and enteroviruses," the authors write. In an accompanying commentary, Michelle Science, MD, and Upton Allen, MBBS, both infectious disease consultants at the Hospital for Sick Children, Toronto, Ontario, Canada, note that the study did not examine underlying asthma severity as a potential confounder. "In this regard, it would be important to ensure that the study groups were comparable with respect to the proportion of patients with severe asthma in each group — patients with severe asthma are more likely to be admitted to hospital and receive the aforementioned interventions regardless of their EV-D68 status." The editorialists call for further studies to define whether EV-D68 is truly a more severe pathogen than other enteroviruses and rhinoviruses for all patients, or whether there are certain populations at increased risk for severe disease. "Such research should also address whether there are factors that are related to viral or patient genetic variation that might be associated with disease severity." This study received no funding. Dr Mertz is supported by an award from the Hamilton Health Sciences Foundation. The authors and commentators have declared no competing interests.

美日腸病毒D68型台無病例  2015/10/2513:33最新更新：2015/10/2513:33（中央社記者龍珮寧台北25日電）疾管署表示，腸病毒D68型在美國、日本出現急性無力肢體麻痺個案。國內6至9月監測7例，症狀輕微，主要症狀是上呼吸道感染及出現呼吸困難，未出現類似美、日肢體麻痺病例。疾病管制署22日發布致醫界通函表示，腸病毒D68型在美國與日本造成急性無力肢體麻痺個案，近期國內亦陸續發現該型病毒，請醫師提高警覺，儘速通報與採檢。疾管署副署長莊人祥今天受訪時表示，今年6至9月間，疾管署社區病毒監視發現7例腸病毒D68型（EV-D68）感染的病例，年齡介於1歲至22歲，多以發燒、流鼻水、咳嗽、喉嚨痛等上呼吸道感染症狀表現。他說，回顧2014年美國EV-D68流行疫情，有部分病例出現嚴重呼吸道症狀，及因急性無力脊髓炎（acuteflaccidmyelitis,AFM）而發生肢體麻痺，再看近期日本亦有1例EV-D68感染者出現AFM症狀。不過，相較之下，台灣個案的症狀明顯輕微，而台灣自2007年就出現個案，只是屬於零星病例。疾管署分析近2年國內EV-D68病毒株的基因序列發現和美國2014年疫情流行株系有顯著差異，是否為疾病嚴重度相異的原因仍待驗證。不過，EV-D68病毒在美國已造成重大健康危害。他說，國內自6月中旬起，請醫師在通報急性無力肢體麻痺（AFP）病例時，除要採集2件糞便檢體外，也要同時採集一件咽喉擦拭檢體以加驗EV-D68，至今還沒有AFP病例檢出EV-D68。這樣的作法是為了輔助社區病毒、腸病毒重症監視系統的功能，提高對EV-D68的監測敏感度，同時掌握該型病毒的流行與致病情形。國內法定傳染病通報系統截至10月20日，尚無AFP病例檢出EV-D68。莊人祥說，目前是腸病毒流行期，第41週(10月14-20日)門診就診人次較前一週上升，全國門急診人次高於近4年同期，社區主要流行病毒株為克沙奇A16，本週新檢出1例感染EV71輕症個案。他說，2015年迄今共5例腸病毒重症確定病例，感染病毒型別為3例克沙奇B5、2例克沙奇A16，其中2例死亡。疾管署提醒，腸病毒傳染力極強，家中有嬰幼兒的民眾應注意自身及幼兒的健康狀況，並落實正確勤洗手、戴口罩等，克沙奇表現比較典型的手足口症，而EV-D68會呼吸困難。