Nature研究亮点：抗击流感注意事项

　　

生物通报道：2007年自然出版集团宣布《Nature》出版集团的新出版物、名为Nature China的网站（www.naturechina.com.cn）正式启动。这一网站致力于聚焦中国大陆地区和香港的优秀科学成果，每周都会针对最新发表的论文，在此网站撰写摘要和评述。

来自香港大学公共健康学院的研究人员发表了题为“Facemasks and hand hygiene to prevent influenza transmission in households.”，提示公众为预防患上甲流，需要注意的事项。这篇文章入选了本期的Nature中国研究亮点。

2009年甲型流感席卷全球，卫生部专家预计中国年内甲型流病毒出现毒力增强的突变可能性较小；疫情近期将维持在较高的发病水平，一些地区将逐步进入高发期，局部地区可能出现疫情爆发。

目前重症和死亡病例数显著增加。患有慢性基础病、肥胖和妊娠是发生重症和死亡的危险因素；死亡病例的并发症主要为肺炎、呼吸衰竭和呼吸窘迫综合征、心衰和感染性休克等。

要想预防甲流，除了接种疫苗之外，来自香港大学公共健康学院的研究人员进行了抽样调查，提出洗手和帯口罩能有效的阻止家庭流感病毒的传播。虽然许多建议时常听到，但如果人们从这些细节认真做起，整个社会就能够从很大程度上降低流感蔓延的几率。

流感病毒传播的另一条传播途径是“人们打喷嚏或咳嗽时从口鼻中飞溅出的唾液”。专家因此建议，人们打喷嚏时弯起手臂，用手臂挡住口鼻，防止唾液进入空气。

“把唾液留在上衣或袖子上比任由唾液飞向物体表面，甚至直接喷到他人身上好得多，”卫生专家乔治·迪费迪南多说。当然，之后还记得要洗手。佩戴手术专用口罩也能防止唾液四溅。不过，医学界对人们每天佩戴口罩是否可行尚无定论。但如果流感病毒蔓延至整个社会，那么“佩戴口罩无疑将起到良效”。

手是呼吸道病毒传播的主要途径之一。预防流感，当务之急就是勤洗手。这一方法虽然听上去简单，但只有洗得彻底、到位才能有效远离病毒。专家说，人们应该尽量用温水或热水洗手，使用肥皂时，不仅要涂抹手指和手掌，还要涂抹指甲下部、手腕周围和指缝之间。双手互相揉搓足够长时间后再用清水洗净。

除方法得当，手还需洗得勤快、频繁。专家说，不管有没有得流感，人们在饭前便后、打完喷嚏和咳嗽后都应洗手。如果已经感染流感病毒，患者更应“加足马力”洗手，防止病毒通过这名患者接触过的东西再次传播。

（生物通：万纹）

原文摘要：

Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households
A Cluster Randomized Trial
Background: Few data are available about the effectiveness of nonpharmaceutical interventions for preventing influenza virus transmission.

Objective: To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza.

Design: Cluster randomized, controlled trial. Randomization was computer generated; allocation was concealed from treating physicians and clinics and implemented by study nurses at the time of the initial household visit. Participants and personnel administering the interventions were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00425893)

Setting: Households in Hong Kong.

Patients: 407 people presenting to outpatient clinics with influenza-like illness who were positive for influenza A or B virus by rapid testing (index patients) and 794 household members (contacts) in 259 households.

Intervention: Lifestyle education (control) (134 households), hand hygiene (136 households), or surgical facemasks plus hand hygiene (137 households) for all household members.

Measurements: Influenza virus infection in contacts, as confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or diagnosed clinically after 7 days.

Results: Sixty (8%) contacts in the 259 households had RT-PCR–confirmed influenza virus infection in the 7 days after intervention. Hand hygiene with or without facemasks seemed to reduce influenza transmission, but the differences compared with the control group were not significant. In 154 households in which interventions were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR–confirmed infection seemed reduced, an effect attributable to fewer infections among participants using facemasks plus hand hygiene (adjusted odds ratio, 0.33 [95% CI, 0.13 to 0.87]). Adherence to interventions varied.

Limitation: The delay from index patient symptom onset to intervention and variable adherence may have mitigated intervention effectiveness.

Conclusion: Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza.