China’s latest SARS outbreak has been contained, but biosafetyconcerns remain – Update 7

18 May 2004

It has been more than three weeks since the last case was placed inisolation in China’s latest SARS outbreak, prompting the WorldHealth Organization to declare that the chain of human-to-humantransmission appears to have been broken.

However, WHO experts and the Chinese authorities are still tryingto determine the exact cause of the outbreak. The investigation hascentred primarily on the National Institute of Virology in Beijingwhere experiments using live and inactivated SARS coronavirus havebeen carried out. Two researchers at the Institute developed SARSin late March and mid-April. The outbreak was reported on April 22and the Institute was closed a day later.

Preliminary findings in the investigation have yet to identify asingle infectious source or single procedural error at theInstitute – and it is conceivable that an exact answer may never bedetermined. Neither of the researchers is known to have directlyconducted experiments using live SARS coronavirus. However,investigators have serious concerns about biosafety procedures atthe Institute – including how and where procedures using SARScoronavirus were carried out, and how and where SARS coronavirussamples were stored.

WHO and Chinese authorities view with concern the occurrence oflaboratory-associated SARS cases. WHO urges all Member States toview this latest outbreak as an opportunity to review the biosafetypractices of institutions and laboratories working with SARScoronavirus.

During and after the SARS outbreak of 2003, a large number ofspecimens were collected from possible human cases, animals and theenvironment. These specimens, which may contain live SARScoronavirus, are still kept in various laboratories around theworld. Some of them are stored in laboratories at an inappropriatecontainment level. SARS coronavirus has also been propagated inreference and research laboratories, and distributed to otherlaboratories for research purposes. Research using live andinactivated SARS coronavirus – and other pathogens capable ofcausing serious illness -- is being conducted in manylaboratories.

WHO has issued the following laboratory safety guidelines andrecommendations:

• WHO biosafety guidelines for handling of SARS specimens

(25 April 2003)

• Summary of the discussion and recommendations of the SARSlaboratory workshop of 22 October 2003

• WHO post-outbreak biosafety guidelines for handling of SARScoronavirus specimens and cultures

(18 December 2003)

In these guidelines, WHO strongly recommends Biosafety Level 3 (BSL3) as the minimum containment level to work with live SARScoronavirus. WHO also urges Member States to maintain a thoroughinventory of laboratories working with and/or storing live SARScoronavirus and to ensure that necessary biosafety standards are inplace.

WHO commends the Chinese authorities for taking swift action tocontain the latest outbreak once it was recognized and reported, byway of extensive contact tracing and the quarantine and medicalobservation of such individuals. Once again, it has beendemonstrated that SARS is a containable disease.

中国最近一次SARS爆发已经得到控制

但仍然需要注意生物安全问题

最近中国SARS爆发中出现的最后一例病例自隔离已经超过三周，所以，WHO可以宣布人与人之间的传播链已经阻断。

但是，WHO专家和中国当局还在努力确定爆发原因。调查主要集中在北京的国家病毒所，该所使用活的或灭活的SARS冠状病毒开展实验。该所的两名研究人员于3月末和4月中出现SARS症状。4月22日报告发生爆发，一天后关闭了该研究所。

初步的调查结果没能确定出传染源，也没有发现该所实验操作方面的失误，可以说没有获得所想象的结果。而且患病的两位研究人员均没有直接使用SARS冠状病毒进行实验。但是，调查者还是特别关注该所的生物安全程序规范，包括使用SARS冠状病毒进行实验时，是如何采取生物安全防范，在哪些操作环节上采取防范，以及SARS冠状病毒样品是如何储存、储存在哪里？

WHO和中国当局认真审视了此次与实验室相关的SARS病例的发生。WHO鼓励所有的成员国以此为契机，对从事SARS冠状病毒研究的研究所和实验室的生物安全方面问题进行一次认真检查。

在2003年SARS爆发期间和过后，从可能的人类病例、动物和环境中收集了大量的样品。目前全世界的许多实验室中仍然保存着这些可能包含活的SARS冠状病毒的样品。其中有些样品存放的实验室不符合标准。在参比研究实验室中已经大量繁殖SARS冠状病毒，并以研究目的向其它实验室分发。目前，许多实验室使用活的和灭活的SARS冠状病毒以及其它可能导致严重疾病的病原体开展研究。

WHO已经已经发布了以下实验室安全指南和建议：

• WHO关于处理SARS样品生物安全指南（2003年4月25日）

• 有关SARS实验室工作讨论及建议概要（2003年10月22日）

 • 爆发结束后，WHO提出有关SARS冠状病毒样品处理和培养方面的生物安全指南（2003年12月18日）

在这些指南中，WHO特别提出，从事活SARS冠状病毒工作生物安全级别最低要达到3级。WHO还鼓励成员国将从事和/或储存活SARS冠状病毒的实验室列出目录，确保达到必要的生物安全标准。

WHO称赞中国当局发现爆发后迅速报告，迅速采取行动，通过广泛追踪接触者，并对这些人进行隔离和医学观察及时地控制了爆发。再一次证实了SARS是一种可以控制的疾病。

（WHO OUTBREAK NEWS 18 May 2004 张晶 译）