SARS: Precautions need not await scientific proof

'Good faith turned out to be tragically wrong'

The medical response to severe acute respiratory syndrome (SARS) in the 2003 outbreak in Toronto was undermined by a "turf war" between infection control and industrial hygienists, with health care workers ultimately suffering as a result, according to the final report by the Ontario Commission to Investigate the Introduction and Spread of SARS.

The massive report leaves no stone unturned and throws a few of them in the direction of the infection control community. At issue is the failure of some ICPs and medical officials to urge rigorous airborne precautions from the onset of the emerging infection, even though the report itself acknowledges that "the jury is still out on the extent of airborne SARS [transmission]." The following excerpt from the report outlines the central conflict and tragic results:

"One of the biggest bones of contention during SARS was the N95, a respirator that protects much more than a surgical mask and that was mandated for health workers caring for SARS patients. Although Ontario law since 1993 required that anyone using an N95 had to be properly trained and fit tested to ensure proper protection, few hospitals complied with this law. Some medical experts even denied the very existence of this legal requirement. Fit testing was the subject of official confusion and heated debate. . . . The debate about respiratory protection and fit testing can be understood only in the context of the heavy burden of disease that fell on hospital workers, paramedics and others who worked in Ontario's health system during SARS. Two nurses and a doctor died from SARS. Almost half of those who contracted SARS in the health system were people who got the disease on the job. Most of these workers were nurses whose jobs brought them into the closest and lengthiest contact with sick patients. And this does not show the full burden of SARS on nurses, paramedics, and other health workers. Nurses sick with undetected SARS inadvertently brought illness, and in some cases death, home to their families.

"Again and again, nurses were told they were safe if they would only do what they were told by the health system. Again and again, these scientific assurances, though well intentioned and issued in the best of good faith, turned out to be tragically wrong. It is no wonder that nurses became alarmed when they saw their colleagues sicken and die. It is no wonder that they became angry when they saw such incidents recur again and again with no apparent improvement in their safety. As SARS continued and more health workers fell ill, the resulting justified lack of confidence in health care safety systems fueled a heated debate about the need for the N95 respirator and for the safety requirement that workers be fit tested and trained in its use. Some infection control experts argued in good faith that the fit testing law was ill-advised; that N95 respirators were not needed because SARS was droplet spread, not airborne; that the Provincial Operations Centre was wrong to require fitted N95s; and that nurses would be safe if they followed the advice of their employers instead of the safety procedures required by law. Nurses pushed back with understandable heat, saying that hospitals should follow then the Ontario Department of Labour should fulfill its enforcement mandate and make them do so."

Debate recalls U.S. TB acrimony

The issues raised during SARS in Canada recall the philosophical antagonism between infection control and industrial hygiene approaches seen in the United States in the 1990s, when federal regulators were trying to create a tuberculosis standard to protect health care workers. Familiar arguments about the utility and efficacy of masks, respirators, fit-testing, et al resurfaced in Ontario during the outbreak. In addition, the disagreement about whether SARS could spread by the airborne route — in addition to droplets — created a mid-outbreak debate that opened ICPs to criticism that that they were more concerned about scientific certainty than protecting health care workers.

"There were two solitudes during SARS: infection control and worker safety," the report states. "Infection control insisted that SARS was mostly spread by large droplets which do not travel far from an infectious person. Given that case, in their view, a surgical mask was sufficient to protect health workers in most situations. Worker safety experts said workers at risk should have the higher level of protection of an N95. They said not enough is known about how SARS is spread to rule out airborne transmission by much smaller particles, and besides, hospitals are dynamic places where unforeseen events and accidents can always happen. Infection control relied on its understanding of scientific research as it stood at the time. Worker safety experts relied on the precautionary principle that reasonable action to reduce risk should not await scientific certainty."

In the tragic aftermath, the precautionary principle was seen as the approach for future epidemics and some ICPs found themselves on the wrong side of history when it came to SARS. The report calls for an end to acrimonious debate and acknowledgement that people on all sides acted in good faith.

"The point is not who is right and who is wrong about airborne transmission," the report concludes. "The point is not science, but safety. Scientific knowledge changes constantly. Yesterday's scientific dogma is today's discarded fable. When it comes to worker safety in hospitals, we should not be driven by the scientific dogma of yesterday or even the scientific dogma of today. We should be driven by the precautionary principle that reasonable steps to reduce risk should not await scientific certainty. Until this precautionary principle is fully recognized, mandated, and enforced in Ontario's hospitals, workers will continue to be at risk."

(Editor's note: The final report of the SARS Commission in Ontario, Canada, is available at