Severe acute respiratory syndrome

Editor—Detailed measures to protect healthcare workers from severe acute respiratory syndrome (SARS) are paramount. The equipment of choice for respiratory protection is thought to be the disposable N95 respirator. However, without testing the fit, a poor facial seal may result in a reduction to only 33% of ambient levels.¹

Guidelines were developed through a collaborative process involving the Workers' Compensation Board of British Columbia (the state's regulatory agency), the Occupational Health and Safety Agency for Healthcare (jointly governed by healthcare unions and employers), and provincial experts in public health, infection control, and infectious disease.² An important component was a risk assessment designed to reduce the exclusive use of fit tested N95 respirators without diminishing worker safety.

At initial presentation all patients with respiratory symptoms are considered potentially to have SARS, and healthcare workers are required to wear a fit tested N95 respirator and protective eyewear until risk assessment is completed and reasons for admission are ascertained. During the initial period of greatest risk, full personal protective equipment is required (table). As the patient recovers and the risk of aerosolisation reduces, the requirement for a fitted respirator and face protection declines.

Table 1.

Risk level and measures to protect healthcare workers from SARS

Risk level	Hazard	N95 required*	Surgical mask acceptable	Gown†	Gloves†	Goggles, safety glasses, or face shield†	Handwashing
High	Acute illness with potential aerosol formation by clinical behaviour‡, procedures§, or medication∥	Yes	No	Yes	Yes	Yes	Yes
Medium	Stable or improving illness: afebrile for 10 days* *, with cough††, or requiring nasal oxygen	No	Yes	Only if direct contact	Only if direct contact	Only if direct contact	Yes
Low	Stable improved illness; afebrile, and no cough	No respirator or mask required		Standard precautions apply	Standard precautions apply	Not required	Yes

^*If approved N95 respirator is required, it must be fit tested.

^†Care must be taken when removing gloves, gowns, or eye protection to avoid self contamination.

^‡Coughing, sneezing, shouting, forceful vomiting, severe diarrhoea.

^§Includes, but not limited to, intubation, bronchoscopy, percussive therapy, cough induction.

^∥Humidified oxygen, or nebulised pharmacotherapy.

^{* *}A patient may be febrile due to a secondary infection and no longer be infectious for SARS. While culture and molecular testing are becoming available, currently neither has been validated; this guideline is based on epidemiological information on transmission, consistent with that used by the World Health Organization to determine the period of communicability. When assessing risk, all available information should be taken into consideration, including viral cultures where known or results from amplification by polymerase chain reaction.

^††Respiratory protection (surgical mask) is standard practice in caring for any patient, whether known to be infectious or not, in the presence of aerosolising procedure/behaviour.

Throughout, critical emphasis is placed on hand hygiene and careful use and removal of personal protective equipment to prevent accidental autoinoculation. Staffing must be adequate to meet the increased workload that occurs with SARS patients, to allow healthcare workers to maintain vigilance.

Seto et al noted that transmission of infection was equal among workers wearing either surgical masks or N95 respirators, when high risk of aerosolisation was excluded.³ On the other hand, a review of cases of SARS in Toronto found that some healthcare workers who acquired SARS were not fit tested and had not been trained to use personal protective equipment, which potentially results in accidental autoinoculations.⁴ This supports the need for a formal programme including fit testing, education on use, and removal of personal protective equipment, as well as a risk assessment approach with full equipment for high risk activities.

Detailed documents on how to apply a risk based approach are now circulating throughout the province along with a programme to train the trainer.⁵ We hope that lessons learnt from SARS will strengthen our ability to protect healthcare workers and the public from other pathogens.