U.S. hospitals act to prevent the spread of SARS to health workers
Five HCWs have SARS, but transmission is limited
Continued hospital transmission of severe acute respiratory syndrome (SARS) in Canada raised new questions about infection control precautions and whether those precautions were providing enough protection for health care workers. So far, swift identification of cases and adherence to infection control procedures have prevented widespread infection of U.S. health care workers, as has occurred in Asia and Canada. At least five U.S. health care workers may have contracted SARS from caring for patients, and one hospital worker was among the nation’s 52 probable cases reported by April 28.
Yet breakthrough cases among health care workers in the critical care and SARS units at Sunnybrook and Women’s College Health Sciences Centre and at Mount Sinai Hospital in Toronto caused concern worldwide. Four health care workers were admitted to the hospital with suspected SARS after they intubated a patient with SARS. Other health care workers also have come down with SARS despite the protective equipment.
James Young, MD, Ontario’s Commissioner of Public Security, said there likely was a breach of infection control due to fatigue and "inadvertent actions." The Centers for Disease Control and Prevention (CDC) dispatched a team that included an environmental engineer, an industrial hygienist, and a medical epidemiologist to Toronto to assist in the investigation.
The team members will look for possible lapses in infection control procedures, including the fit of respirators and the functioning of negative pressure rooms, said CDC director Julie Gerberding, MD, MPH. "If there’s any leakage around the mask, it really negates the whole value of having that filtration factor in front of your breathing zone."
Meanwhile, the World Health Organization (WHO) in Geneva advised those working with SARS patients should wear respirators equivalent to an N100 or N99 — providing 99.97% and 99% efficiency respectively. N95 respirators "could be worn where no acceptable higher protection alternatives are available," the WHO said. (For more detailed recommendations, go to: www.who.int/csr/sars/infectioncontrol/en/.)
Health officials also warned of the risk of surface contamination. In the investigation of transmission in Hong Kong, researchers found that the coronavirus identified in the SARS outbreak survived on surfaces for as long as 24 hours, the CDC reported. Both the CDC and WHO have emphasized the importance of disinfection and hand hygiene.
"Soiled gloves, stethoscopes, and other equipment have the potential to spread infection," the WHO reported.
Toronto-area health care workers in high-risk units now wear N95 respirators, full-face shields, double gloves, and double gowns. "I just feel the incredible pressure they’re under," says Barb Wahl, RN, president of the Ontario Nurses Association. "It’s very difficult physically to work when you’re gloved, gowned, masked, and wearing eye shields. To know that there were people who became ill despite the precautions is very, very stressful."
U.S. hospitals have expanded their respiratory protection programs, but purchasing additional N95 respirators has become difficult because the respirators are diverted to Hong Kong, Singapore, Canada, and other countries struggling to contain transmission. By late April, several countries had made progress in containing the SARS outbreak. The WHO removed Vietnam from its list of affected areas and canceled the travel advisory it had imposed that discouraged travel to Canada. Gro Harlem Brundtlands, MD, WHO director-general, noted that no new cases of community transmission had occurred for 20 days in Toronto. However, cases continued to mount in China, reaching a total of 3,303 probable cases and 148 deaths there.
Meanwhile, the Occupational Safety and Health Administration (OSHA) reminded employers of their duty to protect workers from recognized hazards. (Go to OSHA’s web site: www.osha.gov/dep/sars/index.html.) The agency stressed the need to train workers, to use standard precautions and personal protective equipment, and to comply with the bloodborne pathogens standard.
Yet the potential for an OSHA citation pales in comparison with the chaos that can occur from an undiagnosed case of SARS. In Ontario, the spread of SARS from a single undiagnosed patient led to the quarantine of hundreds of health care workers, the restriction of hospital visitors, and even the closing of hospitals. An undiagnosed case in a Hong Kong hospital before SARS had been identified led to transmission to 99 health care workers.
Active cases in Canada have declined, and Canadian health officials had lauded the stringent efforts of hospitals to contain the disease. The key, said Young, is identifying suspect cases based on symptoms and travel or contact with travelers to affected areas. Some patients have an atypical presentation and may not have a fever, he noted.
"They must approach every patient with a high index of suspicion that they have SARS, particularly if they have any type of respiratory illness, and treat everyone as if they had SARS until it is determined they do not," he said.
With posters in emergency departments (EDs) and alert personnel, U.S. hospitals have raised awareness of SARS and implemented screening. As of April 28, there were 272 suspected or probable SARS cases in the United States. There had been 353 deaths worldwide, but none in the United States.
Hospitals were anxious to obtain a diagnostic test that would help them identify, or rule out, SARS. Researchers in Canada and the CDC had moved with record speed to decode the genome of the new coronavirus, and Emory University in Atlanta became the first to develop a rapid PCR test to identify a genetic sequence in patients who presented to the hospital there. The CDC also was developing and testing a diagnostic tool.
But Gerberding cautioned, "Although we have tests that can identify it when it’s present, we don’t know how sensitive they are. If they are not very sensitive, there may be patients who really have infection, but the test is negative because it just doesn’t have the sensitivity to pick it up."
Gerberding also warned that United States remains vulnerable to broader transmission. "We have to remain vigilant because it is only one highly transmissible patient that can affect a large number of people," she said. "We must continue to identify suspect cases and isolate individuals as quickly as we can . . . so we don’t end up with an epidemic that is as rapidly progressive as what we are seeing in some parts of Asia."
Julie Hall, MD, medical officer with the Global Outbreak Alert and Response Operations of the WHO, stressed the risk of failing to use appropriate infection control practices.
"Attack rates at hospitals where infection control precautions had not been taken can be greater than 50%, highlighting the real need for infection control," she said. For example, in one Hong Kong hospital, 16 medical students examined a SARS patient without respiratory protection. All 16 subsequently developed SARS.
By stepping up preparedness for bioterrorism, many hospitals improved their ability to handle emerging infectious diseases, such as SARS. They installed new negative pressure rooms, improved internal communication, and conducted training.
But preventing transmission still relies on basic tasks. Here are some recommendations from Linda Chiarello, RN, MS, of CDC’s division of health care quality promotion:
- Provide surgical masks to patients with respiratory symptoms who enter the ED until they can be evaluated for SARS.
- Patients with suspected SARS should be segregated as soon as possible, preferably in a private room under negative pressure.
- Use of a nebulizer should be avoided because of the greater potential for spread of the disease to health care workers.
- If health care workers are working in a SARS ward, they may wear the same gown to care for different patients. However, disposable respirators should be discarded, gloves should be changed, and hand hygiene should be performed between each patient contact. Health care workers also should wear fit-tested N95 respirators and eye protection.
"Because there is evidence that coronavirus can survive on surfaces, protection of the environment of care is critical to interrupting transmission," says Chiarello. "It should be assumed that the immediate environment around the patient is highly contaminated."
That means hospitals should disinfect bedrails, bed tables, sinks, and other surfaces in the SARS patient’s room every day, she says. Linens and laundry should be placed in designated bags.
"Hand hygiene is the cornerstone of prevention — traditional hand washing followed by drying, or use of alcohol-based hand rubs. Alcohol-based hand rubs may be used as an alternative when hands are not visibly soiled."
Health care workers who are exposed to a SARS patient before infection control measures are taken should be monitored for symptoms, but the CDC has not recommended quarantine.
Beyond infection control, hospitals must cope with anxiety and the unknown. At Presbyterian Hospital in Albuquerque, NM, a patient with respiratory symptoms who had traveled to Hong Kong came into the ED on March 14 — the day the CDC activated its Emergency Operations Center to handle a new atypical pneumonia that had occurred in Asia.
Within six minutes, the triage nurse and other ED personnel suspected a connection between the apparent pneumonia and a newly emerging disease. They placed a mask on the patient and ushered him into a negative pressure room. They donned protective gear. The patient was discharged with a diagnosis of pneumonia, then contacted two days later and readmitted to the hospital. By mid-April, the patient had recovered, and the case still will be counted as a probable incidence of SARS. As a precaution, 15 ED workers, including the triage nurse, were asked to stay home until seven days after their brief, unprotected exposure. "We have no indications that any employee has shown any symptoms," says hospital spokesman Todd Sandman. "We feel that we have a case that was very well-contained, if this does, in fact, turn out to be SARS."
At El Camino Hospital in Mountainview, CA, located in Santa Clara County where several SARS cases have been identified, epidemiology coordinator Peggy Takizawa, MS, RN, went on rounds to reassure worried health care workers. She also uses a rapid influenza test to help rule out SARS among patients with respiratory symptoms. "Everybody has respiratory symptoms right now. The question is to ask about their travel or if anyone they have contact with has been in [affected countries]."
While hospitals respond to the threat of SARS, they should be honing their capacity to deal with any infectious disease, advises Paul Penn, MS, CHEM, CHSP, founder of Enmagine, a health care emergency management and health and safety consulting firm based in Diamond Springs, CA.
"The annual flu, anthrax, smallpox, SARS — no matter what the origin is — my recommendation is that they look at it as an overall infectious disease prevention and control approach," he says. "Rather than creating new approaches for every new disease, let us deal with an approach that addresses all diseases."
(Editor’s note: For updates on SARS, go to: www.cdc.gov/ncidod/sars/index.htm.)