Ghost of SARS: Emerging MERS-CoV poses infection threat to HCWs
22 cases linked to one hospital in Saudi Arabia
An emerging SARS-like novel coronavirus may pose a particular threat for hospital outbreaks that could spread infections to both patients and health care workers.
The first sporadic cases of MERS-CoV (Middle East Respiratory Syndrome Coronavirus) occurred in Jordan in April 2012, but by late May of 2013, 43 cases had been detected in eight countries: Jordan, Saudi Arabia, Qatar, the United Kingdom, France, Germany, Tunisia and the United Arab Emirates. The mortality rate is about 50% for known cases, although milder infections may be going unidentified.
Half of the known MERS-CoV cases came from a single outbreak at a hospital in an eastern province of Saudi Arabia. Two health care workers were among those who developed MERS-CoV there after contact with infected patients. Ten people died.
“Increasingly, this virus is acting much the way SARS did,” says Eric Toner, MD, senior associate with the Center for Health Security at the University of Pittsburgh Medical Center. “It doesn’t seem to transmit well in the general community, like SARS. But it does seem to transmit within hospitals and between close contacts.
“The lessons for hospitals are the lessons from SARS,” he says. “Transmission is related to unrecognized cases and inadequate infection control.”
As of late May, no MERS-CoV cases had been identified in North America. But that could change in a moment, cautions Gabor Lantos, MD, P.Eng, MBA, president of Occupational Health Management Services in Toronto and a consultant to hospitals.
“One has to be very vigilant,” he says. “Just the way [MERS-CoV] went to Paris, it just takes a different plane to come here. Dubai is now an airline hub. Who’s to say the next plane won’t be coming here with an infected person?”
In fact, the Centers for Disease Control and Prevention advises that any clusters of severe acute respiratory illness among health care workers in the United States should be “thoroughly investigated. Occurrence of a SARI cluster of unknown etiology should prompt immediate notification of local public health for further notification and testing.”
Ask about travel to Arabian Peninsula
MERS-CoV is described as an acute respiratory infection, yet not all patients initially presented with respiratory symptoms. The World Health Organization recommends droplet and contact precautions, but acknowledged that “the exact mode of transmission is unknown.”
“So far, no evidence of sustained transmission beyond the clusters into the community has been observed,” the WHO reported.
One thing is clear: MERS-CoV is a reminder of the importance of vigilant infection control. Failing to promptly identify suspect cases and put the patients in airborne isolation and failing to use proper personal protective equipment led to hospital outbreaks of SARS, notes Toner.
“As we saw with SARS, you can stop transmission with those measures,” he says. “It should be a wakeup call to hospitals that you really should be doing this routinely.”
CDC advises health care providers to evaluate patients for the novel coronavirus if they developed a severe acute lower respiratory infection within 14 days of travel to the Arabian peninsula or neighboring countries or if they were in close contact with a symptomatic traveler who developed fever and acute respiratory illness within 10 days of being in that region. Close contacts include health care workers.
The countries in that region of concern are: Bahrain, Iraq, Iran, Israel, Jordan, Kuwait, Lebanon, Oman, Palestinian territories, Qatar, Saudi Arabia, Syria, the United Arab Emirates (UAE), and Yemen.
Toner suggests that hospitals may want to be even more sensitive to fever and illness among travelers to or near the Arabian Peninsula. The French cluster originated with a man who had traveled to the Persian Gulf and came to the emergency room with a fever and gastrointestinal symptoms, Toner says. Because he didn’t initially have respiratory symptoms, he was not isolated.
“Health care providers need to have a high index of suspicion,” he says.
The WHO cautioned, “Clinicians are reminded that MERS-CoV infection should be considered even with atypical signs and symptoms, such as diarrhea, in patients who are immunocompromised.”
The WHO issued infection control guidelines that recommend the use of a mask when in close contact with a suspected MERS-CoV patient and the use of a respirator, eye protection, gown and gloves when performing aerosol-generating procedures. (See box below.)
“The infection of two health care workers who had contact with infected patients and other examples of nosocomial transmission re-emphasize the need for meticulous adherence to appropriate infection control measures when MERS-CoV is suspected, beginning with initial patient triage,” the WHO said.
Old SARS closed hospitals
SARS illustrated how suddenly and unpredictably a novel infection could spread. A few “superspreaders” were highly infectious and linked to aerosolized transmission. Ultimately, outbreaks led to the closing of hospitals, the quarantine of nurses, and the illness and deaths of health care workers.
So far, MERS-CoV transmission has been limited. But caution is the lesson from SARS. A SARS Commission convened in Ontario issued a final report in 2007, urging the adoption of a “precautionary principle that safety comes first, that reasonable efforts to reduce risk need not await scientific proof.”1
Today, that means hospitals need to be prepared to prevent airborne spread of a novel infectious disease, Lantos says. He urges hospitals to include an industrial hygienist or safety officer with knowledge about respiratory protection in the preparedness task force.
Reducing the risk of airborne transmission may require an understanding of the hospital’s air flow, the impact of facility design, and the best selection and use of respiratory protection, he says.
This is a good time for hospitals to beef up health care worker education about proper respirator use (such as donning and doffing) and to monitor PPE use and hand hygiene, Lantos says.
So far, the human-to-human transmission of MERS-CoV has been limited. “It is, I think, likely that there will be continued sporadic cases,” Allison McGeer, MD, director of infection control at Mount Sinai Hospital in Toronto told The Canadian Press after a visit to Saudi Arabia. “But whether this is a stable, sporadic virus that will continue to do what it’s been doing and not change very much or whether it’s a virus that’s in the process of changing and is going to cause more trouble is, I think, a completely open question.”
As hospitals and public health authorities cope with the MERS-CoV threat, they might consider the conclusions of the SARS Commission:
“SARS taught us that we must be ready for the unseen. There is no longer any excuse for governments and hospitals to be caught off-guard and no longer any excuse for health workers not to have available the maximum level of protection through appropriate equipment and training.”
Editor’s note: Updated information about MERS-CoV from the CDC is available at www.cdc.gov/coronavirus/ncv/case-def.html.
1. Campbell JA. Spring of Fear: The SARS Commission Final Report, Toronto, 2006. Available at www.archives.gov.on.ca/en/e_records/sars/index.html. Accessed on May 23, 2013.
WHO precautions for health workers
The World Health Organization has issued the following recommendations for those caring for suspected or confirmed MERS-CoV patients
• Limit the number of HCWs, family members and visitors in contact with a patient with probable or confirmed nCoV (novel coronavirus) infection.
• To the extent possible, assign probable or confirmed cases to be cared for exclusively by a group of skilled HCWs both for continuity of care and to reduce opportunities for inadvertent infection control breaches that could result in unprotected exposure.
• Family members and visitors in contact with a patient should be limited to those essential for patient support and should be trained on the risk of transmission and on the use of the same infection control precautions as HCWs who are providing routine care. Further training may be needed in settings where hospitalized patients are often cared for by family members.
In addition to Standard Precautions, all individuals, including visitors and HCWs, when in close contact (within 1 meter) or upon entering the room or cubicle of patients with probable or confirmed nCoV infection should always:
• wear a medical mask
• wear eye protection (goggles or a face shield);
• wear a clean, non-sterile, long-sleeved gown; and gloves (some procedures may require sterile gloves);
• perform hand hygiene before and after contact with the patient and his or her surroundings and immediately after removal of PPE.
• If possible, use either disposable equipment or dedicated equipment (e.g. stethoscopes, blood pressure cuffs and thermometers). If equipment needs to be shared among patients, clean and disinfect it between each patient use. HCWs should refrain from touching their eyes, nose or mouth with potentially contaminated gloved or ungloved hands.
• Place patients with probable or confirmed nCoV infection in adequately ventilated single rooms or
Airborne Precaution rooms; if possible, situate the rooms used for isolation (i.e. single rooms) in an area that is clearly segregated from other patient -care areas. When single rooms are not available, put patients with the same diagnosis together. If this is not possible, place patient beds at least 1 meter apart.
In addition, for patients with probable or confirmed nCoV infection:
• Avoid the movement and transport of patients out of the isolation room or area unless medically necessary. The use of designated portable X-ray equipment and other important diagnostic equipment may make this easier. If transport is required, use routes of transport that minimize exposures of staff, other patients and visitors.
• Notify the receiving area of the patient’s diagnosis and necessary precautions as soon as possible before the patient’s arrival.
• Clean and disinfect patient-contact surfaces (e.g. bed) after use.
• Ensure that HCWs who are transporting patients wear appropriate PPE and perform hand hygiene afterwards.