Infection Control Protects Hospital Staff From COVID-19

MARCH 2020 — Hospital-related infections have been widely reported during the ongoing coronavirus outbreak, with healthcare professionals bearing a disproportionate risk. However, a proactive response in Hong Kong’s public hospital system appears to have bucked this trend and successfully protected both patients and staff from SARS-CoV-2, according to a study published online in Infection Control & Hospital Epidemiology.

During the first 42 days of the outbreak, the 43 hospitals in the network tested 1275 suspected cases and treated 42 patients with confirmed COVID-19, the disease caused by SARS-CoV-2 infection. Yet, there were no nosocomial infections or infections among healthcare personnel, report Vincent C.C. Cheng, MD, FRCPath, the hospital’s infection control officer, and colleagues.

Cheng and colleagues note that 11 out of 413 healthcare workers who treat patients with confirmed infections had unprotected exposure and were in quarantine for 14 days, but none became ill.

In comparison, they note, the 2003 SARS outbreak saw almost 60% of nosocomial cases occurring in healthcare workers.

Proactive Bundle

The Hong Kong success story may be due to a stepped-up proactive bundle of measures that included enhanced laboratory surveillance, early airborne infection isolation, and rapid-turnaround molecular diagnostics. Other strategies included staff forums and one-on-one discussions about infection control, employee training in protective equipment use, hand-hygiene compliance enforcement, and contact tracing for workers with unprotected exposure.

In addition, surgical masks were provided for all healthcare workers, patients, and visitors to clinical areas, a practice previously associated with reduced in-hospital transmission during influenza outbreaks, the authors note.

Hospitals also mandated use of personal protective equipment (PPE) for aerosol-generating procedures (AGPs), such as endotracheal intubation, open suctioning, and high-flow oxygen use, as AGPs had been linked to nosocomial transmission to healthcare workers during the 2003 SARS outbreak.

The infection control measures, which were part of a preparedness plan developed after the SARS outbreak, were initiated on December 31, when the first reports of a cluster of infections came from Wuhan, China.

As the outbreak evolved, the Hong Kong hospitals quickly widened the epidemiologic criteria for screening, from initially including only those who had been to a wet market in Wuhan within 14 days of symptom onset, to eventually including anyone who had been to Hubei province, been in a medical facility in mainland China, or in contact with a known case.

All suspected cases were sent to an airborne-infection isolation room (AIIR) or a ward with at least a meter of space between patients.

“Appropriate hospitalinfection control measures could prevent nosocomial transmission of SARS-CoV-2,” the authors write. “Vigilance in hand hygiene practice, wearing of surgical mask in the hospital, and appropriate use of PPE in patient care, especially [when] performing AGPs, are the key infection control measures to prevent nosocomial transmission of SARS-CoV-2 even before the availability of effective antiviral agents and vaccine.”

Asked for his perspective on the report, Aaron E. Glatt, MD, chairman of the Department of Medicine and chief of infectious diseases at Mount Sinai South Nassau in Oceanside, New York, said that apart from the widespread issuing of surgical masks to workers, patients, and visitors, the measures taken in Hong Kong are not different from standard infection-control practices in American hospitals. Glatt, who is also a hospital epidemiologist, said it was unclear how much impact the masks would have.

“Although the infection control was impressive, I don’t see any evidence of a difference in care,” he told Medscape Medical News.

Could zero infection transmission be achieved in the more far-flung and variable settings of hospitals across the United States? “The ability to get zero transmission is only possible if people adhere to the strictest infection-control guidelines,” Glatt said. “That is clearly the goal, and it will take time to see if our existing strict guidelines are sufficient to maintain zero or close to zero contamination and transmission rates in our hospitals.”

Rather than looking to change US practices, he stressed adherence to widely established tenets of care. “It’s critically important to keep paying close attention to the basics, to the simple blocking and tackling, and to identify which patients are at risk, and therefore, when workers need protective equipment,” he said.

“Follow the recommended standards,” continued Glatt, who is also a spokesperson for the Infectious Diseases Society of America and did not participate in this study.

In a finding from an ancillary pilot experiment, the Hong Kong researchers found exhaled air from a patient with a moderate coronavirus load showed no evidence of the virus, whether the patient was breathing normally or heavily, speaking, or coughing. And spot tests around the room detected the virus in just one location.

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“We may not be able to make a definite conclusion based on the analysis of a single patient,” the authors write. “However, it may help to reassure our staff that the exhaled air may be rapidly diluted inside the AIIR with 12 air changes per hour, or probably the SARS-CoV-2 may not be predominantly transmitted by [the] airborne route.”

However, a recent Singapore study showed widespread environmental contamination by SARS-CoV-2 through respiratory droplets and fecal shedding, underlining the need for strict adherence to environmental and hand hygiene. Post-cleaning samples tested negative, suggesting that standard decontamination practices are effective.

This work was partly supported by the Consultancy Service for Enhancing Laboratory Surveillance of Emerging Infectious Diseases of the Department of Health, Hong Kong Special Administrative Region; and the Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Ministry of Education of China. The authors and Glatt have disclosed no relevant financial relationships.

Infect Control Hosp Epidemiol. Published online March 2020. Abstract