A proactive infection prevention plan implemented widely in a Hong Kong healthcare system was a significant factor preventing the spread of influenza strain A H7N9, otherwise known as Avian flu.
The study was published in the January issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America (SHEA).
“The emergence of A H7N9 influenza in March 2013 posed a public health threat both locally and internationally because of the risk for airborne transmission,” said K.Y. Yuen, MD, FRCPath, a lead author of the study. “Despite the delay in airborne precaution implementation, we suspect that high hand hygiene compliance, as a result of continuous implementation of proactive control measures against various viruses and multidrug-resistant organisms, protected frontline healthcare workers against many challenges of emerging infectious diseases.”
Risk for person-to-person transmission in A H7N9 is lower compared to other viruses including certain influenza strains, but some cases were identified as being spread between relatives. The strain is associated with high mortality and morbidity.
Researchers examined the effectiveness of preparedness measures in controlling the spread of the virus at Queen Mary Hospital in Hong Kong for 13 months (April 2013-May 2014). Infection control staff implemented an integrated approach, utilizing active and enhanced surveillance, early airborne infection isolation, rapid molecular diagnostic testing, and extensive tracing for healthcare workers with unprotected exposure. Additionally, open forum sessions were conducted to brief frontline staff on proper protocols.
During the study period, 126 of 163,456 admitted patients were tested for the strain and two cases tested positive for A H7N9 influenza. Seventy healthcare workers had unprotected exposure during patient care activities by not wearing an N95 respirator during aerosol-generating procedures. However, most of the healthcare workers exposed complied with standard precautions, including wearing a surgical mask and performing hand hygiene. No staff tested positive for the strain.
“As we look at lessons learned from this outbreak, the high false-positive screening rate and other delays in diagnosis may have resulted in unprotected exposure of frontline staff. However, enhanced surveillance methods appeared to be an important safety net for the detection of A H7N9,” said Yuen.