Infection Rates of HCW
3.5-20% of HCW has been reported to be infected.(1, 37-40)
Initially, during the index outbreak in Wuhan, 13 HCWs were infected.(41) They became the vectors of transmission to their colleagues and families, and 42 000 HCWs had to be brought in to treat patients as HCWs succumbed to COVID-19.(41, 42)
Wang D et al found nosocomial infection rate of 41.3%.(43) In a case series of 138 patients, 29% (n=40) of these were HCW: 31 (77.5%) worked on general wards, 7 (17.5%) in emergency department, and 2 (5%) in intensive care unit.(43) They reported patient who presented with abdominal symptom infected >10 HCW in the department.(43)
There was a report of a patient who was not identified as infected early in the Wuhan outbreak and proceeded to infected 14 HCW during a stay for transnasal pituitary surgery.(44) However, the patient was transferred to 4 different wards and infected 10 neurosurgical nurses and 4 medical staff who had no PPE, rather than the operating room team and neurosurgeon.(29) Certain specialty like otolaryngology are disproportionately affected in most countries affected by the COVID-19 pandemic.(44)
Wang X et al found none of the 278 staff in the quarantined area with high exposure to the 28 patients with 2019-nCoV infection were infected.(45) They wore N95 respirators, disinfected and performed hand hygiene. Those in the Hepatobiliary Pancreatic Surgery, Trauma and Microsurgery, and Urology departments wore no masks, but disinfected and performed hand hygiene occasionally as there were not considered high risk in the early days of the outbreak in January(45). 10 of the 213 staff were confirmed to be infected, despite their lower risk of exposure.(45) The adjusted odds ration (OR) was 464.82.(45) The found no infections in two other hospitals in the N95 respirators groups.(45)
The increasing evidence of aerosol transmission during routine care in absence of AGPs, and concerns regarding efficient human transmission has resulted in recommendation for airborne precautions with a fit-tested N95 respirator and other PPE.(46, 47)
When the Chinese hospitals instituted full body PPE with goggles, head coverings, N95 respirators, hazmat suits, and they were housed away from their families, there was no new infections.(41) Since then, nosocomial transmission has not been a major amplifier of transmission in China, due to prevention and control.(31) It is believed that with the absence of major nosocomial outbreaks, these are acquired in their families where 85% of human-to-human transmission occurred.(12, 14, 15, 24, 31, 48)