High percentage of exposed HCWs infected in Ebola, Marburg outbreaks
Based on findings from more than 20 past and present Ebola and Marburg outbreaks, researchers reported consistently high infection rates among exposed health care workers, highlighting an urgent need to strengthen infection control practices, they said.
Writing in The Journal of Infectious Diseases, Saranya A. Selvaraj, MD, of the University of Maryland Medical Center in Baltimore, and colleagues noted that health care workers are at an increased risk for infection during outbreaks, especially in the absence of appropriate prevention and safety measures.
During two recent Ebola virus outbreaks in the Democratic Republic of the Congo, health care workers were the first to receive an experimental Ebola vaccine, underlining their unique risk for infection.
“Outbreaks of deadly infection among [health care workers] are considered red flags that should trigger suspicion for EVD or MVD and often result in nosocomial spread between staff and patients and then spread back into the community,” Selvaraj and colleagues wrote.
To identify infection rates among health care workers and compare them with the general population — and determine the occupations at the highest risk and the most frequent exposure risks — Selvaraj and colleagues searched the EMBASE and PubMed databases to identify articles posted before Dec. 27, 2017, and extracted data on health care worker infections and exposures. They included 94 articles related to 22 outbreaks in the study. In them, Selvaraj and colleagues found that health care worker infections comprised anywhere from 2% to 100% of cases in Ebola outbreaks and 5% to 50% of cases in Marburg outbreaks. Among exposed workers, between 0.6% and 92% developed Ebola virus disease and 1% to 10% developed Marburg virus disease.
Selvaraj and colleagues found that nursing staff were the most frequently infected — they were identified in 91% of reports — followed by medical staff and laboratory staff. The articles showed other occupations at risk, including students, pharmacists and transporters.
According to Selvaraj and colleagues, the most common causes of infection were insufficient or incorrect use of personal protective equipment (PPE) and exposure to undiagnosed patients. Deficiencies in PPE use, the researchers wrote, were often caused by lack of availability of appropriate equipment and the lack of training in personal protective equipment use during patient care, or both; patient transport and cleaning activities; and engaging in activities such as rubbing eyes, smoking and even using mobile telephones.
Additionally, Selvaraj and colleagues found that clusters with the highest proportion of cases occurring in health care workers came in countries where the viruses were introduced by an isolated traveler.
They noted that “exposure to unrecognized patients has been reduced by the use of triage tools, isolation of suspect cases, use of standard precautions and barrier nursing techniques, and improvement in laboratory infrastructures to reduce the time to diagnosis, such as the introduction of new point-of-care tests for [Ebola virus disease] that can be run quickly at health centers lacking laboratory facilities.”
“High [health care worker] infection rates and similar exposure risk factors in both past and recent [Ebola and Marburg] outbreaks highlight the need to urgently strengthen [infection prevention and control] program implementation at the facility level to ensure patient and [health care worker] safety in everyday care service delivery and in the event of an outbreak,” Selvaraj and colleagues wrote. “Our data also represent a useful addition to inform models designed to estimate the impact of various prevention strategies and to emphasize that [health care workers] also risk their lives for the patients under their care.” – by Caitlyn Stulpin
Disclosure: The authors report no relevant financial disclosures.