Annual Burden of Occupationally‐Acquired Influenza Infections in Hospitals and Emergency Departments in the United States

Abstract

Infections among health-care personnel (HCP) occur as a result of providing care to patients with infectious diseases, but surveillance is limited to a few diseases. The objective of this study is to determine the annual number of influenza infections acquired by HCP as a result of occupational exposures to influenza patients in hospitals and emergency departments (EDs) in the United States. A risk analysis approach was taken. A compartmental model was used to estimate the influenza dose received in a single exposure, and a dose-response function applied to calculate the probability of infection. A three-step algorithm tabulated the total number of influenza infections based on: the total number of occupational exposures (tabulated in previous work), the total number of HCP with occupational exposures, and the probability of infection in an occupational exposure. Estimated influenza infections were highly dependent upon the dose-response function. Given current compliance with infection control precautions, we estimated 151,300 and 34,150 influenza infections annually with two dose-response functions (annual incidence proportions of 9.3% and 2.1%, respectively). Greater reductions in infectious were achieved by full compliance with vaccination and IC precautions than with patient isolation. The burden of occupationally-acquired influenza among HCP in hospitals and EDs in the United States is not trivial, and can be reduced through improved compliance with vaccination and preventive measures, including engineering and administrative controls.

Environmental Contact and Self-contact Patterns of Healthcare Workers: Implications for Infection Prevention and Control

“…Mechanistic mathematical modeling describes how pathogens move through the environment, to estimate the magnitude of exposure among HCWs and patients, while quantitative microbial risk assessment estimates the probability of infection given an exposure in a susceptible person. Previous applications of this approach have characterized the contribution of different transmission routes to influenza risk [26] and the burden of occupationally acquired influenza in acute care hospitals [4]. Data collected about contact patterns in this study can inform the design and parameter values in such mechanistic exposure models, and will be explored in future work in conjunction with measured pathogen values.…”

“…During the 2003 SARS-CoV outbreak, healthcare workers accounted for 20% of the cases worldwide [3]. With respect to seasonal influenza, Jones and Xia estimated that tens of thousands of HCWs in acute care settings in the United States are infected through occupational exposure annually [4]. Environmental surfaces in the hospital have been found to be contaminated with influenza viruses and SARS-CoV, including the hospital bed, bedside table, and television remote control [5][6][7].…”

Influenza virus RNA recovered from droplets and droplet nuclei emitted by adults in an acute care setting

“…In one risk analysis, between 34,150 and 151,300 occupationallyacquired cases of influenza are estimated to occur annually in the United States. [37] Inconsistent application of infection prevention and control measures by both HCWs and patients has been studied, and there are opportunities for improvement among these groups, as well as from an administrative perspective. [38][39][40] The recovery of viral RNA in droplet nuclei and beyond 1 m from naturally-infected participants in the healthcare setting invites a concerted effort to address the issues of (a) virus viability and potential risk with exposure and (b) determinants of emission.…”

Clinician perceptions of respiratory infection risk; a rationale for research into mask use in routine practice

“…Sub-optimal protective mask use can increase this risk, which is exacerbated during high-risk periods such as the winter respiratory virus season. Staff illness from respiratory infections has a direct impact on the workforce resulting in loss of productivity and associated economic burden within the healthcare setting, particularly with influenza [18].…”