Infection prevention and control studies for care of patients with suspected or confirmed filovirus disease in healthcare settings, with focus on Ebola and Marburg: an integrative review

Abstract

Objective To review evidence pertaining to methods for preventing healthcare-associated filovirus infections (including the survivability of filoviruses in clinical environments and the chlorine concentration required for effective disinfection), and to assess protocols for determining the risk of health worker (HW) exposures to filoviruses.Design Integrative review.Data sources PubMed, Embase, Google Scholar, internet-based sources of international health organisations (eg, WHO, CDC), references of the included literature and grey literature.Study selection Laboratory science, clinical research and real-world observational studies identified through comprehensive search strings that pertained to Ebola disease and Marburg disease and the three research objectives.Methods Using the framework of population, intervention or exposure, outcomes, study types and report characteristics, reviewers extracted data and critically appraised the evidence using predefined data extraction forms and summary tables. The extraction forms, summary tables and critical appraisals varied based on the included literature; we used both the QUIPS Risk-of-Bias tool when possible and an internally developed instrument to systematically extract and review the evidence from observational and experimental studies. Evidence was then synthesised and summarised to create summary recommendations.Results Thirty-six studies (including duplicates across research questions) were included in our reviews. All studies that related to the review questions were either (1) descriptive, real-world studies (ie, environmental audits of various surfaces in operational Ebola Treatment Units) or (2) controlled, laboratory studies (ie, experimental studies on the survivability of ebolaviruses in controlled conditions), presenting a range of concerns pertaining to bias and external validity. Our reviews of viral survivability evidence revealed significant disconnections between laboratory-based and real-world findings. However, there is greater viral persistence in liquid than dried body fluids, with the possible exception of blood, and ebolaviruses can survive for significant periods of time in dried substrate. Evidence suggests that 0.5% hypochlorite solution should be used for disinfection activity. Spills should be cleaned with covering and soaking for 15 min. Existing literature suggests that within a well-resourced clinical environment with trained, foreign HWs and established protocols, transmission of ebolaviruses as an occupational risk is a rare event. Despite the high rates of HW infections within public African healthcare settings, no evidence with low risk of bias exists to assess the risk of various occupational exposures given that all high-quality studies were conducted on foreign Ebola clinicians who had low overall rates of infection. This review underscores the critical need for better-quality evidence to inform best practices to ensure HW safety during filovirus disease epidemics.