Assessment of Environmental Contamination and Environmental Decontamination Practices within an Ebola Holding Unit, Freetown, Sierra Leone.

Daniel Youkee,Oliver Johnson,Colin S Brown,Andrew Simpson,Nandini Shetty,Thaim B Kamara,Marta Lado,Tim Brooks,Neil Bentley,Naomi F Walker,Paul Lilburn,Jens H Kuhn

doi:10.1371/journal.pone.0145167

Abstract

Evidence to inform decontamination practices at Ebola holding units (EHUs) and treatment centres is lacking. We conducted an audit of decontamination procedures inside Connaught Hospital EHU in Freetown, Sierra Leone, by assessing environmental swab specimens for evidence of contamination with Ebola virus by RT-PCR. Swabs were collected following discharge of Ebola Virus Disease (EVD) patients before and after routine decontamination. Prior to decontamination, Ebola virus RNA was detected within a limited area at all bedside sites tested, but not at any sites distant to the bedside. Following decontamination, few areas contained detectable Ebola virus RNA. In areas beneath the bed there was evidence of transfer of Ebola virus material during cleaning. Retraining of cleaning staff reduced evidence of environmental contamination after decontamination. Current decontamination procedures appear to be effective in eradicating persistence of viral RNA. This study supports the use of viral swabs to assess Ebola viral contamination within the clinical setting. We recommend that regular refresher training of cleaning staff and audit of environmental contamination become standard practice at all Ebola care facilities during EVD outbreaks.

Highlights

Ebola virus is transmitted through direct contact with blood and other bodily fluids of an infected person
The results demonstrate that Ebola virus RNA is detectable in limited areas around the patient bedside in the absence of visible contamination, in contrast to previous work in the clinical setting [1]
More recent publications show even lower positive readmission rates of between 1–3% across Ebola Holding Units (EHUs) in Freetown, including Connaught Hospital EHU [15]. These results suggest that regular and effective environmental decontamination can reduce the presence of viral RNA around the bedside

Summary

Introduction

Ebola virus is transmitted through direct contact with blood and other bodily fluids of an infected person. Mechanisms of transmission through direct contact with infected patients and body fluids have been studied in some depth but environmental transmission of the virus, PLOS ONE | DOI:10.1371/journal.pone.0145167. Ebola virus has been shown to survive for a potentially significant period of time [4]; studies in laboratory environments under optimal conditions have recovered viable virus from solid surfaces from 8–26 days [5][6]. A recently published laboratory study using simulated West African conditions matched for relative humidity and temperature levels, recovered viable virus from surfaces after 5 days [7]. The potential for nosocomial transmission is highest within EHUs that have a rapid turnover of suspect patients

Objectives

Methods

Discussion

Conclusion