Good laboratory practices guarantee biosafety in the Sierra Leone-China friendship biosafety laboratory

Background:The outbreak of Ebola virus disease(EVD)in West Africa between 2014 and 2015 was the largest EDV epidemic since the identification of Ebola virus(EBOV)in 1976,and the countries most strongly affected were Sierra Leone,Guinea,and Liberia.Findings:The Sierra Leone-China Friendship Biological Safety Laboratory(SLE-CHN Biosafety Lab),a fixed Biosafety Level 3 laboratory in the capital city of Sierra Leone,was established by the Chinese government and has been active in EBOV detection since 11 March 2015.Complete management and program documents were created for the SLE-CHN Biosafety Lab,and it was divided into four zones(the green,yellow,brown,and red zones)based on the risk assessment.Different types of safe and appropriate personnel protection equipment(PPE)are used in different zones of the laboratory,and it fully meets the Biosafety Level 3 laboratory standards of the World Health Organization.Conclusion:Good preparedness,comprehensive risk assessment and operation documents,appropriate PPE,effective monitoring and intensive training,together with well-designed and reasonable laboratory sectioning are essential for guaranteeing biosafety.

Serological Investigation of Laboratory-Confirmed and Suspected Ebola Virus Disease Patients During the Late Phase of the Ebola Outbreak in Sierra Leone

This study aimed to investigate the serological characteristics of Ebola virus(EBOV) infection during the late phase of the Ebola outbreak in Sierra Leone. In total, 877 blood samples from 694 suspected Ebola virus disease(EVD) cases assessed from March to December 2015, were analyzed via real-time reverse transcription polymerase chain reaction(RT-PCR) for viral RNA and enzyme-linked immunosorbent assay(ELISA) and Luminex to detect antibodies against EBOV. Viral load and EBOV-specific IgM/IgG titers displayed a declining trend during March to December 2015. Viral RNA load decreased rapidly at earlier stages after disease onset, while EBOV-specific IgM and IgG still persisted in 58.1%(18/31) and 93.5%(29/31) of the confirmed EVD patients and in 3.8%(25/663) and 17.8%(118/663) of the RNA-negative suspected patients in the later phase, respectively. Dynamic analysis of longitudinally collected samples from eight EVD patients revealed typically reversed trends of declining viral load and increasing IgM and/or IgG titers in response to the EBOV infection.The present results indicate that certain populations of Sierra Leone developed immunity to an EBOV infection in the late phase of the outbreak, providing novel insights into the risk assessment of EBOV infections among human populations.

HIV prevalence in suspected Ebola cases during the 2014-2016 Ebola epidemic in Sierra Leone

Background:The 2014-2016 Ebola virus epidemic in West Africa was the largest outbreak of Ebola virus disease(EVD)in history.Clarifying the influence of other prevalent diseases such as human immunodeficiency virus infection and acquired immune deficiency syndrome(HIV/AIDS)will help improve treatment and supportive care of patients with EVD.Case presentation:We examined HIV and hepatitis C virus(HCV)antibody prevalence among suspected EVD cases from the Sierra Leone-China Friendship Biological Safety Laboratory during the epidemic in Sierra Leone.HIV and HCV antibodies were tested in 678 EVD-negative samples by enzyme-linked immunosorbent assay.A high HIV prevalence(17.6%)and low HCV prevalence(0.22%)were observed among the suspected cases.Notably,we found decreased HIV positive rates among the suspected cases over the course of the epidemic.This suggests a potentially beneficial effect of an improved public health system after assistance from the World Health Organization and other international aid organizations.Conclusions:This EVD epidemic had a considerable impact on the public health system and influenced the prevalence of HIV found among suspected cases in Sierra Leone,but also provided an opportunity to establish a better surveillance network for infectious diseases.