South African Ebola diagnostic response in Sierra Leone: A modular high biosafety field laboratory

Abstract

BackgroundIn August 2014, the National Institute for Communicable Diseases (NICD) in South Africa established a modular high-biosafety field Ebola diagnostic laboratory (SA FEDL) near Freetown, Sierra Leone in response to the rapidly increasing number of Ebola virus disease (EVD) cases.Methods and findingsThe SA FEDL operated in the Western Area of Sierra Leone, which remained a “hotspot” of the EVD epidemic for months. The FEDL was the only diagnostic capacity available to respond to the overwhelming demand for rapid EVD laboratory diagnosis for several weeks in the initial stages of the EVD crisis in the capital of Sierra Leone. Furthermore, the NICD set out to establish local capacity amongst Sierra Leonean nationals in all aspects of the FEDL functions from the outset. This led to the successful hand-over of the FEDL to the Sierra Leone Ministry of Health and Sanitation in March 2015. Between 25 August 2014 and 22 June 2016, the laboratory tested 11,250 specimens mostly from the Western Urban and Western Rural regions of Sierra Leone, of which 2,379 (21.14%) tested positive for Ebola virus RNA.ConclusionsThe bio-safety standards and the portability of the SA FEDL, offered a cost-effective and practical alternative for the rapid deployment of a field-operated high biocontainment facility. The SA FEDL teams demonstrated that it is highly beneficial to train the national staff in the course of formidable disease outbreak and accomplished their full integration into all operational and diagnostic aspects of the laboratory. This initiative contributed to the international efforts in bringing the EVD outbreak under control in Sierra Leone, as well as capacitating local African scientists and technologists to respond to diagnostic needs that might be required in future outbreaks of highly contagious pathogens.

Molecular diagnostics in South Africa and challenges in the establishment of a molecular laboratory in developing countries

“…Between 25 August 2014 and 22 June 2016, 11256 specimens were tested of which 2379 (21.1%) were positive for Ebola virus RNA. Although challenges were experienced in the establishment of the laboratory, rapid molecular laboratory confirmation was crucial for the detection of Ebola Virus Disease cases, contact tracing and secure burial practices in Sierra Leone [23].…”

Challenges and perspectives on the use of mobile laboratories during outbreaks and their use for vaccine evaluation

“…The contents of a mobile lab have evolved with time, for example from a simple sample collection kit and light microscope used during a melioidosis outbreak in northern Australia in 1997 1 to fully self-reliant and equipped vehicles containing the latest in molecular diagnostic and biocontainment equipment used during the West Africa Ebola virus outbreak in 2014-2016. [2][3][4] The contents of a mobile laboratory will be dependent on the type of work to be conducted and the environment in which it will be conducted. In "peace time", those periods inbetween outbreaks when the goal is to perform routine surveillance of pathogens circulating in the environment and/or the local animal populations, researchers have time to establish study sites from the fixed National laboratory, and to obtain all the necessary approvals for sample collection and transportation.…”

“…Serological assays such as enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assays are advantageous for the testing of disease states that have progressed beyond those capable of detection via molecular methods (convalescence). 5 While some believe that serological testing is unlikely to occur as part of routine outbreak response, 3 cases were identified in real-time at the site of the outbreak using serological testing in conjunction with epidemiological data during the 2017 Ebola outbreak in Democratic Republic of Congo (DRC). 6 Serological testing can also be used to identify the source of an outbreak through the testing of animal carcasses or to identify the index case through back tracing of suspected cases who have recovered.…”

“…Various groups have noted the value of differential testing but warn that in large outbreaks it can be extremely difficult if not impossible due to a lack of time and resources. 3,9 While real-time RT-PCR has become the gold standard in molecular testing for mobile laboratories, this technique still has a number of drawbacks. For example, moderately large and sophisticated pieces of equipment are required for running and analyzing samples.…”

“…rain and extreme heat and humidity, to ensure their proper functioning and to prevent breakdowns. 3 Realtime RT-PCR also requires specific primers/probes in order to accurately identify the pathogen. Should the outbreak pathogen significantly mutate over the course of time or another pathogen emerge in the meantime, the protocols established for a specific pathogen may no longer be adequate.…”