Implementation and evaluation of new tools for Ebola Virus Disease response during eastern Democratic Republic of Congo outbreaks: from rapid diagnostic tests to genomic sequencing

Project Details

Layman's description

Ebola Viral Disease (EVD) still is a worldwide public health emergency with case fatality rates ranging from 25 to 90% in untreated humans. Strains involved in human outbreak include Sudan virus (SUDV), Tai Forest virus (TAFV), Bundibugyo virus (BDBV), Reston virus (REBOV) and Ebolavirus (EBOV). This latter is the causative agent of the 2 deadliest EVD outbreaks in Western Africa and Eastern DRC [1].
Identification and control of EVD outbreaks relies on rapid and reliable diagnosis of EVD cases based on laboratory testing. Generally, this is based on detection of the viral RNA using reverse transcription-quantitative PCR (RT-qPCR) technology such as the Cepheid® GeneXpert Ebola assay, a rapid and fully automated quantitative RT-PCR considered as the gold-standard. The tool combining high sensitivity and specificity also has several disadvantages as it is expensive and demanding in terms of laboratory infrastructure, training of staff and electricity supply, and sometimes subject to stock ruptures. These features hamper decentralization to lower levels of the health care system and to the community [2, 3]. To address this, rapid diagnostic tests (RDTs) detecting different viral antigens have been developed targeting a sensitivity of at least 98% and a specificity of at least 99%. However, the questions on diag-nostic performance and usability remain, since the decisions to authorize were made based on small-scale evaluations and often with a reference standard which was less performant in patients with lower viral loads [4-7].
In the first part of our PhD, we would like to study the performance of Ebola RDTs compared to the reference standard the GeneXpert®. The first step is to evaluate the performance of QuickNaviTM-Ebola RDT compared to the RT-PCR (GeneXpert®) during the tenth DRC EVD outbreak. In the second step, we will use the OraQuick® RDT alongside with the GeneXpert® as confirmatory test to screen EBOV infec-tion in cadavers during the post-epidemic to enhance the surveillance period. The third step of our study will be to evaluate the performance of three Ebola RDTs used in the field for during the tenth in comparison to the GeneXpert® as the reference standard. And the fourth step of our study will be to estimate the head-to-head performance of four Ebola RDTs against GeneXpert® on the same set of archived samples from eastern DRC EVD outbreaks. Based on the results obtained, we envision devel-oping algorithms of Ebola RDTs for different use-cases and epidemic phases. With algorithms gener-ated, we aim updating or proposing new strategies for Ebola testing.
In the second part of our PhD, we describe the use of new tools in the fight against EVD outbreaks in eastern DRC such as Next generation Sequencing (NGS), Serology (Luminex®), RT-PCR (GeneXpert®). The first study will show the utility of real-time viral genomic data supported public health decision making and issues that impacted the actionability of the data. The second study will report the role of new EBOV diagnostic tools (GeneXpert®, serology, genomic sequencing) in the detection of EVD re-lapse causing meningoencephalitis among two EBOV survivors several months after their discharge. The third study will describe the deployment and management of field laboratories in terms of set-up, and related logistics, technicalities, materials, human resources and security during tenth DRC EVD outbreak in eastern DRC.
Effective start/end date1/07/2227/03/23

IWETO expertise domain

  • B780-tropical-medicine


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