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

Abstract

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.

Comparative performance study of three Ebola rapid diagnostic tests in Guinea

“…This may be because the Fever Panel test contained additional antibodies for pan-Ebola selectivity (Ebola Zaire, Sudan, and Bundibugyo), while the other two assays are optimized only for Ebola Zaire (personal communication, Chembio). If this holds true in other datasets, the Ebola and Ebola-Malaria tests might be suitable for symptomatic patients with high viral loads, but might not be recommended for contact tracing, for convalescent patients with lower viral burden, or in cases where the outbreak is not confirmed to be Ebola Zaire [21].…”

Comprehensive Clinical and Laboratory Follow-up of a Female Patient With Ebola Virus Disease: Sierra Leone Ebola Virus Persistence Study

“…: 20143402058) that targets the GP and NP genes of EBOV (Zaire strain) [3]. d Enzyme-linked immunosorbent assay was performed by the SLE-C Biosafety Lab for IgG and IgM (Wantai, Beijing, China) [9]. e Virus isolation was performed by the US CDC in Biosafety Level 4 conditions using Vero cells, as previously described [11].…”

“… d Enzyme-linked immunosorbent assay was performed by the SLE-C Biosafety Lab for IgG and IgM (Wantai, Beijing, China) [9]. …”

“…Immune responses were evaluated on 7 convalescent venous blood samples collected from days 4 to 73 covering both the acute and convalescent phases [9]. The serological responses to EBOV of the patient presented an ascending trend for IgG after virus infection (Figure 1B).…”

Ebola virus VP35 has novel NTPase and helicase-like activities

“…EBOV is highly pathogenic, whose infection causes severe Ebola virus disease (EVD), also known as Ebola haemorrhagic fever (EHF), in humans with high mortality rates between 25 and 90% (1–3). From 2014 to 2016, West Africa has experienced the largest Ebola outbreak in the history that has resulted in more than 28 000 cases and over 11 000 deaths (4) (https://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/index.html). Moreover, the most recent Ebola outbreak is still on-going and deteriorating in DR Congo, which has caused 1290 EVD cases and 833 deaths until 16 April 2019 (http://www.who.int/ebola/situation-reports/drc-2018/en/).…”