RESUMEN
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.
Asunto(s)
Brotes de Enfermedades , Ebolavirus/genética , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/sangre , Fiebre Hemorrágica Ebola/epidemiología , Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática , Fiebre Hemorrágica Ebola/virología , Humanos , ARN Viral/sangre , Reacción en Cadena en Tiempo Real de la Polimerasa , Sierra Leona/epidemiología , Factores de Tiempo , Carga ViralRESUMEN
Ebola virus disease reemerged in Western Africa in 2014. Chinese Center for Disease Control and Prevention dispatched the first Ebola virus (EBOV) detection team to run newly established Sierra Leone-China Friendship Biological Safety Laboratory. The aims of study were to understand epidemiology, clinical manifestations and survival time of EBOV in patient's blood. A total of 913 specimens were tested between March 11 and April 20, 2015. EBOV positivity occurred in 7.37% of the blood and 0.53% in throat swabs. Most commonly reported symptoms of laboratory confirmed patients were intense fatigue, anorexia, and fever. EBOV RNAs persisted in blood for almost 4 weeks and the real-time RT-PCR Ct values showed close correlation with the sampling time after onset.
Asunto(s)
Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/sangre , Adolescente , Adulto , Anciano , Sangre/virología , Niño , Preescolar , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/virología , Humanos , Lactante , Laboratorios , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Sierra Leona/epidemiología , Adulto JovenRESUMEN
The quality control process throughout the Ebola virus nucleic acid detection in Sierra Leone-China Friendship Biological Safety Laboratory (SLE-CHN Biosafety Lab) was described in detail, in order to comprehensively display the scientific, rigorous, accurate and efficient practice in detection of Ebola virus of first batch detection team in SLE-CHN Biosafety Lab. Firstly, the key points of laboratory quality control system was described, including the managements and organizing, quality control documents and information management, instrument, reagents and supplies, assessment, facilities design and space allocation, laboratory maintenance and biosecurity. Secondly, the application of quality control methods in the whole process of the Ebola virus detection, including before the test, during the test and after the test, was analyzed. The excellent and professional laboratory staffs, the implementation of humanized management are the cornerstone of the success; High-level biological safety protection is the premise for effective quality control and completion of Ebola virus detection tasks. And professional logistics is prerequisite for launching the laboratory diagnosis of Ebola virus. The establishment and running of SLE-CHN Biosafety Lab has landmark significance for the friendship between Sierra Leone and China, and the lab becomes the most important base for Ebola virus laboratory testing in Sierra Leone.