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In this study, a simple one-step reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for rapid detection of Lassa virus (LASV) was established. The two primer sets were designed to detect LASV circulating in Sierra Leone and northeastern Nigeria. The RT-LAMP assay using these primer sets was able to detect 100 copies of the in vitro transcribed artificial LASV RNA within 25 min. The assay was also evaluated using intact viral RNA extracted from cell culture-propagated viruses and confirmed to be highly specific for LASV. The RT-LAMP assay developed in this study is rapid, simple, and highly specific for the detection of LASV, although its sensitivity is slightly lower than that of real-time RT-PCR. In addition, because the RT-LAMP assay does not require the use of sophisticated equipment, it would be advantageous for clinical diagnosis of LASV infection in developing countries. It might also be employed in cases of deliberate release during bioterrorism attacks or in epidemiological surveillance for disease outbreaks. [ABSTRACT FROM AUTHOR]

Background: Ebola virus (EBOV) causes periodic outbreaks of life-threatening EBOV disease in Africa. Historically, these outbreaks have been relatively small and geographically contained; however, the magnitude of the EBOV outbreak that began in 2014 in West Africa has been unprecedented. The aim of this study was to describe the viral kinetics of EBOV during this outbreak and identify factors that contribute to outbreak progression.Methods: From July to December 2014, one laboratory in Sierra Leone processed over 2,700 patient samples for EBOV detection by quantitative PCR (qPCR). Viremia was measured following patient admission. Age, sex, and approximate time of symptom onset were also recorded for each patient. The data was analyzed using various mathematical models to find trends of potential interest.Results: The analysis revealed a significant difference (P = 2.7 × 10(-77)) between the initial viremia of survivors (4.02 log10 genome equivalents [GEQ]/ml) and nonsurvivors (6.18 log10 GEQ/ml). At the population level, patient viral loads were higher on average in July than in November, even when accounting for outcome and time since onset of symptoms. This decrease in viral loads temporally correlated with an increase in circulating EBOV-specific IgG antibodies among individuals who were suspected of being infected but shown to be negative for the virus by PCR.Conclusions: Our results indicate that initial viremia is associated with outcome of the individual and outbreak duration; therefore, care must be taken in planning clinical trials and interventions. Additional research in virus adaptation and the impacts of host factors on EBOV transmission and pathogenesis is needed. [ABSTRACT FROM AUTHOR]

West Africa experienced the first epidemic of Ebola virus infection, with by far the greatest number of cases in Guinea, Sierra Leone, and Liberia. The unprecedented epidemic triggered an unparalleled response, including the deployment of multiple Ebola treatment units and mobile/field diagnostic laboratories. The National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention deployed a joint laboratory to Monrovia, Liberia, in August 2014 to support the newly founded Ebola treatment unit at the Eternal Love Winning Africa (ELWA) campus. The laboratory operated initially out of a tent structure but quickly moved into a fixed-wall building owing to severe weather conditions, the need for increased security, and the high sample volume. Until May 2015, when the laboratory closed, the site handled close to 6000 clinical specimens for Ebola virus diagnosis and supported the medical staff in case patient management. Laboratory operation and safety, as well as Ebola virus diagnostic assays, are described and discussed; in addition, lessons learned for future deployments are reviewed., (Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

This paper describes patient characteristics, including Ebola viral load, associated with mortality in a Médecins Sans Frontières Ebola case management centre (CMC).Out of 780 admissions between June and October 2014, 525 (67%) were positive for Ebola with a known outcome. The crude mortality rate was 51% (270/525). Ebola viral load (whole-blood sample) data were available on 76% (397/525) of patients. Univariate analysis indicated viral load at admission, age, symptom duration prior to admission, and distance traveled to the CMC were associated with mortality (P < .05). The multivariable model predicted mortality in those with a viral load at admission greater than 10 million copies per milliliter (P < .05, odds ratio >10), aged ≥ 50 years (P = .08, odds ratio = 2) and symptom duration prior to admission less than 5 days (P = .14). The presence of confusion, diarrhea, and conjunctivitis were significantly higher (P < .05) in Ebola patients who died.These findings highlight the importance viral load at admission has on mortality outcomes and could be used to cohort cases with viral loads greater than 10 million copies into dedicated wards with more intensive medical support to further reduce mortality., (© The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.)