Ebola viral load at diagnosis associates with patient outcome and outbreak evolution
Marc-Antoine de La Vega, … , Michel Van Herp, Gary P. Kobinger
Marc-Antoine de La Vega, … , Michel Van Herp, Gary P. Kobinger
Published December 1, 2015; First published November 9, 2015
Citation Information: J Clin Invest. 2015;125(12):4421-4428. https://doi.org/10.1172/JCI83162.
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Categories: Clinical Medicine Infectious disease Virology

Ebola viral load at diagnosis associates with patient outcome and outbreak evolution

Abstract

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.

Authors

Marc-Antoine de La Vega, Grazia Caleo, Jonathan Audet, Xiangguo Qiu, Robert A. Kozak, James I. Brooks, Steven Kern, Anja Wolz, Armand Sprecher, Jane Greig, Kamalini Lokuge, David K. Kargbo, Brima Kargbo, Antonino Di Caro, Allen Grolla, Darwyn Kobasa, James E. Strong, Giuseppe Ippolito, Michel Van Herp, Gary P. Kobinger

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Figure 3

Viral kinetics of individual patients throughout the outbreak.

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Viral kinetics of individual patients throughout the outbreak. The virem...
The viremia of individual patients was graphically represented by number of days after onset of symptoms. (A–E)Patients were divided by months of the outbreak in Kailahun, Sierra Leone, in July (n = 10) (A), August (n = 8) (B), September (n = 8) (C), October (n = 4) (D), and November (n = 10) (E). Each symbol for a given panel represents a single patient. Survivors are shown in blue, and nonsurvivors are shown in red.