Detection of Marburg virus antibodies 25 years after outbreak in Watsa, Democratic Republic of the Congo

Authors: MERRITT, SYDNEY - University Of California (UCLA); KOMPANY, JEAN PAUL - Institute National Research Biomedical; MUKADI, PATRICK - Institute National Research Biomedical; HALBROOK, MEGAN - University Of California (UCLA); MUSENE, KAMY - University Of California (UCLA); MARTIN, SKYLAR - University Of California (UCLA); BEYA, MICHAEL - University Of Kinshasa; TAMBU, MERLY - Institute National Research Biomedical; WONG, TERRI ANN - University Of Hawaii; Hensley, Lisa; KABA, DIDINE - University Of Kinshasa; LEHRER, AXEL - University Of Hawaii; KINDRACHUK, JASON - University Of Manitoba; HOFF, NICOLE - University Of California (UCLA); MBALA-KINGEBENI, PLACIDE - Institute National Research Biomedical; RIMOIN, ANNE - University Of California (UCLA); MUYEMBE-TAMFUM, JEAN JACQUES - Institute National Research Biomedical

Submitted to: Journal of Infectious Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2026
Publication Date: 3/16/2026
Citation: Merritt, S., Kompany, J., Mukadi, P.K., Halbrook, M., Musene, K., Martin, S.A., Beya, M., Tambu, M., Wong, T.S., Hensley, L.E., Kaba, D.K., Lehrer, A.T., Kindrachuk, J., Hoff, N.A., Mbala-Kingebeni, P., Rimoin, A.W., Muyembe-Tamfum, J. 2026. Detection of Marburg virus antibodies 25 years after outbreak in Watsa, Democratic Republic of the Congo. Journal of Infectious Diseases. Article jiag155. https://doi.org/10.1093/infdis/jiag155.
DOI: https://doi.org/10.1093/infdis/jiag155

Interpretive Summary: Marburg virus (MARV) is a close relative of Ebolavirus, and responsible for Marburg virus disease (MVD) outbreaks in Sub-Saharan Africa. While the last outbreak in the Democratic Republic of the Congo was reported in 1998-2000 in the Watsa/Durba region, MVD outbreaks are not uncommon, with suspected cases reported in Rwanda and Tanzania in the past year. Given the sporadic nature of MVD outbreaks, and the potentially fatal outcomes of MARV infection, we sought to better understand immune responses to MARV among individuals living in the Watsa/Durba region 25 years following the outbreak. We assessed seroreactivity, or relative antibody/immune responses of 308 individuals in the region, including survivors and health care workers. We show low level reactivity to the MARV targets, as well as cross-reactivity to other viruses of the same family. While risk factors of MVD have been defined, we show no association between these factors and those individuals who were reactive to the presented MARV targets. Ultimately, these results demonstrate the need for additional surveillance and better understanding of MVD in the region.

Technical Abstract: Background–Marburg virus (MARV) causes infrequent but often fatal disease in humans with recent expansion of outbreaks to new geographic regions including Tanzania and Rwanda. Approximately 20 Marburg virus disease (MVD) outbreaks have been reported almost exclusively within Sub-Saharan Africa. From 1998-2000, a large MVD outbreak was reported in the Watsa/Durba region, Democratic Republic of the Congo (DRC), with 154 cases and 128 deaths (83% CFR). Given the ongoing public health risks posed by MARV, the lack of approved vaccines and therapeutics, and the unpredictable frequency of future outbreaks, this study sought to elucidate the prevalence of anti-MARV antibodies among a mixed cohort of residents in Watsa/Durba. Methods–This sample (n=313)—collected in May 2023—included known MVD survivors of the outbreak (n=5), close contacts (n=22) and healthcare workers. Using a multiplex bead immunoassay, seroreactivity was determined to MARV antigens and other pan-filovirus targets. Findings–Among the Watsa/Durba cohort, 3.8% and 1.0% were seroreactive to MARV glycoprotein (GP) and VP40, respectively. Yet only one seroreactive individual was a known MVD survivor. No associations between travel to Uganda, receiving injections nor employment as a goldminer and MARV seroreactivity were shown. Of those 12 MARV GP-reactive individuals, 91.7% were cross-reactive to other pan-filoviral GP targets. Interpretation–This varying seroprevalence and pan-filovirus reactivity highlights the need for additional investigation; detected seroprevalence among individuals with no known history of exposure nor significant association with reported behavioral risk factors may indicate continued exposure to MARV or MARV-like antigens almost 25 years after the conclusion of the outbreak. Beyond MARV reactivity, detected cross-reactivity to pan-filovirus targets further emphasizes a need for increased surveillance, and the potential for asymptomatic, un-detected cases in the region. Funding–This work was supported by the US Food and Drug Administration (Grant No. 75F40119C10128).