#Genomic Insights into #Marburg Virus Strains from 2023 and 2025 #Outbreaks in Kagera, #Tanzania

 

Abstract

Marburg virus (MARV) is the primary cause of Marburg virus disease (MVD), a severe hemorrhagic fever with a high case-fatality rate. The first reported MVD outbreak in Tanzania occurred in 2023, followed by a second outbreak in 2025, both within the Kagera region. During those MVD outbreaks, 174 suspected cases were identified; of those, 10 were laboratory confirmed. After complete genome assembly and bioinformatic analyses, we found the MARV strains of the 2023 and 2025 outbreaks to be closely related and clustered with MARV strains that caused outbreaks in Rwanda (2024) and Uganda (2014). The sequences from both MVD outbreaks in Tanzania showed >99.71% nucleotide identity, suggesting a possible single spillover event followed by limited human-to-human virus transmission. Further ecologic studies are essential to identify potential spillover events, but our findings indicate that closely related MARV strains circulate in Kagera, Tanzania, posing a risk for future outbreak recurrence.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/1/25-1314_article

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#Marburg Virus #Disease in #Rwanda, 2024 — Public Health and Clinical Responses

 

Abstract

Background

On September 27, 2024, Rwanda reported an outbreak of Marburg virus disease (MVD), after a cluster of cases of viral hemorrhagic fever was detected at two urban hospitals.

Methods

We report key aspects of the epidemiology, clinical manifestations, and treatment of MVD during this outbreak, as well as the overall response to the outbreak. We performed a retrospective epidemiologic and clinical analysis of data compiled across all pillars of the outbreak response and a case-series analysis to characterize clinical features, disease progression, and outcomes among patients who received supportive care and investigational therapeutic agents.

Results

Among the 6340 patients with suspected MVD who underwent testing, 66 had laboratory-confirmed MVD, 51 (77%) of whom were health care workers. The median estimated incubation period was 10 days (interquartile range, 8 to 13), and symptom onset occurred a median of 2 days (interquartile range, 1 to 3) before hospital admission. The results of epidemiologic investigations were highly suggestive of a zoonotic origin of the outbreak: an index patient was identified who had been exposed to Egyptian fruit bats at a mining site. The case fatality rate in the outbreak was 23% (15 deaths among 66 patients). Remdesivir and the monoclonal antibody MBP091 were used under expanded access and clinical trial protocols. In addition, 1710 frontline workers and high-risk contacts received the chimpanzee adenovirus 3–vectored vaccine ChAd3-MARV under emergency use authorization in a phase 2 clinical trial.

Conclusions

Implementation of containment measures, advanced supportive care, and access to investigational countermeasures may have contributed to reduced mortality from MVD in this outbreak. Enhancing surveillance, improving infection prevention and control in health care settings, and ensuring timely deployment of medical countermeasures will be critical for mitigating the effects of future filovirus disease outbreaks.

Source: The New England Journal of Medicine, https://www.nejm.org/doi/full/10.1056/NEJMoa2415816?query=TOC

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Heterologous two-dose #Ebola #vaccine regimen in #pregnant women in #Rwanda: a randomized controlled phase 3 trial

 

Abstract

Risk of death for both mother and fetus following Ebola virus infection is extremely high. In this study, healthy women in Rwanda aged ≥18 years were randomized to two-dose Ebola vaccination (Ad26.ZEBOV, MVA-BN-Filo) during pregnancy (group A) or postpartum (group B). Unvaccinated pregnant group B women served as control. This was a parallel, randomized, controlled, open-label, single-center trial to evaluate the safety (primary endpoint—outcomes of interest and serious adverse events (SAEs)) and immunogenicity (secondary endpoint) of the two-dose Ebola vaccination. Among 3,484 women screened, 2,013 were randomized, and 2,012 women and 1,945 infants born alive were descriptively analyzed. Adverse outcomes of interest occurred in women (5.2% in group A and 7.3% in group B) and infants (26.0% in group A and 25.6% in group B). The most common maternal outcome of interest was pathways to preterm birth (3.2% in group A and 3.4% in group B), and the most common infant outcome of interest was small for gestational age (14.3% in group A and 11.8% in group B). Maternal/fetal and neonatal/infant SAE frequencies were comparable between groups (9.8% in group A, 9.0% in group B and 21.9% in group A, 15.9% in group B, respectively). Anti-Ebola virus glycoprotein-specific binding antibody response (secondary endpoint) was sustained in ≥90% of women at 1 year postdose 1. In group A, binding antibodies were detected in cord blood (99%) and infant serum (95%) samples 14 weeks postbirth. The trial met all primary and secondary objectives. Ad26.ZEBOV, MVA-BN-Filo did not raise concerns regarding adverse maternal/fetal or neonatal/infant outcomes, had no unexpected safety issues, and induced binding antibody responses in women and offspring through passive transfer. ClinicalTrials.gov registration: NCT04556526.

Source: Nature Medicine, https://www.nature.com/articles/s41591-025-03932-z

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#Marburg virus disease - #Rwanda

 {Summary}

Situation at a glance

On 20 December 2024, after two consecutive incubation periods (total of 42 days) since the second negative PCR test was conducted on 7 November for the last confirmed Marburg case, and without a new confirmed case reported, the Ministry of Health of Rwanda declared the end of the Marburg virus disease (MVD) outbreak, as per the WHO recommendations. 

The outbreak had been declared on 27 September 2024. 

As of 19 December 2024, 66 confirmed cases,15 deaths with a case fatality ratio (CFR) of 23%, and 51 recovered cases have been reported. 

The last confirmed case was reported on 30 October 2024. 

WHO through its country office and development partners provided technical and financial support to the government to contain this outbreak. 

The risk of re-emergence of MVD still remains even after the official declaration of the end of the outbreak, linked to viral persistence in body fluids (mostly semen) of recovered patients and the animal reservoir in the country. 

WHO encourages maintaining early case detection and care capacities in addition to sustaining the ability to quickly respond, also underscoring the importance of the recovered patient program, psychosocial support, and continued risk communication and community engagement.

(...)

Source: World Health Organization, https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON548

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