MARBURG VIRUS 2025: IS THE UK FACING A NEW OUTBREAK?

What Is Marburg virus Disease?

Marburg Virus Disease (MVD) is a highly infectious and often fatal viral infection caused by the Marburg virus (MARV), a member of the Filoviridae family, closely related to the Ebola virus (EBOV). The disease was first identified in late summer of 1967, when an outbreak affected 31 individuals in Germany and Yugoslavia, resulting in seven deaths. The initial transmission occurred through contact with African green monkeys used in laboratory research. Clinically, Marburg Virus Disease is characterized by: Sudden onset of high fever, Headache and fatigue, Diarrhoea, A distinctive rash, Severe bleeding (internal and external), Central nervous system involvement, and Widespread organ failure due to cell necrosis. The incubation period ranges from 4 to 7 days. The virus was detected in various body fluids, including blood, urine, throat secretions, and semen, which confirms its high transmission potential.

The Marburg virus is an RNA virus of zoonotic origin, meaning it is transmitted from animals to humans. Its natural reservoir hosts are believed to be fruit bats (particularly Rousettus aegyptiacus). Transmission to humans occurs through direct or indirect contact with infected bats, their bodily fluids, or contaminated environments.

Once introduced to the human population, the virus can spread through human-to-human transmission, especially via: Contact with infected blood or bodily fluids, Contaminated medical equipment, Exposure in healthcare settings without proper infection control. The absence of an approved vaccine or specific antiviral treatment, combined with the virus’s ability to spread across regions, makes it a critical public health threat. Diagnosis relies on advanced laboratory tests, while prevention depends on strict personal protective measures and containment protocols.

RECENT OUTBREAKS (2023–2025)

Equatorial Guinea (Feb–Jun 2023): First-ever outbreak in this country. WHO reports 17 confirmed cases and 23 probable cases; 12 of the confirmed and all probable cases were fatal (≈75% CFR for confirmed). The outbreak was contained by June 8, 2023 (42 days with no new cases).

Tanzania (Mar–May 2023): First national outbreak in Kagera region (northwest Tanzania). CDC notes 9 total cases (8 confirmed, 1 probable) with 6 deaths (67% CFR). All cases occurred near the Rwanda/Uganda borders; WHO declared the outbreak over on May 31, 2023, after no new cases.

Rwanda (Sep–Dec 2024): First-ever MVD outbreak in Rwanda (Huye/Kigali districts). WHO reports 66 confirmed cases with 15 deaths (CFR ≈23%). Healthcare workers accounted for ~78% of cases. The last case onset was Oct 30, 2024; Rwanda declared the outbreak over Dec 20, 2024 (42 days later).

Tanzania (Jan–Mar 2025): Second outbreak in Kagera. WHO was notified Jan 14, and an outbreak was declared Jan 20, 2025. CDC reports 2 confirmed and 8 probable cases (all 10 died). No new cases appeared after mid-February; WHO declared the outbreak over Mar 13, 2025 (42 days after the last case). The CDC outbreak map (above) highlights Katela and Ruziba villages as epicenters.

Genetic and Virological Insights

Genomic Analysis of Recent Outbreaks: Sequencing of Marburg viruses from the 2024 Rwanda outbreak (18 cases) shows very low diversity, implying a single spillover event. These genomes were 99.3–99.6% identical to a 2014 Ugandan strain, suggesting a long-divergent bat lineage. In short, genetic data indicate the Rwanda outbreak came from a fruit-bat reservoir (mining cave exposure) with limited human-to-human transmission.

Marburg Variants: Marburg virus has two main variants: Marburg virus (MARV) and Ravn virus (RAVV). They differ by about 22% at the nucleotide level. Phylogenetic studies show multiple lineages co-circulate in Africa (e.g. “Angola-like” vs East African strains). Recent phylogenies cluster bat-derived and human-derived sequences together, reinforcing that the same virus strains circulate between bats and people in a region.

Genomic Surveillance: Over 70 full Marburg genomes have been sequenced from past outbreaks (since 1967). This growing database improves tracking of virus evolution and outbreak sources. However, few sequences come directly from bats, so experts urge active genomic surveillance of bat colonies to identify hotspots and predict spillovers.

 

Symptoms of Marburg Virual Disease

                                            

NHS Guidelines & Testing for Marburg Virus Disease (MVD)

Marburg Virus Disease (MVD) is a rare but highly fatal viral infection that requires biosafety level 4 (BSL-4) containment for diagnostic testing. Due to the virus’s high risk, testing and case management are handled by national reference laboratories and supported by international networks coordinated by the World Health Organization (WHO).

Initial Clinical Assessment

Patients with symptoms and recent travel or exposure to endemic regions should immediately report to their nearest infectious disease center or public health authority.

Sample Collection

Blood, serum, or plasma samples are collected using strict personal protective equipment (PPE) protocols.

 

Laboratory Testing

Conducted using: RT-PCR (real-time polymerase chain reaction) Antigen-capture ELISA IgM and IgG antibody testing Virus isolation in BSL-4 labs

 

Referral to WHO-Affiliated Labs (if needed)

In countries lacking high-containment labs, samples are shipped to WHO collaborating centres under IHR (International Health Regulations).

Treatment options for the Marburg virus

Currently, there are no licensed vaccines or specific antiviral treatments available for Marburg Virus Disease. As a result, treatment primarily focuses on supportive care, which can significantly improve survival—especially when started early in the course of illness.

Current Treatment Options

Replacement of blood components to manage hemorrhagic symptoms

Balancing fluids and electrolytes to prevent dehydration and maintain cellular function

Maintaining oxygen status and blood pressure to support vital organ function

Organ support, such as dialysis or mechanical ventilation, when needed

Treatment of co-infections or complications to reduce additional strain on the immune system

Infection Control and Prevention Measures:

Strict isolation of suspected or confirmed cases

Use of Personal Protective Equipment (PPE) by all healthcare workers and caregivers

Avoiding direct contact with the bodily fluids of infected individuals

Safe burial practices to prevent post-mortem transmission

Emerging Treatments for Marburg Virus Disease (MVD)

No Approved Therapies: As with Ebola, no specific antiviral or antibody is licensed for Marburg disease. Treatment is primarily supportive: rehydration (oral or IV fluids), electrolyte and blood pressure support, oxygen, and treating secondary infections. High-quality intensive care improves survival.

Antiviral – Remdesivir: Gilead’s antiviral remdesivir (Veklury) – licensed for COVID-19 – has shown activity against filoviruses in animal studies and was used compassionately in the 2023 Equatorial Guinea outbreak. WHO and CDC consider remdesivir a leading candidate; it was recently incorporated into clinical trials in Africa. Notably, prior Ebola studies showed remdesivir could reduce mortality, so it was pre-positioned for Marburg trials

Monoclonal Antibodies: Mapp Biopharmaceutical’s MBP091 (also called FM-202) is a monoclonal antibody cocktail targeting Marburg virus. BARDA supports its development. In late 2024, WHO launched the first-ever Marburg treatment trial in Rwanda to evaluate remdesivir and MBP091 for safety/efficacy. (Phase 1 data for MBP091 are limited, but it neutralizes Marburg in animal models.) Other monoclonal preparations are in early R&D.

Experimental Regimens: Early reports indicate some outbreak patients received combinations of experimental therapies (remdesivir, MBP091) via clinical protocols. Published observations suggest 5 of 12 treated patients recovered, implying a possible benefit, but the numbers are small. Overall, these trials and compassionate uses represent the first steps toward approved MVD treatments.

Supportive Care: In all outbreaks, prompt supportive care (fluids, electrolytes, symptomatic relief) has markedly lowered fatality. For example, Rwanda’s outbreak CFR (23%) was far below the historical average (~50%), likely reflecting aggressive supportive care and outbreak management.

Marburg Virus: Prevention and NHS Guidance

Avoid direct exposure: Marburg transmits only by touching infected blood/fluids or contaminated objects. Do not handle bats, monkeys, or sick/dead animals in affected areas. UK health advice stresses that Marburg “is not spread through routine, social contact” (e.g., handshakes), so ordinary social interactions are safe.

Practice good hygiene: Wash hands frequently with soap or sanitizer and clean common surfaces. If caring for someone unwell, follow strict infection-control (gloves, gowns, masks). WHO emphasises standard precautions – hand hygiene, respiratory etiquette, and PPE – to block any contact with infected materials. Avoid sharing needles or other sharp instruments.

Vaccine status: There is currently no licensed vaccine or specific cure for Marburg. Research is underway: the University of Oxford’s team began first human trials of a “ChAdOx1 Marburg” vaccine in 2024, and other candidates (e.g., by the Sabin Institute) are in advanced clinical trials. Currently, the Marburg vaccine is not available in the UK.

Travel precautions: If you plan to travel to Africa or areas with outbreaks, check official travel advice (e.g. UK TravelHealthPro) for updates. Avoid high-risk activities like spelunking in bat caves or handling wild animals. After travel, watch for fever or symptoms up to 21 days out. If you become ill, call NHS 111 (NHS 24 in Scotland) before visiting a clinic and mention your recent travel, even though a Marburg infection is very unlikely.

Conclusion:

Although the Marburg virus does not pose an immediate threat to the UK, it represents a serious emerging infectious disease with pandemic potential. Continued public awareness, international cooperation, and vaccine research are essential to prevent its spread. UK residents returning from outbreak regions should remain alert, report symptoms early, and follow NHS guidance for testing and isolation.