Recent advances in marburgvirus research

The mortality, modes of infection, diagnostic tests, and treatments of Marburg virus disease: A systematic review

Background and Aims

Marburg virus (MARV) has regularly affected people since 1967 causing multiple outbreaks. There are presently no authorized therapies for the fatal Marburg virus disease (MVD), which poses an imminent risk to global public health. The MVD has so far claimed the lives of numerous people, with an increased number of cases being seen throughout the African continent. Hence, a review was carried out to analyze the geographical distribution of MVD, mortality, routes of transmission, and diagnostic and treatment modalities.

Methods

PubMed, Scopus, Web of Science, Google Scholar, and ProMED servers were used to conduct a systematic search in compliance with the PRISMA guidelines. The results were tabulated and analyzed.

Results

A total of 11 studies (7 case reports and 4 case series) were included in the final analysis, and 21 cases of MVD were analyzed. The most frequent symptoms were fever (66.67%), vomiting (57.14%), headache (52.38%), diarrhea (52.38%), and pain (47.62%). The most commonly used diagnostic test was RT-PCR (42.11%). Contact transmission (50%) and zoonotic transmission (37.5%) were the most prevalent routes of transmission. Antibiotics (61.5%) were the first line of treatment. The most common complications were hemorrhage (60%) and coagulopathies (33.3%). The mortality rate was 57.1%.

Conclusion

To avoid disastrous consequences, it is essential to reiterate the necessity of early diagnosis and treatment of MVD.

Advancements in Marburg (MARV) Virus Vaccine Research With Its Recent Reemergence in Equatorial Guinea and Tanzania: A Scoping Review

Given the recent outbreaks of the Marburg (MARV) virus within the first quarter of the year 2023, interest in the MARV virus has been re-ignited given its shared phylogeny with the dreadful Ebola virus. This relation gives some insight into its virulence, associated morbidities, and mortality rates. The first outbreak of MARV recorded was in Germany, in 1967, of which seven died out of 31 reported cases. Ever since, subsequent cases have been reported all over Africa, a continent replete with failing healthcare systems.  This reality impresses a need for a contemporary and concise revision of the MARV virus existing publications especially in the areas of vaccine research. A functional MARV vaccine will serve as a panacea to ailing communities within the African healthcare landscape.  The objective of this scoping review is to provide pertinent information relating to MARV vaccine research beginning with an outline of MARV's pathology and pathogenesis in addition to the related morbidities, existing therapies, established outbreak protocols as well as areas of opportunities.

Marburg virus and the disease it causes

Over the 50 years since its discovery, many properties of the Marburg virus have been studied, but no reliable medical remedies of preventing and treating the infection it causes have been developed, although it can potentially cause large-scale epidemics. Marburg fever is relevant due to the risk of importation to other countries. The source of infection in nature is bats (reservoir) and monkeys (intermediate host), and the routes of transmission are aerosol, contact and alimentary. The mortality rate in recent outbreaks has reached 90%. In convalescents the causative agent was identified in tears, semen, and liver biopsies weeks and months after recovery. The lack of therapeutic and prophylactic antiviral drugs, high rates of mortality, infectivity, the ability of aerosol contamination, and a high epidemic potential all together define Marburg fever as a serious global threat to international health. The development of medical protection against this infection should be an urgent task of ensuring the biological safety of the population of the Russian Federation. The most promising ways to develop vaccines against Marburg fever are the construction of recombinants based on adenovirus, vesicular stomatitis virus or alphavirus replicon, DNA vaccines. A reliable protective effect of the chemotherapy drug remdesivir in combination with human antibodies, as well as an etiotropic drug with an antisense mechanism of action and an interferon inducer has been shown. In model experiments with pseudovirus, fundamentally new ways of developing pathogen inhibitors were found preventing its exit from cells, as well as the construction of anti-gene-binding Fab fragments that inhibit the synthesis of viral RNA.

Development of a Well-Characterized Cynomolgus Macaque Model of Marburg Virus Disease for Support of Vaccine and Therapy Development

Marburg virus (MARV) is a filovirus that can infect humans and nonhuman primates (NHPs), causing severe disease and death. Of the filoviruses, Ebola virus (EBOV) has been the primary target for vaccine and therapeutic development. However, MARV has an average case fatality rate of approximately 50%, the infectious dose is low, and there are currently no approved vaccines or therapies targeted at infection with MARV. The purpose of this study was to characterize disease course in cynomolgus macaques intramuscularly exposed to MARV Angola variant. There were several biomarkers that reliably correlated with MARV-induced disease, including: viral load; elevated total clinical scores; temperature changes; elevated ALT, ALP, BA, TBIL, CRP and decreased ALB values; decreased lymphocytes and platelets; and prolonged PTT. A scheduled euthanasia component also provided the opportunity to study the earliest stages of the disease. This study provides evidence for the application of this model to evaluate potential vaccines and therapies against MARV and will be valuable in improving existing models.

Marburg virus disease: A summary for clinicians

OBJECTIVES

This article summarizes the countermeasures for Marburg virus disease, focusing on pathogenesis, clinical features and diagnostics. There is an emphasis on therapies and vaccines that have demonstrated, through their evaluation in nonhuman primates (NHPs) and/or in humans, potential for use in an emergency situation.

METHODS

A standardized literature review was conducted on vaccines and treatments for Marburg virus disease, with a focus on human and nonhuman primate data published in the last five years. More detail on the methods that were used is summarized in a companion methods paper.

RESULTS

The study identified six treatments and four vaccine platforms that have demonstrated, through their efficacy in NHPs, potential benefit for treating or preventing infection in humans.

CONCLUSION

Succinct summaries of Marburg countermeasures are provided to give the busy clinician a head start in reviewing the literature if faced with a patient with Marburg virus disease. Links to other authoritative sources of information are also provided.