Clinical Strategies and Therapeutics for Human Monkeypox Virus: A Revised Perspective on Recent Outbreaks

Prediction of potential public health risk of the recent multicountry monkeypox outbreak: An update after the end declaration of global public health emergency

Background and Aims

A double-stranded DNA virus called monkeypox virus (MPV) belonging to the Poxviridae family and Orthopoxvirus genus causes monkeypox (mpox) infection. This virus used to infect only Central, East, and West Africa. However, it has spread to an extent outside Africa recently. The range of MPV outbreaks was so high that on July 23, 2022, the World Health Organization (WHO) declared it a Public Health Emergency of International Concern (PHEIC). About a year later, the WHO notified the end of a global public health emergency for mpox on May 11, 2023. Here, we aimed to assess the current pathogenicity and potential risk of MPV causing public health emergencies.

Methods

We searched information from published articles available in PubMed, Scopus, and ScienceDirect. We used monkeypox, mpox, monkeypox outbreak, and monkeypox virus as keywords during the literature search.

Results

Many new variants of MPV have emerged throughout the world that created PHEIC for mpox. Considering the low lethality and transmission rate, mpox is no longer a global public health threat. In addition, the availability of therapeutic and preventive measures helped the healthcare authorities fight the mpox infection in an efficient manner. In this review, we have portrayed the history and evolution of mpox from past to present and an idea of its future outcomes. Also, we have discussed the symptoms related to mpox and approved antiviral treatment strategies to fight off the infection in this piece. This review also emphasized the preventive guidelines set by the WHO for patients, caregivers, and healthcare providers to control the outbreak of mpox infection.

Conclusion

We believe this article would give an idea about the potential public health threats of the recent multi-country monkeypox outbreak to the healthcare authorities for taking measures accordingly.

Monkeypox virus infection of human astrocytes causes gasdermin B cleavage and pyroptosis

Monkeypox virus (MPXV) infections in humans cause neurological disorders while studies of MPXV-infected animals indicate that the virus penetrates the brain. Pyroptosis is an inflammatory type of regulated cell death, resulting from plasma membrane rupture (PMR) due to oligomerization of cleaved gasdermins to cause membrane pore formation. Herein, we investigated the human neural cell tropism of MPXV compared to another orthopoxvirus, vaccinia virus (VACV), as well as its effects on immune responses and cell death. Astrocytes were most permissive to MPXV (and VACV) infections, followed by microglia and oligodendrocytes, with minimal infection of neurons based on plaque assays. Aberrant morphological changes were evident in MPXV-infected astrocytes that were accompanied with viral protein (I3) immunolabelling and detection of over 125 MPXV-encoded proteins in cell lysates by mass spectrometry. MPXV- and VACV-infected astrocytes showed increased expression of immune gene transcripts (IL12, IRF3, IL1B, TNFA, CASP1, and GSDMB). However, MPXV infection of astrocytes specifically induced proteolytic cleavage of gasdermin B (GSDMB) (50 kDa), evident by the appearance of cleaved N-terminal-GSDMB (30 kDa) and C-terminal- GSDMB (18 kDa) fragments. GSDMB cleavage was associated with release of lactate dehydrogenase and increased cellular nucleic acid staining, indicative of PMR. Pre-treatment with dimethyl fumarate reduced cleavage of GSDMB and associated PMR in MPXV-infected astrocytes. Human astrocytes support productive MPXV infection, resulting in inflammatory gene induction with accompanying GSDMB-mediated pyroptosis. These findings clarify the recently recognized neuropathogenic effects of MPXV in humans while also offering potential therapeutic options.

Antivirals against Monkeypox (Mpox) in Humans: An Updated Narrative Review

As of 29 August 2023, a total of 89,596 confirmed cases of Mpox (monkeypox) have been documented across 114 countries worldwide, with 157 reported fatalities. The Mpox outbreak that transpired in 2022 predominantly affected young men who have sex with men (MSM). While most cases exhibited a mild clinical course, individuals with compromised immune systems, particularly those living with HIV infection and possessing a CD4 count below 200 cells/mm3, experienced a more severe clinical trajectory marked by heightened morbidity and mortality. The approach to managing Mpox is primarily symptomatic and supportive. However, in instances characterized by severe or complicated manifestations, the utilization of antiviral medications becomes necessary. Despite tecovirimat's lack of official approval by the FDA for treating Mpox in humans, a wealth of positive clinical experiences exists, pending the outcomes of ongoing clinical trials. Brincidofovir and cidofovir have also been administered in select cases due to the unavailability of tecovirimat. Within the scope of this narrative review, our objective was to delve into the clinical attributes of Mpox and explore observational studies that shed light on the utilization of these antiviral agents.