Monkeypox Virus Infection in Humans across 16 Countries — April–June 2022

An atypical presentation of monkeypox associated with scrotal and penile shaft edema

Monkeypox: Considerations as a New Pandemic Looms

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.

Mpox: What Practicing Gastroenterologists Need to Know

A 60-year-old man presented due to two centrally crustose pustules on the penis of 1 week duration. The patient denied any unprotected sexual intercourse; however, admitted protected sexual contact with a male random acquaintance. The patient denied any local trauma, manipulation, or previous pathologies at that or any other site. He also reported having a fever the day before. He was diagnosed with HIV 14 years previously and maintained a good immune-virological control under antiretroviral treatment. In addition to his history of HIV, he had a history of high blood pressure, depression, and gastro-oesophageal reflux disease. He took candesartan-hydrochlorothiazide, escitalopram, pantoprazole, and trazodone hydrochloride medication on a regular basis. On clinical examination, two sharply demarcated pustules, centrally coated with a necrotic crust were visible on the penis (Fig. 1). Palpating them, they had a hard, infiltrated form. No inguinal lymphadenopathy was present. The oral cavity, as well as palmoplantar region, were unsuspicious. He had no exanthema on the body and had no signs of follicular involvement. However, during the whole-body examination, multiple umbilicated pustules were detected in the perianal region, clinically highly suspicious for monkeypox virus (MPXV) infection. Pustule exudate was collected, and PCR testing confirmed MPXV. Syphilis serology showed no active infection (rapid plasma reagin test negative; Treponema pallidum particle agglutination test [1:1280], screening test reactive, T. pallidum membrane particle agglutination test immunoglobulin M negative). Furthermore, hepatitis B and hepatitis C were excluded serologically. As PCR for Neisseria gonorrhoeae was negative, diagnosis of a disseminated gonococcal infection was unlikely. The pustule was tested for 11 relevant sexually transmitted infections (STIs) including: Chlamydia trachomatis, N. gonorrhoeae, herpes simplex virus 1 (HSV-1) and (HSV-2), Haemophilus ducreyi, Mycoplasma genitalium, Mycoplasma hominis, T. pallidum, Trichomonas vaginalis, Ureaplasma parvum, and Ureaplasma urealyticum, all of which were negative. The MPXV infection was reported to the local health department and patient was sent to quarantine. The patient was advised to abstain from any physical and sexual contact until the complete healing of the pustules and to present for a control visit in order to guarantee complete healing. After 1 month the patient came back to the department of dermatology and presented with complete healing of the lesions (Fig. 2). In the case of genital pustules and/or ulcers generally infections (sexually transmitted or transmittable) should be considered. The pathogens T. pallidum, HSV-1 and HSV-2, and more, seldomly Haemophilus ducreyi are known to elicit vesico-pustules or ulcers at first sight. In May 2022 an outbreak in central Europe of the zoonotic MPXV infection was observed [1-3]. By 25 August 2022, >17 000 cases had been reported in European countries [4]. The MPXV, a double-stranded DNA virus, belongs to the group of orthopoxviruses, that seldomly cause infections in humans, except in Africa where it is endemic [1, 3]. Transmission is not only possible via respiratory droplets, but also by direct skin-to-skin contact with infected lesions [1, 3]. Diagnosis is usually made via PCR testing of skin (pustules and/or crusts), oropharyngeal swab, or of blood [1-3]. Screening of STIs is highly recommended in patients suspicious for MPXV infection. The vast majority of those who are infected, belong to the group of men who have sex with men (MSM) with a median age of 35–38 years [1-3]. A considerable number of those infected have HIV [2]. The incubation period is believed to range up to 21 days, followed by prodromes, including fever, myalgia, arthralgia, lymphadenopathy, headache, or fatigue amongst others [1, 3]. According to the latest outbreak and due to observational cohort studies most patients present with fever (62–72%) and adenopathy (56%–85%) [1, 2]. Only some days after the fever does the typical rash on the face and body appear [1]. This rash might transform from macular to papular, vesicular, pustular, and crustose stages [1, 3]. The typical clinical feature of MPXV is umbilicated pustules, with or without an ulceronecrotic centre. According to the latest data from observational cohort studies and case series the main sites that are affected are the genitals and perianal region, followed by trunk or extremities [1-3]. Many patients have only a small number of lesions (20 or much more frequently even less) [1, 2]. Patel et al. [3] reported about a median of five lesions in their observation of 197 cases. It is of outmost importance to keep in mind that even patients with solitary lesions due to MPXV infection (11% in the observational study of Patel et al. [3]) may present to clinicians [1, 3]. Solitary lesions due to MPXV may easily be misdiagnosed with other solitary genital lesions, like syphilis I or lymphogranuloma venereum (the invasive variants of C. trachomatis). In the case of the perianal region being affected, anal pain and even proctitis are common and often need pain medication or even hospitalisation [1-3]. Antiviral treatment with tecovirimat or cidofovir is possible, but uncommon in the clinical setting [1, 2]. A specific treatment (including vaccination) is currently not available, and usually not necessary in this self-limiting disease, as most cases follow a mild course [1, 3]. Lesions heal within 2–4 weeks and in some cases leave a mild scar [3]. A patient with MPXV infection is contagious until all sores have crusted over, all scabs have fallen off, and an intact, new skin has formed. However, it is still under debate, whether and how long after complete healing of (muco-)cutaneous lesions, MPXV can be transmitted (e.g., via semen [1]) and the European Centre for Disease Prevention and Control (ECDC) recommends condom usage for 12 weeks after recovery from a MPXV infection. Partner notification should be based on national guidelines and national public health authorities. In general, it is recommended that sexual partners and close contacts should self-monitor for at least 21 days after contact with a patient with MPXV. Vaccination against smallpox is believed to offer protection in a high percentage, and some countries recommend vaccination in risk groups, including clinicians, laboratory personnel, those who have contact with MPXV-infected individuals, and the MSM community. Differential diagnosis of multiple genital ulcerated nodular-papular-vesicular lesions include mainly infections with herpes variants, syphilis I–II, and chancre (Table 1). Monkeypox virus infections are on the rise, mimicking clinical aspects of syphilis and herpes variants and should be kept in mind, especially in those patients presenting with pustules and systemic symptoms including mainly fever, myalgia or arthralgia among the MSM community. None of the contributing authors have any conflicts of interest, including specific financial interests, relationships, and affiliations relevant to the subject matter or materials discussed in the manuscript.

Human monkeypox virus infection in women and non-binary individuals during the 2022 outbreaks: a global case series

Monkeypox virus (MPXV) is spreading globally and nearly half of the infected people were human immunodeficiency virus (HIV) positive. Therefore, an in-depth understanding of the effects of HIV infection on the outcomes of MPXV infection is urgently needed. This study aimed to explore the clinical features, viral dynamics, and antibody response to MPXV infections in men who had sex with men (MSM) with and without HIV co-infection. MPXV-infected patients diagnosed by PCR were recruited in this study and were divided into MPXV and MPXV + HIV groups based on whether they were co-infected with HIV. Clinical data and samples were collected during of the hospital stay and follow up interviews. The symptoms and signs, laboratory examinations, viral shedding in various body fluids or swabs, antibody dynamics were tracked and compared between the two groups. A total of 41 MPXV patients were recruited through June 2023 to September 2023 in Guangzhou. The MPXV group and MPXV + HIV group comprised 20 and 21 MSM, respectively. Patients in the two groups exhibited similar clinical characteristics except for pruritus and eschar, both were significantly fewer in MPXV + HIV group than in MPXV only group. Among the 355 clinical samples collected, MPXV DNA was detected in 100% of scabs, 97.4% of skin swabs, and 92.3% of exudate swabs from lesions, while the positive rate was 87.5% from oropharyngeal swabs, 59% from saliva, 51.3% from anal swabs, 50% from feces, 30.6% from urine samples, 37.5% of semen, and 28.2% from sera. Dynamics analysis revealed that viral DNA was undetectable in most patients 20 days after symptom onset. IgM and IgG antibodies to MPXV were detected in all patients with 3-5 days earlier in the MPXV group than in the MPXV + HIV group. This cohort analysis based on a large outbreak among MSM in Guangzhou indicated no obvious differences in clinical symptoms, viral DNA data, but antibody responses were 3-5 days later in mpox patients with HIV infection.

Monkeypox, a neglected and re-emergent zoonotic disease caused by monkeypox virus (MPXV) infection, has been endemic in Central and Western Africa for decades. More recently, an outbreak has spread to a global level, occurring in sites with no previous reported cases and being clustered among men who have sex with men, suggesting new modes of transmission. There is an urgent need for research for a better understanding of the genomic evolution and changing epidemiology of the Orthopoxvirus group. Our work aimed to characterize the clinical and epidemiological features of a cohort of patients with MPXV infection in a Portuguese hospital, admitted between 5 May and 26 July 2022. In this retrospective observational study, aggregate data of a case series on the presentation, clinical course, and outcomes of confirmed MPXV infections are reported. The study included 40 men and 1 woman, with a mean age of 37.2 years old; 92.7% identified as men who have sex with men, 90.2% had unprotected sex or sex with multiple or anonymous partners in the previous month, and 39.0% reported to have had sex with an MPXV-confirmed case; 59.5% had previously known human immunodeficiency virus (HIV) infection, all of whom were under antiretroviral therapy, and no patients had acquired immunodeficiency syndrome (AIDS) criteria. About a quarter of patients were observed only a week after symptom onset. All patients had skin or mucosal lesions and the anogenital region was the most frequent lesion site. There were no statistically significant clinical differences between HIV-positive and negative individuals. Four patients were admitted to the inpatient clinic, two of whom had proctitis with difficult-to-manage anal pain. There were no reported deaths. Our findings suggest the sexual route as a relevant mode of transmission of MPXV and confirm the mostly benign presentation of this disease.

Long-term consequences of monkeypox virus infection or modified vaccinia virus Ankara vaccination in Belgium (MPX-COHORT and POQS-FU-PLUS): a 24-month prospective and retrospective cohort study.

Zoonotic monkeypox virus is maintained in a large number of rodent and, to a lesser extent, nonhuman primate species in West and central Africa. Although monkeypox virus was discovered in 1958, the prototypic human cases were not witnessed until the early 1970s. Before this time, it is assumed that infections were masked by smallpox, which was then widely endemic. Nevertheless, since the 1970s, reported monkeypox virus infections of humans have escalated, as have outbreaks with reported human-to-human transmission. This increase is likely due to numerous factors, such as enhanced surveillance efforts, environmental degradation and human urbanization of areas where monkeypox virus is maintained in its animal reservoir(s) and, consequently, serve as a nidus for human infection. Furthermore, viral genetic predispositions enable monkeypox virus to infect many animal species, represented in expansive geographic ranges. Monkeypox virus was once restricted to specific regions of Africa, but its environ has expanded, in one case intercontinentally--suggesting that human monkeypox infections could continue to intensify. As a zoonotic agent, monkeypox virus is far less sensitive to typical eradication measures since it is maintained in wild-animal populations. Moreover, human vaccination is becoming a less viable option to control poxvirus infections in today's increasingly immunocompromised population, particularly with the emergence of HIV in Sub-Saharan Africa. An increased frequency of human monkeypox virus infections, especially in immunocompromised individuals, may permit monkeypox virus to evolve and maintain itself independently in human populations.

Monkeypox virus (MPXV) infection has recently expanded in geographic distribution and can be fatal in up to 10% of cases. The intravenous (i.v.) inoculation of nonhuman primates (NHPs) results in an accelerated fulminant disease course compared to that of naturally occurring MPXV infection in humans. Alternative routes of inoculation are being investigated to define an NHP model of infection that more closely resembles natural disease progression. Our goal was to determine if the intrabronchial (i.b.) exposure of NHPs to MPXV results in a systemic disease that better resembles the progression of human MPXV infection. Here, we compared the disease course following an i.v. or i.b. inoculation of NHPs with 10-fold serial doses of MPXV Zaire. Classical pox-like disease was observed in NHPs administered a high virus dose by either route. Several key events were delayed in the highest doses tested of the i.b. model compared to the timing of the i.v. model, including the onset of fever, lesion appearance, peak viremia, viral shedding in nasal and oral swabs, peak cytokine levels, and time to reach endpoint criteria. Virus distribution across 19 tissues was largely unaffected by the inoculation route at the highest doses tested. The NHPs inoculated by the i.b. route developed a viral pneumonia that likely exacerbated disease progression. Based on the observations of the delayed onset of clinical and virological parameters and endpoint criteria that may more closely resemble those of human MPXV infection, the i.b. MPXV model should be considered for the further investigation of viral pathogenesis and countermeasures.

In early 2022, a cluster of monkeypox virus (MPXV) infection (mpox) cases were identified within the UK with no prior travel history to MPXV-endemic regions. Subsequently, case numbers exceeding 80,000 were reported worldwide, primarily affecting gay, bisexual, and other men who have sex with men (GBMSM). Public health agencies worldwide have offered the IMVANEX Smallpox vaccination to these individuals at high-risk to provide protection and limit the spread of MPXV. We have developed a comprehensive array of ELISAs to study poxvirus-induced antibodies, utilising 24 MPXV and 3 Vaccinia virus (VACV) recombinant antigens. Panels of serum samples from individuals with differing Smallpox-vaccine doses and those with prior MPXV infection were tested on these assays, where we observed that one dose of Smallpox vaccination induces a low number of antibodies to a limited number of MPXV antigens but increasing with further vaccination doses. MPXV infection induced similar antibody responses to diverse poxvirus antigens observed in Smallpox-vaccinated individuals. We identify MPXV A27 as a serological marker of MPXV-infection, whilst MPXV M1 (VACV L1) is likely IMVANEX-specific. Here, we demonstrate analogous humoral antigen recognition between both MPXV-infected or Smallpox-vaccinated individuals, with binding to diverse yet core set of poxvirus antigens, providing opportunities for future vaccine (e.g., mRNA) and therapeutic (e.g., mAbs) design.

ABSTRACTMonkeypox virus (MPXV) infections in humans have historically been restricted to regions of endemicity in Africa. However, in 2022, an alarming number of MPXV cases were reported globally, with evidence of person-to-person transmission. Because of this, the World Health Organization (WHO) declared the MPXV outbreak a public health emergency of international concern. The supply of MPXV vaccines is limited, and only two antivirals, tecovirimat and brincidofovir, approved by the U.S. Food and Drug Administration (FDA) for the treatment of smallpox, are currently available for the treatment of MPXV infection. Here, we evaluated 19 compounds previously shown to inhibit different RNA viruses for their ability to inhibit orthopoxvirus infections. We first used recombinant vaccinia virus (rVACV) expressing fluorescence (mScarlet or green fluorescent protein [GFP]) and luciferase (Nluc) reporter genes to identify compounds with antiorthopoxvirus activity. Seven compounds from the ReFRAME library (antimycin A, mycophenolic acid, AVN-944, pyrazofurin, mycophenolate mofetil, azaribine, and brequinar) and six compounds from the NPC library (buparvaquone, valinomycin, narasin, monensin, rotenone, and mubritinib) showed inhibitory activity against rVACV. Notably, the anti-VACV activity of some of the compounds in the ReFRAME library (antimycin A, mycophenolic acid, AVN-944, mycophenolate mofetil, and brequinar) and all the compounds from the NPC library (buparvaquone, valinomycin, narasin, monensin, rotenone, and mubritinib) were confirmed with MPXV, demonstrating their inhibitory activity in vitro against two orthopoxviruses.IMPORTANCE Despite the eradication of smallpox, some orthopoxviruses remain important human pathogens, as exemplified by the recent 2022 monkeypox virus (MPXV) outbreak. Although smallpox vaccines are effective against MPXV, access to those vaccines is limited. In addition, current antiviral treatment against MPXV infections is limited to the use of the FDA-approved drugs tecovirimat and brincidofovir. Thus, there is an urgent need to identify novel antivirals for the treatment of MPXV infection and other potentially zoonotic orthopoxvirus infections. Here, we show that 13 compounds, derived from two different libraries, previously found to inhibit several RNA viruses, also inhibit VACV. Notably, 11 compounds also displayed inhibitory activity against MPXV.

Vaccination Approach Toward Monkeypox: An Urgent Call

Cases of Monkeypox virus infection in humans have been identified in the United Kingdom since 2022, then followed by several countries. World Health Organization has declared Monkeypox virus as a global health emergency. Monkeypox virus infects humans in the form of Intracellular Mature Virion (IMV) structure through E8L protein. IMV E8L protein has a region that can be recognized to antibodies, called a B-cell epitope. B-cell epitope have been extensively studied to construct peptide-based vaccine ingredients. The aim of this study was to find potential B cell epitope sequences for peptide-based vaccine candidates. This research was conducted in silico through B-cell epitope mapping, then several epitope candidates were tested based on several parameters such as antigenicity test, allergenicity test, docking simulation, and analysis of molecular interactions. This study identified four potential B-cell epitopes of the Monkeypox virus E8L protein as promising peptide-based vaccine candidates based on antigenicity and allergenicity analyses. Among these, the epitope KKKYSSYYEEAKK demonstrated the strongest interaction with the B-cell receptor (PDB ID: 5IFH), exhibiting a binding energy of -274.0 kJ/mol. Molecular docking revealed that the interaction was primarily mediated through lysine (positions 1 and 2) and tyrosine (position 4) residues, indicating stable and specific molecular recognition. These findings suggest that the E8L protein contains immunodominant regions capable of eliciting B-cell responses, supporting its potential as a subunit vaccine candidate against Monkeypox virus. The in silico approach applied in this study provides a cost-effective and time-efficient screening platform for epitope-based vaccine development prior to in vitro and in vivo validation. Furthermore, this study contributes to the rational design of next-generation peptide vaccines that minimize adverse immune reactions through early molecular-level evaluation of immunogenicity and allergenicity.