Transmission dynamics of monkeypox in the United Kingdom: contact tracing study

Experimental inoculation of pigs with monkeypox virus results in productive infection and transmission to sentinels

Monkeypox virus (MPXV) is a re-emerging zoonotic poxvirus responsible for producing skin lesions in humans. Endemic in sub-Saharan Africa, the 2022 outbreak with a clade IIb strain has resulted in ongoing sustained transmission of the virus worldwide. MPXV has a relatively wide host range, with infections reported in rodent and non-human primate species. However, the susceptibility of many domestic livestock species remains unknown. Here, we report on a susceptibility/transmission study in domestic pigs that were experimentally inoculated with a 2022 MPXV clade IIb isolate or served as sentinel contact control animals. Several principal-infected and sentinel contact control pigs developed minor lesions near the lips and nose starting at 12 through 18 days post-challenge (DPC). No virus was isolated and no viral DNA was detected from the lesions; however, MPXV antigen was detected by IHC in tissue from a pustule of a principal infected pig. Viral DNA and infectious virus were detected in nasal and oral swabs up to 14 DPC, with peak titers observed at 7 DPC. Viral DNA was also detected in nasal tissues or skin collected from two principal-infected animals at 7 DPC post-mortem. Furthermore, all principal-infected and sentinel control animals enrolled in the study seroconverted. In conclusion, we provide the first evidence that domestic pigs are susceptible to experimental MPXV infection and can transmit the virus to contact animals.

Incubation Period and Serial Interval of Mpox in 2022 Global Outbreak Compared with Historical Estimates

Understanding changes in the transmission dynamics of mpox requires comparing recent estimates of key epidemiologic parameters with historical data. We derived historical estimates for the incubation period and serial interval for mpox and contrasted them with pooled estimates from the 2022 outbreak. Our findings show the pooled mean infection-to-onset incubation period was 8.1 days for the 2022 outbreak and 8.2 days historically, indicating the incubation periods remained relatively consistent over time, despite a shift in the major mode of transmission. However, we estimated the onset-to-onset serial interval at 8.7 days using 2022 data, compared with 14.2 days using historical data. Although the reason for this shortening of the serial interval is unclear, it may be because of increased public health interventions or a shift in the mode of transmission. Recognizing such temporal shifts is essential for informed response strategies, and public health measures remain crucial for controlling mpox and similar future outbreaks.

The real-time infection hospitalisation and fatality risk across the COVID-19 pandemic in England

The COVID-19 pandemic led to 231,841 deaths and 940,243 hospitalisations in England, by the end of March 2023. This paper calculates the real-time infection hospitalisation risk (IHR) and infection fatality risk (IFR) using the Office for National Statistics Coronavirus Infection Survey (ONS CIS) and the Real-time Assessment of Community Transmission Survey between November 2020 to March 2023. The IHR and the IFR in England peaked in January 2021 at 3.39% (95% Credible Intervals (CrI): 2.79, 3.97) and 0.97% (95% CrI: 0.62, 1.36), respectively. After this time, there was a rapid decline in the severity from infection, with the lowest estimated IHR of 0.32% (95% CrI: 0.27, 0.39) in December 2022 and IFR of 0.06% (95% CrI: 0.04, 0.08) in April 2022. We found infection severity to vary more markedly between regions early in the pandemic however, the absolute heterogeneity has since reduced. The risk from infection of SARS-CoV-2 has changed substantially throughout the COVID-19 pandemic with a decline of 86.03% (80.86, 89.35) and 89.67% (80.18, 93.93) in the IHR and IFR, respectively, since early 2021. From April 2022 until March 2023, the end of the ONS CIS study, we found fluctuating patterns in the severity of infection with the resumption of more normative mixing, resurgent epidemic waves, patterns of waning immunity, and emerging variants that have shown signs of convergent evolution.

Sexual Exposures Associated With Mpox Infection: California, November 2022 to June 2023

BACKGROUND

Exposures associated with mpox infection remain imperfectly understood.

METHODS

We conducted a case-control study enrolling participants who received molecular tests for mpox/orthopoxvirus in California from November 2022 through June 2023. We collected data on behaviors during a 21-day risk period before symptom onset or testing among mpox case patients and test-negative controls.

RESULTS

Thirteen of 54 case patients (24.1%) and 5 of 117 controls (4.3%) reported sexual exposure to individuals they identified as potential mpox case patients ("index contacts"; odds ratio [OR], 7.7 [95% confidence interval (CI), 2.5-19.3] relative to individuals who did not report exposure to potential mpox case patients). Among these participants, 10 of 13 case patients (76.9%) and 2 of 5 controls (40.0%) reported that their index contacts were not experiencing symptoms visible to participants during sex (OR, 14.9 [95% CI, 3.6-101.8]). Only 3 of 54 case patients (5.6%) reported exposure to symptomatic index contacts. Case patients reported more anal/vaginal sex partners than did controls (adjusted OR, 2.2 [95% CI, 1.0-4.8] for 2-3 partners and 3.8 [1.7-8.8] for ≥4 partners). Male case patients with penile lesions more commonly reported insertive anal/vaginal sex than those without penile lesions (adjusted OR, 9.3 [95% CI, 1.6-54.8]). Case patients with anorectal lesions more commonly reported receptive anal sex than those without anorectal lesions (adjusted OR, 14.4 [95% CI, 1.0-207.3]).

CONCLUSIONS

Sexual exposure to contacts known or suspected to have experienced mpox was associated with increased risk of infection, often when index contacts lacked apparent symptoms. Exposure to more sex partners, including those whom participants did not identify as index contacts, was associated with increased risk of infection in a site-specific manner. While participants' assessment of symptoms in partners may be imperfect, these findings suggest that individuals without visibly prominent mpox symptoms transmit infection.

Detection of Mpox Virus Using Microbial Cell-Free DNA: The Potential of Pathogen-Agnostic Sequencing for Rapid Identification of Emerging Pathogens

BACKGROUND

The 2022 global outbreak of Monkeypox virus (MPXV) highlighted challenges with polymerase chain reaction detection as divergent strains emerged and atypical presentations limited the applicability of swab sampling. Recommended testing in the United States requires a swab of lesions, which arise late in infection and may be unrecognized. We present MPXV detections using plasma microbial cell-free DNA (mcfDNA) sequencing.

METHODS

Fifteen plasma samples from 12 case-patients were characterized through mcfDNA sequencing. Assay performance was confirmed through in silico inclusivity and exclusivity assessments. MPXV isolates were genotyped using mcfDNA, and phylodynamic information was imputed using publicly available sequences.

RESULTS

MPXV mcfDNA was detected in 12 case-patients. Mpox was not suspected in 5, with 1 having documented resolution of mpox >6 months previously. Six had moderate to severe mpox, supported by high MPXV mcfDNA concentrations; 4 died. In 7 case-patients, mcfDNA sequencing detected coinfections. Genotyping by mcfDNA sequencing identified 22 MPXV mutations at 10 genomic loci in 9 case-patients. Consistent with variation observed in the 2022 outbreak, 21 of 22 variants were G > A/C > T. Phylogenetic analyses imputed isolates to sublineages arising at different time points and from different geographic locations.

CONCLUSIONS

We demonstrate the potential of plasma mcfDNA sequencing to detect, quantify, and, for acute infections with high sequencing coverage, subtype MPXV using a single noninvasive test. Sequencing plasma mcfDNA may augment existing mpox testing in vulnerable patient populations or in patients with atypical symptoms or unrecognized mpox. Strain type information may supplement disease surveillance and facilitate tracking emerging pathogens.

Characteristics of the Sexual Networks of Men Who Have Sex With Men in Montréal, Toronto, and Vancouver: Insights from Canada's 2022 Mpox Outbreak

BACKGROUND

The 2022-2023 global mpox outbreak disproportionately affected gay, bisexual, and other men who have sex with men (GBM). We investigated differences in GBM's sexual partner distributions across Canada's 3 largest cities and over time, and how they shaped transmission.

METHODS

The Engage Cohort Study (2017-2023) recruited GBM via respondent-driven sampling in Montréal, Toronto, and Vancouver (n = 2449). We compared reported sexual partner distributions across cities and periods: before COVID-19 (2017-2019), pandemic (2020-2021), and after lifting of restrictions (2021-2023). We used Bayesian regression and poststratification to model partner distributions. We estimated mpox's basic reproduction number (R0) using a risk-stratified compartmental model.

RESULTS

Pre-COVID-19 pandemic distributions were comparable: fitted average partners (past 6 months) were 10.4 (95% credible interval: 9.4-11.5) in Montréal, 13.1 (11.3-15.1) in Toronto, and 10.7 (9.5-12.1) in Vancouver. Sexual activity decreased during the pandemic and increased after lifting of restrictions, but remained below prepandemic levels. Based on reported cases, we estimated R0 of 2.4 to 2.7 and similar cumulative incidences (0.7%-0.9%) across cities.

CONCLUSIONS

Similar sexual partner distributions may explain comparable R0 and cumulative incidence across cities. With potential for further recovery in sexual activity, mpox vaccination and surveillance strategies should be maintained.

Time Scales of Human Mpox Transmission in The Netherlands

Mpox has spread rapidly to many countries in nonendemic regions. After reviewing detailed exposure histories of 109 pairs of mpox cases in the Netherlands, we identified 34 pairs where transmission was likely and the infectee reported a single potential infector with a mean serial interval of 10.1 days (95% credible interval, 6.6-14.7 days). Further investigation into pairs from 1 regional public health service revealed that presymptomatic transmission may have occurred in 5 of 18 pairs. These findings emphasize that precaution remains key, regardless of the presence of recognizable symptoms of mpox.

The decline of the 2022 Italian mpox epidemic: Role of behavior changes and control strategies

In 2022, a global outbreak of mpox occurred, predominantly impacting men who have sex with men (MSM). The rapid decline of this epidemic is yet to be fully understood. We investigated the Italian outbreak by means of an individual-based mathematical model calibrated to surveillance data. The model accounts for transmission within the MSM sexual contact network, in recreational and sex clubs attended by MSM, and in households. We indicate a strong spontaneous reduction in sexual transmission (61-87%) in affected MSM communities as the possible driving factor for the rapid decline in cases. The MSM sexual contact network was the main responsible for transmission (about 80%), with clubs and households contributing residually. Contact tracing prevented about half of the potential cases, and a higher success rate in tracing contacts could significantly amplify its effectiveness. Notably, immunizing the 23% of MSM with the highest sexual activity (10 or more partners per year) could completely prevent new mpox resurgences. This research underscores the importance of augmenting contact tracing, targeted immunization campaigns of high-risk groups, and fostering reactive behavioral changes as key strategies to manage and prevent the spread of emerging sexually transmitted pathogens like mpox within the MSM community.

Understanding the infection severity and epidemiological characteristics of mpox in the UK

In May 2022, individuals infected with the monkeypox virus were detected in the UK without clear travel links to endemic areas. Understanding the clinical characteristics and infection severity of mpox is necessary for effective public health policy. The study period of this paper, from the 1st June 2022 to 30th September 2022, included 3,375 individuals that tested positive for the monkeypox virus. The posterior mean times from infection to hospital admission and length of hospital stay were 14.89 days (95% Credible Intervals (CrI): 13.60, 16.32) and 7.07 days (95% CrI: 6.07, 8.23), respectively. We estimated the modelled Infection Hospitalisation Risk to be 4.13% (95% CrI: 3.04, 5.02), compared to the overall sample Case Hospitalisation Risk (CHR) of 5.10% (95% CrI: 4.38, 5.86). The overall sample CHR was estimated to be 17.86% (95% CrI: 6.06, 33.11) for females and 4.99% (95% CrI: 4.27, 5.75) for males. A notable difference was observed between the CHRs that were estimated for each sex, which may be indicative of increased infection severity in females or a considerably lower infection ascertainment rate. It was estimated that 74.65% (95% CrI: 55.78, 86.85) of infections with the monkeypox virus in the UK were captured over the outbreak.

Asymptomatic transmission of human mpox

Monkeypox virus belongs to the genus Orthopoxvirus There was a worldwide mpox outbreak in 2022, with many cases reported in Europe in gay, bisexual and other men who have sex with men. Here, we report a case of mpox diagnosed in a heterosexual woman in her twenties without any known history of exposure. This is a very rare event. Despite lesions remaining for more than 1 month, she recovered fully with no sequelae. We highlight the diagnosis of mpox in a heterosexual woman without a known or suspected history of exposure or any risk factor for acquiring the infection.

Pockenvirusinfektionen in der Dermatologie: Poxvirus infections in dermatology - the neglected, the notable, and the notorious

Die Familie Poxviridae umfasst derzeit 22 Gattungen, die Wirbeltiere infizieren können. Humanpathogene Pockenviren gehören den Gattungen Ortho‐, Para‐, Mollusci‐ und Yatapoxvirus an. Bis zur Eradikation der Variola vera im Jahr 1979 waren die Pocken, im Volksmund auch Blattern genannt, eine schwerwiegende Gesundheitsbedrohung für die Bevölkerung. Noch heute sind Dermatologen mit zahlreichen Pockenvirusinfektionen konfrontiert, wie den Bauernhofpocken, die als Zoonosen nach Tierkontakten in ländlichen Gebieten oder nach Massenversammlungen auftreten können. In den Tropen können Erkrankungen durch Tanapox‐ oder Vaccinia‐Viren zu den Differenzialdiagnosen gehören. Dellwarzen sind weltweit verbreitet und werden in bestimmten Fällen als sexuell übertragbare Pockenvirusinfektion angesehen. In jüngster Zeit hatten sich Mpox (Affenpocken) zu einer gesundheitlichen Notlage von internationaler Tragweite entwickelt, die eine rasche Identifizierung und angemessene Behandlung durch Dermatologen und Infektiologen erfordert. Fortschritte und neue Erkenntnisse über Epidemiologie, Diagnose, klinische Manifestationen und Komplikationen sowie Behandlung und Prävention von Pockenvirusinfektionen erfordern ein hohes Maß an Fachwissen und interdisziplinärer Zusammenarbeit in den Bereichen Virologie, Infektiologie und Dermatologie. Dieser CME‐Artikel bietet einen aktualisierten systematischen Überblick, um praktizierende Dermatologen bei der Identifizierung, Differenzialdiagnose und Behandlung klinisch relevanter Pockenvirusinfektionen zu unterstützen.

Poxvirus infections in dermatology - the neglected, the notable, and the notorious

The family Poxviridae currently comprises 22 genera that infect vertebrates. Of these, members of the Ortho-, Para-, Mollusci- and Yatapoxvirus genera have been associated with human diseases of high clinical relevance in dermatology. Historically, smallpox had been a notorious health threat until it was declared eradicated by the World Health Organization in 1979. Today, dermatologists are confronted with a variety of poxviral infections, such as farmyard pox, which occurs as a zoonotic infection after contact with animals. In the tropics, tanapox or vaccinia may be in the differential diagnosis as neglected tropical dermatoses. Molluscum contagiosum virus infection accounts for significant disease burden worldwide and is classified as a sexually transmitted infection in certain scenarios. Recently, mpox (monkeypox) has emerged as a public health emergency of international concern, requiring rapid recognition and appropriate management by dermatologists and infectious disease specialists. Advances and new insights into the epidemiology, diagnosis, clinical manifestations and complications, treatment, and prevention of poxviral infections require a high level of expertise and interdisciplinary skills from healthcare professionals linking virology, infectious diseases, and dermatology. This CME article provides a systematic overview and update to assist the practicing dermatologist in the identification, differential diagnosis, and management of poxviral infections.

Retrospective testing for mpox virus in routine STI screens from men who have sex with men in England, August-October 2022

OBJECTIVES

A global outbreak of mpox (monkeypox) has been ongoing since 2022, with most cases in the UK detected in gay, bisexual and other men who have sex with men (GBMSM). Asymptomatic and pauci-symptomatic mpox infection has been reported outside of the UK. We aimed to investigate whether mpox could be detected in specimens from GBMSM in England who were attending sexual health services (SHSs) for asymptomatic sexually transmitted infection screening.

METHODS

Anonymised, residual clinical specimens from GBMSM undertaking routine asymptomatic screening for gonorrhoea (Neisseria gonorrhoeae (NG)) and chlamydia (Chlamydia trachomatis (CT)) infection were tested for the presence of mpox virus. Specimens were collected between 1 August and 7 October 2022 from three SHSs in high-mpox incidence areas in England. Testing was performed using a dual-clade, mpox virus-specific real-time PCR.

RESULTS

During the collection period, 2927 clinical specimens (951 pharyngeal swabs, 1022 urine specimens and 954 rectal swabs) were obtained from 1159 GBMSM. Mpox virus was detected in four specimens from two participants who attended the same SHS at different times (the first during the week 8-12 of August, the second during the week 19-23 of September). One participant was positive in the urine specimen only, while the other tested positive at all three sites.

CONCLUSIONS

A very low prevalence (2 of 1159, 0.17%) of mpox infection was detected in GBMSM attending SHS in England for asymptomatic NG/CT screening, suggesting that undetected infection in this population was unlikely to be a main driver of transmission. Confirmed mpox cases in the UK declined from over 1100 per month in June and July to 764 cumulatively during the collection period. These data give reassurance that the observed reduction in cases during the collection period was not due to undetected infection or changes in presentation among SHS attendees. Currently, there is insufficient evidence to support routine testing of asymptomatic GBMSM for mpox infection in England.

A Review of the Past, Present, and Future of the Monkeypox Virus: Challenges, Opportunities, and Lessons from COVID-19 for Global Health Security

Monkeypox, a rare but significant zoonotic and orthopoxviral disease, has garnered increasing attention due to its potential for human-to-human transmission and its recent resurgence in multiple countries throughout Europe, North America, and Oceania. The disease has emerged as a novel threat to the global health systems that are still striving to recover from the major shocks of the COVID-19 pandemic. The unusual manifestation of the illness highlights a substantial knowledge deficit and necessitates the immediate development of a public health action strategy, considering the epidemiological differences observed in the ongoing outbreak and the appearance of cases in non-endemic nations. This literature review aims to synthesize existing knowledge on monkeypox, encompassing its historical context, etiology, epidemiology, surveillance, prevention, transmission, clinical presentation, diagnosis, treatments, and recent outbreak. Particular attention is given to both advances and gaps in our understanding of monkeypox, and we point toward future directions for research and intervention efforts as pertains to vaccine development and distribution. Lastly, we will also review the recent outbreak through a sociopolitical lens as relates to decision-making strategies, especially given the lessons learned from COVID-19.

Self-sampling monkeypox virus testing in high-risk populations, asymptomatic or with unrecognized Mpox, in Spain

The recent monkeypox virus (MPXV) outbreak was of global concern and has mainly affected gay, bisexual and other men who have sex with men (GBMSM). Here we assess prevalence of MPXV in high-risk populations of GBMSM, trans women (TW) and non-binary people without symptoms or with unrecognized monkeypox (Mpox) symptoms, using a self-sampling strategy. Anal and pharyngeal swabs are tested by MPXV real-time PCR and positive samples are tested for cytopathic effect (CPE) in cell culture. 113 individuals participated in the study, 89 (78.76%) were cis men, 17 (15.04%) were TW. The median age was 35.0 years (IQR: 30.0-43.0), 96 (85.02%) individuals were gay or bisexual and 72 (63.72%) were migrants. Seven participants were MPXV positive (6.19% (95% CI: 1.75%-10.64%)). Five tested positive in pharyngeal swabs, one in anal swab and one in both. Six did not present symptoms recognized as MPXV infection. Three samples were positive for CPE, and showed anti-vaccinia pAb staining by FACS and confocal microscopy. This suggests that unrecognized Mpox cases can shed infectious virus. Restricting testing to individuals reporting Mpox symptoms may not be sufficient to contain outbreaks.

Spatiotemporal cluster of mpox in men who have sex with men: A modeling study in 83 countries

Mpox outbroke globally during 2022-2023, with more than 90% of cases occurring in men who have sex with men (MSM). However, the spatiotemporal distribution of mpox is not well established yet. This study aimed to explore the spatiotemporal clustering of mpox cases in MSM worldwide. We obtained the numbers of mpox cases from Our World in Data, the number of MSM from the Joint United Nations Programme on HIV/AIDS (UNAIDS), UNAIDS DATA 2021 and UNAIDS Global AIDS Update 2022 and literature. We evaluated the spatiotemporal cluster of mpox in MSM using retrospective space-time analyses method. The total number of mpox cases was 85 795 during May 1, 2022 to March 31, 2023. The most likely cluster was Spain (likelihood ratio = 4764.97; p < 0.001), with a cluster period from July 26 to August 14, 2022. There were 11 secondary clusters, which included 46 countries located in western Europe, eastern and northern South America, northern Europe, Canada, Central Africa, southern and central Europe, Latin America, Turkey, Dominican Republic, New Zealand, and Australia. The findings may inform current and future control strategies of mpox and might provide references for the identification of the spatiotemporal distribution of new and emerging infectious diseases in specific populations.

[Management from Primary Care of monkeypox infection (MPOX) in humans]

Monkeypox (MPOX) is a viral zoonosis endemic in West or Central African countries that is sporadically exported to another area. In May 2022, a global outbreak of MPOX smallpox began to occur in several countries in Europe and North America. Most of the reported cases are identified at the outpatient level and mainly affect men who have sex with men (MSM). Transmission is by close contact with lesions, body fluids, respiratory secretions or contaminated material from an infected person or animal. The clinical picture is similar to human smallpox, with less severity. Mild, self-limiting skin involvement predominates after 2-4 weeks. In MSM, atypical skin lesions appear due to the mode of infection. Severe forms or complications may appear in certain risk groups. The case fatality rate is 3%-6% depending on the clade responsible. The diagnosis of suspicion is confirmed by detection of the virus from exudates of lesions or scabs, with nucleic acid amplification techniques by conventional or real-time PCR. Clinical management in most cases is performed in primary care (PC), by monitoring the main symptoms. Between 5-10% require hospital management and there are some specific antiviral treatment options. Human smallpox vaccines protect against MPOX and are used as pre- and post-exposure prophylaxis for persons at risk. Measures to reduce exposure to the virus are the main MPOX prevention strategy. In addition, the role of the family physician is key to controlling the spread of MPOX through active surveillance and early diagnosis of the disease.

Monkeypox presenting as a chancre-like rash: A case report

BACKGROUND

Since May 2022, outbreaks of monkeypox have occurred in many countries around the world, and several cases have been reported in China.

CASE SUMMARY

A 38-year-old man presented with a small, painless, shallow ulcer on the coronary groove for 8 d. One day after the rash appeared, the patient developed inguinal lymphadenopathy with fever. The patient had a history of male-male sexual activity and denied a recent history of travel abroad. Monkeypox virus was detected by quantitative polymerase chain reaction from the rash site and throat swab. Based on the epidemiological history, clinical manifestations and nucleic acid test results, the patient was diagnosed with monkeypox.

CONCLUSION

Monkeypox is an emerging infectious disease in China. Monkeypox presenting as a chancre-like rash is easily misdiagnosed. Diagnosis can be made based on exposure history, clinical manifestations and nucleic acid test results.

Nowcasting the 2022 mpox outbreak in England

In May 2022, a cluster of mpox cases were detected in the UK that could not be traced to recent travel history from an endemic region. Over the coming months, the outbreak grew, with over 3000 total cases reported in the UK, and similar outbreaks occurring worldwide. These outbreaks appeared linked to sexual contact networks between gay, bisexual and other men who have sex with men. Following the COVID-19 pandemic, local health systems were strained, and therefore effective surveillance for mpox was essential for managing public health policy. However, the mpox outbreak in the UK was characterised by substantial delays in the reporting of the symptom onset date and specimen collection date for confirmed positive cases. These delays led to substantial backfilling in the epidemic curve, making it challenging to interpret the epidemic trajectory in real-time. Many nowcasting models exist to tackle this challenge in epidemiological data, but these lacked sufficient flexibility. We have developed a nowcasting model using generalised additive models that makes novel use of individual-level patient data to correct the mpox epidemic curve in England. The aim of this model is to correct for backfilling in the epidemic curve and provide real-time characteristics of the state of the epidemic, including the real-time growth rate. This model benefited from close collaboration with individuals involved in collecting and processing the data, enabling temporal changes in the reporting structure to be built into the model, which improved the robustness of the nowcasts generated. The resulting model accurately captured the true shape of the epidemic curve in real time.

Mpox Outbreak 2022: A Comparative Analysis of the Characteristics of Individuals Receiving MVA-BN Vaccination and People Diagnosed with Mpox Infection in Milan, Italy

Mpox caused a worldwide outbreak in 2022, disproportionately affecting MSM reporting high-risk sexual behaviors. The aim of this study was to compare the characteristics of people receiving MVA-BN vaccination with those of individuals diagnosed with mpox to guide future vaccination policies. This was a retrospective study on people with mpox infection or vaccination at San Raffaele Scientific Institute, Milan, Italy, from May to November 2022. Characteristics were compared using Mann-Whitney or chi-square/Fisher's exact tests; multivariable logistic regression and classification tree analysis were applied. Overall, 473 vaccinated individuals and 135 with mpox were included; 472/473 and 134/135 were MSM. People with mpox were more frequently living with HIV (48.9% vs. 22.4%, p < 0.001), had ≥1 previous STI (75.6% vs. 35.7%, p < 0.001), were chemsex users (37.8% vs. 6.34%, p < 0.001), were with a higher number of partners (23.0% vs. 1.69%, p < 0.001), and had engaged in group sex (55.6% vs. 24.1%, p < 0.001). At multivariable analysis, PLWH (aOR = 2.86, 95%CI = 1.59-5.19, p < 0.001), chemsex users (aOR = 2.96, 95%CI = 1.52-5.79, p = 0.001), those with previous syphilis (aOR = 4.11, 95%CI = 2.22-7.72, p < 0.001), and those with >10 partners (aOR = 11.56, 95%CI = 6.60-21.09, p < 0.001) had a higher risk of infection. This study underscores the importance of prioritizing MSM with prior STIs and multiple partners as well as chemsex users in vaccination policies to curb mpox spread. A destigmatized assessment of sexual history is vital for comprehensive sexual health strategies.

The role of vaccination and public awareness in forecasts of Mpox incidence in the United Kingdom

Beginning in May 2022, Mpox virus spread rapidly in high-income countries through close human-to-human contact primarily amongst communities of gay, bisexual and men who have sex with men (GBMSM). Behavioural change arising from increased knowledge and health warnings may have reduced the rate of transmission and modified Vaccinia-based vaccination is likely to be an effective longer-term intervention. We investigate the UK epidemic presenting 26-week projections using a stochastic discrete-population transmission model which includes GBMSM status, rate of formation of new sexual partnerships, and clique partitioning of the population. The Mpox cases peaked in mid-July; our analysis is that the decline was due to decreased transmission rate per infected individual and infection-induced immunity among GBMSM, especially those with the highest rate of new partners. Vaccination did not cause Mpox incidence to turn over, however, we predict that a rebound in cases due to behaviour reversion was prevented by high-risk group-targeted vaccination.

Mpox and Monkeypox Virus: Special Considerations for Athletes in Contact Sports

Monkeypox virus infections (mpox) in humans have become increasingly common since the virus was first identified in 1970. Coverage of the ongoing mpox outbreak has emphasized the role of skin-to-skin contact in monkeypox virus transmission and has focused on the community of men who have sex with men. While close contact from sexual activity is currently the main mechanism of monkeypox virus transmission, the potential for contact sports to exacerbate the 2022 outbreak has largely been overlooked. Infectious diseases rapidly spread in sports with significant skin-to-skin contact (i.e., wrestling and other combat sports, American football, and rugby). Mpox has not yet reached the athletic community, but once it does, it may follow a similar pattern of other infectious skin diseases in sports. Thus, it is critical to initiate a discussion of the risk of mpox and potential preventive measures within a sports context. This Current Opinion aims to provide stakeholders within the sports community with a brief review of infectious skin diseases in athletes, an overview of mpox and why it is relevant to athletes, and recommendations to reduce the risk of monkeypox virus transmission within sports settings. Guidelines for sports participation in athletes exposed to mpox and those with suspected, probable, and confirmed cases of monkeypox are provided.

Estimated incubation period distributions of mpox using cases from two international European festivals and outbreaks in a club in Berlin, May to June 2022

BackgroundSince May 2022, an mpox outbreak affecting primarily men who have sex with men (MSM) has occurred in numerous non-endemic countries worldwide. As MSM frequently reported multiple sexual encounters in this outbreak, reliably determining the time of infection is difficult; consequently, estimation of the incubation period is challenging.AimWe aimed to provide valid and precise estimates of the incubation period distribution of mpox by using cases associated with early outbreak settings where infection likely occurred.MethodsColleagues in European countries were invited to provide information on exposure intervals and date of symptom onset for mpox cases who attended a fetish festival in Antwerp, Belgium, a gay pride festival in Gran Canaria, Spain or a particular club in Berlin, Germany, where early mpox outbreaks occurred. Cases of these outbreaks were pooled; doubly censored models using the log-normal, Weibull and Gamma distributions were fitted to estimate the incubation period distribution.ResultsWe included data on 122 laboratory-confirmed cases from 10 European countries. Depending on the distribution used, the median incubation period ranged between 8 and 9 days, with 5th and 95th percentiles ranging from 2 to 3 and from 20 to 23 days, respectively. The shortest interval that included 50% of incubation periods spanned 8 days (4-11 days).ConclusionCurrent public health management of close contacts should consider that in approximately 5% of cases, the incubation period exceeds the commonly used monitoring period of 21 days.

A Comprehensive Review on Monkeypox Viral Disease with Potential Diagnostics and Therapeutic Options

The purpose of this review is to give an up-to-date, thorough, and timely overview of monkeypox (Mpox), a severe infectious viral disease. Furthermore, this review provides an up-to-date treatment option for Mpox. The monkeypox virus (MPXV) has remained the most virulent poxvirus for humans since the elimination of smallpox approximately 41 years ago, with distribution mainly in central and west Africa. Mpox in humans is a zoonotically transferred disease that results in symptoms like those of smallpox. It had spread throughout west and central Africa when it was first diagnosed in the Republic of Congo in 1970. Mpox has become a major threat to global health security, necessitating a quick response by virologists, veterinarians, public health professionals, doctors, and researchers to create high-efficiency diagnostic tests, vaccinations, antivirals, and other infection control techniques. The emergence of epidemics outside of Africa emphasizes the disease's global significance. A better understanding of Mpox's dynamic epidemiology may be attained by increased surveillance and identification of cases.

Critical Elements of an Mpox Vaccination Model at the Largest Public Health Hospital System in the United States

In the spring of 2022, mpox spread to non-endemic countries, including the United States. In New York City (NYC), vaccine demand grew as quickly as case counts. With the leadership of the Regional Emerging Special Pathogens Treatment Center (RESPTC) at NYC Health and Hospitals/Bellevue (NYC H+H)-part of the largest public hospital system in the United States-an innovative vaccination model was established that overcame challenges involving health inequities, inadequate access, and lack of vaccine uptake, to successfully administer JYNNEOS vaccines to over 12,000 patients. Transmission has slowed since its peak in August 2022, which has been attributed to successful vaccination campaigns, infection-induced immunity, and behavioral changes among those at highest risk; however, a Centers for Disease Control and Prevention (CDC) assessment released on 4 April 2023 suggests jurisdictions with low vaccination levels (<35%) remain at risk for an mpox resurgence. Here, we summarize the critical aspects of our mpox vaccination model in NYC, which include integration into routine clinical care, prioritization of health equity, and reutilization of COVID-19 vaccination systems, to provide valuable insights for healthcare institutions as we move into the next stage of this ongoing outbreak.

Epidemiological and Clinical Characteristics of Patients Admitted to a Secondary Hospital with Suspected MPOX Virus Infection: Is HIV Playing a Role?

MPOX (monkeypox) is a zoonotic viral disease, endemic in some Central and West African countries. However, in May 2022, cases began to be reported in non-endemic countries, demonstrating community transmission. Since the beginning of the outbreak, different epidemiological and clinical behaviors have been observed. We conducted an observational study at a secondary hospital in Madrid to characterize suspected and confirmed cases of MPOX epidemiologically and clinically. Besides the general descriptive analysis, we compared data between HIV-positive and HIV-negative subjects; 133 patients were evaluated with suspected MPOX, of which 100 were confirmed. Regarding positive cases, 71.0% were HIV positive, and 99.0% were men with a mean age of 33. In the previous year, 97.6% reported having sex with men, 53.6% used apps for sexual encounters, 22.9% practiced chemsex, and 16.7% went to saunas. Inguinal adenopathies were significantly higher in MPOX cases (54.0% vs. 12.1%, p < 0.001), as the involvement of genital and perianal area (57.0% vs. 27.3% and 17.0% vs. 1.0%, p = 0.006 and p = 0.082 respectively). Pustules were the most common skin lesion (45.0%). In HIV-positive cases, only 6.9% had a detectable viral load, and the mean CD4 count was 607.0/mm³. No significant differences were observed in the disease course, except for a greater tendency towards the appearance of perianal lesions. In conclusion, the MPOX 2022 outbreak in our area has been related to sexual intercourse among MSM, with no severe clinical cases nor apparent differences in HIV and non-HIV patients.

Detection of Asymptomatic Mpox Carriers among High-Ri Men Who Have Sex with Men: A Prospective Analysis

Mpox is traditionally considered a zoonotic disease with endemic circulation in Africa, but the 2022-2023 outbreak reached an unprecedented high number of cases in non-endemic countries, so that it was declared a public health emergency of international concern. The reasons for this extensive global spread, characterized by sexual transmission amongst men who have sex with men (MSM), have not been fully clarified. The existence of asymptomatic carriers with viable viral shedding might be an explanation and is under-debated after retrospective studies suggested that infection without symptoms might have a prevalence of 6.5%. We aimed to prospectively assess the presence of mpox infection in asymptomatic high-risk MSM using HIV pre-exposure prophylaxis and living with HIV. We selected individuals with no signs of active infection nor suggestive symptoms in the previous 21 days. Eligible individuals collected oral and anal swabs to undergo point-of-care testing for mpox and completed a 21-days follow-up. Seventy-two individuals were enrolled, and none tested positive for mpox infection nor developed symptoms during follow-up. We selected a high-risk population with a significant history of sexual exposure, but we failed to detect any asymptomatic infection. This observation might have important consequences in terms of contact management and epidemic control.

Insights into the challenging multi-country outbreak of Mpox: a comprehensive review

Human monkeypox virus (hMpoxV) is of zoonotic origin and is closely related to the once-dreaded smallpox virus. It is largely endemic to the African continent but has moved out of the endemic regions as sporadic clusters in the past 20 years, raising concerns worldwide. Human Mpox is characterized by a mild to severe, self-limiting infection, with mortality ranging from less than 1% to up to 10% during different outbreaks caused by different clades of MpoxV. Bushmeat hunting is one of the primary reasons for its transmission from animals to humans. Various international and national health regulatory bodies are closely monitoring the disease and have laid down guidelines to manage and prevent hMpox cases. Emergency Use Status has been granted to Tecovirimat and Brincidofovir to treat severe cases and vaccination with the smallpox vaccine is recommended for high-risk group individuals. Strategies to repurpose and discover novel therapeutics and vaccines to control the outbreak are being researched. The current Mpox outbreak that has mainly affected men as approximately 96% of all cases are reported in men, is probably the result of a complex intersection of various factors. This necessitates a strong One Health response coordination involving human, animal and environmental health institutions. This review is an attempt to provide an all-inclusive overview of the biology, history, epidemiology, pathophysiology, diagnosis and management of hMpox in context to the recent 2022-2023 multi-country outbreak which is termed by WHO a 'Public Health Emergency of International Concern (PHEIC)'.

Monkeypox: a review of epidemiological modelling studies and how modelling has led to mechanistic insight

Human monkeypox (mpox) virus is a viral zoonosis that belongs to the Orthopoxvirus genus of the Poxviridae family, which presents with similar symptoms as those seen in human smallpox patients. Mpox is an increasing concern globally, with over 80,000 cases in non-endemic countries as of December 2022. In this review, we provide a brief history and ecology of mpox, its basic virology, and the key differences in mpox viral fitness traits before and after 2022. We summarize and critique current knowledge from epidemiological mathematical models, within-host models, and between-host transmission models using the One Health approach, where we distinguish between models that focus on immunity from vaccination, geography, climatic variables, as well as animal models. We report various epidemiological parameters, such as the reproduction number, R0, in a condensed format to facilitate comparison between studies. We focus on how mathematical modelling studies have led to novel mechanistic insight into mpox transmission and pathogenesis. As mpox is predicted to lead to further infection peaks in many historically non-endemic countries, mathematical modelling studies of mpox can provide rapid actionable insights into viral dynamics to guide public health measures and mitigation strategies.

Presymptomatic viral shedding in high-risk mpox contacts: A prospective cohort study

The risk of infection after exposure to clade IIb mpox virus (MPXV) is unknown, and potential presymptomatic shedding of MPXV remains to be demonstrated. High-risk contacts of mpox patients were followed-up in a prospective longitudinal cohort study. Individuals reporting sexual contact, >15 min skin-to-skin contact, or living in the same household with an mpox patient were recruited in a sexual health clinic in Antwerp, Belgium. Participants kept a symptom diary, performed daily self-sampling (anorectal, genital, and saliva), and presented for weekly clinic visits for physical examination and sampling (blood and oropharyngeal). Samples were tested for MPXV by PCR. Between June 24 and July 31, 2022, 25 contacts were included, of which 12/18 (66.0%) sexual and 1/7 (14.0%) nonsexual contacts showed evidence of infection by MPXV-PCR. Six cases had typical mpox symptoms. Viral DNA was detected as early as 4 days before symptom onset in 5 of them. In 3 of these cases, replication-competent virus was demonstrated in the presymptomatic phase. These findings confirm the existence of presymptomatic shedding of replication-competent MPXV and emphasize the high risk of transmission during sexual contact. Sexual contacts of mpox cases should abstain from sex during the incubation period, irrespective of symptoms.

Differential Diagnosis, Prevention, and Treatment of mpox (Monkeypox): A Review for Dermatologists

The current 2022 mpox (monkeypox) outbreak has been officially recognized as a public health emergency. The mpox clinical symptoms include high fever, fatigue, chills, headache, swollen lymph nodes, muscle aches, and a disseminated painful rash. However, recent cases of mpox have shown a shift in clinical symptoms, with anogenital skin lesions emerging as the predominant feature. Due to the predominant skin manifestations of mpox, dermatologists could be crucial in detecting new mpox cases and educating frontline healthcare professionals about mpox. The mpox virus is continuously evolving and has several variants. Genome sequencing has revealed that the Clade IIb variant is responsible for the 2022 mpox outbreak. Mpox spread may occur through animal-to-human and human-to-human transmission; however, unlike coronavirus disease 2019 (COVID-19), long-range airborne transmission has not been reported. Healthcare professionals are at higher risk of becoming infected since they are usually in close contact with both the patients and potentially contaminated fomites (e.g., examination table, gowns, gloves). Both public and healthcare professionals should take preventive and avoidance measures to limit the spread. Mpox is usually self-limiting and may require only symptomatic treatment; however, it may cause severe complications in special populations such as immunocompromised individuals. For severe infection, clinicians may consider antiviral drugs (off-label), tecovirimat and brincidofovir, originally approved for smallpox treatment. Two smallpox vaccines, ACAM2000^® and JYNNEOS^TM, can be used as pre-exposure prophylaxis against mpox. JYNNEOS^TM, which carries approval for mpox use, has less adverse effect potential than ACAM2000^®, and may also be used as post-exposure prophylaxis, preferably within 4 days of exposure.

Monkeypox (mpox) in immunosuppressed patients

The World Health Organization (WHO) proclaimed a public health emergency in July 2022 due to the emergence of Mpox (formerly monkeypox) while the globe was still dealing with the COVID-19 epidemic. The characteristics of mpox in immunocompetent individuals are well-characterized, despite difficulties in diagnostics, immunization, and access to treatment that persist in low-income countries. Patients with weakened immune systems are more likely to spread an illness and die from it than healthy people because they cannot mount a protective immune response against it, such as a neutralizing IgG and poxvirus-specific Th1 response. A health warning on severe mpox in people who are immunocompromised due to Human Immunodeficiency virus (HIV) and other illnesses was released by the U.S. Centers for Disease Control and Prevention (CDC) on September 29, 2022. The advice does not specifically include primary immunodeficiency, but it does define other immunocompromising disorders as “having autoimmune disease with immunodeficiency as a clinical component”. Both those with healthy immune systems and those with weakened immune systems, such as those who are immunosuppressed, older people, children, etc., have encountered serious health issues, but the latter group is more likely to do so. According to the advisory, “of the people with severe mpox manifestations for whom CDC has been consulted, the majority have had HIV with CD4 counts 200 cells/ml, indicating substantial immunosuppression”. However, new cases are still expected to be discovered, especially in low-income countries with limited access to diagnosis, treatment, and prevention, and where a large percentage of the mpox-infected population also has advanced HIV infection. Thus, further research is always needed to determine the best way to treat mpox in immunocompromised people. In this context, we discussed /reviewed the mpox clinical presentation, available treatment options and current preventive guidelines in immunocompromised patients.

Transmission of monkeypox/mpox virus: A narrative review of environmental, viral, host, and population factors in relation to the 2022 international outbreak

Monkeypox virus (MPXV) has spread globally. Emerging studies have now provided evidence regarding MPXV transmission, that can inform rational evidence-based policies and reduce misinformation on this topic. We aimed to review the evidence on transmission of the virus. Real-world studies have isolated viable viruses from high-touch surfaces for as long as 15 days. Strong evidence suggests that the current circulating monkeypox (mpox) has evolved from previous outbreaks outside of Africa, but it is yet unknown whether these mutations may lead to an inherently increased infectivity of the virus. Strong evidence also suggests that the main route of current MPXV transmission is sexual; through either close contact or directly, with detection of culturable virus in saliva, nasopharynx, and sperm for prolonged periods and the presence of rashes mainly in genital areas. The milder clinical presentations and the potential presence of presymptomatic transmission in the current circulating variant compared to previous clades, as well as the dominance of spread amongst men who have sex with men (MSMs) suggests that mpox has a developed distinct clinical phenotype that has increased its transmissibility. Increased public awareness of MPXV transmission modalities may lead to earlier detection of the spillover of new cases into other groups.

Current Insights into Diagnosis, Prevention Strategies, Treatment, Therapeutic Targets, and Challenges of Monkeypox (Mpox) Infections in Human Populations

In the wake of the emergence and worldwide respread of a viral infection called Monkeypox (Mpox), there is a serious threat to the health and safety of the global population. This viral infection was endemic to the western and central parts of Africa, but has recently spread out of this endemic area to various countries, including the United Kingdom (UK), Portugal, Spain, the United States of America (USA), Canada, Sweden, Belgium, Italy, Australia, Germany, France, the Netherlands, Israel, and Mexico. This is a timely review focusing on recent findings and developments in the epidemiology, clinical features, therapeutic targets, diagnosis, prevention mechanisms, research challenges and possible treatment for Mpox. To date (29 November 2022), there have been around 81,225 reported cases of Mpox. In most cases, this illness is mild; however, there is a fatality rate ranging from 1 to 10%, which might be increased due to associated complications and/or secondary infections. There is a real challenge in the diagnosis of Mpox, since its symptoms are very similar to those of other infections, including smallpox and chickenpox. Generally, to prevent/limit the risk and transmission of Mpox, the detection and isolation of infected individuals, as well as hand hygiene and cleanliness, are essential and effective approaches to control/combat this viral infection. Nevertheless, updated information about Mpox from different angles is lacking. Thus, this review provides updated and comprehensive information about the Mpox illness, which should highlight the global burden, pathogenicity, symptoms, diagnosis, prevention measures and possible treatment of this emerging disease.

Monkeypox

Monkeypox is a zoonotic illness caused by the monkeypox virus, an Orthopoxvirus in the same genus as the variola, vaccinia, and cowpox viruses. Since the detection of the first human case in the Democratic Republic of the Congo in 1970, the disease has caused sporadic infections and outbreaks, mainly restricted to some countries in west and central Africa. In July, 2022, WHO declared monkeypox a Public Health Emergency of International Concern, on account of the unprecedented global spread of the disease outside previously endemic countries in Africa and the need for global solidarity to address this previously neglected disease. The 2022 outbreak has been primarily associated with close intimate contact (including sexual activity) and most cases have been diagnosed among men who have sex with men, who often present with novel epidemiological and clinical characteristics. In the 2022 outbreak, the incubation period ranges from 7 days to 10 days and most patients present with a systemic illness that includes fever and myalgia and a characteristic rash, with papules that evolve to vesicles, pustules, and crusts in the genital, anal, or oral regions and often involve the mucosa. Complications that require medical treatment (eg, antiviral therapy, antibacterials, and pain control) occur in up to 40% of patients and include rectal pain, odynophagia, penile oedema, and skin and anorectal abscesses. Most patients have a self-limited illness; between 1% and 13% require hospital admission (for treatment or isolation), and the case-fatality rate is less than 0·1%. A diagnosis can be made through the presence of Orthopoxvirus DNA in PCRs from lesion swabs or body fluids. Patients with severe manifestations and people at risk of severe disease (eg, immunosuppressed people) could benefit from antiviral treatment (eg, tecovirimat). The current strategy for post-exposure prophylaxis or pre-exposure prophylaxis for people at high risk is vaccination with the non-replicating modified vaccinia Ankara. Antiviral treatment and vaccines are not yet available in endemic countries in Africa.

Mpox virus and transmission through sexual contact: Defining the research agenda

In a Policy Forum piece, Dr. Nicola Low and colleagues define the research agenda for Mpox virus and transmission through sexual contact.

Transmission Dynamics of Monkeypox Virus in Nigeria during the Current COVID-19 Pandemic and Estimation of Effective Reproduction Number

Monkeypox virus (MPXV) continues to pose severe threats to global public health, especially in non-endemic areas. Like all other regions, Africa faces potential public health crises due to the ongoing COVID-19 pandemic and other infectious disease outbreaks (such as Lassa fever and malaria) that have devastated the region and overwhelmed the healthcare systems. Owing to the recent surge in the MPXV and other infections, the COVID-19-control efforts could deteriorate and further worsen. This study discusses the potential emergencies of MPXV transmission during the current COVID-19 pandemic. We hypothesize some of the underlying drivers that possibly resulted in an increase in rodent-to-human interaction, such as the COVID-19 pandemic's impact and other human behavioral or environmental factors. Furthermore, we estimate the MPXV time-varying effective reproduction number (Rt) based on case notification in Nigeria. We find that Rt reached a peak in 2022 with a mean of 1.924 (95% CrI: 1.455, 2.485) and a median of 1.921 (95% CrI: 1.450, 2.482). We argue that the real-time monitoring of Rt is practical and can give public health authorities crucial data for circumstantial awareness and strategy recalibration. We also emphasize the need to improve awareness programs and the provision of adequate health care resources to suppress the outbreaks. These could also help to increase the reporting rate and, in turn, prevent large community transmission of the MPXV in Nigeria and beyond.

Overview of case definitions and contact tracing indications in the 2022 monkeypox outbreak

Background

In 2022, a new outbreak of the Mpox virus occurred outside of Africa, its usual endemic area. The virus was detected in European, American, Asian, and Oceanian countries where Mpox is uncommon or had not been reported previously and where the spread was rapid. The study aims to compare the case definition and the indications for contact tracing in case of Mpox infection among the World Health Organization (WHO), the European Centre for Disease Prevention and Control (ECDC), and four European Countries.

Methods

From August 2022 to November 2022, we conducted research, first on the WHO and ECDC official websites and then on the official websites of the Ministry of Health or National Health Agencies of four European Countries (Italy, France, Spain, and Portugal). All reports found were compared to enlighten the differences in the definition of the case and indications for contact tracing.

Results

The WHO divides the case definition into four categories: suspected, probable, confirmed, and discarded, while the ECDC divides cases into confirmed and probable. The ECDC defines contact as close and others, while the WHO divides it into high, medium, and minimal risk. The four countries analyzed show heterogeneity in both the case definitions and the indications for contact tracing.

Conclusions

Our analysis revealed heterogeneity in the case definition between the WHO and ECDC. Different countries followed different indications or have given their indications for both the case definition and contact tracing indications. Harmonization strengthens public health preparedness and response and creates unified communication.