Modelling the impact of human behavior using a two-layer Watts-Strogatz network for transmission and control of Mpox.

PURPOSE: This study aims to evaluate the effectiveness of mitigation strategies and analyze the impact of human behavior on the transmission of Mpox. The results can provide guidance to public health authorities on comprehensive prevention and control for the new Mpox virus strain in the Democratic Republic of Congo as of December 2023. METHODS: We develop a two-layer Watts-Strogatz network model. The basic reproduction number is calculated using the next-generation matrix approach. Markov chain Monte Carlo (MCMC) optimization algorithm is used to fit Mpox cases in Canada into the network model. Numerical simulations are used to assess the impact of mitigation strategies and human behavior on the final epidemic size. RESULTS: Our results show that the contact transmission rate of low-risk groups and susceptible humans increases when the contact transmission rate of high-risk groups and susceptible humans is controlled as the Mpox epidemic spreads. The contact transmission rate of high-risk groups after May 18, 2022, is approximately 20% lower than that before May 18, 2022. Our findings indicate a positive correlation between the basic reproduction number and the level of heterogeneity in human contacts, with the basic reproduction number estimated at 2.3475 (95% CI: 0.0749-6.9084). Reducing the average number of sexual contacts to two per week effectively reduces the reproduction number to below one. CONCLUSION: We need to pay attention to the re-emergence of the epidemics caused by low-risk groups when an outbreak dominated by high-risk groups is under control. Numerical simulations show that reducing the average number of sexual contacts to two per week is effective in slowing down the rapid spread of the epidemic. Our findings offer guidance for the public health authorities of the Democratic Republic of Congo in developing effective mitigation strategies.

Human monkeypox virus: Epidemiologic review and research progress in diagnosis and treatment.

Monkeypox virus (MPXV) is responsible for causing a zoonotic disease called monkeypox (mpox), which sporadically infects humans in West and Central Africa. It first infected humans in 1970 and, along with the variola virus, belongs to the genus Orthopoxvirus in the poxvirus family. Since the World Health Organization declared the MPXV outbreak a "Public Health Emergency of International Concern" on July 23, 2022, the number of infected patients has increased dramatically. To control this epidemic and address this previously neglected disease, MPXV needs to be better understood and reevaluated. In this review, we cover recent research on MPXV, including its genomic and pathogenic characteristics, transmission, mutations and mechanisms, clinical characteristics, epidemiology, laboratory diagnosis, and treatment measures, as well as prevention of MPXV infection in light of the 2022 and 2023 global outbreaks. The 2022 MPXV outbreak has been primarily associated with close intimate contact, including sexual activity, with most cases diagnosed among men who have sex with men. The incubation period of MPXV infection usually lasts from 6 to 13 days, and symptoms include fever, muscle pains, headache, swollen lymph nodes, and a characteristic painful rash, including several stages, such as macules, papules, blisters, pustules, scabs, and scab shedding involving the genitals and anus. Polymerase chain reaction (PCR) is usually used to detect MPXV in skin lesion material. Treatment includes supportive care, antivirals, and intravenous vaccinia immune globulin. Smallpox vaccines have been designed with four givens emergency approval for use against MPXV infection.

Underdetected dispersal and extensive local transmission drove the 2022 mpox epidemic.

The World Health Organization declared mpox a public health emergency of international concern in July 2022. To investigate global mpox transmission and population-level changes associated with controlling spread, we built phylogeographic and phylodynamic models to analyze MPXV genomes from five global regions together with air traffic and epidemiological data. Our models reveal community transmission prior to detection, changes in case reporting throughout the epidemic, and a large degree of transmission heterogeneity. We find that viral introductions played a limited role in prolonging spread after initial dissemination, suggesting that travel bans would have had only a minor impact. We find that mpox transmission in North America began declining before more than 10% of high-risk individuals in the USA had vaccine-induced immunity. Our findings highlight the importance of broader routine specimen screening surveillance for emerging infectious diseases and of joint integration of genomic and epidemiological information for early outbreak control.

Transmission potential of mpox in mainland China, June-July 2023: estimating reproduction number during the initial phase of the epidemic.

Despite reporting very few mpox cases in early 2023, mainland China observed a surge of over 500 cases during the summer. Amid ambiguous prevention strategies and stigma surrounding mpox transmission, the epidemic silently escalated. This study aims to quantify the scale of the mpox epidemic and assess the transmission dynamics of the virus by estimating the effective reproduction number (Re) during its early phase. Publicly available data were aggregated to obtain daily mpox case counts in mainland China, and the Re value was estimated using an exponential growth model. The mean Re value was found to be 1.57 (95% credible interval [1.38-1.78]), suggesting a case doubling time of approximately 2 weeks. This estimate was compared with Re values from 16 other countries' national outbreaks in 2022 that had cumulative case count exceeding 700 symptomatic cases by the end of that year. The Re estimates for these outbreaks ranged from 1.13 for Portugal to 2.31 for Colombia. The pooled mean Re was 1.49 (95% credible interval [1.32-1.67]), which aligns closely with the Re for mainland China. These findings underscore the need for immediate and effective control measures including targeted vaccination campaigns to mitigate the further spread and impact of the epidemic.

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.

JYNNEOS™ effectiveness as post-exposure prophylaxis against mpox: Challenges using real-world outbreak data.

BACKGROUND: JYNNEOSTM vaccine has been used as post-exposure prophylaxis (PEP) during a mpox outbreak in New York City (NYC). Data on effectiveness are limited. METHODS: Effectiveness of a single dose of JYNNEOSTM vaccine administered subcutaneously ≤ 14 days as PEP for preventing mpox disease was assessed among individuals exposed to case-patients from May 22, 2022-August 24, 2022. Individuals were evaluated for mpox through 21 days post-exposure. An observational study was conducted emulating a sequence of nested "target" randomized trials starting each day after exposure. Results were adjusted for exposure risk and race/ethnicity. Analyses were conducted separately based on last (PEPL) and first (PEPF) exposure date. We evaluated the potential to overestimate PEP effectiveness when using conventional analytic methods due to exposed individuals developing illness before they can obtain PEP (immortal time bias) compared to the target trial. RESULTS: Median time from last exposure to symptom onset (incubation period) among cases that did not receive PEPL was 7 days (range 1-16). Time to PEPL receipt was 7 days (range 0-14). Among 549 individuals, adjusted PEPL and PEPF effectiveness was 19 % (95 % Confidence Interval [CI], -54 % to 57 %) and -7% (95 % CI, -144 % to 53 %) using the target trial emulation, respectively, and 78 % (95 % CI, 50 % to 91 %) and 73 % (95 % CI, 31 % to 91 %) using conventional analysis. CONCLUSIONS: Determining PEP effectiveness using real-world data during an outbreak is challenging. Time to PEP in NYC coupled with the observed incubation period resulted in overestimated PEP effectiveness using a conventional method. The target trial emulation, while yielding wide confidence intervals due to small sample size, avoided immortal time bias. While results from these evaluations cannot be used as reliable estimates of PEP effectiveness, we present important methodologic considerations for future evaluations.

Detection of Mpox Virus in Seminal Fluids: Implications for Sexual Transmission.

The 2022 outbreak of the human mpox virus, formerly known as monkeypox, raised global health concerns with widespread transmission across multiple countries. Sexual transmission emerged as a significant mode of spread, particularly among high-risk groups like MSM and PLWH. This manuscript focuses on the implications of seminal fluids in the transmission of mpox. The virus has been detected in various bodily fluids, including semen, indicating the potential for sexual transmission. Studies have reported high positivity rates of mpox DNA in seminal fluids. Despite some concern about possible contamination due to genital lesions, the presence of replication-competent virus in seminal fluids has been confirmed and mpox virus was also detected in this specimen among people who engaged only in receptive sexual intercourse. Antiviral treatment with tecovirimat showed efficacy in reducing viral presence in semen with detection of the antiviral in this specimen. Virus clearance from semen is relatively rapid and parallels healing from infection, with no reported cases of seminal fluid relapses. The WHO recommendation to avoid condomless intercourse for 12 weeks after clinical healing still appears prudent. Continued research and surveillance are essential to understand viral dynamics and develop effective prevention measures to combat the spread of mpox through sexual transmission and protect key-populations.

Trends in Monkeypox transmission: Investigation into 30 most affected countries.

This research is based on the analysis of Monkeypox transmission, from may 7, 2022 to October 11, 2022, in 30 most affected countries around the globe. The most affected countries are selected through the cut point of at least 100 reported confirmed cases of infected persons over the aforementioned time span. We novely argue the exhibition of distributional similarities between the viral flow and well known power law in context of this neglected zoonotic disease. Moreover, model-based evidence suggesting the capability of pathogen to spread far and wide around its nucleus, are collected and presented. It is estimated that 70 % of the reported confirmed cases belonged to 20 % of the top most affected countries. Also, 70 % of the reported transmission was inflicted in 34 % of the days of reporting at least one case, on average.

Epidemiological, clinical and virological characteristics of patients with monkeypox. A retrospective study.

INTRODUCTION: The outbreak of monkeypox occurred in 2022 and led to a fast spread of the disease worldwide. The goal of this study is to describe the epidemiological, clinical, virological and evolving characteristics of the disorder. METHODS: We conducted a retrospective, observational and analytical study between July and October, 2022, in a Dermatology Unit. RESULTS: 124 subjects were included. Mean age was 31.5 years, 123 (99.2%) were men and 75 (60.5%) were HIV positive. The main transmission route was sexual and the incubation period was 7 days. The onset of the rash were the genitalia and perianal region in 74.2% of cases, and median time elapsed until the last scab fell off was 16 days. All patients developed a vesicular rash and 86.3% of them had systemic symptoms. Disease was moderate in 68.5% of patients and complications occurred most often when systemic symptoms and/or disseminated skin disease were present. Proctitis was the most frequent complication (59.4%) and its greater incidence was seen in the population with HIV. No significant difference was observed in real-time PCR cycle threshold values with regards to type of sample or duration of disease. Survival rate was 99.2% and other concomitant sexually transmitted infections were detected in 33.8% of patients. DISCUSSION: It is important to suspect the disease in subjects with high-risk sexual practices and a consistent clinical presentation. Swab samples of lesions as well as of scabs have proven useful for the diagnosis.

Introducción: El brote de viruela símica 2022 se extendió rápidamente por todo el mundo. El objetivo del presente trabajo es describir las características epidemiológicas, clínicas, evolutivas y virológicas. Métodos: Estudio retrospectivo, observacional y analítico entre julio-octubre del 2022 en pacientes atendidos en una Unidad de Dermatología. Resultados: Se incluyeron 124 individuos. La mediana de edad fue de 31.5 años, siendo 123 (99.2%) hombres y 70 (60.5%) HIV positivos. La vía principal de contagio fue la transmisión sexual y el período de incubación de 7 días. Las lesiones se iniciaron en la región genital y perianal en el 74.2% de los casos y el tiempo hasta la caída de la última costra presentó una mediana de 16 días. Todos desarrollaron exantema vesiculoso, el 86.3% de los individuos presentó síntomas sistémicos. La enfermedad fue moderada en el 68.5% de los pacientes y las complicaciones se observaron con mayor frecuencia en aquellos con síntomas sistémicos y/o enfermedad diseminada. Proctitis fue la complicación más destacada (59.4%) y su mayor incidencia se observó en la población con HIV. No hubo diferencias significativas en los valores de Ct de la qPCR al evaluar tipo de muestra procesada o tiempo de evolución de la enfermedad. La sobrevida fue del 99.2% y en el 33.8% de los pacientes se detectaron otras infecciones concomitantes de transmisión sexual. Discusión: Se debe sospechar la enfermedad en individuos con cuadro compatible y prácticas sexuales de riesgo. Las muestras de hisopado de lesiones y de costra resultaron útiles para el diagnóstico.

Simulating the impact of optimized prevention and control measures on the transmission of monkeypox in the United States: A model-based study.

This study aimed to develop a modified susceptible-exposed-infected-recovered (SEIR) model to evaluate monkeypox epidemics in the United States and explore more optimized prevention and control measures. To further assess the impact of public health measures on the transmission of monkeypox, different intervention scenarios were developed based on the classic SEIR model, considering reducing contact, enhancing vaccination, diagnosis delay, and environmental transmission risk, respectively. We evaluated the impact of different measures by simulating their spread in different scenarios. During the simulation period, 8709 people were infected with monkeypox. The simulation analysis showed that: (1) the most effective measures to control monkeypox transmission during the early stage of the epidemic were reducing contact and enhancing vaccination, with cumulative infections at 51.20% and 41.90% of baseline levels, respectively; (2) shortening diagnosis time would delay the peak time of the epidemic by 96 days; and (3) the risk of environmental transmission of monkeypox virus was relatively low. This study indirectly proved the effectiveness of the prevention and control measures, such as reducing contact, enhancing vaccination, shortening diagnosis time, and low risk of environmental transmission, which also provided an important reference and containment experience for nonepidemic countries.

Supercritical and homogenous transmission of monkeypox in the capital of China.

Starting from May 31, 2023, the local transmission of monkeypox (Mpox) in mainland China began in Beijing. Till now, the transmission characteristics have not been explored. Based on the daily Mpox incidence data in the first 3 weeks of Beijing (from May 31 to June 21, 2023), we employed the instant-individual heterogeneity transmission model to simultaneously calculate the effective reproduction number (Re ) and the degree of heterogeneity (k) of the Beijing epidemic. We additionally simulated the monthly infection size in Beijing from July to November and compared with the reported data to project subsequent transmission dynamics. We estimated Re to be 1.68 (95% highest posterior density [HPD]: 1.12-2.41), and k to be 2.57 [95% HPD: 0.54-83.88], suggesting the transmission of Mpox in Beijing was supercritical and didn't have considerable transmission heterogeneity. We projected that Re fell in the range of 0.95-1.0 from July to November, highlighting more efforts needed to further reduce the Mpox transmissibility. Our findings revealed supercritical and homogeneous transmission of the Mpox epidemic in Beijing. Our results could serve as a reference for understanding and predicting the ongoing Mpox transmission in other regions of China and evaluating the effect of control measures.

Modifications to Sexual Behaviors Associated With Mpox (Monkeypox) Virus Transmission Among Persons Presenting for mpox Vaccination, Washington, DC, August-October, 2022.

BACKGROUND: Over 30,000 mpox cases were reported during the 2022 mpox outbreak with many cases occurring among gay, bisexual and other men who have sex with men (MSM). Decreases in U.S. mpox cases were likely accelerated by a combination of vaccination and modifications to sexual behaviors associated with mpox virus transmission. We assessed reports of sexual behavior change among participants receiving mpox vaccination in Washington, DC. METHODS: During August to October 2022, 711 adults aged ≥18 years receiving mpox vaccination at two public health clinics in Washington, DC completed a self-administered questionnaire that asked whether sexual behaviors changed since learning about mpox. We calculated the frequency and percentages of participants reporting an increase, decrease, or no change in 4 of these behaviors by demographic, clinical, and behavioral characteristics with 95% confidence intervals. RESULTS: Overall, between 46% and 61% of participants reported a decrease in sexual behaviors associated with mpox virus transmission, 39% to 54% reported no change in these behaviors, and <1% reported an increase. Approximately 61% reported decreases in one-time sexual encounters (95% confidence interval [CI], 56.8%-64.7%), 54.3% reduced numbers of sex partners (95% CI, 50.4%-58.0%), 53.4% decreased sex via a dating app or sex venue (95% CI, 49.7%-58.0%), and 45.6% reported less group sex (95% CI, 40.4%-50.9%). Reported decreases in these behaviors were higher for MSM than women; in non-Hispanic Black than non-Hispanic White participants; and in participants with human immunodeficiency virus than participants without human immunodeficiency virus. CONCLUSIONS: Most participants receiving mpox vaccination reported decreasing sexual behaviors associated with mpox virus transmission, including groups disproportionately affected by the outbreak.

Estimation of Incubation Period of Mpox during 2022 Outbreak in Pereira, Colombia.

We estimated the incubation period for mpox during an outbreak in Pereira, Colombia, using data from 11 confirmed cases. Mean incubation period was 7.1 (95% CI 4.9-9.9) days, consistent with previous outbreaks. Accurately estimating the incubation period provides insights into transmission dynamics, informing public health interventions and surveillance strategies.

Transmission dynamics and effect of control measures on the 2022 outbreak of mpox among gay, bisexual, and other men who have sex with men in England: a mathematical modelling study.

BACKGROUND: The 2022 global outbreak of mpox (formerly known as monkeypox) spread primarily among gay, bisexual, and other men who have sex with men (GBMSM), with the initial cluster being identified in England in May, 2022. Understanding its epidemiological characteristics and the reasons for its downturn in July, 2022, will help to control future outbreaks. METHODS: We collated data for all diagnosed mpox cases (3621) from England from May 1, 2022, to Nov 16, 2022. Data from 75 individuals with mpox allowed estimation of the incubation period, while data from 121 case-contact pairs were used to estimate the serial interval. Six methods, including a structured dynamic compartmental transmission model, were used to estimate the basic reproduction number (R0). The structured model assumed all male individuals with mpox were GBMSM, who were then stratified into subgroups for those at low risk and high risk for mpox. This best fitting model was used to estimate the reduction in transmissibility, and the effective infectious period (before isolating), that resulted in the outbreak downturn, and the effect of vaccination initiated from June 27, 2022. Bayesian methods were used for parameter estimation and model calibration. FINDINGS: Most cases occurred in men (3544 of 3621, 97·9%). The median incubation period for mpox was 6·90 days (95% credible interval [CrI] 4·08-20·21), and the serial interval was 8·82 days (5·22-25·81). R0 estimates ranged from 1·41 to 2·17. The structured transmission model estimated that 83·8% of infections (95% CrI 83·5-85·3) resulted from sexual partnerships with GBMSM individuals at high risk of mpox. The outbreak downturn probably resulted from a 44·5% reduction in the sexual partner rate among all GBMSM (24·9-55·8) and 20·0% reduction in the effective infectious period (4·1-33·9), preventing 165 896 infections (115 584-217 730). Vaccination marginally increased the number of infections prevented (166 081, 115 745-217 947), but minimised a resurgence in cases from January, 2023, and could have averted four times more infections if initiated earlier. Our findings were sensitive to assumptions regarding the vaccine's effectiveness and the GBMSM subgroup at high risk of mpox. INTERPRETATION: The mpox outbreak in England probably resulted from high sexual partner rates among some GBMSM, with reductions in partner rates reversing the outbreak, and with vaccination minimising future outbreaks. FUNDING: National Institute for Health Research (UK).

[Monkeypox transmission and oral prevention].

Monkeypox is becoming a viral infectious disease of global concern. WHO has reported monkeypox outbreaks in more than 50 countries. Since the first imported case has been confirmed and reported by Taiwan, China, in June 2022, the monkeypox has draw high attention from the national public health and epidemic prevention department. Among the key tasks of Shanghai high-quality healthcare development in 2023, monkeypox has been identified as one of the key infectious diseases that need to be under strict prevention and control. The diagnosis and treatment in dental department are mainly performed face-to-face, with patients' masks taken-off. Large amount of aerosol spray will be generated during the operation. At the same time, dental diagnosis and treatment is in outpatient department, where the patient flow is large. Once monkeypox patients have been diagnosed and treated in the dental diagnosis and treatment area, and the preventive measures are not implemented, it will provide convenience for monkeypox to transmit. In order to avoid this kind of situation, this article made a review of monkey-pox from the following 3 aspects: epidemic transmission history of monkeypox, systemic and oral symptoms of monkeypox, and oral prevention of monkeypox, to improve the knowledge and prevention ability of dental medical staff on monkeypox for early recognition and prevention.

APOBEC3 deaminase editing in mpox virus as evidence for sustained human transmission since at least 2016.

Historically, mpox has been characterized as an endemic zoonotic disease that transmits through contact with the reservoir rodent host in West and Central Africa. However, in May 2022, human cases of mpox were detected spreading internationally beyond countries with known endemic reservoirs. When the first cases from 2022 were sequenced, they shared 42 nucleotide differences from the closest mpox virus (MPXV) previously sampled. Nearly all these mutations are characteristic of the action of APOBEC3 deaminases, host enzymes with antiviral function. Assuming APOBEC3 editing is characteristic of human MPXV infection, we developed a dual-process phylogenetic molecular clock that-inferring a rate of ~6 APOBEC3 mutations per year-estimates that MPXV has been circulating in humans since 2016. These observations of sustained MPXV transmission present a fundamental shift to the perceived paradigm of MPXV epidemiology as a zoonosis and highlight the need for revising public health messaging around MPXV as well as outbreak management and control.

Monkeypox Virus: A comprehensive narrative review.

Monkeypox virus, now known as Mpox virus is a large, enveloped, double stranded deoxyribonucleic acid (DNA) virus belonging to the Orthopox viridae genus of the Poxviridae family. Though, Mpox, have earlier been endemic to only African countries, the 2022 outbreak has shown its rapid spread throughout the world. The May 2022 outbreak have shown primarily human to human transmission in contrast to animal to human transmission that had been seen previously. Recent data also suggest a possibility of a pre symptomatic spread. After an incubation period of 9 days, patients with Mpox can present with a prodrome of symptoms followed by a rash. If untreated, severe complications develop in the high-risk groups especially children and pregnant woman. Such groups of people will benefit from antiviral treatments. The current approach to prevent against it is pre-exposure and post exposure prophylaxis with vaccines. The vaccines that have been approved by Food and Drug Administration to date is ACAM2000 and JYNNEOS. Several diagnostic methods exist, among which polymerase chain reaction has proven to be the most specific and sensitive. In this review, we will discuss its epidemiology, the clinical manifestations, diagnostic modalities, complications, treatment approaches and preventive measures.