Underdetected dispersal and extensive local transmission drove the 2022 mpox epidemic

Viral genetics and transmission dynamics in the second wave of mpox outbreak in Portugal and forecasting public health scenarios

In 2023, a second wave of the global mpox epidemic, which is mainly affecting men who have sex with men (MSM), was observed in some countries. Herein, we benefited from a large viral sequence sampling (76/121; 63%) and vast epidemiological data to characterise the re-emergence and circulation of the Monkeypox virus (MPXV) in Portugal during 2023. We also modelled transmission and forecasted public health scenarios through a compartmental susceptible-exposed-infectious-recovered (SEIR) model. Our results suggest that the 2023 mpox wave in Portugal resulted from limited introduction(s) of MPXV belonging to C.1.1 sublineage, hypothetically from Asia, followed by sustained viral transmission and potential exportation to other countries. We estimated that the contribution of the MSM high sexual activity group to mpox transmission was 120 (95% CrI: 30-3553) times higher than that of the low sexual activity group. However, among the high sexual activity group, vaccinated individuals likely contributed approximately eight times less [0.123 (95% CrI: 0.068-0.208)] than the unvaccinated ones. Vaccination was also linked to potential reduced disease severity, with a Mpox Severity Score of 6.0 in the vaccinated group compared to 7.0 in unvaccinated individuals. Scenario analysis indicated that transmission is highly sensitive to sexual behaviour, projecting that a slight increase in the MSM sub-population with high sexual activity can trigger new mpox waves. This study strongly supports that continued vaccination, targeted awareness among risk groups and routine genomic epidemiology is needed to anticipate and respond to novel MPXV threats (e.g. global dissemination of clade I viruses).

Impact of vaccination with third generation modified vaccinia Ankara and sexual behaviour on mpox incidence in men who have sex with men: analysis among participants of the ANRS-174 DOXYVAC trial

Background

Mpox was first reported in France on May 19 and third-generation live Modified Vaccinia Ankara (MVA-BN) vaccination of multiple-partner men who have sex with men (MSM) was recommended as of July 11, 2022. We assessed the impact of vaccination and of sexual behavior adopted during the epidemic period on mpox incidence in the ANRS-174-DOXYVAC trial enrolling MSM on HIV pre-exposure prophylaxis (PrEP) with history of sexually-transmitted infections (STI) in the previous year.

Methods

We compared pre-epidemic socio-behavioral characteristics and change in sexual behaviors after the onset of the epidemic of participants with mpox and mpox-free. Then we compared incidence rates of mpox per 1000 person-months (p-m) between May 9-July 10 (before vaccination of MSM, period-1) and July 11-September 20 2022 (after vaccination launch, period-2) and explored factors explaining the period effect using Poisson regression model.

Findings

472 MSM had data before and after May 9, 2022. Twenty percent had received smallpox vaccine during childhood. Mpox occurred in 77/472 participants (incidence 49.3 per 1000 p-m (95% CI 38.9-61.6)). MVA-BN vaccination roll-out was rapid, with 86% (341/398) of eligible participants having received at least one dose by September 20, 2022. Sexual behavior significantly changed before and after May 9, with a decrease in the proportion of mpox-free participants with >10 partners during last 3 months (45% vs 38%, p = 0.0035). Mpox incidence was 67.4 per 1000 p-m (95% CI 51.6-86.6) in period-1, and 24.4 per 1000 p-m (95% CI 13.9-39.6) in period-2, with an incidence rate ratio of 0.36 (95% CI 0.21-0.63). In multivariable Poisson regression model, only MVA-BN vaccination in 2022 remained significantly associated with mpox incidence, with a 99% risk reduction (95% CI 96.6-99.7).

Interpretation

In MSM on PrEP enrolled in the ANRS-174-DOXYVAC trial, rapid roll-out of MVA-BN vaccination was associated with a strong reduction in mpox incidence.

Funding

ANRS Maladies Infectieuses Emergentes (ANRS/MIE).

A Microsimulation Model of Mpox in Los Angeles County: Implications for Future Disease Prevention and Control Strategies among Men Who Have Sex with Men

Background

The 2022 monkeypox (mpox) outbreak in Los Angeles County (LAC) emphasized the need to prepare for emergent infectious disease outbreaks. Vaccination and promotion of sexual risk reduction practices appeared successful in LAC, as mpox cases declined starting in August. Nonetheless, questions persisted regarding the effectiveness of targeting vaccinations and the role of sexual risk reduction in reducing mpox cases.

Methods

We collaborated with the LAC Department of Public Health to develop a microsimulation for men who have sex with men (MSM). This model tracked mpox dynamics by age, race/ethnicity, and HIV status and was calibrated and validated against surveillance data. We simulated counterfactual scenarios to understand the effects of variation in vaccination rates, timing of vaccination rollout, vaccine allocation, and sexual contact rates.

Results

In the simulation, doubling the vaccination rate reduced cumulative cases over a 40-week time horizon by 13% but would necessitate 88 995 additional doses. Initiating vaccination 2 weeks earlier decreased cases by 11%, while an 8-week delay yielded a 20% increase in cases. A 3-week earlier decrease in sexual contact rates reduced cumulative cases by 60%, while a 3-week delay resulted in a 95% increase. Prioritizing people with HIV (PWH) for vaccination reduced cumulative cases, while allocating vaccines to a single racial/ethnic group was not effective.

Conclusions

Our study highlights the significance of policies to support timely vaccination and sexual partnership reduction to address mpox outbreaks among MSM. These findings also underscore the need to target vulnerable risk groups, such as PWH.

Mpox outbreak: Time series analysis with multifractal and deep learning network

This article presents an overview of an mpox epidemiological situation in the most affected regions-Africa, Americas, and Europe-tailoring fractal interpolation for pre-processing the mpox cases. This keen analysis has highlighted the irregular and fractal patterns in the trend of mpox transmission. During the current scenario of public health emergency of international concern due to an mpox outbreak, an additional significance of this article is the interpretation of mpox spread in light of multifractality. The self-similar measure, namely, the multifractal measure, is utilized to explore the heterogeneity in the mpox cases. Moreover, a bidirectional long-short term memory neural network has been employed to forecast the future mpox spread to alert the outbreak as it seems to be a silent symptom for global epidemic.

Mpox cases finding: Evaluation of a Primary Care detection program in the Northern Metropolitan area from Barcelona (Spain)

MAIN AIM

In July 2022, an extensive outbreak of Mpox (monkeypox) was considered by WHO as a Public Health Emergency. The objective of this study is to describe the obtained results from a Mpox case detection program in a semi-urban healthcare area where approximately 420 Primary Care physicians work.

DESIGN

An observational prospective study performed between June 01, 2022 and December 31, 2023.

SETTING

The Northern Metropolitan area of Barcelona, with 1400.000hab (Catalonia, Spain).

METHODS

An unified Mpox management procedure was agreed, including a prior online training of Primary Care professionals, to individually assess all Mpox suspected cases from a clinical and epidemiological perspective.

PARTICIPANTS

All patients who met clinical and/or epidemiological criteria of Mpox.

DATA COLLECTION

Age, gender, risk classification (suspected/probable), cluster-linked (yes/no), high-risk sexual contact (yes/no), general symptoms, genital lesion and final diagnostic.

RESULTS

A total of 68 suspected Mpox cases were included, from which 16 (26.6%) were Mpox confirmed by PCR. Up to 13 (81.2%) were male and, among them, 12 (75%) men who have sex with men (MSM). The series, however, included two minors and three women. Among MSM, 3 (18.7%) were HIV positive and 3 had no regular access to the Public Healthcare system. Among discarded patients, any infectious disease was diagnosed in 55% of cases.

CONCLUSIONS

In spite of the short series, this Primary Care community-based study identified a sub-population group showing a different profile of Mpox cases compared to other published series (lower HIV prevalence, higher representativeness of heterosexual transmission and hard to reach population).

One Country, Different Reactions- How did the Gay Community in Israel Respond to the New Mpox Threat?

Mpox affected mainly men who have sex with men (MSM). This study aimed to assess MSM's response to the threat, and compare MSM living in central Israel vs. its periphery. Data were collected by anonymous electronic surveys between September and October 2022 through a geospatial application ("Grindr"). Of the 665 MSM participants, 221 (33.2%) were vaccinated against mpox. In the multivariate analysis, living in central Israel, being in steady relationships, HIV infection, PrEP use, noticing suspicious skin lesions, and changing sexual behavior predicted vaccination. Of all participants, 317 (47.6%) changed their sexual behavior. In the multivariate analysis, living in central Israel, engaging in risky sexual behavior and being vaccinated against mpox predicted sexual behavior change. Of the 444 participants who were not vaccinated, 245 (55.1%) lived in peripheral regions of Israel. Those who lived in the periphery were less likely to get vaccinated or change their sexual behavior compared with MSM who lived in central Israel. Although the study was limited in size and the study population was relatively homogeneous, MSM perceived mpox as a potential threat on health, and almost 50% changed their sexual behavior and nearly one-third were vaccinated against mpox. The trend was mainly observed in MSM who were at high risk to acquire mpox and those who lived in central Israel.

Effectiveness of probabilistic contact tracing in epidemic containment: The role of superspreaders and transmission path reconstruction

The recent COVID-19 pandemic underscores the significance of early stage nonpharmacological intervention strategies. The widespread use of masks and the systematic implementation of contact tracing strategies provide a potentially equally effective and socially less impactful alternative to more conventional approaches, such as large-scale mobility restrictions. However, manual contact tracing faces strong limitations in accessing the network of contacts, and the scalability of currently implemented protocols for smartphone-based digital contact tracing becomes impractical during the rapid expansion phases of the outbreaks, due to the surge in exposure notifications and associated tests. A substantial improvement in digital contact tracing can be obtained through the integration of probabilistic techniques for risk assessment that can more effectively guide the allocation of diagnostic tests. In this study, we first quantitatively analyze the diagnostic and social costs associated with these containment measures based on contact tracing, employing three state-of-the-art models of SARS-CoV-2 spreading. Our results suggest that probabilistic techniques allow for more effective mitigation at a lower cost. Secondly, our findings reveal a remarkable efficacy of probabilistic contact-tracing techniques in performing backward and multistep tracing and capturing superspreading events.

Genomic epidemiology reveals 2022 mpox epidemic in New York City governed by heavy-tailed sexual contact networks

The global mpox epidemic in 2022 was likely caused by transmission of mpox virus (MPXV) through sexual contact networks, with New York City (NYC) experiencing the first and largest outbreak in the United States. By performing a phylogeographic and epidemiological analysis of MPXV, we identify at least 200 introductions of MPXV into NYC and 84 leading to onward transmission. Through a comparative analysis with human immunodeficiency virus (HIV) in NYC, we find that both MPXV and HIV genomic cluster sizes are best fit by scale-free distributions and that people in MPXV clusters are more likely to have previously received an HIV diagnosis (odds ratio=1.58; p=0.012) and be a member of a recently growing HIV transmission cluster, indicating overlapping sexual contact networks. We then model the transmission of MPXV through sexual contact networks and show that highly connected individuals would be disproportionately infected at the start of an epidemic, thereby likely resulting in the exhaustion of the most densely connected parts of the sexual network. This dynamic explains the rapid expansion and decline of the NYC outbreak, as well as the estimated cumulative incidence of less than 2% within high-risk populations. By synthesizing the genomic epidemiology of MPXV and HIV with epidemic modeling, we demonstrate that MPXV transmission dynamics can be understood by general principles of sexually transmitted pathogens.

How fast are viruses spreading in the wild?

Genomic data collected from viral outbreaks can be exploited to reconstruct the dispersal history of viral lineages in a two-dimensional space using continuous phylogeographic inference. These spatially explicit reconstructions can subsequently be used to estimate dispersal metrics allowing to unveil the dispersal dynamics and evaluate the capacity to spread among hosts. Heterogeneous sampling intensity of genomic sequences can however impact the accuracy of dispersal insights gained through phylogeographic inference. In our study, we implement a simulation framework to evaluate the robustness of three dispersal metrics - a lineage dispersal velocity, a diffusion coefficient, and an isolation-by-distance signal metric - to the sampling effort. Our results reveal that both the diffusion coefficient and isolation-by-distance signal metrics appear to be robust to the number of samples considered for the phylogeographic reconstruction. We then use these two dispersal metrics to compare the dispersal pattern and capacity of various viruses spreading in animal populations. Our comparative analysis reveals a broad range of isolation-by-distance patterns and diffusion coefficients mostly reflecting the dispersal capacity of the main infected host species but also, in some cases, the likely signature of rapid and/or long-distance dispersal events driven by human-mediated movements through animal trade. Overall, our study provides key recommendations for the lineage dispersal metrics to consider in future studies and illustrates their application to compare the spread of viruses in various settings.

Ultrasensitive single-step CRISPR detection of monkeypox virus in minutes with a vest-pocket diagnostic device

The emerging monkeypox virus (MPXV) has raised global health concern, thereby highlighting the need for rapid, sensitive, and easy-to-use diagnostics. Here, we develop a single-step CRISPR-based diagnostic platform, termed SCOPE (Streamlined CRISPR On Pod Evaluation platform), for field-deployable ultrasensitive detection of MPXV in resource-limited settings. The viral nucleic acids are rapidly released from the rash fluid swab, oral swab, saliva, and urine samples in 2 min via a streamlined viral lysis protocol, followed by a 10-min single-step recombinase polymerase amplification (RPA)-CRISPR/Cas13a reaction. A pod-shaped vest-pocket analysis device achieves the whole process for reaction execution, signal acquisition, and result interpretation. SCOPE can detect as low as 0.5 copies/µL (2.5 copies/reaction) of MPXV within 15 min from the sample input to the answer. We validate the developed assay on 102 clinical samples from male patients / volunteers, and the testing results are 100% concordant with the real-time PCR. SCOPE achieves a single-molecular level sensitivity in minutes with a simplified procedure performed on a miniaturized wireless device, which is expected to spur substantial progress to enable the practice application of CRISPR-based diagnostics techniques in a point-of-care setting.