Slowly declining growth rates and dynamic reporting delays characterise the Monkeypox epidemic in the UK over May-August 2022

Panovska‐Griffiths, Jasmina; Hinch, Robert; Park, Josie; Ward, Thomas; Charlett, André; Cumming, Fergus; Watkins, Nicholas A.; Fraser, Christophe

doi:10.21203/rs.3.rs-2298855/v1

Cited by 3 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The outbreak in the Netherlands started between the middle of April and the middle of May 2022. After May 23 rd , we assumed that awareness increased during the outbreak, resulting in a reduced time between symptom onset and diagnosis in health care, and a reduction in new sexual partners by up to 50% (27, 28). Individuals that recovered from mpox are assumed to not be infectious to others.…”

Section: Methodsmentioning

confidence: 99%

The risk of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data

Shamier,

Zaeck,

Götz

et al. 2023

Preprint

View full text Add to dashboard Cite

SummaryBackgroundIn the wake of the 2022-2023 mpox outbreak, crucial knowledge gaps exist regarding orthopoxvirus-specific immunity in risk groups and its impact on future outbreaks. Here, we combined cross-sectional seroprevalence studies in two cities in the Netherlands with mathematical modelling to evaluate the risk of future mpox outbreaks among men who have sex with men (MSM).MethodsSerum samples were obtained from 1,065 MSM visiting the Centres for Sexual Health (CSH) in Rotterdam or Amsterdam after the introduction of vaccination and the peak of the Dutch mpox outbreak. For MSM visiting the CSH in Rotterdam, sera were linked to epidemiological and vaccination data. An in-house developed ELISA was used to detect vaccinia virus (VACV)- specific IgG; plaque reduction neutralization tests (PRNT) were performed on a selection of samples. These observations were combined with literature data on infection dynamics and vaccine effectiveness to inform a stochastic transmission model to estimate the risk on future mpox outbreaks.FindingsThe seroprevalence of VACV-specific IgG was 45.4% and 47.1% in Rotterdam and Amsterdam, respectively. Based on the correlation between serological parameters, we identified confirmed MPXV infections and inferred nine undiagnosed infections in individuals without childhood smallpox vaccination in the Rotterdam cohort (5.1%). Transmission modelling showed that the overall number of mpox cases in new outbreaks would be low, but that the current level of immunity alone may not prevent future outbreaks. Maintaining a short time-to-diagnosis will be a key component of any strategy to prevent new outbreaks.InterpretationOur findings indicate a reduced likelihood of future mpox outbreaks among MSM in the Netherlands under the current conditions, but emphasise the importance of maintaining population immunity, diagnostic capacities, and disease awareness.FundingNational Institute for Public Health and the Environment (RIVM), HORIZON-HLTH-2022-MPX-14 (101115188).Research in contextEvidence before this studyWe searched PubMed from database inception to July 24th, 2023, using the search terms (“monkeypox” OR “mpox” OR “orthopoxvirus”) AND (“immunity” OR “antibodies” OR vaccin*) OR (model*) OR (“epidemiology” OR “outbreak”) OR (“seroprevalence” OR “serosurveillance”), with no date or language restrictions. We included the cited references of retrieved publications in our search. We found that there are crucial knowledge gaps with respect to monkeypox virus (MPXV)-specific immunity and the impact of risk group vaccination with third-generation smallpox vaccines on the prevention of future outbreaks. No seroprevalence studies following the 2022-2023 mpox outbreak have been published yet. Recent observational studies from Israel, the United Kingdom, and the United States reported adjusted vaccine effectiveness levels between 36% - 86% following one or two doses of MVA. After the massive 2022-2023 outbreak, the number of new cases is now at a very low level, although there are continouing reports of small clusters of infections, including breakthrough infections and re-infections. This long tail to the epi curve, raises concerns about the potential of future outbreaks. We found no studies that predicted the risk of future mpox outbreaks after risk group vaccination based on measured seroprevalence data.Added value of this studyThe primary goal of this study was to estimate the risk of future mpox outbreaks among men who have sex with men (MSM) in the Netherlands using mathematical modelling based on real-world data. To this end, we used a combination of serological assays to determine the presence and abundance of (functional) poxvirus-specific antibodies in a Dutch MSM cohort. Next, we demonstrate the impact of rapid diagnosis (followed by isolation) of mpox cases on the size and duration of future outbreaks employing a mathematical model.Implications of all the available evidenceA seroprevalence level of approximately 45% among MSM in the Netherlands visiting the Centres for Sexual Health was found. Modelling showed that this seroprevalence level alone may not be sufficient to prevent future outbreaks, which emphasises the importance of continued disease awareness, and maintaining population immunity and diagnostic capacities. These insights have important implications for public health policy making and fill critical knowledge gaps to help inform surveillance activities and guide vaccination strategies.

show abstract

Section: Methodsmentioning

confidence: 99%

The risk of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data

Shamier,

Zaeck,

Götz

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…The outbreak in the Netherlands started between the middle of April and the middle of May 2022. After 23 May, we assumed that awareness had increased, resulting in reduced time between symptom onset and diagnosis and a reduction in new sexual partners by up to 50% [32,33]. Individuals who had recovered from mpox were assumed not to be infectious.…”

Section: Stochastic Modelmentioning

confidence: 99%

Scenarios of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data from the Netherlands, 2022

Shamier,

Zaeck,

Götz

et al. 2024

Eurosurveillance

View full text Add to dashboard Cite

Background Following the 2022–2023 mpox outbreak, crucial knowledge gaps exist regarding orthopoxvirus-specific immunity in risk groups and its impact on future outbreaks. Aim We combined cross-sectional seroprevalence studies in two cities in the Netherlands with mathematical modelling to evaluate scenarios of future mpox outbreaks among men who have sex with men (MSM). Methods Serum samples were obtained from 1,065 MSM attending Centres for Sexual Health (CSH) in Rotterdam or Amsterdam following the peak of the Dutch mpox outbreak and the introduction of vaccination. For MSM visiting the Rotterdam CSH, sera were linked to epidemiological and vaccination data. An in-house developed ELISA was used to detect vaccinia virus (VACV)-specific IgG. These observations were combined with published data on serial interval and vaccine effectiveness to inform a stochastic transmission model that estimates the risk of future mpox outbreaks. Results The seroprevalence of VACV-specific antibodies was 45.4% and 47.1% in Rotterdam and Amsterdam, respectively. Transmission modelling showed that the impact of risk group vaccination on the original outbreak was likely small. However, assuming different scenarios, the number of mpox cases in a future outbreak would be markedly reduced because of vaccination. Simultaneously, the current level of immunity alone may not prevent future outbreaks. Maintaining a short time-to-diagnosis is a key component of any strategy to prevent new outbreaks. Conclusion Our findings indicate a reduced likelihood of large future mpox outbreaks among MSM in the Netherlands under current conditions, but emphasise the importance of maintaining population immunity, diagnostic capacities and disease awareness.

show abstract

“…onset date is the least [30]. However, the coverage of data on symptom onset date has fluctuated throughout the epidemic, declining from very high (over 90%) coverage before June 2022 to 50% coverage in August 2022.…”

Section: Plos Computational Biologymentioning

confidence: 99%

Nowcasting the 2022 mpox outbreak in England

Overton,

Abbott,

Christie

et al. 2023

PLoS Comput Biol

View full text Add to dashboard Cite

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.

show abstract

Slowly declining growth rates and dynamic reporting delays characterise the Monkeypox epidemic in the UK over May-August 2022

Cited by 3 publications

References 9 publications

The risk of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data

The risk of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data

Scenarios of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data from the Netherlands, 2022

Nowcasting the 2022 mpox outbreak in England

Contact Info

Product

Resources

About