{
  "abstract": "Objectives Following the global mpox outbreak in 2022, cases have continued to occur in England at a low but persistent rate. Differences in access or application of testing along with widespread roll-out of vaccination (which may affect the clinical presentation of infection) may lead to under-detection of cases. We sought to investigate the prevalence of potentially undiagnosed clade IIb mpox using residual samples from men tested for suspected lymphogranuloma venereum (LGV) or syphilis infection.Methods Anonymised, residual DNA extracts from specimens (including urogenital swabs, rectal swabs and ulcer swabs) from men referred to the national UK Health Security Agency Sexually Transmitted Infections Reference Laboratory between 1 October and 30 November 2024 (inclusive), for LGV or syphilis detection, were tested using a dual-clade monkeypox virus (MPXV) real-time PCR.Results A total of 1043 (805/1043, 77.2% requested for LGV; 238/1043, 22.8% requested for syphilis) anonymised DNA extracts were tested for MPXV. Four (4/1043, 0.38%; 95% CI 0.1 to 0.9) extracts tested positive for mpox, 3/805 (0.37%; 95% CI 0.08 to 1.09) were from LGV referrals and 1/238 (0.42%; 95% CI 0.01 to 2.32) was from a syphilis referral. Clade typing was successful for ¾ mpox-positive samples, all were clade II.Conclusions This study identified a small number of mpox cases in England that may not have been detected using the standard diagnostic and clinical pathways. This study represents proof of concept for rapid assessment of the scale of missed cases and could be repeated should shifts in epidemiology suggest an increase in undiagnosed cases.",
  "authors": [
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Rachel Pitt-Kendall"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Michelle Jayne Cole"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Shridaniya Sunthararajah"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Joshua Millward"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Hannah Charles"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Hamish Mohammed"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Laura Viviani"
    },
    {
      "affiliations": [
        "Croydon University Hospital, Croydon, UK"
      ],
      "name": "David Phillips"
    },
    {
      "affiliations": [
        "North Cumbria Integrated Care NHS Foundation Trust, Penrith, UK"
      ],
      "name": "Matt Phillips"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Helen Fifer"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Katy Sinka"
    },
    {
      "affiliations": [
        "UK Health Security Agency, London, UK"
      ],
      "name": "Sarah Alexander"
    }
  ],
  "title": "Investigating the possibility of undetected MPOX cases in England: results from the advanced mpox laboratory investigation for finding the undetected (AMPLIFY) study",
  "uid": "c1ca0439-df00-53c2-ac4e-19cd7c092a1a"
}