Outcomes of 54 cases of monkeypox (MPX) in London: fewer early symptoms but higher rates of genital lesions – urgency of funding sexual health

Simon Collins, HIV i-Base

Results from a retrospective review of 54 early cases of PCR-confirmed monkeypox (MPX) seen at four sexual health clinics in central London from 14 – 25 May 2022 are published in the 1 July 2022 edition of Lancet Infectious Diseases. [1]

All cases were in gay/bisexual men (n=52/2) mainly seen at sexual health clinics, with two admitted through A&E. Median age was 41 (IQR: 34 to 45);  38/54 (70%) were white, eight (15%) were Black or mixed race four (7%) were Asian and four (7%) were of other ethnicities. Although travel outside the UK was reported by half the cases, this was only to European countries.

Approximately 1 in 4 (13/54) were living with HIV (all on ART with CD4 >500 cells/mm3) and nearly everyone else was using PrEP.

Roughly two-thirds reported fatigue, one-third fever – generally lasting less than three days – but 10/54 (18%) reported no prodromal symptoms.

All cases included skin lesions: nearly all (89%) involving more that one body site and 94% including anogenital ulcers.

One in four patients were diagnosed with one or more STIs: 13 with gonococcal or chlamydial infections (6 with pharyngeal gonorrhoea, 2 for urethral gonorrhoea, 1 for rectal gonorrhoea, 4 for rectal chlamydia, and 2 for urethral chlamydia).

Although roughly half and one-third of cases reported having >5 or >10 partners in the previous three months, this is likely an underestimate in many cases.

Only 5/54 cases (9%) included hospital admission mainly for pain management or for antibiotic treatment for local skin complications including cellulitis.

This summary noted fewer initial symptoms and that genital lesions were more common that previously reported in Nigerian studies. Also that high rates of STIs suggest transmission due to skin to skin context in a sexual context, although it is unclear whether sexual fluids are an additional risk.

The study also describes procedures for developing a centralised clinic to safely diagnose and manage cases and the urgency of emergency funding to enable sexual health services to manage this new and extended outbreak.


So far the rapid escalation to more than 1200 cases within six weeks doesn’t appear to have been predicted though none of the early public health modelling for this outbreak has been publicly released.

Similar outbreaks have been reported in several other European countries, including Germany, Spain, France and Portugal. [2]

It is likely that updated modelling, also not released publicly, projects a significant increase in the weeks after Pride.

i-Base, together with some other community organisations has suggested the potential benefits from self-limiting use of situations where multiple partners in an anonymised setting for four weeks. This could reduce cases and protect health services until the current outbreaks is more clearly understood. [3, 4]

We also call for the urgency of emergency funding. [5]

Many countries, including the UK, have announced vaccine programmes for men at highest risk. [6]

  1. Girometti N et al. Demographic and clinical characteristics of confirmed human monkeypox virus cases in individuals attending a sexual health centre in London UK: an observational analysis. Lancet Infectious Diseases, doi 10.1016/ S1473-3099(22)00411-X. (1 July 2022).
  2. International Monkeypox case tracker. [Kraemer MUG et al. Lancet Inf Dis, DOI: 10.1016/S1473-3099(22)00359-0].
  3. i-Base Q&A. How can I avoid monkeypox during Pride week? (24 June 2022).
  4. i-Base Q&A. Why is i-Base saying to not have sex during Pride? (24 June 2022).
  5. Monkeypox crisis in the UK needs urgent funding: sex, vaccines and Pride. HTB (1 July 2022).
  6. UK offers limited vaccine to gay and bisexual men at risk of monkeypox: full dose offered in NYC. HTB (1 July 2022).
This report was first published on 2 July 2022.

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