Herpes simplex virus viral shedding in patients diagnosed of Monkeypox.

Abstract

Since May 2022, an outbreak of more than 30,000 cases of human monkeypox (MP) has been documented in non-endemic countries, especially in men that have sex with men (MSM), prompting the World Health Organisation to declare MP an ‘evolving threat of moderate public health concern’.1, 2 MP is a smallpox-like self-limiting disease with symptoms lasting 2–4 weeks;1 there are no data available whether concurrent sexually transmitted infections (STIs) can contribute to its spreading or alter its clinical expression.3 In a review of 528 patients with MP from Thornhill et al.2 Herpes Simplex Virus (HSV) was found in 1% of the cases. Herein, we report ten individuals tested both for MP and HSV1-2 at the STIs outpatient service of our Dermatology Unit in Milan to analyse the phenomenon of herpetic viral shedding in MP-infected patients. All patients declared having had unprotected sexual encounters in the preceding 3 months. They identified themselves as MSM, and median age was equal to 35 years old. Six out of ten patients had a positive STI history, of whom only one was a man living with HIV. Regarding MP, eight patients had systemic symptoms (myalgia, asthenia and fever), while anogenital area was involved in all cases (Table 1). In our clinic diagnostic work up to confirm MP included both pharyngeal, vesico-pustular fluid swabs and lesional HSV1-2 swab (real-time polymerase chain reaction) to rule out differential diagnoses. In all patients, monkeypox infection was confirmed: in eight subjects, viral DNA was detected both on pharyngeal and cutaneous swab, while in the other two it was found only in vesico-pustular fluid. Moreover, HSV-1 was revealed in three of the ten skin lesional swab performed. Since history was unremarkable for acute herpetic outbreak and none of them displayed on examination skin lesions suggestive of herpetic infection, we hypothesized viral shedding occurred. It has been documented that viral shedding is common among asymptomatic carriers, facilitating HSV transmission. Specifically, it can happen until 20% of all days, especially during the first year of infection.4 Additionally, it has been demonstrated that the presence of concomitant STIs (e.g. HIV and bacterial vaginosis) increase odd ratio of HSV shedding of 3.1 point.4 Similarly, we assume that the presence of monkeypox infection may influences virus release in carrier patients. The acknowledgement of a possible association between MP and HSV could reduce herpetic transmission during sexual contact. Until our findings could be further accredited by new observations, physicians should research HSV1-2 in all MP suspicion cases in order to reduce the risk of HSV transmission to uninfected partners. None. None. The authors declare no conflict of interest.