Aleksandra Pettke (1), Finn A Filén (2), Katarina Widgren (3, 6), Hedvig Glans (4, 5), Sara Gredmark Russ (5, 6, 7) Klara Sondén (1, 5), Hilmir Ásgeirsson (4, 5)

Affiliates

(1) Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden (2) Venhälsan Outpatient Clinic, Stockholm South Hospital, Stockholm, Sweden (3) Department of Communicable Disease Control and Prevention, Stockholm County Council, Sweden (4) Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden (5) Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden (6) Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden (7) The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå, Sweden

Abstract

Background
Monkeypox is a zoonosis caused by Monkeypox virus (MPXV), belonging to the Orthopoxvirus genus of the Poxviridae family. Monkeypox outbreaks have historically been described mainly in central and west Africa (1) with only rare, imported cases outside Africa (2, 3).
In May 2022, a multinational outbreak emerged with thousands of cases in previously non-endemic areas such as Europe or the Americas (42 954 cases as of 22nd august). The cases related to the outbreak are characterised by a unique clinical presentation with mucosal lesions in the genital area, anal pain, proctitis and tonsillitis. Common systemic symptoms include fever, lymphadenopathy. The outbraek clustered in men who have sex with men (4).

We present the first Monkeypox case detected in Sweden in the context of this outbreak with a special focus on the clinical presentation, microbial diagnostic findings, and viral kinetics in different sample materials over the longest reported follow-up time within the context of the outbreak.

Case report
The previously healthy, male patient presented with an inguinal swelling small skin lesion on his foreskin. Over the next days, the lesion progressed to a deeper, well-circumscribed lesion with local lymphadenopathy, accompanied by fever peaking at 39°C. One week after symptom onset, the patient presented at an outpatient clinic, where testing for sexually transmitted infections was initiated, but returned negative results. By then, the fever had subsided. No new lesions appeared, but at a follow up after a few days, the lesion had further increased in size with increasing local lymphadenopathy resulting in spontaneous rupture of the local lymph node with discharge.
Analysis for MPXV was initiated at the Public Health Agency of Sweden following reports from the UK and Portugal on Monkeypox cases with unusual presentation as genital skin lesions.
Positive Realtime PCRs for Orthopoxvirus DNA and MPXV DNA were confirmed with Sanger sequencing. Metagenomics sequencing suggests that the case belongs to the West African clade and is closely related with sequences reported from the current outbreak.

Repeated samples were collected during a follow-up period of ten weeks from the genital lesion, a ruptured local lymph node, urine, semen, blood and respiratory tract. Eight weeks after laboratory-confirmed monkeypox infection viral DNA was still detectable in semen, and as long as ten weeks in saliva.

In conclusion, the case presents a comprehensive characterization of viral kinetics and provides new insights on monkeypox as an emerging pathogen. The implications of prolonged persistence of viral DNA in semen and saliva need to be studied further.

1. Organization W-WH. Monkeypox 2022 [Available from: https://www.who.int/news-room/fact-sheets/detail/monkeypox.
2. Adler H, Gould S, Hine P, Snell LB, Wong W, Houlihan CF, et al. Clinical features and management of human monkeypox: a retrospective observational study in the UK. The Lancet Infectious Diseases. 2022.
3. Vaughan A, Aarons E, Astbury J, Brooks T, Chand M, Flegg P, et al. Human-to-Human Transmission of Monkeypox Virus, United Kingdom, October 2018. Emerg Infect Dis. 2020;26(4):782-5.
4. Control E-ECfDPa. Epidemiological update: Monkeypox multi-country outbreak 2022 [Available from: https://www.ecdc.europa.eu/en/news-events/epidemiological-update-monkeypox-multi-country-outbreak.