The evaluation phase of Pox Reference ended on 13 August.
Updates are suspended until further notice.
By the COVID Reference Team
Paper of the week
2 August 2022: Transmission
Lapa D, Carletti F, Mazzotta V, et al. Monkeypox virus isolation from a semen sample collected in the early phase of infection in a patient with prolonged seminal viral shedding. Lancet Infect Dis. 2022 Aug 2:S1473-3099(22)00513-8. PubMed: https://pubmed.gov/35931095. Full text: https://doi.org/10.1016/S1473-3099(22)00513-8
“Semen collected on day 6 after symptom onset was inoculated in Vero E6 cells (ATCC; Manassas VA, USA). Clear cytopathic effect was observed 48 h after the inoculum and monkeypox virus replication was confirmed by real-time PCR on DNA purified from cell growth medium collected after 48 h, 72 h, and 96 h.” The authors conclude that prolonged shedding of monkeypox virus DNA might occur in the semen of infected patients for weeks after symptoms onset.
In early May 2022, the first cases of monkeypox infection were diagnosed in Europe and in multiple other countries. The disease is caused by monkeypox virus (MPXV), a member of the orthopox family of viruses. Animal-to-human and human-to-human transmission can occur through direct contact with the blood, body fluids, or skin and mucosal lesions.
Monkeypox is usually a self-limited disease (2 to 4 weeks). The incubation period is 6 to 13 days but can range from 5 to 21 days. During the so-called invasion period patients may experience fever, headache, myalgia and asthenia. Lymphadenopathy is common in monkeypox, whereas this is not the case in chickenpox, measles, and smallpox. The skin eruption begins within 1–3 days of the onset of fever.
PCR is diagnostic. Treatment is largely symptomatic (analgesics, fluids, antibiotics for secondary bacterial infections). In 2022, the European Medicines Agency (EMA) approved the antiviral agent tecovirimat for the treatment of monkeypox. In some countries, a replication-deficient live Vaccinia virus vaccine (EU: Imvanex; US: Jynneos) is being investigated for monkeypox prevention and control. Awareness of MPXV transmission routes is key to successful prevention of further outbreaks.
See also our collection of case reports and short overviews.
Previous Papers of the Week
28 July 2022: Clinical Presentation
Patel A, Bilinska J, Tam JCH, et al. Clinical features and novel presentations of human monkeypox in a central London centre during the 2022 outbreak: descriptive case series. BMJ. 2022 Jul 28;378:e072410. PubMed: https://pubmed.gov/35902115. Full text: https://doi.org/10.1136/bmj-2022-072410
Report on 197 patients with PCR-confirmed monkeypox infection (all men, median age: 38 years). All patients presented with mucocutaneous lesions, most commonly on the genitals (56.3%) or in the perianal area (41.6%). 86.3% of the patients reported systemic illness. The most common systemic symptoms were fever (61.9%), lymphadenopathy (57.9%), and myalgia (31.5%). 61.5% of the patients developed systemic features before the onset of mucocutaneous manifestations. 13.7% presented exclusively with mucocutaneous manifestations without systemic features. 36.0% reported rectal pain, 16.8% sore throat, and 15.7% penile oedema. 13.7% had oral lesions and 4.6% had tonsillar signs. 35.9% of the participants had concomitant HIV infection. 56 (31.5%) of those screened for sexually transmitted infections had a concomitant sexually transmitted infection. Overall, 10.2% of the participants were admitted to hospital for the management of symptoms, most commonly rectal pain and penile swelling.
23 July 2022: Pediatric cases
Tutu van Furth AM, van der Kuip M, van Els AL, et al. Paediatric monkeypox patient with unknown source of infection, the Netherlands, June 2022. Euro Surveill. 2022 Jul;27(29). PubMed: https://pubmed.gov/35866435. Full text: https://doi.org/10.2807/1560-7917.ES.2022.27.29.2200552
A pediatric case of monkeypox infection in the Netherlands. Three weeks before presenting to the hospital, a young boy complained of a sore throat. He had no fever and was fine the next day. The next day, he went with his parents on vacation to Turkey. When he returned a week later, the boy noticed two small circular lesions on the left side of his face, one in front of his lower jaw and the other on his cheek. No plausible source of the monkeypox (MPX) infection could be identified. Physicians should know that monkeypox can develop in children and be present in the general population. The authors “advise prompt diagnostic testing in case of clinical symptoms potentially related to MPX to prevent potential undetected transmission in the community.”