Detection of mpox virus in ambient air in a sexual health clinic.

Although transmitted mainly through direct (sexual) contact, mpox virus (MPXV) can be detected in ambient air. We explored the use of air sampling for diagnosis or (genomic) surveillance of mpox in a sexual health clinic. For six out of six patients who were infected with MPXV, all four of our ambient air PCR tests were positive. For 14 uninfected patients, PCR was positive in three ambient air samples, albeit with higher cycle threshold (Ct) values. Genomic sequencing of samples from two positive patients showed matching sequences between air and clinical samples.

Persistent morbidity in Clade IIb mpox patients: interim results of a long-term follow-up study, Belgium, June to November 2022.

While mpox was well characterised during the 2022 global Clade IIb outbreak, little is known about persistent morbidity. We present interim results of a prospective cohort study of 95 mpox patients assessed 3-20 weeks post-symptom onset. Two-thirds of participants had residual morbidity, including 25 with persistent anorectal and 18 with genital symptoms. Loss of physical fitness, new-onset/worsened fatigue and mental health problems were reported in 36, 19 and 11 patients, respectively. These findings require attention by healthcare providers.

Severe mpox (formerly monkeypox) disease in five patients after recent vaccination with MVA-BN vaccine, Belgium, July to October 2022.

Vaccination is important in containing the 2022 mpox (formerly monkeypox) epidemic. We describe five Belgian patients with localised severe symptoms of proctitis and penile oedema, occurring between 4 and 35 days after post-exposure preventive vaccination or after one- or two-dose off-label pre-exposure preventive vaccination with MVA-BN vaccine. Genome sequencing did not reveal evidence for immune escape variants. Healthcare workers and those at risk should be aware of possible infections occurring shortly after vaccination and the need for other preventive measures.

Potential determinants of the decline in mpox cases in Belgium: a behavioral, epidemiological and seroprevalence study.

OBJECTIVE: The 2022 mpox epidemic reached a peak in Belgium and the rest of Europe in July 2022, after which it unexpectedly subsided. This study investigates epidemiological, behavioral, and immunological factors behind the waning of the epidemic in Belgium. METHODS: We investigated temporal evolutions in the characteristics and behavior of mpox patients using national surveillance data and data from a prospective registry of mpox patients in the Institute of Tropical Medicine (Antwerp). We studied behavioral changes in the population at risk using a survey among HIV-pre-exposure prophylaxis (PrEP) users. We determined the seroprevalence of anti-orthopoxvirus antibodies among HIV-PrEP users across four time points in 2022. RESULTS: Mpox patients diagnosed at the end of the epidemic had less sexual risk behavior compared to those diagnosed earlier: they engaged less in sex at mass events, had fewer sexual partners and were less likely to belong to the sexual network's central group. Among HIV-PrEP users there were no notable changes in sexual behavior. Anti-orthopoxvirus seroprevalence did not notably increase before the start of national vaccination campaigns. CONCLUSION: The observed changes in group immunity and behavior in the population at greater risk of exposure to mpox seem unable to explain the waning of the mpox epidemic. A change in the profile of mpox patients might have contributed to the decline in cases.

Characteristics of confirmed mpox cases among clinical suspects: A prospective single-centre study in Belgium during the 2022 outbreak.

Background: The presentation of mpox clade IIb during the 2022 outbreak overlaps with a range of other diseases. Understanding the factors associated with mpox is important for clinical decision making. Methods: We described the characteristics of mpox patients who sought care at Belgian sexual health clinic. Furthermore we compared their characteristics to those of patients with a clinical suspicion of mpox but who tested negative on polymerase chain reaction. Results: Between May 23 and September 20, 2022, 155 patients were diagnosed with mpox, and 51 patients with suspected symptoms tested negative. All mpox patients self-identified as men and 148/155 (95.5%) as gay or bisexual MSM. Systemic symptoms were present in 116/155 (74.8%) patients. All but 10 patients (145/155, 93.5%) presented with skin lesions. Other manifestations were lymphadenopathy (72/155, 46.5%), proctitis (50/155, 32.3%), urethritis (12/155, 7.7%), tonsillitis (2/155, 1.3%). Complications involved bacterial skin infection (13/155, 8.4%) and penile oedema with or without paraphimosis (4/155, 2.6%). In multivariable logistic regression models, the presence of lymphadenopathy (OR 3.79 95% CI 1.44-11.49), skin lesions (OR 4.35 95% CI 1.15-17.57) and proctitis (OR 9.41 95% CI 2.72-47.07) were associated with the diagnosis of mpox. There were no associations with age, HIV status, childhood smallpox vaccination, number of sexual partners and international travel. Conclusions: The presence of proctitis, lymphadenopathies and skin lesions should increase clinical suspicion of mpox in patients with compatible symptoms.