Sustained human outbreak of a new MPXV clade I lineage in eastern Democratic Republic of the Congo.

Outbreaks of monkeypox (mpox) have historically resulted from zoonotic spillover of clade I monkeypox virus (MPXV) in Central Africa and clade II MPXV in West Africa. In 2022, subclade IIb caused a global epidemic linked to transmission through sexual contact. Here we describe the epidemiological and genomic features of an mpox outbreak in a mining region in eastern Democratic Republic of the Congo, caused by clade I MPXV. Surveillance data collected between September 2023 and January 2024 identified 241 suspected cases. Genomic analysis demonstrates a distinct clade I lineage divergent from previously circulating strains in the Democratic Republic of the Congo. Of the 108 polymerase chain reaction-confirmed mpox cases, the median age of individuals was 22 years, 51.9% were female and 29% were sex workers, suggesting a potential role for sexual transmission. The predominance of APOBEC3-type mutations and the estimated emergence time around mid-September 2023 imply recent sustained human-to-human transmission.

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

OBJECTIVES: 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-preexposure 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.

Air pollution and bronchiolitis: a case-control study in Antwerp, Belgium.

This case-control study aimed to investigate the association between short-term (1 to 5 days) and medium-term (31 days) exposure to air pollutants (PM2.5, PM10, BC, NO2) at home/daycare and the risk of 'severe bronchiolitis' (defined as 'requiring hospitalization for bronchiolitis') in children under 2 years in Antwerp, Belgium. We included 118 cases and 79 controls admitted to three general hospitals from October 2020 to June 2021. Exposure levels were predicted using an interpolation model based on fixed measuring stations. We used unconditional logistic regression analysis to assess associations, with adjustment for potential confounders. There were hardly any significant differences in the day-to-day air pollution values between cases and controls. Medium-term (31 days) exposure to PM2.5, PM10, and NO2 was however significantly higher in cases than controls in univariate analysis. Logistic regression revealed an association between severe bronchiolitis and interquartile range (IQR) increases of PM2.5 and PM10 at home and in daycare, as well as IQR increases of NO2 in daycare. Controls were however overrepresented in low pollution periods. Time-adjustment reduced the odds ratios significantly at home for PM2.5 and PM10 (aOR 1.54, 95%CI 0.51-4.65; and 2.69, 95%CI 0.94-7.69 respectively), and in daycare for. PM2.5 (aOR 2.43, 95%CI 0.58-10.1). However, the association between severe bronchiolitis and medium-term air pollution was retained in daycare for IQR increases of PM10 (aOR 5.13, 95%CI 1.24-21.28) and NO2 (aOR 3.88, 95%CI 1.56-9.61) in the time-adjusted model.  Conclusion: This study suggests a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. Larger studies are warranted to confirm these findings. What is Known: • Bronchiolitis is a leading cause of hospitalization in infants globally and causes a yearly seasonal wave of admissions in paediatric departments worldwide. • Existing studies, mainly from the USA, show heterogeneous outcomes regarding the association between air pollution and bronchiolitis. What is New: • There is a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. • Larger studies are needed to validate these trends.

Co-Circulating Monkeypox and Swinepox Viruses, Democratic Republic of the Congo, 2022.

In September 2022, deaths of pigs manifesting pox-like lesions caused by swinepox virus were reported in Tshuapa Province, Democratic Republic of the Congo. Two human mpox cases were found concurrently in the surrounding community. Specific diagnostics and robust sequencing are needed to characterize multiple poxviruses and prevent potential poxvirus transmission.

Not only vaccine hesitancy, but also vaccination campaign hesitancy drives measles epidemics in conflict-torn eastern DR Congo.

The COVID-19 pandemic and vaccine hesitancy are not the only causes of the increase in measles cases in low- and middle-income countries. Measles epidemics, like the recent one in eastern DRC, are often quickly halted by mass vaccination in 'easy to reach' refugee camps. However, governmental and humanitarian actors fail to respond effectively in 'hard-to-reach' areas like Masisi, frequently limiting themselves to more accessible areas close to big cities.

No Varicella Zoster Virus Infection among Mpox Cases in Antwerp, Belgium.

Several studies in tropical settings have reported that ∼20% of patients infected with Monkeypox virus (MPXV) also tested polymerase chain reaction (PCR) positive for Varicella zoster virus (VZV). Researchers have hypothesized that VZV infection predisposes to monkeypox (mpox), or vice versa, or that MPXV triggers the reactivation of VZV. We tested samples for VZV from a cohort of patients infected with clade IIb MPXV diagnosed between May 23 and October 14, 2022 in Antwerp, Belgium. Leftover DNA extracts of skin lesion samples from 108 mpox patients were tested with in-house PCR for VZV. No VZV infections were found. The absence of concurrent VZV-MPXV infections in our cohort indicates that VZV did not cocirculate in the population at risk for MPXV during the Belgian 2022 outbreak, but also that MPXV does not commonly trigger reactivation of latent VZV in adult men.

The Human Mpox Global Outbreak: Available Control Tools and the Opportunity to Break a Cycle of Neglect in Endemic Countries.

The 2022 global outbreak of human Mpox (formerly monkeypox) virus (MPXV) infection outside of the usual endemic zones in Africa challenged our understanding of the virus's natural history, transmission dynamics, and risk factors. This outbreak has highlighted the need for diagnostics, vaccines, therapeutics, and implementation research, all of which require more substantial investments in equitable collaborative partnerships. Global multidisciplinary networks need to tackle MPXV and other neglected emerging and reemerging zoonotic pathogens to address them locally and prevent or quickly control their worldwide spread. Political endorsement from individual countries and financial commitments to maintain control efforts will be essential for long-term sustainability.

Emergence of mpox in the post-smallpox era-a narrative review on mpox epidemiology.

BACKGROUND: The 2022 mpox outbreak drew global attention to this neglected pathogen. While most of the world was taken by surprise, some countries have seen this pathogen emerge and become endemic several decades prior to this epidemic. OBJECTIVES: This narrative review provides an overview of mpox epidemiology since its discovery through the 2022 global outbreak. SOURCES: We searched PubMed for relevant literature about mpox epidemiology and transmission through 28 February 2023. CONTENT: The emergence of human mpox is intertwined with the eradication of smallpox and the cessation of the global smallpox vaccination campaign. The first human clade I and II monkeypox virus (MPXV) infections were reported as zoonoses in Central and West Africa, respectively, around 1970 with sporadic infections reported throughout the rest of the decade. Over the next five decades, Clade I MPXV was more common and caused outbreaks of increasing size and frequency, mainly in the Democratic Republic of the Congo. Clade II MPXV was rarely observed, until its re-emergence and ongoing transmission in Nigeria, since 2017. Both clades showed a shift from zoonotic to human-to-human transmission, with potential transmission through sexual contact being observed in Nigeria. In 2022, clade II MPXV caused a large human outbreak which to date has caused over 86,000 cases in 110 countries, with strong evidence of transmission during sexual contact. By February 2023, the global epidemic has waned in most countries, but endemic regions continue to suffer from mpox. IMPLICATIONS: The changing epidemiology of mpox demonstrates how neglected zoonosis turned into a global health threat within a few decades. Thus, mpox pathophysiology and transmission dynamics need to be further investigated, and preventive and therapeutic interventions need to be evaluated. Outbreak response systems need to be strengthened and sustained in endemic regions to reduce the global threat of mpox.

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.

Estimated incubation period distributions of mpox using cases from two international European festivals and outbreaks in a club in Berlin, May to June 2022.

BackgroundSince May 2022, an mpox outbreak affecting primarily men who have sex with men (MSM) has occurred in numerous non-endemic countries worldwide. As MSM frequently reported multiple sexual encounters in this outbreak, reliably determining the time of infection is difficult; consequently, estimation of the incubation period is challenging.AimWe aimed to provide valid and precise estimates of the incubation period distribution of mpox by using cases associated with early outbreak settings where infection likely occurred.MethodsColleagues in European countries were invited to provide information on exposure intervals and date of symptom onset for mpox cases who attended a fetish festival in Antwerp, Belgium, a gay pride festival in Gran Canaria, Spain or a particular club in Berlin, Germany, where early mpox outbreaks occurred. Cases of these outbreaks were pooled; doubly censored models using the log-normal, Weibull and Gamma distributions were fitted to estimate the incubation period distribution.ResultsWe included data on 122 laboratory-confirmed cases from 10 European countries. Depending on the distribution used, the median incubation period ranged between 8 and 9 days, with 5th and 95th percentiles ranging from 2 to 3 and from 20 to 23 days, respectively. The shortest interval that included 50% of incubation periods spanned 8 days (4-11 days).ConclusionCurrent public health management of close contacts should consider that in approximately 5% of cases, the incubation period exceeds the commonly used monitoring period of 21 days.

Presymptomatic viral shedding in high-risk mpox contacts: A prospective cohort study.

The risk of infection after exposure to clade IIb mpox virus (MPXV) is unknown, and potential presymptomatic shedding of MPXV remains to be demonstrated. High-risk contacts of mpox patients were followed-up in a prospective longitudinal cohort study. Individuals reporting sexual contact, >15 min skin-to-skin contact, or living in the same household with an mpox patient were recruited in a sexual health clinic in Antwerp, Belgium. Participants kept a symptom diary, performed daily self-sampling (anorectal, genital, and saliva), and presented for weekly clinic visits for physical examination and sampling (blood and oropharyngeal). Samples were tested for MPXV by PCR. Between June 24 and July 31, 2022, 25 contacts were included, of which 12/18 (66.0%) sexual and 1/7 (14.0%) nonsexual contacts showed evidence of infection by MPXV-PCR. Six cases had typical mpox symptoms. Viral DNA was detected as early as 4 days before symptom onset in 5 of them. In 3 of these cases, replication-competent virus was demonstrated in the presymptomatic phase. These findings confirm the existence of presymptomatic shedding of replication-competent MPXV and emphasize the high risk of transmission during sexual contact. Sexual contacts of mpox cases should abstain from sex during the incubation period, irrespective of symptoms.

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.

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.