PRI’s MPV (Monkeypox) Situation Update – September 29

Sep 29, 2022 | News

Created by PRI for NYC Health Department. Latest editions Tuesday and Thursdays. While we use the language “MPV”, most sources do not, and readers will see the language fluctuate within the report. For questions and feedback, please email info@pri.nyc

Summary

Case Counts/Trends and Large Guidance/Response Changes (Limited by latest reporting)

  • GLOBAL: From 1 January through 18 September 2022, 61 753 laboratory-confirmed cases of monkeypox and 23 deaths have been reported to WHO from 105 countries/territories/areas (hereafter ‘countries’[i]) in all six WHO Regions (Table 1). Since the last edition published on 7 September 2022, 8757 new cases (16.5% increase in total cases) and five new deaths have been reported. In the past seven days, 23 countries reported an increase in the weekly number of cases, with the highest increase reported in Chile. Three new countries also reported their first case in the past seven days: Guam (12 September), Ukraine (15 September), and Bahrain (16 September). Overall, 33 countries have not reported new cases for over 21 days, the maximum incubation period of the disease. (WHO Sit Rep – Latest 9/21/2022 / Dashboard)
  • US: Total confirmed MPV cases: 25,509 (9.28.2022). (full version). 
  • NY State: As of September 21 2022, a total of 3,759 confirmed orthopoxvirus/monkeypox cases – a designation established by the Centers for Disease Control and Prevention (CDC), 323 in counties excluding NYC. (NY Sit Rep and County List) 
  • What’s behind dramatic drop in monkeypox cases in the US (ABC News) “There’s been a terrific amount of public health education that’s gone out and it’s gone out particularly to the MSM community and the LBGTQ community that’s been primarily affected,” he said. “So, you have a target population, they’ve been literally flooded, in some instances, with information about monkeypox, and what you as an individual can do to protect yourself against becoming infected.”

US Updates/News

  • The First U.S. Data Show the Monkeypox Vaccine Is Effective (Time) On Sept. 28, the U.S. Centers for Disease Control and Prevention (CDC) posted preliminary data from 32 jurisdictions in the U.S. that reported monkeypox case rates and rates of vaccination with Jynneos, the vaccine currently being used against monkeypox.

Global Updates/News

  • Egypt announces second monkeypox case (Ahram Online) Egypt officially declared its first monkeypox case in early September in a 42-year-old Egyptian who has residency in a European country and frequently visited it, according to the health ministry.

Official Guidance Sources

Articles by Category

Epi/Transmission/Mitigation

Transmission characteristics, replication patterns and clinical manifestations of human monkeypox virus – an in-depth analysis of four cases from Germany (Hornuss et al., Clinical Microbiology and Infection)

This study shows aspects of clinical manifestations as well as epidemiological and virological features impacting transmission, for which only scarce data are available so far. The authors present a descriptive study consisting of epidemiological, clinical and virological data of four patients with confirmed MPX diagnosis. Follow-up examinations included in-depth virological investigations including MPXV-specific quantitative PCR (qPCR) and virus isolation. Between May 22nd, and June 21st, four patients with MPX were evaluated. The number of lesions ranged between one and more than 30, with asynchronous eruption. The periorificial distribution of initial lesions together with the case histories strongly suggest human-to-human transmission during intimate contacts in sexual activities. None of the patients reported about memorable lesions on the skin of potential risk contacts. Virological sampling showed positive MPXV qPCR results from swabs of the primary lesions (until day 22 after symptom onset), pharyngeal and anal mucosa, urine, seminal fluid, blood, and samples of non-affected skin. Virus isolation was positive in 6/14 samples (lesional skin, anal and pharyngeal mucosa). One patient required inpatient treatment due to bacterial superinfection, in another patient three sexually transmitted co-infections were present. In summary, this report demonstrates asynchronous multiple-site lesions of MPX with prolonged PCR positivity in mucosal swabs, swabs of non-affected skin, urine and seminal fluid. In addition, infectious virus was confirmed on lesional skin and mucosal swabs. The observed virological kinetics together with suspected presymptomatic transmission may lead to effective and sustained human-to-human transmission particularly in sexual networks.

Environmental Persistence of Monkeypox Virus on Surfaces in Household of Person with Travel-Associated Infection, Dallas, Texas, USA, 2021 (Morgan et al., Emerging Infectious Diseases)

In July 2021, researchers conducted environmental sampling at the residence of a person in Dallas, Texas, USA, who had travel-associated human West African monkeypox virus (MPXV-WA). They carried out targeted environmental swab sampling 15 days after the person who had monkeypox left the household. The results indicate extensive MPXV-WA DNA contamination, and viable virus from 7 samples was successfully isolated in cell culture. There was no statistical difference (p = 0.94) between MPXV-WA PCR positivity of porous (9/10, 90%) vs. nonporous (19/21, 90.5%) surfaces, but there was a significant difference (p<0.01) between viable virus detected in cultures of porous (6/10, 60%) vs. nonporous (1/21, 5%) surfaces. The researchers conclude that these findings indicate that porous surfaces (e.g., bedding, clothing) may pose more of a MPXV exposure risk than nonporous surfaces (e.g., metal, plastic). Overall viable MPXV was detected on household surfaces after at least 15 days. However, low titers (<102 PFU) indicate a limited potential for indirect transmission.

Evaluating the risk of transfusion and transplant-transmitted monkeypox infections (Harvala et al., Transfusion Medicine)

The recent emergence of monkeypox virus (MPXV) in the UK and elsewhere is of urgent public health concern. Several aspects of MPXV epidemiology and pathogenesis, including its systemic spread and viraemia during acute infection, furthermore represent an important potential threat to the safety of blood transfusion and organ transplantation. Reported infections in the UK have been exponentially increasing over the last 2 months, with 1552 reported cases in the UK by 7th July 2022. This is likely to be considerable underestimate given current limitations in diagnostic capacity and clinical diagnoses hampered by its similar disease presentations to other causes of rash and genitourinary disease. While MPXV infections are currently most widespread in gay, bisexual or other men who have sex with men, wider spread of MPXV outside defined risk groups for infection may prevent identification of infection risk in donors. While typically mild disease outcomes have been reported in UK cases, case fatality rates ranging from 1% to over 10% are reported for different MPXV strains in its source area in sub-Saharan Africa. Recipients of blood components and organs transplant, especially those who are immunosuppressed, may reproduce the greater systemic spread and morbidity of those infected through percutaneous routes. There is a potential risk of MPXV transmission and severe disease outcomes in blood and transplant recipients. In addition to current risk assessments performed in the UK and exclusion of donors with recent MPXV exposure, determining viraemia frequencies in donors and directly evaluating transmission risk would be of considerable value in assessing whether MPXV nucleic acid screening should be implemented.

Heavy-tailed sexual contact networks and monkeypox epidemiology in the global outbreak, 2022 (Endo et al., Science)

The outbreak of monkeypox across non-endemic regions confirmed in May 2022 shows epidemiological features that are distinct from previous imported outbreaks, most notably its observed growth and predominance amongst men who have sex with men (MSM). We use a transmission model fitted to empirical sexual partnership data to show that the heavy-tailed sexual partnership distribution, where a handful of individuals have disproportionately many partners, can explain the sustained growth of monkeypox over the MSM sexual network may be substantially above 1, which poses challenges to outbreak containment. Ensuring support and tailored messaging to facilitate prevention and early detection among MSM with highest numbers of partners is warranted. 

Transmission characteristics, replication patterns and clinical manifestations of human monkeypox virus – an in-depth analysis of four cases from Germany (Hornuss et al., Clinical Microbiology and Infection) 

Since April 2022, increasing numbers of monkeypox (MPX) cases are reported outside endemic areas as part of an international outbreak. Our study shows aspects of clinical manifestations as well as epidemiological and virological features impacting transmission, for which only scarce data are available so far. We present a descriptive study consisting of epidemiological, clinical and virological data of four patients with confirmed MPX diagnosis. Follow-up examinations included in-depth virological investigations including MPXV-specific quantitative PCR (qPCR) and virus isolation. Between May 22nd, and June 21st, four patients with MPX were evaluated. The number of lesions ranged between one and more than 30, with asynchronous eruption. The periorificial distribution of initial lesions together with the case histories strongly suggest human-to-human transmission during intimate contacts in sexual activities. None of the patients reported about memorable lesions on the skin of potential risk contacts. Virological sampling showed positive MPXV qPCR results from swabs of the primary lesions (until day 22 after symptom onset), pharyngeal and anal mucosa, urine, seminal fluid, blood, and samples of non-affected skin. Virus isolation was positive in 6/14 samples (lesional skin, anal and pharyngeal mucosa). One patient required inpatient treatment due to bacterial superinfection, in another patient three sexually transmitted co-infections were present. Our report demonstrates asynchronous multiple-site lesions of MPX with prolonged PCR positivity in mucosal swabs, swabs of non-affected skin, urine and seminal fluid. In addition, infectious virus was confirmed on lesional skin and mucosal swabs. The observed virological kinetics together with suspected presymptomatic transmission may lead to effective and sustained human-to-human transmission particularly in sexual networks. Preventive measures such as vaccination and post-exposure prophylaxis may become important for MPX control in vulnerable groups.

Vaccine

Effectiveness of a single-dose Modified Vaccinia Ankara in Human Monkeypox: an observational study (Arbel et al., Europe PMC)

The recent global outbreak of the human monkeypox virus (MPXV) was declared a public health emergency by the World Health Organization. Modified Vaccinia Ankara (MVA) is currently the only FDA-approved vaccine against MPXV that was approved for this indication based on a study in non-human primates. Since there is currently scarce evidence of the efficacy in humans, our objective was to evaluate real-life vaccine effectiveness (VE) after providing one vaccine dose to individuals at risk of MPVX infection. The study cohort included all Clalit Health Services (CHS) members eligible for the MVA vaccine as defined by the Israeli Ministry of Health. The study commenced on July 31, 2022, when the MVA vaccination campaign was initiated in CHS, and participants were followed until September 12, 2022. A Cox proportional-hazards regression model with time-dependent covariates was used to estimate the association between vaccination and MPXV infections with adjustment for sociodemographic and clinical risk factors. A total of 1,970 subjects met the study eligibility criteria (0.04% of CHS members). Of them, 873 (44%) were vaccinated with MVA and completed at least 25 days of follow-up. 18 infections were confirmed in CHS during the study period, 3 in vaccinated and 15 in unvaccinated status (40.0 versus 6.4 per 100,000 person days). VE was estimated at 79% (95% CI: 24%-94%). Interpretation Our results suggest that a single dose of MVA is associated with a significantly lower risk for MPVX infection in high-risk individuals. These findings highlight that urgent MVA vaccination of high-risk individuals may contribute to the containment of the current MPXV outbreak.

Virology

Human Immunodeficiency Virus infection may be a contributing factor to Monkeypox infection: analysis of a 42-case series (Alpalhão et al., Journal of the American Academy of Dermatology)

In the article, dermatologists present a retrospective analysis of 42 confirmed monkeypox cases, including their clinical and epidemiological characteristics, in a dermatology department at a hospital in Lisbon, Portugal. All the cases were among cisgender males presenting with lesions in the genital, perianal, or perioral areas. The dermatologists observed a disproportionate number of individuals living with the human immunodeficiency virus (HIV). Of the 42 patients, 22 (52.4%) had concomitant HIV infection, corresponding to a prevalence of HIV infection more than 100 times higher than that of the general Portuguese population (0.4%). One individual was diagnosed with acute HIV infection concurrently with monkeypox, while the others were already receiving appropriate antiretroviral treatment. The HIV-infected patients tended to be older, but this did not reach statistical significance. This could explain the differences in smallpox vaccination between the two groups. The prevalence of genital, perianal, and perioral lesions was similar overall. All patients had lesions in at least one of these sites, which are typically affected by sexually transmitted infections (STIs). A marked difference between the two cohorts was in the prevalence of the disseminated form of the disease. Lesions at sites other than the genital, perianal, and perioral areas were found more frequently in patients with HIV infection (63.3% vs. 30.0%, p-value 0.037). The frequency of constitutional symptoms (fever, myalgias/arthralgias, and headache) and lymph node enlargement was similar in both groups. These data suggest individuals living with HIV infection are at higher risk of acquiring monkeypox.

Development and Characterization of Recombinase-Based Isothermal Amplification Assays (RPA/RAA) for the Rapid Detection of Monkeypox Virus (Mao et al., Viruses)

Monkeypox is a zoonotic disease caused by monkeypox virus (MPXV), in which outbreaks mainly occurred in West and Central Africa, with only sporadic spillovers to countries outside Africa due to international travel or close contact with wildlife. During May 2022, multiple countries in Europe, North and South America, Australia, Asia, and Africa reported near-simultaneous outbreaks of MPXV, the first time that patient clusters were reported over such a large geographical area. Cases have no known epidemiological links to MPXV-endemic countries in West or CentralAfrica. Real-time PCR is currently the gold standard for MPXV diagnostics, but it requires trained laboratory personnel and specialized equipment, and results can only be obtained after several hours. A rapid and simple-to-operate point-of-care diagnostic test for MPXV is crucial for limiting its spread and controlling outbreaks. Here, three recombinase-based isothermal amplification assays (RPA/RAA) for the rapid detection of MPXV isolates were developed. These three assays target the MPXV G2R gene, and the limit of detection for these systems is approximately 100 copies of DNA per reaction. The assays were found to be specific and non-cross reactive against other pox viruses, such as vaccinia virus, and the results can be visualized within 20–30 min. The assays were validated with DNA extracted from 19 clinical samples from suspected or confirmed MPXV patients from Central Africa, and found to be consistent with findings from traditional qPCR. These results provide a solid platform for the early diagnosis of potential MPXV cases, and will help with the control and prevention of current and future outbreaks.