Modelling the impact of vaccination and sexual behaviour adaptations on mpox cases in the USA during the 2022 outbreak.

BACKGROUND: The 2022 mpox outbreak has infected over 30 000 people in the USA, with cases declining since mid-August. Infections were commonly associated with sexual contact between men. Interventions to mitigate the outbreak included vaccination and a reduction in sexual partnerships. Understanding the contributions of these interventions to decreasing cases can inform future public health efforts. METHODS: We fit a dynamic network transmission model to mpox cases reported by Washington DC through 10 January 2023. This model incorporated both vaccine administration data and reported reductions in sexual partner acquisition by gay, bisexual or other men who have sex with men (MSM). The model output consisted of daily cases over time with or without vaccination and/or behavioural adaptation. RESULTS: We found that initial declines in cases were likely caused by behavioural adaptations. One year into the outbreak, vaccination and behavioural adaptation together prevented an estimated 84% (IQR 67% to 91%) of cases. Vaccination alone averted 79% (IQR 64% to 88%) of cases and behavioural adaptation alone averted 25% (IQR 10% to 42%) of cases. We further found that in the absence of vaccination, behavioural adaptation would have reduced the number of cases, but would have prolonged the outbreak. CONCLUSIONS: We found that initial declines in cases were likely caused by behavioural adaptation, but vaccination averted more cases overall and was key to hastening outbreak conclusion. Overall, this indicates that outreach to encourage individuals to protect themselves from infection was vital in the early stages of the mpox outbreak, but that combination with a robust vaccination programme hastened outbreak conclusion.

Modifications to Sexual Behaviors Associated With Mpox (Monkeypox) Virus Transmission Among Persons Presenting for mpox Vaccination, Washington, DC, August-October, 2022.

BACKGROUND: Over 30,000 mpox cases were reported during the 2022 mpox outbreak with many cases occurring among gay, bisexual and other men who have sex with men (MSM). Decreases in U.S. mpox cases were likely accelerated by a combination of vaccination and modifications to sexual behaviors associated with mpox virus transmission. We assessed reports of sexual behavior change among participants receiving mpox vaccination in Washington, DC. METHODS: During August to October 2022, 711 adults aged ≥18 years receiving mpox vaccination at two public health clinics in Washington, DC completed a self-administered questionnaire that asked whether sexual behaviors changed since learning about mpox. We calculated the frequency and percentages of participants reporting an increase, decrease, or no change in 4 of these behaviors by demographic, clinical, and behavioral characteristics with 95% confidence intervals. RESULTS: Overall, between 46% and 61% of participants reported a decrease in sexual behaviors associated with mpox virus transmission, 39% to 54% reported no change in these behaviors, and <1% reported an increase. Approximately 61% reported decreases in one-time sexual encounters (95% confidence interval [CI], 56.8%-64.7%), 54.3% reduced numbers of sex partners (95% CI, 50.4%-58.0%), 53.4% decreased sex via a dating app or sex venue (95% CI, 49.7%-58.0%), and 45.6% reported less group sex (95% CI, 40.4%-50.9%). Reported decreases in these behaviors were higher for MSM than women; in non-Hispanic Black than non-Hispanic White participants; and in participants with human immunodeficiency virus than participants without human immunodeficiency virus. CONCLUSIONS: Most participants receiving mpox vaccination reported decreasing sexual behaviors associated with mpox virus transmission, including groups disproportionately affected by the outbreak.

Evidence of Mpox Virus Infection Among Persons Without Characteristic Lesions or Rash Presenting for First Dose of JYNNEOS Vaccine-District of Columbia, August 2022.

We assessed mpox virus prevalence in blood, pharyngeal, and rectal specimens among persons without characteristic rash presenting for JYNNEOS vaccine. Our data indicate that the utility of risk-based screening for mpox in persons without skin lesions or rash via pharyngeal swabs, rectal swabs, and/or blood is likely limited.

Estimated Effectiveness of JYNNEOS Vaccine in Preventing Mpox: A Multijurisdictional Case-Control Study - United States, August 19, 2022-March 31, 2023.

As of March 31, 2023, more than 30,000 monkeypox (mpox) cases had been reported in the United States in an outbreak that has disproportionately affected gay, bisexual, and other men who have sex with men (MSM) and transgender persons (1). JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) was approved by the Food and Drug Administration (FDA) in 2019 for the prevention of smallpox and mpox via subcutaneous injection as a 2-dose series (0.5 mL per dose, administered 4 weeks apart) (2). To expand vaccine access, an Emergency Use Authorization was issued by FDA on August 9, 2022, for dose-sparing intradermal injection of JYNNEOS as a 2-dose series (0.1 mL per dose, administered 4 weeks apart) (3). Vaccination was available to persons with known or presumed exposure to a person with mpox (postexposure prophylaxis [PEP]), as well as persons at increased risk for mpox or who might benefit from vaccination (preexposure mpox prophylaxis [PrEP]) (4). Because information on JYNNEOS vaccine effectiveness (VE) is limited, a matched case-control study was conducted in 12 U.S. jurisdictions,† including nine Emerging Infections Program sites and three Epidemiology and Laboratory Capacity sites,§ to evaluate VE against mpox among MSM and transgender adults aged 18-49 years. During August 19, 2022-March 31, 2023, a total of 309 case-patients were matched to 608 control patients. Adjusted VE was 75.2% (95% CI = 61.2% to 84.2%) for partial vaccination (1 dose) and 85.9% (95% CI = 73.8% to 92.4%) for full vaccination (2 doses). Adjusted VE for full vaccination by subcutaneous, intradermal, and heterologous routes of administration was 88.9% (95% CI = 56.0% to 97.2%), 80.3% (95% CI = 22.9% to 95.0%), and 86.9% (95% CI = 69.1% to 94.5%), respectively. Adjusted VE for full vaccination among immunocompromised participants was 70.2% (95% CI = -37.9% to 93.6%) and among immunocompetent participants was 87.8% (95% CI = 57.5% to 96.5%). JYNNEOS is effective at reducing the risk for mpox. Because duration of protection of 1 versus 2 doses remains unknown, persons at increased risk for mpox exposure should receive the 2-dose series as recommended by the Advisory Committee on Immunization Practices (ACIP),¶ regardless of administration route or immunocompromise status.

Utility of a Test-to-Return Strategy to Identify Individuals With Coronavirus Disease 2019 (COVID-19) in the Prekindergarten Through Grade 12 School Setting-District of Columbia, January 2022.

The highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant led to increased hospitalizations, staffing shortages, and increased school closures. To reduce spread in school-aged children during the Omicron peak, the District of Columbia implemented a test-to-return strategy in public and public charter schools after a 2-week break from in-person learning.

Multistate Outbreak of SARS-CoV-2 Infections, Including Vaccine Breakthrough Infections, Associated with Large Public Gatherings, United States.

During July 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.617.2 variant infections, including vaccine breakthrough infections, occurred after large public gatherings in Provincetown, Massachusetts, USA, prompting a multistate investigation. Public health departments identified primary and secondary cases by using coronavirus disease surveillance data, case investigations, and contact tracing. A primary case was defined as SARS-CoV-2 detected <14 days after travel to or residence in Provincetown during July 3-17. A secondary case was defined as SARS-CoV-2 detected <14 days after close contact with a person who had a primary case but without travel to or residence in Provincetown during July 3-August 10. We identified 1,098 primary cases and 30 secondary cases associated with 26 primary cases among fully and non-fully vaccinated persons. Large gatherings can have widespread effects on SARS-CoV-2 transmission, and fully vaccinated persons should take precautions, such as masking, to prevent SARS-CoV-2 transmission, particularly during substantial or high transmission.

Two Cases of Monkeypox-Associated Encephalomyelitis - Colorado and the District of Columbia, July-August 2022.

Monkeypox virus (MPXV) is an orthopoxvirus in the Poxviridae family. The current multinational monkeypox outbreak has now spread to 96 countries that have not historically reported monkeypox, with most cases occurring among gay, bisexual, and other men who have sex with men (1,2). The first monkeypox case in the United States associated with this outbreak was identified in May 2022 in Massachusetts (1); monkeypox has now been reported in all 50 states, the District of Columbia (DC), and one U.S. territory. MPXV is transmitted by close contact with infected persons or animals; infection results in a febrile illness followed by a diffuse vesiculopustular rash and lymphadenopathy. However, illness in the MPXV current Clade II outbreak has differed: the febrile prodrome is frequently absent or mild, and the rash often involves genital, anal, or oral regions (3,4). Although neuroinvasive disease has been previously reported with MPXV infection (5,6), it appears to be rare. This report describes two cases of encephalomyelitis in patients with monkeypox disease that occurred during the current U.S. outbreak. Although neurologic complications of acute MPXV infections are rare, suspected cases should be reported to state, tribal, local, or territorial health departments to improve understanding of the range of clinical manifestations of and treatment options for MPXV infections during the current outbreak.

Epidemiologic and Clinical Characteristics of Monkeypox Cases - United States, May 17-July 22, 2022.

Monkeypox, a zoonotic infection caused by an orthopoxvirus, is endemic in parts of Africa. On August 4, 2022, the U.S. Department of Health and Human Services declared the U.S. monkeypox outbreak, which began on May 17, to be a public health emergency (1,2). After detection of the first U.S. monkeypox case), CDC and health departments implemented enhanced monkeypox case detection and reporting. Among 2,891 cases reported in the United States through July 22 by 43 states, Puerto Rico, and the District of Columbia (DC), CDC received case report forms for 1,195 (41%) cases by July 27. Among these, 99% of cases were among men; among men with available information, 94% reported male-to-male sexual or close intimate contact during the 3 weeks before symptom onset. Among the 88% of cases with available data, 41% were among non-Hispanic White (White) persons, 28% among Hispanic or Latino (Hispanic) persons, and 26% among non-Hispanic Black or African American (Black) persons. Forty-two percent of persons with monkeypox with available data did not report the typical prodrome as their first symptom, and 46% reported one or more genital lesions during their illness; 41% had HIV infection. Data suggest that widespread community transmission of monkeypox has disproportionately affected gay, bisexual, and other men who have sex with men and racial and ethnic minority groups. Compared with historical reports of monkeypox in areas with endemic disease, currently reported outbreak-associated cases are less likely to have a prodrome and more likely to have genital involvement. CDC and other federal, state, and local agencies have implemented response efforts to expand testing, treatment, and vaccination. Public health efforts should prioritize gay, bisexual, and other men who have sex with men, who are currently disproportionately affected, for prevention and testing, while addressing equity, minimizing stigma, and maintaining vigilance for transmission in other populations. Clinicians should test patients with rash consistent with monkeypox,† regardless of whether the rash is disseminated or was preceded by prodrome. Likewise, although most cases to date have occurred among gay, bisexual, and other men who have sex with men, any patient with rash consistent with monkeypox should be considered for testing. CDC is continually evaluating new evidence and tailoring response strategies as information on changing case demographics, clinical characteristics, transmission, and vaccine effectiveness become available.§.

Orthopoxvirus Testing Challenges for Persons in Populations at Low Risk or Without Known Epidemiologic Link to Monkeypox - United States, 2022.

Since May 2022, approximately 20,000 cases of monkeypox have been identified in the United States, part of a global outbreak occurring in approximately 90 countries and currently affecting primarily gay, bisexual, and other men who have sex with men (MSM) (1). Monkeypox virus (MPXV) spreads from person to person through close, prolonged contact; a small number of cases have occurred in populations who are not MSM (e.g., women and children), and testing is recommended for persons who meet the suspected case definition* (1). CDC previously developed five real-time polymerase chain reaction (PCR) assays for detection of orthopoxviruses from lesion specimens (2,3). CDC was granted 510(k) clearance for the nonvariola-orthopoxvirus (NVO)-specific PCR assay by the Food and Drug Administration. This assay was implemented within the Laboratory Response Network (LRN) in the early 2000s and became critical for early detection of MPXV and implementation of public health action in previous travel-associated cases as well as during the current outbreak (4-7). PCR assays (NVO and other Orthopoxvirus laboratory developed tests [LDT]) represent the primary tool for monkeypox diagnosis. These tests are highly sensitive, and cross-contamination from other MPXV specimens being processed, tested, or both alongside negative specimens can occasionally lead to false-positive results. This report describes three patients who had atypical rashes and no epidemiologic link to a monkeypox case or known risk factors; these persons received diagnoses of monkeypox based on late cycle threshold (Ct) values ≥34, which were false-positive test results. The initial diagnoses were followed by administration of antiviral treatment (i.e., tecovirimat) and JYNNEOS vaccine postexposure prophylaxis (PEP) to patients' close contacts. After receiving subsequent testing, none of the three patients was confirmed to have monkeypox. Knowledge gained from these and other cases resulted in changes to CDC guidance. When testing for monkeypox in specimens from patients without an epidemiologic link or risk factors or who do not meet clinical criteria (or where these are unknown), laboratory scientists should reextract and retest specimens with late Ct values (based on this report, Ct ≥34 is recommended) (8). CDC can be consulted for complex cases including those that appear atypical or questionable cases and can perform additional viral species- and clade-specific PCR testing and antiorthopoxvirus serologic testing.

Epidemiologic and Clinical Features of Children and Adolescents Aged <18 Years with Monkeypox - United States, May 17-September 24, 2022.

Data on monkeypox in children and adolescents aged <18 years are limited (1,2). During May 17­September 24, 2022, a total of 25,038 monkeypox cases were reported in the United States,† primarily among adult gay, bisexual, and other men who have sex with men (3). During this period, CDC and U.S. jurisdictional health departments identified Monkeypox virus (MPXV) infections in 83 persons aged <18 years, accounting for 0.3% of reported cases. Among 28 children aged 0­12 years with monkeypox, 64% were boys, and most had direct skin-to-skin contact with an adult with monkeypox who was caring for the child in a household setting. Among 55 adolescents aged 13­17 years, most were male (89%), and male-to-male sexual contact was the most common presumed exposure route (66%). Most children and adolescents with monkeypox were non-Hispanic Black or African American (Black) (47%) or Hispanic or Latino (Hispanic) (35%). Most (89%) were not hospitalized, none received intensive care unit (ICU)­level care, and none died. Monkeypox in children and adolescents remains rare in the United States. Ensuring equitable access to monkeypox vaccination, testing, and treatment is a critical public health priority. Vaccination for adolescents with risk factors and provision of prevention information for persons with monkeypox caring for children might prevent additional infections.

Investigation of Pertussis Cases in a Texas County, 2008-2012.

OBJECTIVES: Within the past 25 years, there has been a dramatic increase in the incidence of pertussis cases in the United States. As such, this investigation reports on the high-risk groups and describes risk factors of pertussis cases in a large Texas county. METHODS: This study was a cross-sectional analysis of data collected by health department employees using the Texas Department of State Health Service's Pertussis Case Track Record, which is the standard investigation form for collecting vital information on pertussis cases. We extracted and analyzed county-level data for a 5-year period (2008-2012). The study population at risk included all current residents in this county, and cases included all who were clinically diagnosed as having confirmed or probable pertussis cases that were reported to the health department according to the Centers for Disease Control and Prevention case definition. The vaccination status of a case was defined as fully vaccinated, partially vaccinated, or not vaccinated. RESULTS: A total of 198 probable and confirmed pertussis cases were included in this analysis. Most of the cases were infants younger than 1 year old (n = 107). The largest category of cases was not vaccinated and of the rest, 32.8% were partially vaccinated, 17.2% had unknown vaccination status, and 13.1% were fully vaccinated. Only 48 (24.2%) sources of exposure were identified and they included fathers (14.6%), sisters (14.6%), brothers (14.6%), other children (14.6%), and mothers (12.5%). Many sources of exposure (n = 26, 54.1%) were unaware of their vaccination history. Hispanics accounted for 84.5% of cases in the younger than 1 year old group and 88.9% of cases were in the 1 to 2 years old group. With respect to race/ethnicity and vaccination status of the cases, 39.46% of Hispanics, 32% of whites, and 50% of blacks were reported to be unvaccinated. CONCLUSIONS: Increasing pertussis vaccination coverage among children, as well as providing booster shots to adults with special attention on the Hispanic population, may prove to be an effective strategy for health departments.

Vaccine-associated paralytic poliomyelitis and BCG-osis in an immigrant child with severe combined immunodeficiency syndrome - Texas, 2013.

Poliovirus transmission has been eliminated in most of the world through the use of inactivated poliovirus vaccine (IPV) and live, attenuated oral poliovirus vaccine (OPV). In the United States, use of OPV was discontinued by the year 2000 because of the potential for vaccine-associated paralytic polio (VAPP); an average of eight cases were reported each year in the United States during 1980-2000. Polio eradication efforts in other parts of the world continue to rely on OPV to take advantage of transmission of poliovirus vaccine strains to unvaccinated persons in the population, lower cost, and ease of administration. In 2013, an infant aged 7 months who recently immigrated to the United States from India was referred to a hospital in San Antonio, Texas. The infant had fever, an enlarging skin lesion in the deltoid region with axillary lymphadenopathy, decreased activity, and inability to bear weight on the left leg, progressing to paralysis of the left leg over a 6-week period. Recognition of lymphopenia on complete blood count led to immune evaluation, which revealed the presence of severe combined immunodeficiency syndrome (SCIDS), an inherited disorder. A history of OPV and bacille Calmette-Guérin (BCG) vaccination in India led to the diagnoses of VAPP and BCG-osis, which were confirmed microbiologically. This report demonstrates the importance of obtaining a comprehensive clinical history in a child who has recently immigrated to the United States, with recognition that differing vaccine practices in other countries might require additional consideration of potential etiologies.

COVID-19 Outbreaks Linked to Workplaces, 23 US Jurisdictions, August-October 2021.

OBJECTIVES: Early in the COVID-19 pandemic, several outbreaks were linked with facilities employing essential workers, such as long-term care facilities and meat and poultry processing facilities. However, timely national data on which workplace settings were experiencing COVID-19 outbreaks were unavailable through routine surveillance systems. We estimated the number of US workplace outbreaks of COVID-19 and identified the types of workplace settings in which they occurred during August-October 2021. METHODS: The Centers for Disease Control and Prevention collected data from health departments on workplace COVID-19 outbreaks from August through October 2021: the number of workplace outbreaks, by workplace setting, and the total number of cases among workers linked to these outbreaks. Health departments also reported the number of workplaces they assisted for outbreak response, COVID-19 testing, vaccine distribution, or consultation on mitigation strategies. RESULTS: Twenty-three health departments reported a total of 12 660 workplace COVID-19 outbreaks. Among the 12 470 workplace types that were documented, 35.9% (n = 4474) of outbreaks occurred in health care settings, 33.4% (n = 4170) in educational settings, and 30.7% (n = 3826) in other work settings, including non-food manufacturing, correctional facilities, social services, retail trade, and food and beverage stores. Eleven health departments that reported 3859 workplace outbreaks provided information about workplace assistance: 3090 (80.1%) instances of assistance involved consultation on COVID-19 mitigation strategies, 1912 (49.5%) involved outbreak response, 436 (11.3%) involved COVID-19 testing, and 185 (4.8%) involved COVID-19 vaccine distribution. CONCLUSIONS: These findings underscore the continued impact of COVID-19 among workers, the potential for work-related transmission, and the need to apply layered prevention strategies recommended by public health officials.

Aiming for Zero: Reducing Transmission of Coronavirus Disease 2019 in the D.C. Department of Corrections.

BACKGROUND: Washington, District of Columbia lowered severe acute respiratory syndrome coronavirus 2 transmission in its large jail while community incidence was still high. METHODS: Coordinated clinical and operational interventions brought new cases to near zero. RESULTS: Aggressive infection control and underlying jail architecture can promote correctional coronavirus disease 2019 management. CONCLUSIONS: More intensive monitoring could help confirm that in-house transmission is truly zero.

Using Systems Science to Inform Population Health Strategies in Local Health Departments: A Case Study in San Antonio, Texas.

OBJECTIVES: Because of state and federal health care reform, local health departments play an increasingly prominent role leading and coordinating disease prevention programs in the United States. This case study shows how a local health department working in chronic disease prevention and management can use systems science and evidence-based decision making to inform program selection, implementation, and assessment; enhance engagement with local health systems and organizations; and possibly optimize health care delivery and population health. METHODS: The authors built a systems-science agent-based simulation model of diabetes progression for the San Antonio Metropolitan Health District, a local health department, to simulate health and cost outcomes for the population of San Antonio for a 20-year period (2015-2034) using 2 scenarios: 1 in which hemoglobin A1c (HbA1c) values for a population were similar to the current distribution of values in San Antonio, and the other with a hypothetical 1-percentage-point reduction in HbA1c values. RESULTS: They projected that a 1-percentage-point reduction in HbA1c would lead to a decrease in the 20-year prevalence of end-stage renal disease from 1.7% to 0.9%, lower extremity amputation from 4.6% to 2.9%, blindness from 15.1% to 10.7%, myocardial infarction from 23.8% to 17.9%, and stroke from 9.8% to 7.2%. They estimated annual direct medical cost savings (in 2015 US dollars) from reducing HbA1c by 1 percentage point ranging from $6842 (myocardial infarction) to $39 800 (end-stage renal disease) for each averted case of diabetes complications. CONCLUSIONS: Local health departments could benefit from the use of systems science and evidence-based decision making to estimate public health program effectiveness and costs, calculate return on investment, and develop a business case for adopting programs.