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.

Risk of Clade II Mpox Associated with Intimate and Nonintimate Close Contact Among Men Who Have Sex with Men and Transgender Adults - United States, August 2022-July 2023.

A global outbreak of clade II mpox associated with sexual contact, disproportionately affecting gay, bisexual, and other men who have sex with men (MSM), has been ongoing since May 2022. Information on types of contact most associated with transmission is limited. This report used data from a multijurisdictional vaccine effectiveness case-control study of sexually active persons aged 18-49 years who identified as MSM or transgender, collected during August 2022-July 2023. Odds of mpox associated with selected types of intimate and nonintimate close contact with a person with mpox were estimated. Among 457 case-patients and 1,030 control patients who met minimum data requirements, 150 (32.8%) case-patients and 57 (5.5%) control patients reported close contact with a person with mpox and were included in this analysis. Adjusted odds of mpox were 5.4 times as high among those who reported having condomless receptive anal sex with a person with mpox, compared with participants who reported close contact with a person with mpox and no condomless receptive anal sex with that person (OR = 5.4; p = 0.031). Although the mpox vaccine is highly effective, vaccination coverage remains low; a multifaceted approach to prevention remains important and should include vaccination promotion, safer sex practices, and increasing awareness that mpox continues to circulate.

Serial Interval and Incubation Period Estimates of Monkeypox Virus Infection in 12 Jurisdictions, United States, May-August 2022.

Using data from 12 US health departments, we estimated mean serial interval for monkeypox virus infection to be 8.5 (95% credible interval 7.3-9.9) days for symptom onset, based on 57 case pairs. Mean estimated incubation period was 5.6 (95% credible interval 4.3-7.8) days for symptom onset, based on 35 case pairs.

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.

HIV and Sexually Transmitted Infections Among Persons with Monkeypox - Eight U.S. Jurisdictions, May 17-July 22, 2022.

High prevalences of HIV and other sexually transmitted infections (STIs) have been reported in the current global monkeypox outbreak, which has affected primarily gay, bisexual, and other men who have sex with men (MSM) (1-5). In previous monkeypox outbreaks in Nigeria, concurrent HIV infection was associated with poor monkeypox clinical outcomes (6,7). Monkeypox, HIV, and STI surveillance data from eight U.S. jurisdictions* were matched and analyzed to examine HIV and STI diagnoses among persons with monkeypox and assess differences in monkeypox clinical features according to HIV infection status. Among 1,969 persons with monkeypox during May 17-July 22, 2022, HIV prevalence was 38%, and 41% had received a diagnosis of one or more other reportable STIs in the preceding year. Among persons with monkeypox and diagnosed HIV infection, 94% had received HIV care in the preceding year, and 82% had an HIV viral load of <200 copies/mL, indicating HIV viral suppression. Compared with persons without HIV infection, a higher proportion of persons with HIV infection were hospitalized (8% versus 3%). Persons with HIV infection or STIs are disproportionately represented among persons with monkeypox. It is important that public health officials leverage systems for delivering HIV and STI care and prevention to reduce monkeypox incidence in this population. Consideration should be given to prioritizing persons with HIV infection and STIs for vaccination against monkeypox. HIV and STI screening and other recommended preventive care should be routinely offered to persons evaluated for monkeypox, with linkage to HIV care or HIV preexposure prophylaxis (PrEP) as appropriate.

Surveillance for Invasive Salmonella Disease in Bamako, Mali, From 2002 to 2018.

BACKGROUND: Salmonella enterica bloodstream infections are an important cause of childhood morbidity and mortality, including in Mali. We report 17 years of surveillance for nontyphoidal and typhoidal S. enterica infections among inpatients and outpatients at l'Hôpital Gabriel Touré, the main source of pediatric tertiary care in Bamako, Mali. METHODS: Between June 2002 and December 2018, a blood culture was collected from 54 748 children aged ≤15 years with fever and/or suspected invasive bacterial infection who provided consent (38 152 inpatients, 16 596 outpatients). Bacterial pathogens were identified using standard microbiological techniques and serovars of S. enterica were determined by PCR and/or agglutination with antisera. RESULTS: Nontyphoidal Salmonella (NTS) was identified in 671 enrolled inpatients (1.8% of all enrolled inpatients, 13.8% of enrolled inpatients with a positive culture). S. Enteritidis, the most common NTS serovar, accounted for 38.5% of all NTS isolates (n = 258), followed by S. Typhimurium (31.7%, n = 213). The median (SD) age of children with a culture positive for NTS was 1.8 (3) years. Overall case fatality was 20.9%. An additional 138 inpatients (0.4%) had a positive culture for typhoidal Salmonella. NTS was identified in 11 outpatients (0.07%), while typhoidal Salmonella was found in 49 outpatients (0.3%). The annual incidence of invasive NTS disease decreased over the study period, but case fatality remained high. CONCLUSIONS: Although incidence decreased, NTS remained a major cause of invasive bacterial infection and mortality among hospitalized children in Bamako, while typhoidal Salmonella was uncommon. Because 87% of NTS belonged to only 4 serovars, a multivalent vaccine may be an effective strategy to reduce the burden and mortality of invasive NTS.

Prevalence of Systemic Hypertension Among HIV-Infected and HIV-Uninfected Young Adults in Baltimore, Maryland.

OBJECTIVES: Adults with perinatally acquired human immunodeficiency virus (PHIV) infection may be at increased risk for nonacquired immunodeficiency syndrome (AIDS) diseases, including systemic hypertension (HTN). The purpose of this study was to examine the prevalence of HTN among young adults with PHIV compared with recently infected and uninfected young adults. METHODS: We conducted a cross-sectional study of young adults with PHIV, frequency matched on race and sex to a stratified random sample of young adults with nonperinatally acquired HIV (NPHIV) and HIV-uninfected young adults. All of the subjects were aged 18 to 29 years. HTN was defined as two systolic blood pressure measurements ≥140 mm Hg or diastolic ≥90 mm Hg at least 3 months apart and/or prescription for an antihypertensive medication. Logistic regression was used to estimate adjusted prevalence odds ratios and 95% confidence intervals (CIs) for the association between HIV infection and HTN. RESULTS: A total of 324 patients were included-108 per exposure group. The prevalence of HTN was 23% among individuals with PHIV, 10% among individuals with NPHIV, and 8% among HIV-uninfected patients. PHIV patients had 3.4 (95% CI 1.48-7.66) times the base odds of having HTN compared with HIV-uninfected patients, and 2.7 (95% CI 1.23-5.71) times the odds compared with NPHIV patients. By multivariable analysis, PHIV patients had 4.7 and 2.9 times the odds of having HTN compared with HIV-uninfected patients and NPHIV patients, respectively, after controlling for sex, race, and family history of hypertension. CONCLUSIONS: Our findings suggest that HTN prevalence among PHIV young adults is significantly higher than sex- and race-matched NPHIV and HIV-uninfected patients of similar age.

Evaluation of Mpox Exposures and Outcomes in Workplaces, 6 Jurisdictions, June 1-August 31, 2022.

OBJECTIVES: The risk for mpox virus (MPXV) transmission in most workplaces has not been thoroughly assessed in the context of the 2022 global mpox outbreak. Our objectives were to describe mpox case patients who worked while infectious and the subsequent workplace contact tracing efforts, risk assessments, and outcomes. METHODS: The Centers for Disease Control and Prevention requested information from health departments in the United States in September 2022 to identify people with confirmed or probable mpox who worked outside the home while infectious, either before or after diagnosis, from June 1 through August 31, 2022. We collected and summarized data on demographic, clinical, and workplace characteristics of case patients and workplace contact investigations. We stratified data by industry and occupation categories. RESULTS: In total, 102 case patients were reported by 6 jurisdictions. The most common industries were accommodation and food services (19.8%) and professional business, management, and technical services (17.0%). Contact investigations identified 178 total contacts; 54 cases (52.9%) had no contacts identified. Of 178 contacts, 54 (30.3%) were recommended to receive postexposure prophylaxis (PEP) and 18 (10.1%) received PEP. None of the contacts developed a rash or were tested for orthopox or mpox, and none were reported to have confirmed or probable mpox. CONCLUSION: Data from 6 jurisdictions suggest that the risk of MPXV transmission from workers to others in workplace settings in many industries is low. These findings might support future updates to exposure risk classifications and work activity recommendations for patients. These findings also demonstrate the importance of collecting and analyzing occupation and industry data in case reports to better understand risks in workplaces.

Analysis of Mpox by Occupation and Industry in Seven U.S. Jurisdictions, May 2022-March 2023.

During responses to outbreaks, the collection and analysis of data on employed case patients' industry and occupation are necessary to better understand the relationship between work and health outcomes. The occurrence of mpox by occupation and industry has not previously been assessed in the context of the 2022 outbreak. We analyzed employment data from 2548 mpox cases reported to the U.S. Centers for Disease Control and Prevention from surveillance systems in seven U.S. jurisdictions and population-based reference data on employment patterns from the U.S. Bureau of Labor Statistics to describe the differential proportionate distribution of cases across occupation and industry groups using the proportionate morbidity ratio. In gender-specific analyses, we found that men employed in certain occupations and industries had a higher relative risk of mpox than others. While occupational transmission cannot be ruled out, it is more likely that individuals with personal and behavioral risk factors for mpox were more likely to work in these occupations and industries. This analysis provides an example of collecting and analyzing occupation and industry data in case reports to understand possible differences in risk by occupation and industry in infectious disease outbreak investigation and help inform resource allocation, messaging, and response.

Understanding COVID-19 Vaccine Hesitancy Among K-12 Staff, Parents, and Students: District of Columbia, February to April, 2022.

OBJECTIVE: Despite widespread availability of COVID-19 vaccines, millions of Americans have not received the recommended vaccine doses. In the District of Columbia (DC), COVID-19 vaccination rates are lowest among residents who are Non-Hispanic (NH) Black and among school-aged children. We assessed COVID-19 vaccine hesitancy among staff and parents of students in DC K-12 public and public charter schools. METHODS: We conducted a telephone-based survey from February 6 to April 16, 2022 to staff, students, and parents of students who participated in school-based COVID-19 screening testing. COVID-19-related survey items included: vaccination status, reasons for not getting vaccinated, perceived vaccine access, and trusted COVID-19 information sources. Utilizing time-to-event analyses, we evaluated differences across demographic groups. RESULTS: The interview response rate was 25.8% (308/1193). Most unvaccinated participants were NH Black and ages 5 to 11 years. Median time from vaccine eligibility to uptake was 236 days for NH Black participants vs. 10 days for NH White participants. Vaccine safety was the top concern among unvaccinated participants. Government and healthcare providers were the most trusted COVID-19 information sources. CONCLUSIONS: Differences in timing of vaccine uptake among respondents and greater vaccine hesitancy among NH Black participants compared to other racial/ethnic groups highlight a need for continued tailored outreach and communication using trusted sources to convey the importance, benefits, and safety of COVID-19 vaccination.

Overdiagnosis of Malaria Illness in an Endemic Setting: A Facility-Based Surveillance Study in Malawi.

In endemic settings where asymptomatic malaria infections are common, malaria infection can complicate fever diagnosis. Factors influencing fever misdiagnosis, including accuracy of malaria rapid diagnostic tests (mRDTs) and the malaria-attributable fraction of fevers (MAF), require further investigation. We conducted facility-based surveillance in Malawi, from January 2012 through December 2013 in settings of high perennial (Chikhwawa), high seasonal (Thoylo), and moderate seasonal (Ndirande) malaria transmission. Consecutive patients presenting to outpatient departments were screened; those with suspected malaria illness were tested by mRDT or routine thick-smear microscopy. Test positivity rates (TPRs), positive predictive value (PPVs) of mRDTs, and MAFs were calculated by site, age, and season. Of 41,471 patients, 10,052 (24.2%) tested positive for malaria. The TPR was significantly greater in Chikhwawa (29.9%; 95% CI, 28.6-30.0) compared with Thyolo (13.2%; 95% CI, 12.5-13.7) and Ndirande (13.1%; 95% CI, 12.2-14.4). The overall PPV was 77.8% (95% CI, 76.8-78.7); it was lowest among infants (69.9%; 95% CI, 65.5-74.2) and highest among school-age children (81.9%; 95% CI, 80.3-83.4). Malaria infection accounted for about 50% of fevers in children younger than 5 years old with microscopy-confirmed Plasmodium falciparum infection, and less than 20% of such fevers in school-age children. Outpatient settings in Malawi had a high burden of malaria illness, but also possible overdiagnosis of malaria illness. Interventions to reduce malaria transmission and rapid testing for other common febrile illness may improve diagnostic clarity among outpatients in malaria endemic settings.