BACKGROUND: Male-to-male sexual transmission continues to account for the greatest proportion of new HIV diagnoses in the United States. However, calculating population-specific surveillance metrics for HIV and other sexually transmitted infections requires regularly updated estimates of the number and proportion of men who have sex with men (MSM) in the United States, which are not collected by census surveys. OBJECTIVE: The purpose of this analysis was to estimate the number and percentage of MSM in the United States from population-based surveys. METHODS: We used data from 5 population-based surveys to calculate weighted estimates of the proportion of MSM in the United States and pooled these estimates using meta-analytic procedures. We estimated the proportion of MSM using sexual behavior-based questions (encompassing anal or oral sex) for 3 recall periods-past 12 months, past 5 years, and lifetime. In addition, we estimated the proportion of MSM using self-reported identity and attraction survey responses. The total number of MSM and non-MSM in the United States were calculated from estimates of the percentage of MSM who reported sex with another man in the past 12 months. RESULTS: The percentage of MSM varied by recall period: 3.3% (95% CI 1.7%-4.9%) indicated sex with another male in the past 12 months, 4.7% (95% CI 0.0%-33.8%) in the past 5 years, and 6.2% (95% CI 2.9%-9.5%) in their lifetime. There were comparable percentages of men who identified as gay or bisexual (3.4%, 95% CI 2.2%-4.6%) or who indicated that they are attracted to other men (4.9%, 95% CI 3.1%-6.7%) based on pooled estimates. Our estimate of the total number of MSM in the United States is 4,230,000 (95% CI 2,179,000-6,281,000) based on the history of recent sexual behavior (sex with another man in the past 12 months). CONCLUSIONS: We calculated the pooled percentage and number of MSM in the United States from a meta-analysis of population-based surveys collected from 2017 to 2021. These estimates update and expand upon those derived from the Centers for Disease Control and Prevention in 2012 by including estimates of the percentage of MSM based on sexual identity and sexual attraction. The percentage and number of MSM in the United States is an important indicator for calculating population-specific disease rates and eligibility for preventive interventions such as pre-exposure prophylaxis.

BACKGROUND: PrEP was approved for HIV prevention in the US in 2012; uptake has been slow. We describe relative equity with the PrEP Equity Ratio (PER), a ratio of PrEP-to-Need Ratios (PnRs). METHODS: We used commercial pharmacy data to enumerate PrEP users by race and ethnicity, sex, and US Census region from 2012 to 2021. We report annual race and ethnicity-, sex-, and region-specific rates of PrEP use and PnR, a metric of PrEP equity, to assess trends. FINDINGS: PrEP use increased for Black, Hispanic and White Americans from 2012 to 2021. By 2021, the rate of PrEP use per population was similar in Black and White populations but slightly lower among Hispanic populations. PnR increased from 2012 to 2021 for all races and ethnicities and regions; levels of PrEP use were inconsistent across regions and highly inequitable by race, ethnicity, and sex. In all regions, PnR was highest for White and lowest for Black people. Inequity in PrEP use by race and ethnicity, as measured by the PER, grew early after availability of PrEP and persisted at a level substantially below equitable PrEP use. INTERPRETATION: From 2012 to 2021, PrEP use increased among Americans, but PrEP equity for Black and Hispanic Americans decreased. The US South lagged all regions in equitable PrEP use. Improved equity in PrEP use will be not only just, but also impactful on the US HIV epidemic; persons most at-risk of acquiring HIV should have the highest levels of access to PrEP. Prevention programs should be guided by PrEP equity, not PrEP equality. FUNDING: National Institutes of Health, Gilead Sciences.

OBJECTIVES: Work is an under-recognized social determinant of health. There is limited research describing US wildland firefighter (WFF) workforce demographics or how to work associates with WFF health behaviors. In this study researchers characterized a WFF cohort and tested hypotheses that WFFs used tobacco, alcohol, and sugar-sweetened beverages (SSBs) differently over the course of the fire season and that different fire crews may exhibit different behavior patterns. METHODS: Researchers collected data in the field with 6 WFF crews during 2 consecutive fire seasons (2018 and 2019). WFF crews completed questionnaires before and after each season. WFFs with an initial preseason questionnaire and at least 1 follow-up questionnaire were included (n = 138). Descriptive statistics summarized WFFs' baseline demographic, employment, and health characteristics. Linear mixed models were used to test for changes in WFFs' substance use over time and assess crew-level differences. A meta-analysis of WFF longitudinal studies' population characteristics was attempted to contextualize baseline findings. RESULTS: WFFs were predominately male, less than 35 yr of age, non-Hispanic White, and had healthy weight. Smokeless tobacco use and binge drinking were prevalent in this cohort (52% and 78%, respectively, among respondents). Longitudinal analyses revealed that during the fire season WFFs' use of tobacco and SSBs increased and the number of days they consumed alcohol decreased. Crew-level associations varied by substance. The meta-analysis was not completed due to cross-study heterogeneity and inconsistent reporting. DISCUSSION: WFF agencies can promote evidence-based substance use prevention and management programs and modify working conditions that may influence WFF stress or substance use.

BACKGROUND: Public health programs varied in ability to reach people with COVID-19 and their contacts to encourage separation from others. For both adult cases of COVID-19 and contacts, we estimated the impact of contact tracing activities on separation behaviors from January, 2020 until March, 2022. METHODS: We used a probability-based panel survey of a nationally representative sample to gather data for estimates and comparisons. RESULTS: An estimated 64,255,351 adults reported a positive SARS-CoV-2 test result; 79.6% isolated for >5 days, 60.2% isolated for >10 days, and 79.2% self-notified contacts. 24,057,139 (37.7%) completed a case investigation and 46.2% reported contacts to health officials. More adults who completed a case investigation isolated than adults who did not (>5 days, 82.6%; >10 days, 69.8% versus >5 days, 78.2% and >10 days 54.8%; p-values for both measures <0.05).84,946,636 adults were a contact to a COVID-19 case; 73.1% learned of their exposure directly from a case; 49.4% quarantined for >5 days, 18.7% quarantined for >14 days, and 13.5% completed a contact tracing call. More who completed a contact tracing call quarantined than those who did not (>5 days, 61.2%; >14 days, 25.2% versus >5 days, 48.5%; >14 days, 18.0%; p-values for both measures <0.05). CONCLUSIONS: Engagement in contact tracing positively correlated with isolation and quarantine. However, most adults with COVID-19 isolated and self-notified contacts regardless of whether the public health workforce was able to reach them. Identifying and reaching contacts was challenging, and limited the ability to promote quarantining, and testing.

Heat stress is associated with workplace injuries, likely through a combination of fatigue, reduced cognitive function, and thermal discomfort. The purpose of this study was to evaluate four cognitive tasks for sensitivity to heat stress. Eight participants performed treadmill exercise followed by assessments of serial reaction time (RT), Stroop effect, verbal delayed memory, and continuous performance working memory in an environmental chamber. A control (21.1 °C) trial, and "Hot 1" and "Hot 2" (both 37.8 °C) trials were run sequentially on two separate days to evaluate the four cognitive tasks. Heat strain (comparing Hot 1 and Hot 2 with the control trial) resulted in impairments in the serial RT test response and Stroop accuracy. Delayed memory was impacted only in the Hot 2 trial compared with the control trial. Given the demonstrated impact of heat on cognitive processes relevant to workers' real-world functioning in the workplace, understanding how to assess and monitor vigilant attention in the workplace is essential.

SARS-CoV-2, the virus that causes COVID-19, can spread rapidly in prisons and can be introduced by staff members and newly transferred incarcerated persons (1,2). On September 28, 2020, the Wisconsin Department of Health Services (DHS) contacted CDC to report a COVID-19 outbreak in a state prison (prison A). During October 6-20, a CDC team investigated the outbreak, which began with 12 cases detected from specimens collected during August 17-24 from incarcerated persons housed within the same unit, 10 of whom were transferred together on August 13 and under quarantine following prison intake procedures (intake quarantine). Potentially exposed persons within the unit began a 14-day group quarantine on August 25. However, quarantine was not restarted after quarantined persons were potentially exposed to incarcerated persons with COVID-19 who were moved to the unit. During the subsequent 8 weeks (August 14-October 22), 869 (79.4%) of 1,095 incarcerated persons and 69 (22.6%) of 305 staff members at prison A received positive test results for SARS-CoV-2. Whole genome sequencing (WGS) of specimens from 172 cases among incarcerated persons showed that all clustered in the same lineage; this finding, along with others, demonstrated that facility spread originated with the transferred cohort. To effectively implement a cohorted quarantine, which is a harm reduction strategy for correctional settings with limited space, CDC's interim guidance recommendation is to serial test cohorts, restarting the 14-day quarantine period when a new case is identified (3). Implementing more effective intake quarantine procedures and available mitigation measures, including vaccination, among incarcerated persons is important to controlling transmission in prisons. Understanding and addressing the challenges faced by correctional facilities to implement medical isolation and quarantine can help reduce and prevent outbreaks.

OBJECTIVE: This study characterizes physiological measures of heat exposure among U.S. underground miners. METHODS: Core body temperature measured by using ingestible sensors during subjects' normal work shifts was categorized into four temperature zones: <37.5 degrees C, 37.5 degrees C to <38 degrees C, 38 degrees C to <38.5 degrees C, and >/=38.5 degrees C. RESULTS: On average, subjects changed temperature zones 13.8 times per shift. Temperatures increased above the recommended limit of 38 degrees C nearly 5 times per shift for an average of 26 minutes each episode. CONCLUSIONS: Unlike previous heat stress research that reported only maximum and mean temperature measurements, this analysis demonstrates a dynamic pattern of physiologic heat strain, with core body temperatures changing frequently and exceeding the 38 degrees C limit multiple times per shift. Further research is needed on the impact of multiple short-term, intermittent heat exposures on miners.

INTRODUCTION: From 2012 through 2015, the Centers for Disease Control and Prevention (CDC) provided funding to 5 health departments for demonstration projects using HIV surveillance data to link people with newly diagnosed HIV to care. We assessed how well these health departments established linkage to care, how the demonstration projects helped them with this work, and if they sustained these activities after CDC funding ended. MATERIALS AND METHODS: We obtained quantitative and qualitative data on linkage-to-care activities from health department communications and progress reports submitted to CDC. We calculated and combined linkage-to-care results for the 5 health departments, and we compared these results with the combined linkage-to-care results for 61 health departments that received CDC funding for routine HIV prevention activities (eg, HIV testing, linkage to and reengagement in HIV care, HIV partner services) and for the same 5 health departments when they used only routine HIV prevention activities for linkage to care. RESULTS: Of 1269 people with a new HIV diagnosis at the 5 health departments, 1124 (89%) were linked to care, a result that exceeded the 2010-2015 National HIV/AIDS Strategy goal (85%), the CDC Funding Opportunity Announcement performance standard (80%), and combined results for the 61 health departments (63%) and the same 5 health departments (66%) using routine HIV prevention activities. Benefits of the projects were improved collaboration and coordination and more accurate, up-to-date surveillance data. All health departments continued linkage-to-care activities after funding ended. PRACTICE IMPLICATIONS: Using HIV surveillance data to link people with HIV to care resulted in substantial clinical and public health benefits. Our observations underscore the importance of collaboration among medical providers, public health staff members, community-based organizations, and people with HIV to ensure the best possible clinical and public health outcomes.