Plague is a rare, potentially fatal flea-borne zoonosis endemic in the western United States. A previous model described interannual variation in human cases based on temperature and lagged precipitation. We recreated this model in northeastern Arizona (1960-1997) to evaluate its capacity to predict recent cases (1998-2022). In recreating the original model, we found that future instead of concurrent temperature had inadvertently been used for the presented fit. Prediction from our revised models with lagged precipitation and temporally plausible temperature relationships aligned with low observed cases in 1998-2022. Elevated precipitation associated with high cases in historical data (>6 inches combined precipitation over two previous springs) was only observed once in the last quarter century, so we could not assess if these conditions were reliably associated with elevated (four or more) human plague cases. Observed weather conditions were similar to those previously associated with low (fewer than or equal to two) case counts, suggesting "baseline" conditions in the last quarter century.

INTRODUCTION: Despite progress in systemic lupus erythematosus (SLE) treatment, challenges persist in medication adherence due to side effects and costs. Precision nutrition, particularly adjusting fatty acid intake, offers a cost-effective strategy for enhancing SLE management. Prior research, including our own, indicates that increased consumption of omega-3 polyunsaturated fatty acids (PUFAs) correlates with improved outcomes in SLE patients. Here we build upon these findings by investigating associations between serum fatty acids-grouped as PUFAs, monounsaturated fatty acids (MUFAs), and saturated fatty acids (SFAs)-and lupus activity, pain, and sleep disturbance. METHODS: Using data from 418 participants with SLE in the Michigan Lupus Epidemiology and Surveillance (MILES) Cohort, we examined associations between serum levels of 25 fatty acids determined by GC-MS and patient-reported outcomes. Disease activity, pain, and sleep quality were assessed using standardized questionnaires. Generalized additive models and partial residual plots were utilized to examine the linearity of fatty acid effects. Variable selection was performed using Least Absolute Shrinkage and Selection Operator (LASSO), followed by multiple linear regression adjusting for sociodemographic factors. RESULTS: Findings indicated favorable associations between ω-3 PUFAs-and, to a lesser extent, ω-6 PUFAs-and patient-reported outcomes, while MUFAs and SFAs showed unfavorable associations. Docosahexaenoic acid (DHA), an omega-3 PUFA, exhibited the most robust favorable associations across all outcomes. Additionally, the omega-3 α-linolenic acid (ALA) was linked to reduced pain, whereas eicosapentaenoic acid (EPA), another omega-3, was associated with worsened disease activity and pain. Among omega-6 PUFAs, dihomo-γ-linolenic acid (DGLA) was favorably associated with disease activity, while the omega-9 PUFA Mead acid was linked to increased pain. DISCUSSION: These findings underscore the prospect that increased tissue levels of long-chain omega-3 PUFAs, particularly DHA, are favorably associated with SLE outcomes. Although further research is needed to establish causal relationships, existing evidence supports the role of omega-3 PUFAs in managing cardiovascular and chronic kidney disease, common SLE comorbidities. Most study participants exhibited low omega-3 PUFA status, suggesting substantial potential for improvement through targeted dietary interventions and supplementation. This study supports a potential role for precision nutrition in comprehensive SLE management, considering the impact of PUFAs, SFAs and MUFAs.

Tularemia is a rare nationally notifiable zoonosis, caused by the tier-1 select agent Francisella tularensis, that has been reported from all U.S. states except Hawaii. Clinical manifestations typically include fever and localized symptoms that vary by route of infection. The case fatality rate of tularemia is typically <2% but can be higher depending on clinical manifestation and infecting strain. Tularemia is treatable with antibiotics. During 2011-2022, a total of 47 states reported 2,462 tularemia cases, but four central states (Arkansas, Kansas, Missouri, and Oklahoma) accounted for 50% of all reported cases. Incidence was highest among children aged 5-9 years (0.083 per 100,000 population) and adult males aged 65-84 years (range = 0.133-0.161). Incidence among American Indian or Alaska Native persons (0.260) was approximately five times that among White persons (0.057). The average annual incidence of tularemia in the United States during 2011-2022 (0.064) was 56% higher than that reported during 2001-2010 (0.041), largely resulting from increased reporting of probable cases. These findings might reflect an actual increase in human infection or improved case detection amid changes in commercially available laboratory tests during this period. Reducing tularemia incidence will require tailored prevention education; mitigating morbidity and mortality will require health care provider education, particularly among providers serving tribal populations, regarding early and accurate diagnosis and treatment.

Tick-borne diseases are commonly reported in the United States, but frequency of tick bites and care-seeking behaviors following tick bites are poorly understood. We used nationally representative survey data to describe the frequency of tick bites among people living in the United States and how often, where, and why care-seeking associated with tick bites occurs. We found that over 31 million people (nearly 1 in 10) living in the United States might experience a tick bite each year and highlight regional trends in associated care-seeking behaviors. These findings emphasize the need for effective tick bite prevention education and regionally tailored healthcare provider recommendations for management of tick-borne diseases.

Bartonella quintana infection can cause severe disease that includes clinical manifestations such as endocarditis, chronic bacteremia, and vasoproliferative lesions of the skin and viscera. B. quintana bacteria is transmitted by the human body louse (Pediculus humanus corporis) and is associated with homelessness and limited access to hygienic services. We report B. quintana infection in 2 kidney transplant recipients in the United States from an organ donor who was experiencing homelessness. One infection manifested atypically, and the other was minimally symptomatic; with rapid detection, both recipients received timely treatment and recovered. B. quintana was identified retrospectively in an archived donor hematoma specimen, confirming the transmission link. Information about the organ donor's housing status was critical to this investigation. Evaluation for B. quintana infection should be considered for solid organ transplant recipients who receive organs from donors with a history of homelessness or of body lice infestation.

In the 40 years since Steere and colleagues first described Lyme disease, the illness has increased in incidence and distribution to become the most common vector-borne disease in the United States. Public health officials have developed, implemented, and revised surveillance systems to describe and monitor the condition. Much has been learned about the epidemiology of the illness, despite practical and logistical constraints that have encumbered the collection and interpretation of surveillance data. Future development of automated data collection from electronic health records as a source of surveillance and clinical information will address practical challenges and help answer ongoing questions about complications and persistent symptoms. Robust surveillance will be essential to monitor the effectiveness and safety of future vaccines and other preventive measures.

Lyme disease, a tickborne zoonosis caused by certain species of Borrelia spirochetes, is the most common vectorborne disease in the United States. Approximately 90% of all cases are reported from 15 high-incidence jurisdictions in the Northeast, mid-Atlantic, and upper-Midwest regions. After the implementation of a revised surveillance case definition in 2022, high-incidence jurisdictions report cases based on laboratory evidence alone, without need for additional clinical information. In 2022, 62,551 Lyme disease cases were reported to CDC, 1.7 times the annual average of 37,118 cases reported during 2017-2019. Annual incidence increased most in older age groups, with incidence among adults aged ≥65 years approximately double that during 2017-2019. The sharp increase in reported Lyme disease cases in 2022 likely reflects changes in surveillance methods rather than change in disease risk. Although these changes improve standardization of surveillance across jurisdictions, they preclude detailed comparison with historical data.

Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted by hematophagous reduviid bugs within the subfamily Triatominae. These vectors take blood meals from a wide range of hosts, and their feeding behaviors have been used to investigate the ecology and epidemiology of T. cruzi. In this study we describe two PCR-based methodologies that amplify a fragment of the 16S mitochondrial rDNA, aimed to improve the identification of blood meal sources for Triatoma infestans: a.--Sequence analyses of two heminested PCRs that allow the identification of mammalian and avian species, and b.--restriction fragment length polymorphism (RFLP) analysis from the mammalian PCR to identify and differentiate multi-host blood meals. Findings from both methodologies indicate that host DNA could be detected and the host species identified in samples from laboratory reared and field collected triatomines. The implications of this study are two-fold. First, these methods can be used in areas where the fauna diversity and feeding behavior of the triatomines are unknown. Secondly, the RFLP method led to the identification of multi-host DNA from T. infestans gut contents, enhancing the information provided by this assay. These tools are important contributions for ecological and epidemiological studies of vector-borne diseases.

BACKGROUND: Tularemia, a potentially fatal zoonosis caused by Francisella tularensis, has been reported from nearly all US states. Information on relative effectiveness of various antimicrobials for treatment of tularemia is limited, particularly for newer classes such as fluoroquinolones. METHODS: Data on clinical manifestations, antimicrobial treatment, and illness outcome of patients with tularemia are provided voluntarily through case report forms to the US Centers for Disease Control and Prevention by state and local health departments. We summarized available demographic and clinical information submitted during 2006-2021 and evaluated survival according to antimicrobial treatment. We grouped administered antimicrobials into those considered effective for treatment of tularemia (aminoglycosides, fluoroquinolones, and tetracyclines) and those with limited efficacy. Logistic regression models with a bias-reduced estimation method were used to evaluate associations between antimicrobial treatment and survival. RESULTS: Case report forms were available for 1163 US patients with tularemia. Francisella tularensis was cultured from a clinical specimen (eg, blood, pleural fluid) in approximately half of patients (592; 50.9%). Nearly three-quarters (853; 73.3%) of patients were treated with a high-efficacy antimicrobial. A total of 27 patients (2.3%) died. After controlling for positive culture as a proxy for illness severity, use of aminoglycosides, fluoroquinolones, and tetracyclines was independently associated with increased odds of survival. CONCLUSIONS: Most US patients with tularemia received high-efficacy antimicrobials; their use was associated with improved odds of survival regardless of antimicrobial class. Our findings provide supportive evidence that fluoroquinolones are an effective option for treatment of tularemia.

In rural Uganda, many people who are ill consult traditional healers prior to visiting the formal healthcare system. Traditional healers provide supportive care for common illnesses, but their care may delay diagnosis and management of illnesses that can increase morbidity and mortality, hinder early detection of epidemic-prone diseases, and increase occupational risk to traditional healers. We conducted open-ended, semi-structured interviews with a convenience sample of 11 traditional healers in the plague-endemic West Nile region of northwestern Uganda to assess their knowledge, practices, and attitudes regarding plague and the local healthcare system. Most were generally knowledgeable about plague transmission and its clinical presentation and expressed willingness to refer patients to the formal healthcare system. We initiated a public health outreach program to further improve engagement between traditional healers and local health centers to foster trust in the formal healthcare system and improve early identification and referral of patients with plaguelike symptoms, which can reflect numerous other infectious and noninfectious conditions. During 2010-2019, 65 traditional healers were involved in the outreach program; 52 traditional healers referred 788 patients to area health centers. The diagnosis was available for 775 patients; malaria (37%) and respiratory tract infections (23%) were the most common diagnoses. One patient had confirmed bubonic plague. Outreach to improve communication and trust between traditional healers and local healthcare settings may result in improved early case detection and intervention not only for plague but also for other serious conditions.

Susceptibility to and infection with SARS-CoV-2 in companion animals has been well-documented throughout the COVID-19 pandemic. Surveillance for the virus in dogs has largely been focused on household pets; however, other canine populations may also be impacted. We partnered with a local veterinary hospital with a high working dog patient volume to conduct viral and neutralizing antibody testing in working dogs and identify potential risk factors in the dog's work and home environments. Surveillance of SARS-CoV-2 in law enforcement and security working dogs in Arizona found 24.81% (32/129) of dogs to be seropositive. Thirteen dogs presenting with clinical signs or with reported exposure to COVID-19 in the 30 days prior to sample collection were also tested by PCR; all samples were negative. 90.7% (n = 117) of dogs were reported to be asymptomatic or have no change in performance at the time of sampling. Two dogs (1.6%) had suspected anosmia as reported by their handlers; one of which was seropositive. Known exposure to the dog's COVID-19 positive handler or household member was identified as a significant risk factor. Demographics factors including sex, altered status, and type of work were not associated with canine seropositivity. Further work is warranted to understand the impact of SARS-CoV-2 and other infectious diseases in working dogs.

Yersinia pestis, the bacterial causative agent of plague, remains an important threat to human health. Plague is a rodent-borne disease that has historically shown an outstanding ability to colonize and persist across different species, habitats, and environments while provoking sporadic cases, outbreaks, and deadly global epidemics among humans. Between September and November 2017, an outbreak of urban pneumonic plague was declared in Madagascar, which refocused the attention of the scientific community on this ancient human scourge. Given recent trends and plague's resilience to control in the wild, its high fatality rate in humans without early treatment, and its capacity to disrupt social and healthcare systems, human plague should be considered as a neglected threat. A workshop was held in Paris in July 2018 to review current knowledge about plague and to identify the scientific research priorities to eradicate plague as a human threat. It was concluded that an urgent commitment is needed to develop and fund a strong research agenda aiming to fill the current knowledge gaps structured around 4 main axes: (i) an improved understanding of the ecological interactions among the reservoir, vector, pathogen, and environment; (ii) human and societal responses; (iii) improved diagnostic tools and case management; and (iv) vaccine development. These axes should be cross-cutting, translational, and focused on delivering context-specific strategies. Results of this research should feed a global control and prevention strategy within a "One Health" approach.

Vazquez et al. report a convincing case of relapsing fever caused by Borrelia lonestari bacteria (1). This discovery highlights an existing problem with the nomenclature for relapsing fever. | | Tick-borne relapsing fever (TBRF) is the name given to illness caused by several genospecies of relapsing fever Borrelia bacteria, all of which are transmitted by argasid (soft) ticks (2). The limitations of this term became apparent after discovery of B. miyamotoi, a related genospecies that is transmitted by ixodid (hard) ticks and causes illness that differs epidemiologically from traditional TBRF (3). Consequently, 3 terms are used in the scientific literature to describe B. miyamotoi infections: Borrelia miyamotoi disease, hard tick–borne relapsing fever, and hard tick relapsing fever (3,4). In the interest of standard nomenclature, it is worth considering objectively the relative merits of each term.

Improving ventilation has been one of several COVID-19 prevention strategies implemented by kindergarten through grade 12 (K-12) schools to stay open for safe in-person learning. Because transmission of SARS-CoV-2 occurs through inhalation of infectious viral particles, it is important to reduce the concentration of and exposure time to infectious aerosols (1-3). CDC examined reported ventilation improvement strategies among U.S. K-12 public school districts using telephone survey data collected during August-December 2022. Maintaining continuous airflow through school buildings during active hours was the most frequently reported strategy by school districts (50.7%); 33.9% of school districts reported replacement or upgrade of heating, ventilation, and air conditioning (HVAC) systems; 28.0% reported installation or use of in-room air cleaners with high-efficiency particulate air (HEPA) filters; and 8.2% reported installation of ultraviolet (UV) germicidal irradiation (UVGI) devices, which use UV light to kill airborne pathogens, including bacteria and viruses. School districts in National Center for Education Statistics (NCES) city locales, the West U.S. Census Bureau region, and those designated by U.S. Census Bureau Small Area Income Poverty Estimates (SAIPE) as high-poverty districts reported the highest percentages of HVAC system upgrades and HEPA-filtered in-room air cleaner use, although 28%-60% of all responses were unknown or missing. Federal funding remains available to school districts to support ventilation improvements. Public health departments can encourage K-12 school officials to use available funding to improve ventilation and help reduce transmission of respiratory diseases in K-12 settings.

Emergency medical service (EMS) providers have a higher potential exposure to infectious agents than the general public (Nguyen et al., 2020, "Risk of COVID-19 Among Frontline Healthcare Workers and the General Community: A Prospective Cohort Study," Lancet Pub. Health, 5(9), pp. e475-e483; Brown et al., 2021, "Risk for Acquiring Coronavirus Disease Illness Among Emergency Medical Service Personnel Exposed to Aerosol-Generating Procedures," Emer. Infect. Disease J., 27(9), p. 2340). The use of protective equipment may reduce, but does not eliminate their risk of becoming infected as a result of these exposures. Prehospital environments have a high risk of disease transmission exposing EMS providers to bioaerosols and droplets from infectious patients. Field intubation procedures may be performed causing the generation of bioaerosols, thereby increasing the exposure of EMS workers to pathogens. Additionally, ambulances have a reduced volume compared to a hospital treatment space, often without an air filtration system, and no control mechanism to reduce exposure. This study evaluated a containment plus filtration intervention for reducing aerosol concentrations in the patient module of an ambulance. Aerosol concentration measurements were taken in an unoccupied research ambulance at National Institute for Occupational Safety and Health (NIOSH) Cincinnati using a tracer aerosol and optical particle counters (OPCs). The evaluated filtration intervention was a containment pod with a high efficiency particulate air (HEPA)-filtered extraction system that was developed and tested based on its ability to contain, capture, and remove aerosols during the intubation procedure. Three conditions were tested (1) baseline (without intervention), (2) containment pod with HEPA-1, and (3) containment pod with HEPA-2. The containment pod with HEPA-filtered extraction intervention provided containment of 95% of the total generated particle concentration during aerosol generation relative to the baseline condition, followed by rapid air cleaning within the containment pod. This intervention can help reduce aerosol concentrations within ambulance patient modules while performing aerosol-generating procedures.

Many respiratory diseases, including COVID-19, can be spread by aerosols expelled by infected people when they cough, talk, sing, or exhale. Exposure to these aerosols indoors can be reduced by portable air filtration units (air cleaners). Homemade or Do-It-Yourself (DIY) air filtration units are a popular alternative to commercially produced devices, but performance data is limited. Our study used a speaker-audience model to examine the efficacy of two popular types of DIY air filtration units, the Corsi-Rosenthal cube and a modified Ford air filtration unit, in reducing exposure to simulated respiratory aerosols within a mock classroom. Experiments were conducted using four breathing simulators at different locations in the room, one acting as the respiratory aerosol source and three as recipients. Optical particle spectrometers monitored simulated respiratory aerosol particles (0.3-3 μm) as they dispersed throughout the room. Using two DIY cubes (in the front and back of the room) increased the air change rate as much as 12.4 over room ventilation, depending on filter thickness and fan airflow. Using multiple linear regression, each unit increase of air change reduced exposure by 10%. Increasing the number of filters, filter thickness, and fan airflow significantly enhanced the air change rate, which resulted in exposure reductions of up to 73%. Our results show DIY air filtration units can be an effective means of reducing aerosol exposure. However, they also show performance of DIY units can vary considerably depending upon their design, construction, and positioning, and users should be mindful of these limitations.

BACKGROUND: The purpose of this study was to determine the effects on smoking and other outcomes of assigning cigarettes with reduced nicotine and/or no menthol to female menthol smokers. METHODS: Non-treatment seeking female menthol smokers (N=263) participated in a randomized controlled trial in which levels of menthol and nicotine in cigarettes were manipulated using experimental cigarettes. After a baseline period, participants were assigned to the following conditions for 6 weeks: 1) their own brand of cigarette (conventional nicotine with menthol); 2) a conventional nicotine cigarette with no menthol; 3) a cigarette with reduced nicotine (RNC) with menthol; or 4) a RNC cigarette and no menthol. Participants then returned to using their own brand and were followed for another 6 weeks. Outcomes included cigarettes smoked, biomarkers of exposure, and dependence measures. RESULTS: Results indicated that, after an initial increase, rates of smoking of all three experimental cigarettes were at or below baseline rates of smoking of one's own brand. Levels of biomarkers also decreased during the experimental phase, but rebounded somewhat after participants resumed smoking their own brand. There was evidence that overall amount of smoking decreased similarly among women switched to non-menthol and/or RNC cigarettes. CONCLUSIONS: These results suggest that no detrimental effect will occur in nicotine or toxicant exposure levels with a ban on characterizing menthol and/or a product standard on nicotine content in cigarettes. IMPLICATIONS: The implication of this work is that there would be no risk to women menthol smokers associated with regulations restricting nicotine and eliminating menthol in cigarettes.

Lyme disease is the most common vector-borne illness in North America and Europe. The etiologic agent, Borrelia burgdorferi sensu lato, is transmitted to humans by certain species of Ixodes ticks, which are found widely in temperate regions of the Northern hemisphere. Clinical features are diverse but death is rare. The risk of human infection is determined by the distribution and abundance of vector ticks, ecologic factors influencing tick infection rates, and human behaviors that promote tick bite. Rates of infection are highest among children aged 5 to 15 years and adults aged more than 50 years. In the northeastern United States where disease is most common, exposure occurs primarily in areas immediately around the home. Knowledge of disease epidemiology is important for patient management and proper diagnosis.

This case study describes how we paired free SARS-CoV-2 rapid antigen testing with on-site case investigation and contact tracing at a drive-through site in an underresourced area of Salt Lake City. Residents of this area had lower rates of employment and health insurance and higher rates of poverty than in the Utah general population. People were given an option to remain on-site and wait until their test results were ready. If a vehicle occupant received a positive test result, the case investigation occurred on-site; contact tracing with the other vehicle occupants was also initiated. People were provided resources to support isolation and quarantine. Bilingual staff who spoke Spanish were incorporated into the workflow. From December 2020 through April 2021, public health staff administered 39 587 rapid tests; 4094 people received a positive test result and 1133 stayed for on-site case investigation. More than half (60.5%) of people with a positive test result who agreed to stay for on-site case investigation were Hispanic or self-reported belonging to a non-Hispanic racial minority group (American Indian/Alaska Native, Asian, Black or African American, Native Hawaiian or Other Pacific Islander, or other racial identities). Pairing rapid antigen testing with on-site case investigation and contact tracing is feasible and improved the timeliness of case investigation by ≥1 day. On-site vaccination services were later integrated. Future emergency responses might consider assisting underresourced communities with on-site services that provide convenient and accessible public health interventions. By providing dependable and reliable services, we were able to achieve buy-in and become a consistent resource for those in the community.

Zika virus (ZIKV) is a mosquito-borne flavivirus that causes congenital defects. Sexual transmission of ZIKV was confirmed in a recent epidemic; however, mechanisms behind ZIKV infection and persistence in the male reproductive tract are unknown. Previously, we found that ∼33% of men with symptomatic ZIKV infections shed ZIKV RNA in semen, and some men shed ZIKV RNA for >3 months. Here, we evaluated the semen of 49 ZIKV-infected men to identify immune factors correlating with long-term ZIKV shedding in semen and ZIKV-infected cell types in semen. We found prolonged ZIKV RNA shedding in semen was associated with male reproductive tract inflammation, indicated by higher leukocyte counts and inflammatory cytokine concentrations in semen of long-term versus short-term shedders. Additionally, we found ZIKV RNA in seminal leukocytes and epithelial cells. This study of human semen from ZIKV-infected men provides critical insights into impacts of ZIKV on male reproductive tract health.

Lyme disease, the most commonly reported vector-borne disease in the United States, is caused by the bacteria Borrelia burgdorferi and is transmitted through the bite of an infected blacklegged tick. In the absence of a licensed vaccine, the prevention of Lyme disease relies heavily on limiting tick exposure. Methods for limiting tick exposure include personal protection measures such as repellent use, wearing protective clothing, avoiding areas where ticks may be present, bathing after exposure to tick habitat and performing regular tick checks. Public health officials typically recommend all these personal protection measures; however, there is limited evidence to promote one behaviour or practice over another. The focus of this article is to review available literature that examines the effectiveness of recommended personal protection measures to prevent Lyme and other Ixodes-transmitted diseases in humans. Articles included in this review were identified through Google Scholar and PubMed searches using specific search terms. We identified over 56,000 articles using Google Scholar and PubMed searches. Of those, 16 studies fit our criteria for inclusion and were reviewed in their entirety. Among the personal protection measures evaluated, no intervention was predominantly or consistently effective across studies, demonstrating that, currently, there is no single best method for primary prevention of Ixodes-transmitted diseases in the United States. Frequently recommended practices such as tick checks, repellent use and protective clothing had mixed results across studies. Study design differences limited comparability among studies, and sample sizes for these studies may have been too small to detect statistically significant results even if a prevention method was effective. Though many of the reviewed personal protection measures are frequently recommended to the public, limited evidence demonstrates their ability to prevent tick-borne disease. Additional standardized studies are needed to evaluate personal protection measures.

Effective COVID-19 prevention in kindergarten through grade 12 (K-12) schools requires multicomponent prevention strategies in school buildings and school-based transportation, including improving ventilation (1). Improved ventilation can reduce the concentration of infectious aerosols and duration of potential exposures (2,3), is linked to lower COVID-19 incidence (4), and can offer other health-related benefits (e.g., better measures of respiratory health, such as reduced allergy symptoms) (5). Whereas ambient wind currents effectively dissipate SARS-CoV-2 (the virus that causes COVID-19) outdoors,* ventilation systems provide protective airflow and filtration indoors (6). CDC examined reported ventilation improvement strategies among a nationally representative sample of K-12 public schools in the United States using wave 4 (February 14-March 27, 2022) data from the National School COVID-19 Prevention Study (NSCPS) (420 schools), a web-based survey administered to school-level administrators beginning in summer 2021.(†) The most frequently reported ventilation improvement strategies were lower-cost strategies, including relocating activities outdoors (73.6%), inspecting and validating existing heating, ventilation and air conditioning (HVAC) systems (70.5%), and opening doors (67.3%) or windows (67.2%) when safe to do so. A smaller proportion of schools reported more resource-intensive strategies such as replacing or upgrading HVAC systems (38.5%) or using high-efficiency particulate air (HEPA) filtration systems in classrooms (28.2%) or eating areas (29.8%). Rural and mid-poverty-level schools were less likely to report several resource-intensive strategies. For example, rural schools were less likely to use portable HEPA filtration systems in classrooms (15.6%) than were city (37.7%) and suburban schools (32.9%), and mid-poverty-level schools were less likely than were high-poverty-level schools to have replaced or upgraded HVAC systems (32.4% versus 48.8%). Substantial federal resources to improve ventilation in schools are available.(§) Ensuring their use might reduce SARS-CoV-2 transmission in schools. Focusing support on schools least likely to have resource-intensive ventilation strategies might facilitate equitable implementation of ventilation improvements.

There is strong evidence associating the indoor environment with transmission of SARS-CoV-2, the virus that causes COVID-19. SARS-CoV-2 can spread by exposure to droplets and very fine aerosol particles from respiratory fluids that are released by infected persons. Layered mitigation strategies, including but not limited to maintaining physical distancing, adequate ventilation, universal masking, avoiding overcrowding, and vaccination, have shown to be effective in reducing the spread of SARS-CoV-2 within the indoor environment. Here, we examine the effect of mitigation strategies on reducing the risk of exposure to simulated respiratory aerosol particles within a classroom-style meeting room. To quantify exposure of uninfected individuals (Recipients), surrogate respiratory aerosol particles were generated by a breathing simulator with a headform (Source) that mimicked breath exhalations. Recipients, represented by three breathing simulators with manikin headforms, were placed in a meeting room and affixed with optical particle counters to measure 0.3-3 µm aerosol particles. Universal masking of all breathing simulators with a 3-ply cotton mask reduced aerosol exposure by 50% or more compared to scenarios with simulators unmasked. While evaluating the effect of Source placement, Recipients had the highest exposure at 0.9 m in a face-to-face orientation. Ventilation reduced exposure by approximately 5% per unit increase in air change per hour (ACH), irrespective of whether increases in ACH were by the HVAC system or portable HEPA air cleaners. The results demonstrate that mitigation strategies, such as universal masking and increasing ventilation, reduce personal exposure to respiratory aerosols within a meeting room. While universal masking remains a key component of a layered mitigation strategy of exposure reduction, increasing ventilation via system HVAC or portable HEPA air cleaners further reduces exposure.

We read with concern the letter by Hurlburt et al Reference Hurlburt, DeKleer and Bryce1 proposing revisions to the recommended room air clearance times for infectious aerosols in healthcare facilities. We believe that the calculations performed to justify the changes are based on flawed assumptions and an erroneous calculation. Experimental data on the survival of airborne SARS-CoV-2 virus and the dynamics of room ventilation do not support their conclusions.

Surveys indicate US residents spent more time outdoors in 2020 than in 2019, but fewer tick bite-related emergency department visits and Lyme disease laboratory tests were reported. Despite ongoing exposure, Lyme disease case reporting for 2020 might be artificially reduced due to coronavirus disease-associated changes in healthcare-seeking behavior.

The most common tickborne disease in both Europe and the United States, Lyme borreliosis (LB) can range from mild to severe forms of illness. If not recognized and treated during early localized disease, which typically presents as a large, slowly expanding erythema migrans rash, the Borrelia spirochete can disseminate, causing diverse pathologies including cranial neuritis, carditis, meningitis, and acute arthritis. Although most patients with LB recover completely when treated with antibiotics, some report persistent symptoms of fatigue, pain, or cognitive impairment lasting months or even years [1]. Because these symptoms are also ubiquitous in the general population, drawing a clear association between these lingering symptoms and treated LB has remained elusive.

With this survey, we investigated healthcare-associated invasive mold infection (HA-IMI) surveillance and air sampling practices in US acute-care hospitals. More than half of surveyed facilities performed HA-IMI surveillance and air sampling. HA-IMI surveillance was more commonly performed in academic versus nonacademic facilities. HA-IMI case definitions and sampling strategies varied widely among respondents.

This report provides CDC recommendations to U.S. health care providers regarding treatment, pre-exposure prophylaxis, and postexposure prophylaxis of plague. Yersinia pestis, the bacterium that causes plague, leads to naturally occurring disease in the United States and other regions worldwide and is recognized as a potential bioterrorism weapon. A bioweapon attack with Y. pestis could potentially infect thousands, requiring rapid and informed decision making by clinicians and public health agencies. The U.S. government stockpiles a variety of medical countermeasures to mitigate the effects of a bioterrorism attack (e.g., antimicrobials, antitoxins, and vaccines) for which the 21st Century Cures Act mandates the development of evidence-based guidelines on appropriate use. Guidelines for treatment and postexposure prophylaxis of plague were published in 2000 by a nongovernmental work group; since then, new human clinical data, animal study data, and U.S. Food and Drug Administration approvals of additional countermeasures have become available. To develop a comprehensive set of updated guidelines, CDC conducted a series of systematic literature reviews on human treatment of plague and other relevant topics to collect a broad evidence base for the recommendations in this report. Evidence from CDC reviews and additional sources were presented to subject matter experts during a series of forums. CDC considered individual expert input while developing these guidelines, which provide recommended best practices for treatment and prophylaxis of human plague for both naturally occurring disease and following a bioterrorism attack. The guidelines do not include information on diagnostic testing, triage decisions, or logistics involved in dispensing medical countermeasures. Clinicians and public health officials can use these guidelines to prepare their organizations, hospitals, and communities to respond to a plague mass-casualty event and as a guide for treating patients affected by plague.

SARS-CoV-2, the virus that causes COVID-19, can be spread by exposure to droplets and aerosols of respiratory fluids that are released by infected persons when they cough, sing, talk, or exhale. To reduce indoor transmission of SARS-CoV-2 between persons, CDC recommends measures including physical distancing, universal masking (the use of face masks in public places by everyone who is not fully vaccinated), and increased room ventilation (1). Ventilation systems can be supplemented with portable high efficiency particulate air (HEPA) cleaners* to reduce the number of infectious particles in the air and provide enhanced protection from transmission between persons (2); two recent reports found that HEPA air cleaners in classrooms could reduce overall aerosol particle concentrations by ≥80% within 30 minutes (3,4). To investigate the effectiveness of portable HEPA air cleaners and universal masking at reducing exposure to exhaled aerosol particles, the investigation team used respiratory simulators to mimic a person with COVID-19 and other, uninfected persons in a conference room. The addition of two HEPA air cleaners that met the Environmental Protection Agency (EPA)-recommended clean air delivery rate (CADR) (5) reduced overall exposure to simulated exhaled aerosol particles by up to 65% without universal masking. Without the HEPA air cleaners, universal masking reduced the combined mean aerosol concentration by 72%. The combination of the two HEPA air cleaners and universal masking reduced overall exposure by up to 90%. The HEPA air cleaners were most effective when they were close to the aerosol source. These findings suggest that portable HEPA air cleaners can reduce exposure to SARS-CoV-2 aerosols in indoor environments, with greater reductions in exposure occurring when used in combination with universal masking.

Lyme disease is the most common vector-borne disease in the United States and is characterized by a bimodal age distribution and male predominance. We examined trends in reported cases during a 25-year period to describe changes in the populations most affected by Lyme disease in the United States. We examined demographic characteristics of people with confirmed cases of Lyme disease reported to the Centers for Disease Control and Prevention during 1992-2016 through the National Notifiable Diseases Surveillance System. We grouped cases into 5-year periods (1992-1996, 1997-2001, 2002-2006, 2007-2011, 2012-2016). We calculated the average annual incidence by age and sex and used incidence rate ratios (IRRs) to describe changes in Lyme disease incidence by age and sex over time. We converted patient age at time of illness into patient birth year to ascertain disease patterns according to birth cohorts. The incidence of Lyme disease in the United States doubled from 1992-1996 to 2012-2016 (IRR = 1.74; 95% CI, 1.70-1.78) and increased disproportionately among males; IRRs were 39%-89% higher among males than among females for most age groups. During the study period, children aged 5-9 years were most frequently and consistently affected. In contrast, the average age of adults with Lyme disease increased over time; of all adults, people born during 1950-1964 were the most affected by Lyme disease. Our findings suggest that age-related behaviors and susceptibilities may drive infections among children, and the shifting peak among adults likely reflects a probability proportional to the relative size of the baby boom population. These findings can inform targeted and efficient public health education and intervention efforts.