Shiga Toxin-Producing Escherichia coli O157:H7 Illness Outbreak Associated with Untreated, Pressurized, Municipal Irrigation Water - Utah, 2023.

During July-September 2023, an outbreak of Shiga toxin-producing Escherichia coli O157:H7 illness among children in city A, Utah, caused 13 confirmed illnesses; seven patients were hospitalized, including two with hemolytic uremic syndrome. Local, state, and federal public health partners investigating the outbreak linked the illnesses to untreated, pressurized, municipal irrigation water (UPMIW) exposure in city A; 12 of 13 ill children reported playing in or drinking UPMIW. Clinical isolates were genetically highly related to one another and to environmental isolates from multiple locations within city A's UPMIW system. Microbial source tracking, a method to indicate possible contamination sources, identified birds and ruminants as potential sources of fecal contamination of UPMIW. Public health and city A officials issued multiple press releases regarding the outbreak reminding residents that UPMIW is not intended for drinking or recreation. Public education and UPMIW management and operations interventions, including assessing and mitigating potential contamination sources, covering UPMIW sources and reservoirs, indicating UPMIW lines and spigots with a designated color, and providing conspicuous signage to communicate risk and intended use might help prevent future UPMIW-associated illnesses.

Socio-ecological drivers of multiple zoonotic hazards in highly urbanized cities.

The ongoing COVID-19 pandemic is a stark reminder of the devastating consequences of pathogen spillover from wildlife to human hosts, particularly in densely populated urban centers. Prevention of future zoonotic disease is contingent on informed surveillance for known and novel threats across diverse human-wildlife interfaces. Cities are a key venue for potential spillover events because of the presence of zoonotic pathogens transmitted by hosts and vectors living in close proximity to dense human settlements. Effectively identifying and managing zoonotic hazards requires understanding the socio-ecological processes driving hazard distribution and pathogen prevalence in dynamic and heterogeneous urban landscapes. Despite increasing awareness of the human health impacts of zoonotic hazards, the integration of an eco-epidemiological perspective into public health management plans remains limited. Here we discuss how landscape patterns, abiotic conditions, and biotic interactions influence zoonotic hazards across highly urbanized cities (HUCs) in temperate climates to promote their efficient and effective management by a multi-sectoral coalition of public health stakeholders. We describe how to interpret both direct and indirect ecological processes, incorporate spatial scale, and evaluate networks of connectivity specific to different zoonotic hazards to promote biologically-informed and targeted decision-making. Using New York City, USA as a case study, we identify major zoonotic threats, apply knowledge of relevant ecological factors, and highlight opportunities and challenges for research and intervention. We aim to broaden the toolbox of urban public health stakeholders by providing ecologically-informed, practical guidance for the evaluation and management of zoonotic hazards.

Hospitalizations Involving an Intensive Care Unit Admission Among Patients Aged 65 Years and Older Within New York City Hospitals During 2000-2014.

OBJECTIVE: To describe hospitalizations involving an intensive care unit (ICU) admission among patients aged 65 years and older within New York City (NYC) hospitals during 2000-2014. DESIGN: Observational study using an all-payer hospital discharge dataset. SETTING: The setting was in NYC hospitals. PATIENTS: Patients aged 65 years and older admitted to an ICU within a NYC hospital during 2000-2014. INTERVENTIONS: No interventions were carried out. MEASUREMENTS AND MAIN RESULTS: We calculated the mean annual number of hospitalizations involving an ICU admission. We also examined characteristics of hospitalizations, including the occurrence of in-hospital death and principal diagnosis. There were 5,338,577 hospitalizations of patients aged ≥65 years within NYC hospitals during 2000-2014, of which 765,084 (14.3%) involved an ICU admission. The mean annual number of hospitalizations involving an ICU admission for this age group decreased from 57,938 during 2000-2002 to 45,785 during 2012-2014. The proportion of hospitalizations involving an ICU admission in which in-hospital death occurred decreased from 15.9% during 2000-2002 to 14.5% during 2012-2014. During 2000-2002, 11.6% of hospitalizations involving an ICU admission listed an "infectious" principal diagnosis, increasing to 20.7% during 2012-2014. Listing of a "cardiovascular" principal diagnosis decreased from 46.4% to 33.4% between these time periods. "Infectious" principal diagnoses accounted for 31.0% of all hospitalizations involving an ICU admission in which in-hospital death occurred during the entire study period, while "cardiovascular" principal diagnoses accounted for 21.3%. CONCLUSIONS: This investigation provides a clearer understanding of ICU utilization among patients aged 65 years and older in NYC. Ongoing monitoring is warranted given projections that the proportion of New Yorkers aged 65 years and older will increase in coming years. In particular, in light of the observed increase of infectious principal diagnoses during the study period, further investigation is needed into the role of infectious disease in causing critical illness in NYC.

Evaluating spatial and temporal patterns of tick exposure in the United States using community science data submitted through a smartphone application.

Research initiatives that engage the public (i.e., community science or citizen science) increasingly provide insights into tick exposures in the United States. However, these data have important caveats, particularly with respect to reported travel history and tick identification. Here, we assessed whether a smartphone application, The Tick App, provides reliable and novel insights into tick exposures across three domains - travel history, broad spatial and temporal patterns of species-specific encounters, and tick identification. During 2019-2021, we received 11,424 tick encounter submissions from across the United States, with nearly all generated in the Midwest and Northeast regions. Encounters were predominantly with human hosts (71%); although one-fourth of ticks were found on animals. Half of the encounters (51%) consisted of self-reported peri­domestic exposures, while 37% consisted of self-reported recreational exposures. Using phone-based location services, we detected differences in travel history outside of the users' county of residence along an urbanicity gradient. Approximately 75% of users from large metropolitan and rural counties had travel out-of-county in the four days prior to tick detection, whereas an estimated 50-60% of users from smaller metropolitan areas did. Furthermore, we generated tick encounter maps for Dermacentor variabilis and Ixodes scapularis that partially accounted for travel history and overall mirrored previously published species distributions. Finally, we evaluated whether a streamlined three-question sequence (on tick size, feeding status, and color) would inform a simple algorithm to optimize image-based tick identification. Visual aides of tick coloration and size engaged and guided users towards species and life stage classification moderately well, with 56% of one-time submitters correctly selecting photos of D. variabilis adults and 76% of frequent-submitters correctly selecting photos of D. variabilis adults. Together, these results indicate the importance of bolstering the use of smartphone applications to engage community scientists and complement other active and passive tick surveillance systems.

Bridging landscape ecology and urban science to respond to the rising threat of mosquito-borne diseases.

The prevalence of diseases borne by mosquitoes, particularly in the genus Aedes, is rising worldwide. This has been attributed, in part, to the dramatic rates of contemporary urbanization. While Aedes-borne disease risk varies within and between cities, few investigations use urban science-based approaches to examine how city structure and function contribute to vector or pathogen introduction and maintenance. Here, we integrate theories from complex adaptive systems, landscape ecology and urban geography to develop an urban systems framework for understanding Aedes-borne diseases. The framework establishes that cities comprise hierarchically structured patches of different land uses and characteristics. Properties of the patches (that is, composition) determine localized disease risk, while configuration and connectivity drive emergent patterns of pathogen spread. Complexity is added by incorporating individual and collective human social structures, considering how feedbacks among social actors and with the landscape drive risk and transmission. We discuss how these concepts apply to case studies of Aedes-borne disease from around the world. Ultimately, the framework strengthens existing theoretical and mixed qualitative-quantitative approaches, and advances considerations of how interventions including urban planning (for example, piped water provisioning) and emerging vector control strategies (for example, Wolbachia-infected mosquitoes) can be implemented to prevent and control the rising threat of Aedes-borne diseases.

Rat-Bite Fever in the United States: An Analysis Using Multiple National Data Sources, 2001-2015.

BACKGROUND: Rat-bite fever is a rare disease associated with rat bites or direct/indirect rodent contact. METHODS: We examined rat-bite fever and rat-bite injury diagnoses in the United States during 2001-2015. We analyzed national, state, and Indian Health Service healthcare encounter datasets for rat-bite fever and rat-bite injury diagnoses. We calculated average-annual encounter rates per 1 000 000 persons. RESULTS: Nationally, the rat-bite fever Emergency Department visit rate was 0.33 (95% confidence interval [CI], 0.19-0.47) and the hospitalization rate was 0.20 (95% CI, 0.17-0.24). The rat-bite injury Emergency Department visit rate was 10.51 (95% CI, 10.13-10.88) and the hospitalization rate was 0.27 (95% CI, 0.23-0.30). The Indian Health Service Emergency Department/outpatient visit rate was 3.00 for rat-bite fever and 18.89 for rat-bite injury. The majority of rat-bite fever encounters were among individuals 0-19 years of age. CONCLUSIONS: Our results support the literature that rat-bite fever is rare and affects children and young adults. Targeted education could benefit specific risk groups.

Environmental Determinants of Aedes albopictus Abundance at a Northern Limit of Its Range in the United States.

Aedes albopictus is a vector of arboviruses with high rates of morbidity and mortality. The northern limit of Ae. albopictus in the northeastern United States runs through New York state (NYS) and Connecticut. We present a landscape-level analysis of mosquito abundance measured by daily counts of Ae. albopictus from 338 trap sites in 12 counties during May-September 2017. During the study period, the mean number of Ae. albopictus caught per day of trapping across all sites was 3.21. We constructed four sets of negative binomial generalized linear models to evaluate how trapping methodology, land cover, as well as temperature and precipitation at multiple time intervals influenced Ae. albopictus abundance. Biogents-Sentinel (BGS) traps were 2.78 times as efficient as gravid traps and 1.49 times as efficient as CO2-baited CDC light traps. Greater proportions of low- and medium-intensity development and low proportions of deciduous cover around the trap site were positively associated with increased abundance, as were minimum winter temperature and March precipitation. The cumulative precipitation within a 28-day time window before the date of collection had a nonlinear relationship with abundance, such that greater cumulative precipitation was associated with increased abundance until approximately 70 mm, above which there was a decrease in abundance. We concluded that populations are established in Nassau, Suffolk, and New York City counties in NYS; north of these counties, the species is undergoing population invasion and establishment. We recommend that mosquito surveillance programs monitoring the northward invasion of Ae. albopictus place BGS traps at sites chosen with respect to land cover.

Usability and Feasibility of a Smartphone App to Assess Human Behavioral Factors Associated with Tick Exposure (The Tick App): Quantitative and Qualitative Study.

BACKGROUND: Mobile health (mHealth) technology takes advantage of smartphone features to turn them into research tools, with the potential to reach a larger section of the population in a cost-effective manner, compared with traditional epidemiological methods. Although mHealth apps have been widely implemented in chronic diseases and psychology, their potential use in the research of vector-borne diseases has not yet been fully exploited. OBJECTIVE: This study aimed to assess the usability and feasibility of The Tick App, the first tick research-focused app in the United States. METHODS: The Tick App was designed as a survey tool to collect data on human behaviors and movements associated with tick exposure while engaging users in tick identification and reporting. It consists of an enrollment survey to identify general risk factors, daily surveys to collect data on human activities and tick encounters (Tick Diaries), a survey to enter the details of tick encounters coupled with tick identification services provided by the research team (Report a Tick), and educational material. Using quantitative and qualitative methods, we evaluated the enrollment strategy (passive vs active), the user profile, location, longitudinal use of its features, and users' feedback. RESULTS: Between May and September 2018, 1468 adult users enrolled in the app. The Tick App users were equally represented across genders and evenly distributed across age groups. Most users owned a pet (65.94%, 962/1459; P<.001), did frequent outdoor activities (recreational or peridomestic; 75.24%, 1094/1454; P<.001 and 64.58%, 941/1457; P<.001, respectively), and lived in the Midwest (56.55%, 824/1457) and Northeast (33.0%, 481/1457) regions in the United States, more specifically in Wisconsin, southern New York, and New Jersey. Users lived more frequently in high-incidence counties for Lyme disease (incidence rate ratio [IRR] 3.5, 95% CI 1.8-7.2; P<.001) and in counties with cases recently increasing (IRR 1.8, 95% CI 1.1-3.2; P=.03). Recurring users (49.25%, 723/1468) had a similar demographic profile to all users but participated in outdoor activities more frequently (80.5%, 575/714; P<.01). The number of Tick Diaries submitted per user (median 2, interquartile range [IQR] 1-11) was higher for older age groups (aged >55 years; IRR 3.4, 95% CI 1.5-7.6; P<.001) and lower in the Northeast (IRR[NE] 0.4, 95% CI 0.3-0.7; P<.001), whereas the number of tick reports (median 1, IQR 1-2) increased with the frequency of outdoor activities (IRR 1.5, 95% CI 1.3-1.8; P<.001). CONCLUSIONS: This assessment allowed us to identify what fraction of the population used The Tick App and how it was used during a pilot phase. This information will be used to improve future iterations of The Tick App and tailor potential tick prevention interventions to the users' characteristics.

Postexposure Prophylaxis After Possible Anthrax Exposure: Adherence and Adverse Events.

Anthrax postexposure prophylaxis (PEP) was recommended to 42 people after a laboratory incident that involved potential aerosolization of Bacillus anthracis spores in 2 laboratories at the Centers for Disease Control and Prevention in 2014. At least 31 (74%) individuals who initiated PEP did not complete either the recommended 60 days of antimicrobial therapy or the 3-dose vaccine regimen. Among the 29 that discontinued the antimicrobial component of PEP, most (38%) individuals discontinued PEP because of their low perceived risk of infection; 9 (31%) individuals discontinued prophylaxis due to PEP-related minor adverse events, and 10% cited both low risk and adverse events as their reason for discontinuation. Most minor adverse events reported were gastrointestinal complaints, and none required medical attention. Individuals taking ciprofloxacin were twice as likely (RR = 2.02, 95% CI = 1.1-3.6) to discontinue antimicrobial prophylaxis when compared to those taking doxycycline. In the event anthrax PEP is recommended, public health messages and patient education materials will need to address potential misconceptions regarding exposure risk and provide information about possible adverse events in order to promote PEP adherence.