Proposing the "Continuum of UTI" for a Nuanced Approach to Diagnosis and Management of Urinary Tract Infections

PURPOSE

Patients with suspected UTIs are categorized into 3 clinical phenotypes based on current guidelines: no UTI, asymptomatic bacteriuria (ASB), or UTI. However, all patients may not fit neatly into these groups. Our objective was to characterize clinical presentations of patients who receive urine tests using the "continuum of UTI" approach.

MATERIALS AND METHODS

This was a retrospective cohort study of a random sample of adult noncatheterized inpatient and emergency department encounters with paired urinalysis and urine cultures from 5 hospitals in 3 states between January 01, 2017, and December 31, 2019. Trained abstractors collected clinical (eg, symptom) and demographic data. A focus group discussion with multidisciplinary experts was conducted to define the continuum of UTI, a 5-level classification scheme that includes 2 new categories: lower urinary tract symptoms/other urologic symptoms and bacteriuria of unclear significance. The newly defined continuum of UTI categories were compared to the current UTI classification scheme.

RESULTS

Of 220,531 encounters, 3392 randomly selected encounters were reviewed. Based on the current classification scheme, 32.1% (n = 704) had ASB and 53% (n = 1614) did not have a UTI. When applying the continuum of UTI categories, 68% of patients (n = 478) with ASB were reclassified as bacteriuria of unclear significance and 29% of patients (n = 467) with "no UTI" were reclassified to lower urinary tract symptoms/other urologic symptoms.

CONCLUSIONS

Our data suggest the need to reframe our conceptual model of UTI vs ASB to reflect the full spectrum of clinical presentations, acknowledge the diagnostic uncertainty faced by frontline clinicians, and promote a nuanced approach to diagnosis and management of UTIs.

Provider-Reported Barriers in Sexual Health Care Services for Women With Upstream Barriers: The Case of Syphilis and Congenital Syphilis in Southern Colorado, 2022

BACKGROUND

Syphilis and congenital syphilis rates have increased sharply in Colorado in the past 5 years. Congenital syphilis is passed during pregnancy in utero and can cause lifelong physical, developmental, and neurologic problems for the child, or can lead to miscarriage, stillbirth, or early infant death. Congenital syphilis is easily prevented if the mother receives timely testing, treatment, and prenatal care. Providers can play a key role in preventing congenital syphilis for women with social vulnerabilities, who have a higher likelihood of syphilis and/or congenital syphilis infection.

METHODS

We surveyed 23 and interviewed 4 health care providers in southern Colorado in 2022 to record their experiences in providing sexual health care services. We asked providers with direct care experience about perceived barriers in effectively treating syphilis.

RESULTS

The most significant barriers reported in the survey were the cost of treatment (26%) and the loss to follow-up (22%). Interviews revealed further challenges, including discretionary testing procedures, delays in screening results, treatment referral issues, and stigma around substance use and sexual activity.

CONCLUSIONS

Elevated syphilis and congenital syphilis rates pose significant public health challenges. Coordinated interventions are necessary to effectively reduce the transmission of syphilis and congenital syphilis among women with upstream barriers. Potential care solutions include expanding rapid, point-of care testing and treatment options, supporting bicillin delivery or web-based inventory systems, offering anti-stigma training for providers, offering mental and behavioral health resources at providers' clinics, and expanding partnerships with syringe access programs.

Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Descriptive Epidemiology of Pathogens Associated with Acute Respiratory Infection in a Community-Based Study of K-12 School Children (2015-2023)

School-based outbreaks often precede increased incidence of acute respiratory infections in the greater community. We conducted acute respiratory infection surveillance among children to elucidate commonly detected pathogens in school settings and their unique characteristics and epidemiological patterns. The ORegon CHild Absenteeism due to Respiratory Disease Study (ORCHARDS) is a longitudinal, laboratory-supported, school-based, acute respiratory illness (ARI) surveillance study designed to evaluate the utility of cause-specific student absenteeism monitoring for early detection of increased activity of influenza and other respiratory viruses in schools from kindergarten through 12th grade. Eligible participants with ARIs provided demographic, epidemiologic, and symptom data, along with a nasal swab or oropharyngeal specimen. Multipathogen testing using reverse-transcription polymerase chain reaction (RT-PCR) was performed on all specimens for 18 respiratory viruses and 2 atypical bacterial pathogens (Chlamydia pneumoniae and Mycoplasma pneumoniae). Between 5 January 2015 and 9 June 2023, 3498 children participated. Pathogens were detected in 2455 of 3498 (70%) specimens. Rhinovirus/enteroviruses (36%) and influenza viruses A/B (35%) were most commonly identified in positive specimens. Rhinovirus/enteroviruses and parainfluenza viruses occurred early in the academic year, followed by seasonal coronaviruses, RSV, influenza viruses A/B, and human metapneumovirus. Since its emergence in 2020, SARS-CoV-2 was detected year-round and had a higher median age than the other pathogens. A better understanding of the etiologies, presentations, and patterns of pediatric acute respiratory infections can help inform medical and public health system responses.

Effectiveness of a bivalent mRNA vaccine dose against symptomatic SARS-CoV-2 infection among U.S. Healthcare personnel, September 2022-May 2023

BACKGROUND

Bivalent mRNA vaccines were recommended since September 2022. However, coverage with a recent vaccine dose has been limited, and there are few robust estimates of bivalent VE against symptomatic SARS-CoV-2 infection (COVID-19). We estimated VE of a bivalent mRNA vaccine dose against COVID-19 among eligible U.S. healthcare personnel who had previously received monovalent mRNA vaccine doses.

METHODS

We conducted a case-control study in 22 U.S. states, and enrolled healthcare personnel with COVID-19 (case-participants) or without COVID-19 (control-participants) during September 2022-May 2023. Participants were considered eligible for a bivalent mRNA dose if they had received 2-4 monovalent (ancestral-strain) mRNA vaccine doses, and were ≥67 days after the most recent vaccine dose. We estimated VE of a bivalent mRNA dose using conditional logistic regression, accounting for matching by region and four-week calendar period. We adjusted estimates for age group, sex, race and ethnicity, educational level, underlying health conditions, community COVID-19 exposure, prior SARS-CoV-2 infection, and days since the last monovalent mRNA dose.

RESULTS

Among 3,647 healthcare personnel, 1,528 were included as case-participants and 2,119 as control-participants. Participants received their last monovalent mRNA dose a median of 404 days previously; 1,234 (33.8%) also received a bivalent mRNA dose a median of 93 days previously. Overall, VE of a bivalent dose was 34.1% (95% CI, 22.6%-43.9%) against COVID-19 and was similar by product, days since last monovalent dose, number of prior doses, age group, and presence of underlying health conditions. However, VE declined from 54.8% (95% CI, 40.7%-65.6%) after 7-59 days to 21.6% (95% CI 5.6%-34.9%) after ≥60 days.

CONCLUSIONS

Bivalent mRNA COVID-19 vaccines initially conferred approximately 55% protection against COVID-19 among U.S. healthcare personnel. However, protection waned after two months. These findings indicate moderate initial protection against symptomatic SARS-CoV-2 infection by remaining up-to-date with COVID-19 vaccines.

Intrapartum antibiotic prophylaxis selects for mutators in group B streptococci among persistently colonized patients

Through vaginal colonization, GBS causes severe pregnancy outcomes including neonatal sepsis and meningitis. Although intrapartum antibiotic prophylaxis (IAP) has reduced early-onset disease rates, persistent GBS colonization has been observed in patients following prophylaxis. To determine whether IAP selects for genomic signatures that enhance GBS survival and persistence in the vaginal tract, whole-genome sequencing was performed on 97 isolates from 58 patients before (prenatal) and after (postpartum) IAP/childbirth. Core-gene mutation analysis identified 7,025 mutations between the paired isolates. Three postpartum isolates accounted for 98% of mutations and were classified as "mutators" because of point mutations within DNA repair systems. In vitro assays revealed stronger biofilms in two mutators. These findings suggest that antibiotics select for mutations that promote survival in vivo, which increases the likelihood of transmission to neonates. They also demonstrate how mutators can provide a reservoir of beneficial mutations that enhance fitness and genetic diversity in the GBS population.

Outbreak of Invasive Serratia marcescens among Persons Incarcerated in a State Prison, California, USA, March 2020-December 2022

Serratia marcescens is an environmental gram-negative bacterium that causes invasive disease in rare cases. During 2020-2022, an outbreak of 21 invasive Serratia infections occurred in a prison in California, USA. Most (95%) patients had a history of recent injection drug use (IDU). We performed whole-genome sequencing and found isolates from 8 patients and 2 pieces of IDU equipment were closely related. We also identified social interactions among patients. We recovered S. marcescens from multiple environmental samples throughout the prison, including personal containers storing Cell Block 64 (CB64), a quaternary ammonium disinfectant solution. CB64 preparation and storage conditions were suboptimal for S. marcescens disinfection. The outbreak was likely caused by contaminated CB64 and propagated by shared IDU equipment and social connections. Ensuring appropriate preparation, storage, and availability of disinfectants and enacting interventions to counteract disease spread through IDU can reduce risks for invasive Serratia infections in California prisons.

Utilization of broad- versus narrow-spectrum antibiotics for the treatment of outpatient community-acquired pneumonia among adults in the United States

PURPOSE

To characterize antibiotic utilization for outpatient community-acquired pneumonia (CAP) in the United States.

METHODS

We conducted a cohort study among adults 18-64 years diagnosed with outpatient CAP and a same-day guideline-recommended oral antibiotic fill in the MarketScan® Commercial Database (2008-2019). We excluded patients coded for chronic lung disease or immunosuppressive disease; recent hospitalization or frequent healthcare exposure (e.g., home wound care, patients with cancer); recent antibiotics; or recent infection. We characterized utilization of broad-spectrum antibiotics (respiratory fluoroquinolone, β-lactam + macrolide, β-lactam + doxycycline) versus narrow-spectrum antibiotics (macrolide, doxycycline) overall and by patient- and provider-level characteristics. Per 2007 IDSA/ATS guidelines, we stratified analyses by otherwise healthy patients and patients with comorbidities (coded for diabetes; chronic heart, liver, or renal disease; etc.).

RESULTS

Among 263 914 otherwise healthy CAP patients, 35% received broad-spectrum antibiotics (not recommended); among 37 161 CAP patients with comorbidities, 44% received broad-spectrum antibiotics (recommended). Ten-day antibiotic treatment durations were the most common for all antibiotic classes except macrolides. From 2008 to 2019, broad-spectrum antibiotic use substantially decreased from 45% to 19% in otherwise healthy patients (average annual percentage change [AAPC], -7.5% [95% CI -9.2%, -5.9%]), and from 55% to 29% in patients with comorbidities (AAPC, -5.8% [95% CI -8.8%, -2.6%]). In subgroup analyses, broad-spectrum antibiotic use varied by age, geographic region, provider specialty, and provider location.

CONCLUSIONS

Real-world use of broad-spectrum antibiotics for outpatient CAP declined over time but remained common, irrespective of comorbidity status. Prolonged duration of therapy was common. Antimicrobial stewardship is needed to aid selection according to comorbidity status and to promote shorter courses.

Assessing the potential for improved predictive capacity of antimicrobial resistance in outpatient Staphylococcus aureus isolates using seasonal and spatial antibiograms

BACKGROUND

While the use of cumulative susceptibility reports, antibiograms, is recommended for improved empiric therapy and antibiotic stewardship, the predictive ability of antibiograms has not been well-studied. While enhanced antibiograms have been shown to better capture variation in susceptibility profiles by characteristics such as infection site or patient age, the potential for seasonal or spatial variation in susceptibility has not been assessed as important in predicting likelihood of susceptibility.

METHODS

Utilizing Staphylococcus aureus isolates obtained in outpatient settings from a nationwide provider of care, the Veterans Health Administration, and a local provider of care, the University of Iowa Hospitals and Clinics, standard, seasonal and spatial antibiograms were created for five commonly used antibiotic classes: cephalosporins, clindamycin, macrolides, tetracycline, trimethoprim/sulfamethoxazole.

RESULTS

A total of 338,681 S. aureus isolates obtained in VHA outpatient settings from 2010 to 2019 and 6,817 isolates obtained in UIHC outpatient settings from 2014 to 2019 were used to generate and test antibiograms. Logistic regression modeling determined the capacity of these antibiograms to predict isolate resistance to each antibiotic class. All models had low predictive capacity, with areas under the curve of < 0.7.

CONCLUSIONS

Standard antibiograms are poor in predicting S. aureus susceptibility to antibiotics often chosen by clinicians, and seasonal and spatial antibiograms do not provide an improved tool in anticipating non-susceptibility. These findings suggest that further refinements to antibiograms may be necessary to improve their utility in informing choice of effective antibiotic therapy.

Direct Evidence of Powassan Virus Vertical Transmission in Ixodes scapularis in Nature

Powassan virus (POWV) is a tick-borne flavivirus endemic in North America and Russia. Experimental infections with POWV have confirmed horizontal, transstadial, vertical, and cofeeding transmission routes for potential virus maintenance. In the field, vertical transmission has never been observed. During New York State tick-borne pathogen surveillance, POWV RNA and/or infectious POWV was detected in five pools of questing Ixodes scapularis larvae. Additionally, engorged female I. scapularis adults were collected from hunter-harvested white-tailed deer (Odocoileus virginianus) in a region with relatively high tick infection rates of POWV and allowed to oviposit under laboratory conditions. POWV RNA was detected in three female adult husks and one pool of larvae from a positive female. Infectious virus was isolated from all three RNA-positive females and the single positive larval pool. The detection of RNA and infectious virus in unfed questing larvae from the field and larvae from replete females collected from the primary tick host implicates vertical transmission as a potential mechanism for the maintenance of POWV in I. scapularis in nature, and elucidates the potential epidemiological significance of larval ticks in the transmission of POWV to humans.

Characterizing Patients Presenting on Hospital Admission with Central Line-Associated Bloodstream Infections: A Multicenter Study

BACKGROUND

There are no systematic measures of central line-associated bloodstream infections (CLABSIs) in patients maintaining central venous catheters (CVCs) outside acute care hospitals. To improve understanding of the burden of CLABSIs outside acute care hospitals, we characterized patients with CLABSI present on hospital admission (POA).

METHODS

Retrospective cross-sectional analysis of patients with CLABSI-POA in three health systems covering eleven hospitals across Maryland, Washington DC, and Missouri from November 2020 to October 2021. CLABSI-POA was defined using an adaptation of the acute care CLABSI definition. Patient demographics, clinical characteristics, and outcomes were collected via chart review. Cox proportional hazard analysis was used to assess factors associated with all-cause mortality within 30 days.

RESULTS

461 patients were identified as having CLABSI-POA. CVCs were most commonly maintained in home infusion therapy (32.8%) or oncology clinics (31.2%). Enterobacterales were the most common etiologic agent (29.2%). Recurrent CLABSIs occurred in a quarter of patients (25%). Eleven percent of patients died during the hospital admission. Among CLABSI-POA patients, mortality risk increased with age (versus ages <20: ages 20-44 years: HR: 11.21, 95% CI: 1.46-86.22; ages 45-64: HR: 20.88, 95% CI: 2.84-153.58; at least 65 years of age: HR: 22.50, 95% CI: 2.98-169.93), and lack of insurance (HR: 2.46; 95% CI: 1.08-5.59), and decreased with CVC removal (HR: 0.57, 95% CI: 0.39-0.84).

CONCLUSION

CLABSI-POA is associated with significant in-hospital mortality. Surveillance is required to understand the burden of CLABSI in the community to identify targets for CLABSI prevention initiatives outside acute care settings.

Assessing the impact of areal unit selection and the modifiable areal unit problem on associative statistics between cases of tick-borne disease and entomological indices

The modifiable areal unit problem (MAUP) is a cause of statistical and visual bias when aggregating data according to spatial units, particularly when spatial units may be changed arbitrarily. The MAUP is a concern in vector-borne disease research when entomological metrics gathered from point-level sampling data are related to epidemiological data aggregated to administrative units like counties or ZIP Codes. Here, we assess the statistical impact of the MAUP when calculating correlations between randomly aggregated cases of anaplasmosis in New York State during 2017 and a geostatistical layer of an entomological risk index for Anaplasma phagocytophilum in blacklegged ticks (Ixodes scapularis Say, Acari: Ixodidae) collected during the fall of 2017. Correlations were also calculated using various administrative boundaries for comparison. We also demonstrate the impact of the MAUP on data visualization using choropleth maps and offer pycnophylactic interpolation as an alternative. Polygon simulations indicate that increasing the number of polygons decreases correlation coefficients and their variability. Correlation coefficients calculated using ZIP Code tabulation area and Census tract polygons were beyond 4 standard deviations from the mean of the simulated correlation coefficients. These results indicate that using smaller polygons may not best incorporate the geographical context of the tick-borne disease system, despite the tendency of researchers to strive for more granular spatial data and associations.

Online trend estimation and detection of trend deviations in sub-sewershed time series of SARS-CoV-2 RNA measured in wastewater

Wastewater surveillance has proven a cost-effective key public health tool to understand a wide range of community health diseases and has been a strong source of information on community levels and spread for health departments throughout the SARS- CoV-2 pandemic. Studies spanning the globe demonstrate the strong association between virus levels observed in wastewater and quality clinical case information of the population served by the sewershed. Few of these studies incorporate the temporal dependence present in sampling over time, which can lead to estimation issues which in turn impact conclusions. We contribute to the literature for this important public health science by putting forward time series methods coupled with statistical process control that (1) capture the evolving trend of a disease in the population; (2) separate the uncertainty in the population disease trend from the uncertainty due to sampling and measurement; and (3) support comparison of sub-sewershed population disease dynamics with those of the population represented by the larger downstream treatment plant. Our statistical methods incorporate the fact that measurements are over time, ensuring correct statistical conclusions. We provide a retrospective example of how sub-sewersheds virus levels compare to the upstream wastewater treatment plant virus levels. An on-line algorithm supports real-time statistical assessment of deviations of virus level in a population represented by a sub-sewershed to the virus level in the corresponding larger downstream wastewater treatment plant. This information supports public health decisions by spotlighting segments of the population where outbreaks may be occurring.

Measuring insecticide resistance in a vacuum: exploring next steps to link resistance data with mosquito control efficacy

Insecticide resistance is a great challenge facing mosquito operational control agencies across the United States, where few active ingredients with unique modes of action are available for use, increasing resistance pressure and further hampering resistance management strategies. Emergence and expansion of insecticide resistance in mosquitoes can be detected by resistance monitoring programs; however, there are gaps in our knowledge regarding the link between resistance bioassay results and operational control outcomes. Here, we review both public health and agricultural studies on pesticide resistance bioassays and control outcomes. A discussion on the main gaps in our knowledge of insecticide resistance and a review of resistance management practices is also presented. We conclude with research questions that can advance our understanding of resistance monitoring and control.

Birth Outcomes Among People with Hepatitis C in Pregnancy - Three U.S. States, 2018-2021

INTRODUCTION

There are limited and conflicting data regarding the impact of hepatitis C in pregnancy on adverse birth outcomes.

METHODS

Using the Surveillance for Emerging Threats to Pregnant People and Infants Network (SET-NET), a large surveillance cohort, we describe birth outcomes among a cohort of people with HCV in pregnancy in total and by reported substance use.

RESULTS

Among 1418 infants, 89% were born to people with reported substance use during pregnancy. The proportion born preterm was 20%, 13% were small-for-gestational age and 34% of term infants required intensive care.

CONCLUSIONS

Assessments of recent changes to recommendations for HCV screening in pregnancy should evaluate the impact on maternal access to care for both HCV treatment as well as comorbidities such as substance use disorder which may contribute to adverse birth outcomes.

Rapid detection of West Nile and Dengue viruses from mosquito saliva by loop-mediated isothermal amplification and displaced probes

Arthropod-borne viruses are major causes of human and animal disease, especially in endemic low- and middle-income countries. Mosquito-borne pathogen surveillance is essential for risk assessment and vector control responses. Sentinel chicken serosurveillance (antibody testing) and mosquito pool screening (by RT-qPCR or virus isolation) are currently used to monitor arbovirus transmission, however substantial time lags of seroconversion and/or laborious mosquito identification and RNA extraction steps sacrifice their early warning value. As a consequence, timely vector control responses are compromised. Here, we report on development of a rapid arbovirus detection system whereby adding sucrose to reagents of loop-mediated isothermal amplification with displaced probes (DP-LAMP) elicits infectious mosquitoes to feed directly upon the reagent mix and expectorate viruses into the reagents during feeding. We demonstrate that RNA from pathogenic arboviruses (West Nile and Dengue viruses) transmitted in the infectious mosquito saliva was detectable rapidly (within 45 minutes) without RNA extraction. Sucrose stabilized viral RNA at field temperatures for at least 48 hours, important for transition of this system to practical use. After thermal treatment, the DP-LAMP could be reliably visualized by a simple optical image sensor to distinguish between positive and negative samples based on fluorescence intensity. Field application of this technology could fundamentally change conventional arbovirus surveillance methods by eliminating laborious RNA extraction steps, permitting arbovirus monitoring from additional sites, and substantially reducing time needed to detect circulating pathogens.

Evaluating completion rates of COVID-19 contact tracing surveys in New York City

IMPORTANCE

Contact tracing is the process of identifying people who have recently been in contact with someone diagnosed with an infectious disease. During an outbreak, data collected from contact tracing can inform interventions to reduce the spread of infectious diseases. Understanding factors associated with completion rates of contact tracing surveys can help design improved interview protocols for ongoing and future programs.

OBJECTIVE

To identify factors associated with completion rates of COVID-19 contact tracing surveys in New York City (NYC) and evaluate the utility of a predictive model to improve completion rates, we analyze laboratory-confirmed and probable COVID-19 cases and their self-reported contacts in NYC from October 1st 2020 to May 10th 2021.

METHODS

We analyzed 742,807 case investigation calls made during the study period. Using a log-binomial regression model, we examined the impact of age, time of day of phone call, and zip code-level demographic and socioeconomic factors on interview completion rates. We further developed a random forest model to predict the best phone call time and performed a counterfactual analysis to evaluate the change of completion rates if the predicative model were used.

RESULTS

The percentage of contact tracing surveys that were completed was 79.4%, with substantial variations across ZIP code areas. Using a log-binomial regression model, we found that the age of index case (an individual who has tested positive through PCR or antigen testing and is thus subjected to a case investigation) had a significant effect on the completion of case investigation - compared with young adults (the reference group,24 years old < age <  = 65 years old), the completion rate for seniors (age > 65 years old) were lower by 12.1% (95%CI: 11.1% - 13.3%), and the completion rate for youth group (age <  = 24 years old) were lower by 1.6% (95%CI: 0.6% -2.6%). In addition, phone calls made from 6 to 9 pm had a 4.1% (95% CI: 1.8% - 6.3%) higher completion rate compared with the reference group of phone calls attempted from 12 and 3 pm. We further used a random forest algorithm to assess its potential utility for selecting the time of day of phone call. In counterfactual simulations, the overall completion rate in NYC was marginally improved by 1.2%; however, certain ZIP code areas had improvements up to 7.8%.

CONCLUSION

These findings suggest that age and time of day of phone call were associated with completion rates of case investigations. It is possible to develop predictive models to estimate better phone call time for improving completion rates in certain communities.

Observed face mask use outside retail chain stores during the COVID-19 pandemic in two cities in the state of Idaho, USA

During the COVID-19 pandemic, public health authorities have encouraged the use of face masks to minimize transmission within the community. To assess mask wear during a COVID-19 surge and guide public health response efforts, including public messaging on mask recommendations, we compared observed mask use in the largest city in each of Idaho's 2 most populous counties, both without a current mask mandate. We recorded mask usage by every third person exiting stores of 5 retail chains in Boise and Nampa during November 8-December 5, 2021. Observations were conducted during three time periods (morning, afternoon, and evening) on weekday and weekend days. A multivariable model with city, retail chain, and city-chain interaction was used to assess mask wear differences by city for each chain. Of 3021 observed persons, 22.0% wore masks. In Boise, 31.3% (430/1376) of observed persons wore masks; in Nampa, 14.3% (236/1645) wore masks. Among all persons wearing masks, > 94% wore masks correctly; cloth and surgical masks were most common. By retail chain, observed individuals at Boise locations were 2.3-5.7 times as likely to wear masks than persons at respective Nampa locations. This study provided a rapid, nonconfrontational assessment of public use of mitigation measures in 2 Idaho cities during a COVID-19 surge.

Impact of Blood Culture Contamination on Antibiotic Use, Resource Utilization, and Clinical Outcomes: A Retrospective Cohort Study in Dutch and US Hospitals

Background

Blood culture contamination (BCC) has been associated with prolonged antibiotic use (AU) and increased health care utilization; however, this has not been widely reevaluated in the era of increased attention to antibiotic stewardship. We evaluated the impact of BCC on AU, resource utilization, and length of stay in Dutch and US patients.

Methods

This retrospective observational study examined adults admitted to 2 hospitals in the Netherlands and 5 hospitals in the United States undergoing ≥2 blood culture (BC) sets. Exclusion criteria included neutropenia, no hospital admission, or death within 48 hours of hospitalization. The impact of BCC on clinical outcomes-overall inpatient days of antibiotic therapy, test utilization, length of stay, and mortality-was determined via a multivariable regression model.

Results

An overall 22 927 patient admissions were evaluated: 650 (4.1%) and 339 (4.8%) with BCC and 11 437 (71.8%) and 4648 (66.3%) with negative BC results from the Netherlands and the United States, respectively. Dutch and US patients with BCC had a mean ± SE 1.74 ± 0.27 (P < .001) and 1.58 ± 0.45 (P < .001) more days of antibiotic therapy than patients with negative BC results. They also had 0.6 ± 0.1 (P < .001) more BCs drawn. Dutch but not US patients with BCC had longer hospital stays (3.36 days; P < .001). There was no difference in mortality between groups in either cohort. AU remained higher in US but not Dutch patients with BCC in a subanalysis limited to BC obtained within the first 24 hours of admission.

Conclusions

BCC remains associated with higher inpatient AU and health care utilization as compared with patients with negative BC results, although the impact on these outcomes differs by country.

Disparities in SARS-CoV-2 Infection by Race, Ethnicity, Language, and Social Vulnerability: Evidence from a Citywide Seroprevalence Study in Massachusetts, USA

OBJECTIVES

Uncovering and addressing disparities in infectious disease outbreaks require a rapid, methodical understanding of local epidemiology. We conducted a seroprevalence study of SARS-CoV-2 infection in Holyoke, Massachusetts, a majority Hispanic city with high levels of socio-economic disadvantage to estimate seroprevalence and identify disparities in SARS-CoV-2 infection.

METHODS

We invited 2000 randomly sampled households between 11/5/2020 and 12/31/2020 to complete questionnaires and provide dried blood spots for SARS-CoV-2 antibody testing. We calculated seroprevalence based on the presence of IgG antibodies using a weighted Bayesian procedure that incorporated uncertainty in antibody test sensitivity and specificity and accounted for household clustering.

RESULTS

Two hundred eighty households including 472 individuals were enrolled. Three hundred twenty-eight individuals underwent antibody testing. Citywide seroprevalence of SARS-CoV-2 IgG was 13.1% (95% CI 6.9-22.3) compared to 9.8% of the population infected based on publicly reported cases. Seroprevalence was 16.1% (95% CI 6.2-31.8) among Hispanic individuals compared to 9.4% (95% CI 4.6-16.4) among non-Hispanic white individuals. Seroprevalence was higher among Spanish-speaking households (21.9%; 95% CI 8.3-43.9) compared to English-speaking households (10.2%; 95% CI 5.2-18.0) and among individuals in high social vulnerability index (SVI) areas based on the CDC SVI (14.4%; 95% CI 7.1-25.5) compared to low SVI areas (8.2%; 95% CI 3.1-16.9).

CONCLUSIONS

The SARS-CoV-2 IgG seroprevalence in a city with high levels of social vulnerability was 13.1% during the pre-vaccination period of the COVID-19 pandemic. Hispanic individuals and individuals in communities characterized by high SVI were at the highest risk of infection. Public health interventions should be designed to ensure that individuals in high social vulnerability communities have access to the tools to combat COVID-19.

Female Aedes aegypti mosquitoes use communal cues to manage population density at breeding sites

Where a female mosquito lays her eggs creates the conditions for reproductive success. Here we identify a communal behavior among ovipositing female mosquitoes. When choosing equal breeding sites, gravid Aedes aegypti aggregate more often than expected. This aggregation occurs when water contact is restricted and does not require the presence of eggs. Instead, the aggregation is regulated by the number of females present at the breeding site. Using assays with both occupied and empty oviposition sites, we show that the Orco olfactory co-receptor and a carbon dioxide receptor, Gr3, detect the presence of mosquitoes. orco mutants aggregate more often in empty sites, suggesting attractive olfactory cues influence females to associate with one another. Gr3 mutant females do not prefer either site, suggesting that the CO2 receptor is necessary to evaluate mosquito population density at breeding sites. Further, raising CO2 levels is sufficient to cause wild-type mosquitoes to avoid empty oviposition sites. Our results demonstrate that female mosquitoes can regulate their own population density at breeding sites using attractive and repellent communal cues.

Knowledge, attitudes and practices regarding the use of mobile travel health apps

We performed a survey of US international travellers to evaluate their knowledge, attitudes and practices regarding mobile technologies related to health. We found that many international travellers carry smartphones and are interested in receiving health information from a mobile app when they travel abroad.

System identifiability in a time-evolving agent-based model

Mathematical models are a valuable tool for studying and predicting the spread of infectious agents. The accuracy of model simulations and predictions invariably depends on the specification of model parameters. Estimation of these parameters is therefore extremely important; however, while some parameters can be derived from observational studies, the values of others are difficult to measure. Instead, models can be coupled with inference algorithms (i.e., data assimilation methods, or statistical filters), which fit model simulations to existing observations and estimate unobserved model state variables and parameters. Ideally, these inference algorithms should find the best fitting solution for a given model and set of observations; however, as those estimated quantities are unobserved, it is typically uncertain whether the correct parameters have been identified. Further, it is unclear what 'correct' really means for abstract parameters defined based on specific model forms. In this work, we explored the problem of non-identifiability in a stochastic system which, when overlooked, can significantly impede model prediction. We used a network, agent-based model to simulate the transmission of Methicillin-resistant staphylococcus aureus (MRSA) within hospital settings and attempted to infer key model parameters using the Ensemble Adjustment Kalman Filter, an efficient Bayesian inference algorithm. We show that even though the inference method converged and that simulations using the estimated parameters produced an agreement with observations, the true parameters are not fully identifiable. While the model-inference system can exclude a substantial area of parameter space that is unlikely to contain the true parameters, the estimated parameter range still included multiple parameter combinations that can fit observations equally well. We show that analyzing synthetic trajectories can support or contradict claims of identifiability. While we perform this on a specific model system, this approach can be generalized for a variety of stochastic representations of partially observable systems. We also suggest data manipulations intended to improve identifiability that might be applicable in many systems of interest.

Racial and Socioeconomic Disparities Evident in Inappropriate Antibiotic Prescribing in the Emergency Department

STUDY OBJECTIVE

Inappropriate antibiotic prescribing for acute respiratory tract infections is a common source of low-value care in the emergency department (ED). Racial and socioeconomic disparities have been noted in episodes of low-value care, particularly in children. We evaluated whether prescribing rates for acute respiratory tract infections when antibiotics would be inappropriate by guidelines differed by race and socioeconomics.

METHODS

A retrospective cross-sectional analysis of adult and pediatric patient encounters in the emergency department (ED) between 2015 and 2023 at 5 hospitals for acute respiratory tract infections that did not require antibiotics by guidelines. Multivariable regression was used to calculate the risk ratio between race, ethnicity, and area deprivation index and inappropriate antibiotic prescribing, controlling for patient age, sex, and relevant comorbidities.

RESULTS

A total of 147,401 ED encounters (55% pediatric, 45% adult) were included. At arrival, 4% patients identified as Asian, 50% as Black, 5% as Hispanic, and 23% as White. Inappropriate prescribing was noted in 7.6% of overall encounters, 8% for Asian patients, 6% for Black patients, 5% for Hispanic patients, and 12% for White patients. After adjusting for age, sex, comorbidities, and area deprivation index, White patients had a 1.32 (95% confidence interval, 1.26 to 1.38) higher likelihood of receiving a prescription compared with Black patients. Patients residing in areas of greater socioeconomic deprivation, regardless of race and ethnicity, had a 0.74 (95% confidence interval, 0.70 to 0.78) lower likelihood of receiving a prescription.

CONCLUSION

Our results suggest that although overall inappropriate prescribing was relatively low, White patients and patients from wealthier areas were more likely to receive an inappropriate antibiotic prescription.

Presence and abundance of malaria vector species in Miami-Dade County, Florida

BACKGROUND

Malaria outbreaks have sporadically occurred in the United States, with Anopheles quadrimaculatus serving as the primary vector in the eastern region. Anopheles crucians, while considered a competent vector, has not been directly implicated in human transmission. Considering the locally acquired Plasmodium vivax cases in Sarasota County, Florida (7 confirmed cases), Cameron County, Texas (one confirmed case), and Maryland (one confirmed case) in the summer of 2023. The hypothesis of this study is that major cities in the United States harbour sufficient natural populations of Anopheles species vectors of malaria, that overlap with human populations that could support local transmission to humans. The objective of this study is to profile the most abundant Anopheles vector species in Miami-Dade County, Florida-An. crucians and An. quadrimaculatus.

METHODS

This study was based on high-resolution mosquito surveillance data from 2020 to 2022 in Miami-Dade County, Florida. Variations on the relative abundance of An. crucians and An. quadrimaculatus was assessed by dividing the total number of mosquitoes collected by each individual trap in 2022 by the number of mosquitoes collected by the same trap in 2020. In order to identify influential traps, the linear distance in meters between all traps in the surveillance system from 2020 to 2022 was calculated and used to create a 4 km buffer radius around each trap in the surveillance system.

RESULTS

A total of 36,589 An. crucians and 9943 An. quadrimaculatus were collected during this study by the surveillance system, consisting of 322 CO2-based traps. The findings reveal a highly heterogeneous spatiotemporal distribution of An. crucians and An. quadrimaculatus in Miami-Dade County, highlighting the presence of highly conducive environments in transition zones between natural/rural and urban areas. Anopheles quadrimaculatus, and to a lesser extent An. crucians, pose a considerable risk of malaria transmission during an outbreak, given their high abundance and proximity to humans.

CONCLUSIONS

Understanding the factors driving the proliferation, population dynamics, and spatial distribution of Anopheles vector species is vital for implementing effective mosquito control and reducing the risk of malaria outbreaks in the United States.

Increased circulation of human adenovirus in 2023: an investigation of the circulating genotypes, upper respiratory viral loads, and hospital admissions in a large academic medical center

IMPORTANCE

The circulation of human adenoviruses (HAdV) increased in 2023. In this manuscript, we show that HAdV-B3 was predominant in 2023 in a cohort characterized by the Johns Hopkins Hospital System. We also show that HAdV-B3 was associated with an increase in viral loads in respiratory samples and provide a correlation with the clinical presentations and outcomes.

Diversity and host specificity of Borrelia burgdorferi's outer surface protein C (ospC) alleles in synanthropic mammals, with a notable ospC allele U absence from mixed infections

Interactions among pathogen genotypes that vary in host specificity may affect overall transmission dynamics in multi-host systems. Borrelia burgdorferi, a bacterium that causes Lyme disease, is typically transmitted among wildlife by Ixodes ticks. Despite the existence of many alleles of B. burgdorferi's sensu stricto outer surface protein C (ospC) gene, most human infections are caused by a small number of ospC alleles ["human infectious alleles" (HIAs)], suggesting variation in host specificity associated with ospC. To characterize the wildlife host association of B. burgdorferi's ospC alleles, we used metagenomics to sequence ospC alleles from 68 infected individuals belonging to eight mammalian species trapped at three sites in suburban New Brunswick, New Jersey (USA). We found that multiple allele ("mixed") infections were common. HIAs were most common in mice (Peromyscus spp.) and only one HIA was detected at a site where mice were rarely captured. ospC allele U was exclusively found in chipmunks (Tamias striatus), and although a significant number of different alleles were observed in chipmunks, including HIAs, allele U never co-occurred with other alleles in mixed infections. Our results suggest that allele U may be excluding other alleles, thereby reducing the capacity of chipmunks to act as reservoirs for HIAs.

Scrub typhus in Indonesia: A cross-sectional analysis of archived fever studies samples

BACKGROUND

Scrub typhus is an understudied vector-borne bacterial infection.

METHODS

We tested archived fever samples for scrub typhus seropositivity to begin charting its geographic distribution in Indonesia. We analysed 1033 serum samples from three sites. IgM and IgG enzyme-linked immunosorbent assay (ELISA) against Orientia tsutsugamushi was performed using Karp, Kato, Gilliam, TA 716 antigens. To determine the cutoff in the absence of a presumed unexposed population and gold standard tests, we identified the visual inflection point, performed change point analysis, and used finite mixture models.

RESULTS

The optical density cutoff values used for IgM and IgG were 0.49 and 0.13, respectively. Across all sites, IgM seropositivity was 4.6% (95% CI: 3.4 to 6.0%) while IgG seropositivity was 4.4% (95% CI: 3.3 to 5.8%). The overall seropositivity across sites was 8.8% (95% CI: 8.1 to 11.7%). The overall seropositivity for Jambi, Denpasar, Tabanan were 9.7% (95% CI: 7.0 to 13.3%), 8.0% (95% CI: 5.7 to 11.0%), 9.0% (95% CI: 6.1 to 13.0%), respectively.

CONCLUSIONS

We conclude that O. tsutsugamushi exposure in humans occurred at all sites analysed and could be the cause of illness in some cases. Though it was not the main cause of acute fever in these locations, it is still important to consider scrub typhus in cases not responding to beta-lactam antibiotics. Future seroprevalence surveys and testing for scrub typhus in acute febrile illness studies will be essential to understand its distribution and burden in Indonesia.

Alpha-synuclein dynamics bridge Type-I Interferon response and SARS-CoV-2 replication in peripheral cells

BACKGROUND

Increasing evidence suggests a double-faceted role of alpha-synuclein (α-syn) following infection by a variety of viruses, including SARS-CoV-2. Although α-syn accumulation is known to contribute to cell toxicity and the development and/or exacerbation of neuropathological manifestations, it is also a key to sustaining anti-viral innate immunity. Consistently with α-syn aggregation as a hallmark of Parkinson's disease, most studies investigating the biological function of α-syn focused on neural cells, while reports on the role of α-syn in periphery are limited, especially in SARS-CoV-2 infection.

RESULTS

Results herein obtained by real time qPCR, immunofluorescence and western blot indicate that α-syn upregulation in peripheral cells occurs as a Type-I Interferon (IFN)-related response against SARS-CoV-2 infection. Noteworthy, this effect mostly involves α-syn multimers, and the dynamic α-syn multimer:monomer ratio. Administration of excess α-syn monomers promoted SARS-CoV-2 replication along with downregulation of IFN-Stimulated Genes (ISGs) in epithelial lung cells, which was associated with reduced α-syn multimers and α-syn multimer:monomer ratio. These effects were prevented by combined administration of IFN-β, which hindered virus replication and upregulated ISGs, meanwhile increasing both α-syn multimers and α-syn multimer:monomer ratio in the absence of cell toxicity. Finally, in endothelial cells displaying abortive SARS-CoV-2 replication, α-syn multimers, and multimer:monomer ratio were not reduced following exposure to the virus and exogenous α-syn, suggesting that only productive viral infection impairs α-syn multimerization and multimer:monomer equilibrium.

CONCLUSIONS

Our study provides novel insights into the biology of α-syn, showing that its dynamic conformations are implicated in the innate immune response against SARS-CoV-2 infection in peripheral cells. In particular, our results suggest that promotion of non-toxic α-syn multimers likely occurs as a Type-I IFN-related biological response which partakes in the suppression of viral replication. Further studies are needed to replicate our findings in neuronal cells as well as animal models, and to ascertain the nature of such α-syn conformations.

Surveillance of Flea-Borne Typhus in California, 2011-2019

Flea-borne typhus (FBT), also referred to as murine typhus, is an acute febrile disease in humans caused by the bacteria Rickettsia typhi. Currently, cases of FBT are reported for public health surveillance purposes (i.e., to detect incidence and outbreaks) in a few U.S. states. In California, healthcare providers and testing laboratories are mandated to report to their respective local public health jurisdictions whenever R. typhi or antibodies reactive to R. typhi are detected in a patient, who then report cases to state health department. In this study, we characterize the epidemiology of flea-borne typhus cases in California from 2011 to 2019. A total of 881 cases were reported during this period, with most cases reported among residents of Los Angeles and Orange Counties (97%). Demographics, animal exposures, and clinical courses for case patients were summarized. Additionally, spatiotemporal cluster analyses pointed to five areas in southern California with persistent FBT transmission.

Operational Considerations for Using Deer-Targeted 4-Poster Tick Control Devices in a Tick-borne Disease Endemic Community

CONTEXT

In the northeastern United States, recommendations to prevent diseases spread by black-legged ticks ( Ixodes scapularis ) and lone star ticks ( Amblyomma americanum ) often rely on individuals to use personal protection or yard-based strategies. The 4-Poster deer treatment stations (4-Posters) suppress tick populations by treating deer hosts with acaricide, potentially offering a community-wide approach for reducing tick-borne diseases in endemic areas. The 4-Poster deployment logistics in mainland community settings are not well documented but are needed for future public health tick control efforts.

PROGRAM

As part of a public health research effort to design a population-based 4-Poster effectiveness study aimed at reducing tick-borne disease incidence, TickNET researchers partnered with the Town of Ridgefield (Connecticut) to understand the feasibility and operational logistics of deploying 4-Posters on public land within a residential community to inform future public health interventions by municipalities or vector control agencies.

IMPLEMENTATION

We deployed three 4-Posters on a municipal property from July to December 2020 and used motion-activated cameras to record wildlife activity nearby. We documented per-device operational details, costs, materials consumed, and animal activity.

EVALUATION

Operation of 4-Posters was feasible, and device challenges were easily remedied. Deer visitation and heavy nontarget animal use were documented at all devices. Unexpectedly, monthly corn consumption was not correlated with monthly deer-view days. The monthly cost per device was US $1279 or US $305 per hectare with an average 21 minutes of weekly service time.

DISCUSSION

Use of 4-Posters by communities, public health agencies, or vector control programs may be a practicable addition to tick management programs in tick-borne disease endemic areas in the Northeast. Such programs should carefully consider local and state regulations, follow manufacturer and pesticide label guidelines, and include wildlife monitoring. High labor costs incurred in this project could be mitigated by training vector control agency or municipality staff to service 4-Posters.

Distribution of pyrethroid insecticides in urban storm drain structures: Catch basins, open channels, and outfalls

Surface water runoff can transport contaminants offsite to downstream aquatic ecosystems. The prevalence of impervious surfaces in urban areas enhances surface runoff and contributes to contamination of urban surface streams. Urban areas have complex drainage systems for the conveyance of drainage water, however, there is a dearth of information on the distribution of contaminants within storm drain system structures. Pyrethroid insecticides are among the most used insecticides in urban areas, and trace levels of pyrethroids are known to exert toxicity to aquatic invertebrates. To investigate pyrethroid occurrence and distribution throughout an urban drainage system, samples of water, sediment, algae, and biofilm were collected from catch basins, open channels, and outfalls in Los Angeles County, California, during the dry season. From 3 catch basins, 7 open channels, and 7 outfalls, a total of 28 water samples, 4 sediment samples, 8 algae samples, and 4 biofilm samples were collected and analyzed. Pyrethroid concentrations above the reporting limit were detected in 89% of water samples and all sediment, algae, and biofilm samples, with bifenthrin and cyfluthrin being the most frequently detected compounds. The median total pyrethroid concentrations in water, sediments, algae, and biofilms were 27 ng/L, 88 ng/g, 356 ng/g, and 3556 ng/g, respectively. Bifenthrin concentrations in catch basins were found to be significantly higher than those in open channels or outfalls. Significant correlations were found for various metrics, including between pyrethroid partitioning in water samples and total suspended solids. These findings highlight the role of underground catch basins as a sink as well as a secondary source for contaminants such as pyrethroid insecticides. Prevention of the input of these urban originated contaminants to catch basins is crucial for protecting the water quality of urban surface waters.

Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores

Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.

Introducing an environmental microbiome to axenic Aedes aegypti mosquitoes documents bacterial responses to a blood meal

IMPORTANCE

The blood meal of the female mosquito serves as a nutrition source to support egg development, so is an important aspect of its biology. Yet, the roles the microbiome may play in blood digestion are poorly characterized. We employed axenic mosquitoes to investigate how the microbiome differs between mosquitoes reared in the insectary versus mosquitoes that acquire their microbiome from the environment. Environmental microbiomes were more diverse and showed larger temporal shifts over the course of blood digestion. Importantly, only bacteria from the environmental microbiome performed hemolysis in culture, pointing to functional differences between bacterial populations. These data highlight that taxonomic differences between the microbiomes of insectary-reared and wild mosquitoes are potentially also related to their functional ecology. Thus, axenic mosquitoes colonized with environmental bacteria offer a way to investigate the role of bacteria from the wild in mosquito processes such as blood digestion, under controlled laboratory conditions.

Factors associated with the decision to receive bivalent COVID-19 booster vaccination among health care personnel

COVID-19 vaccination is effective at reducing SARS-CoV-2 complications, but uptake has been low. Our objective in this study was to compare the importance of factors reported to influence the decision to receive a bivalent COVID-19 booster vaccine among health care personnel (HCP) tested for SARS-CoV-2 between October 2022 and April 2023 in a 20-hospital vaccine effectiveness study in the United States (n = 1656). Compared with those who had not received the booster, the factors most likely to be reported to be important were concerns about contracting COVID-19 (84.0% of those who had received the bivalent booster vs. 47.5% of those who had not, difference 36.6% points (PP), 95% confidence interval [CI] 32.1 to 41.1%), spreading infection to family members (89.2% vs. 62.8%, difference 26.3 PP, 95% CI 22.3 to 30.4%), and spreading infection to colleagues at work (85.5% vs. 59.4%, difference 26.1 PP, 95% CI 21.7 to 30.5%). HCP who had received the booster more frequently cited the primary literature (61.7% vs. 31.8%, difference 29.9 PP, 95% CI 24.6 to 35.2%) and employer recommendations (48.3% vs. 29.8%, difference 18.5 PP, 95% CI 13.2 to 23.9%) as influencing their decision. This analysis provides insight into factors for targeting future vaccine messaging.

Wind Tunnels and Airflow-Driven Assays: Methods for Establishing the Cues and Orientation Mechanisms That Modulate Female Mosquito Attraction to Human Hosts

Understanding how female mosquitoes find a prospective host is crucial to developing means that can interfere with this process. Many methods are available to researchers studying cues and orientation mechanisms that modulate female mosquito attraction to hosts. Behaviors that can be monitored with these assays include activation, taking flight, upwind flight along an odor plume (optomotor anemotaxis), close approach to the stimulus (including hovering), and landing. Video recording can three-dimensionally document flight tracks and can correlate overall distribution patterns and moment-to-moment movements with odor contact and the presence of nearby cues such as a visual target. Here, we introduce mosquito host-seeking behaviors and methods to study them: wind tunnels (which allow orientation in free-flight), airflow-driven assays (using either tethered mosquitoes or small assay chambers that permit flight but also often dictate walking orientation), and still-air assays (wherein in odor concentration and spatial distribution are the orientation cues). We also describe factors that affect the assays and provide assay design considerations.

Rapid Environmental Contamination with Candida auris and Multidrug-Resistant Bacterial Pathogens Near Colonized Patients

BACKGROUND

Environmental contamination is suspected to play an important role in Candida auris transmission. Understanding speed and risks of contamination after room disinfection could inform environmental cleaning recommendations.

METHODS

We conducted a prospective multicenter study of environmental contamination associated with C. auris colonization at six ventilator-capable skilled nursing facilities and one acute-care hospital in Illinois and California. Known C. auris carriers were sampled at five body-sites followed by sampling of nearby room surfaces before disinfection and at 0, 4, 8, and 12-hours post-disinfection. Samples were cultured for C. auris and bacterial multidrug-resistant organisms (MDROs). Odds of surface contamination after disinfection were analyzed using multilevel generalized estimating equations.

RESULTS

Among 41 known C. auris carriers, colonization was detected most frequently on palms/fingertips (76%) and nares (71%). C. auris contamination was detected on 32.2% (66/205) of room surfaces pre-disinfection and 20.5% (39/190) of room surfaces by 4-hours post-disinfection. A higher number of C. auris-colonized body sites was associated with higher odds of environmental contamination at every time point following disinfection, adjusting for facility of residence. In the rooms of 38 (93%) C. auris carriers co-colonized with a bacterial MDRO, 2%-24% of surfaces were additionally contaminated with the same MDRO by 4-hours post-disinfection.

CONCLUSIONS

C. auris can contaminate the healthcare environment rapidly after disinfection, highlighting the challenges associated with environmental disinfection. Future research should investigate long-acting disinfectants, antimicrobial surfaces, and more effective patient skin antisepsis to reduce the environmental reservoir of C. auris and bacterial MDROs in healthcare settings.

Macro-parasites and micro-parasites co-exist in rodent communities but are associated with different community-level parameters

Wildlife species are often heavily parasitized by multiple infections simultaneously. Yet research on sylvatic transmission cycles, tend to focus on host interactions with a single parasite and neglects the influence of co-infections by other pathogens and parasites. Co-infections between macro-parasites and micro-parasites can alter mechanisms that regulate pathogenesis and are important for understanding disease emergence and dynamics. Wildlife rodent hosts in the Lyme disease system are infected with macro-parasites (i.e., ticks and helminths) and micro-parasites (i.e., Borrelia spp.), however, there has not been a study that investigates the interaction of all three parasites (i.e., I. pacificus, Borrelia spp., and helminths) and how these co-infections impact prevalence of micro-parasites. We live-trapped rodents in ten sites in northern California to collect feces, blood, ear tissue, and attached ticks. These samples were used to test for infection status of Borrelia species (i.e., micro-parasite), and describe the burden of ticks and helminths (i.e., macro-parasites). We found that some rodent hosts were co-infected with all three parasites, however, the burden or presence of concurrent macro-parasites were not associated with Borrelia infections. For macro-parasites, we found that tick burdens were positively associated with rodent Shannon diversity while negatively associated with predator diversity, whereas helminth burdens were not significantly associated with any host community metric. Ticks and tick-borne pathogens are associated with rodent host diversity, predator diversity, and abiotic factors. However, it is still unknown what factors helminths are associated with on the community level. Understanding the mechanisms that influence co-infections of multiple types of parasites within and across hosts is an increasingly critical component of characterizing zoonotic disease transmission and maintenance.

Hepatitis C Screening and Antibody Prevalence Among Newly Arrived Refugees to the United States, 2010-2017

Six refugee screening sites collaborated to estimate the prevalence of hepatitis C virus (HCV) antibodies among newly arrived refugees in the United States from 2010 to 2017, identify demographic characteristics associated with HCV antibody positivity, and estimate missed HCV antibody-positive adults among unscreened refugees. We utilized a cross-sectional study to examine HCV prevalence among refugees (N = 144,752). A predictive logistic regression model was constructed to determine the effectiveness of current screening practices at identifying cases. The prevalence of HCV antibodies among the 64,703 refugees screened was 1.6%. Refugees from Burundi (5.4%), Moldova (3.8%), Democratic Republic of Congo (3.2%), Burma (2.8%), and Ukraine (2.0%) had the highest positivity among refugee arrivals. An estimated 498 (0.7%) cases of HCV antibody positivity were missed among 67,787 unscreened adults. The domestic medical examination represents an opportunity to screen all adult refugees for HCV to ensure timely diagnosis and treatment.

A Spatially Resolved and Environmentally Informed Forecast Model of West Nile Virus in Coachella Valley, California

West Nile virus (WNV) is the most significant arbovirus in the United States in terms of both morbidity and mortality. West Nile exists in a complex transmission cycle between avian hosts and the arthropod vector, Culex spp. mosquitoes. Human spillover events occur when humans are bitten by an infected mosquito and predicting these rates of infection and therefore the risk to humans may be associated with fluctuations in environmental conditions. In this study, we evaluate the hydrological and meteorological drivers associated with mosquito biology and viral development to determine if these associations can be used to forecast seasonal mosquito infection rates with WNV in the Coachella Valley of California. We developed and tested a spatially resolved ensemble forecast model of the WNV mosquito infection rate in the Coachella Valley using 17 years of mosquito surveillance data and North American Land Data Assimilation System-2 environmental data. Our multi-model inference system indicated that the combination of a cooler and dryer winter, followed by a wetter and warmer spring, and a cooler than normal summer was most predictive of the prevalence of West Nile positive mosquitoes in the Coachella Valley. The ability to make accurate early season predictions of West Nile risk has the potential to allow local abatement districts and public health entities to implement early season interventions such as targeted adulticiding and public health messaging before human transmission occurs. Such early and targeted interventions could better mitigate the risk of WNV to humans.

Association of Clostridioides difficile infection rates with social determinants of health in Denver area census tracts, 2016-2019

We evaluated the association between census tract measures of socioeconomic status and Clostridioides difficile infection (CDI) rates in the Denver metro area from 2016 to 2019. Social vulnerability index, poverty, and race were associated with CDI. Findings may relate to differences in chronic disease prevalence, antibiotic exposure, and access to quality care.

Early coronavirus disease 2019 (COVID-19) pandemic effects on individual-level risk for healthcare-associated infections in hospitalized patients

OBJECTIVE

We compared the individual-level risk of hospital-onset infections with multidrug-resistant organisms (MDROs) in hospitalized patients prior to and during the coronavirus disease 2019 (COVID-19) pandemic. We also quantified the effects of COVID-19 diagnoses and intrahospital COVID-19 burden on subsequent MDRO infection risk.

DESIGN

Multicenter, retrospective, cohort study.

SETTING

Patient admission and clinical data were collected from 4 hospitals in the St. Louis area.

PATIENTS

Data were collected for patients admitted between January 2017 and August 2020, discharged no later than September 2020, and hospitalized ≥48 hours.

METHODS

Mixed-effects logistic regression models were fit to the data to estimate patients' individual-level risk of infection with MDRO pathogens of interest during hospitalization. Adjusted odds ratios were derived from regression models to quantify the effects of the COVID-19 period, COVID-19 diagnosis, and hospital-level COVID-19 burden on individual-level hospital-onset MDRO infection probabilities.

RESULTS

We calculated adjusted odds ratios for COVID-19-era hospital-onset Acinetobacter spp., P. aeruginosa and Enterobacteriaceae spp infections. Probabilities increased 2.64 (95% confidence interval [CI], 1.22-5.73) times, 1.44 (95% CI, 1.03-2.02) times, and 1.25 (95% CI, 1.00-1.58) times relative to the prepandemic period, respectively. COVID-19 patients were 4.18 (95% CI, 1.98-8.81) times more likely to acquire hospital-onset MDRO S. aureus infections.

CONCLUSIONS

Our results support the growing body of evidence indicating that the COVID-19 pandemic has increased hospital-onset MDRO infections.

Treatment of Mpox with Suspected Tecovirimat Resistance in Immunocompromised Patient, United States, 2022

Reports of tecovirimat-resistant mpox have emerged after widespread use of antiviral therapy during the 2022 mpox outbreak. Optimal management of patients with persistent infection with or without suspected resistance is yet to be established. We report a successfully treated case of severe mpox in California, USA, that had suspected tecovirimat resistance.

Evolution of Influenza A(H3N2) Viruses in 2 Consecutive Seasons of Genomic Surveillance, 2021-2023

Background

The circulation and the genomic evolution of influenza A(H3N2) viruses during the 2021/2022 and 2022/2023 seasons were studied and associated with infection outcomes.

Methods

Remnant influenza A-positive samples following standard-of-care testing from patients across the Johns Hopkins Health System (JHHS) were used for the study. Samples were randomly selected for whole viral genome sequencing. The sequence-based pEpitope model was used to estimate the predicted vaccine efficacy (pVE) for circulating H3N2 viruses. Clinical data were collected and associated with viral genomic data.

Results

A total of 121 683 respiratory specimens were tested for influenza at JHHS between 1 September 2021 and 31 December 2022. Among them, 6071 (4.99%) tested positive for influenza A. Of these, 805 samples were randomly selected for sequencing, with hemagglutinin (HA) segments characterized for 610 samples. Among the characterized samples, 581 were H3N2 (95.2%). Phylogenetic analysis of HA segments revealed the exclusive circulation of H3N2 viruses with HA segments of the 3C.2a1b.2a.2 clade. Analysis of a total of 445 complete H3N2 genomes revealed reassortments; 200 of 227 of the 2022/2023 season genomes (88.1%) were found to have reassorted with clade 3C.2a1b.1a. The pVE was estimated to be -42.53% for the 2021/2022 season and 30.27% for the 2022/2023 season. No differences in clinical presentations or admissions were observed between the 2 seasons.

Conclusions

The increased numbers of cases and genomic diversity of influenza A(H3N2) during the 2022/2023 season were not associated with a change in disease severity compared to the previous influenza season.

Estimating the Burden of Clinically Significant Staphylococcus aureus Infections and Predictors for Hospitalization for Skin and Soft Tissue Infections, Fulton County, Georgia, 2017

Background

Incidence estimates of Staphylococcus aureus infections rarely include the full spectrum of clinically relevant disease from both community and healthcare settings.

Methods

We conducted a prospective study capturing all S aureus infections in Fulton County, Georgia, during 2017. Medical records of patients with any incident infection (clinical cultures growing S aureus from any site, without prior positive culture in previous 14 days) were reviewed. Estimates of disease incidence were calculated using age-, race-, and sex-specific population denominators accounting for weighted sampling methods. Multivariable logistic regression models were used to identify risk factors for hospitalization among patients with skin and soft tissue infections (SSTIs).

Results

The overall incidence of clinically relevant S aureus infection was 405.7 cases per 100 000 people (standard error [SE], 5.62 [range, 400.1-411.3]). Overall incidence for those of Black race was 500.84 cases per 100 000 people (SE, 14.55), whereas White patients had overall incidence of 363.67 cases per 100 000 people (SE, 13.8). SSTIs were the most common infection (2351; 225.8 cases per 100 000 people [SE, 7.1]), and 30% required hospitalization. Among SSTIs, after adjusting for invasive disease, cellulitis, diabetes, and demographics, independent predictors of hospitalization included methicillin-resistant S aureus (adjusted odds ratio [aOR], 1.6 [95% confidence interval {CI}, 1.0-2.7]) and homelessness (aOR, 4.9 [95% CI, 1.1-22]).

Conclusions

The burden of clinically relevant S aureus infections is high, particularly among the Black population, and risks for hospitalization among SSTIs include isolate factors and factors related to patients' vulnerability.

Is Carbapenem Therapy Necessary for the Treatment of Non-CTX-M ESBL-Producing Enterobacterales Bloodstream Infections?

BACKGROUND

Investigations into antibiotics for extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) bloodstream infections (BSIs) have focused on blaCTX-M genes. Outcomes of patients with non-CTX-M-producing ESBL-E BSIs and optimal treatment are unknown.

METHODS

A multicenter observational study investigating 500 consecutive patients with ceftriaxone-resistant Enterobacterales BSIs during 2018-2022 was conducted. Broth microdilution and whole genome sequencing confirmed antibiotic susceptibilities and ESBL gene presence, respectively. Inverse probability weighting (IPW) using propensity scores was employed to ensure patients infected with non-CTX-M and CTX-M ESBL-E BSIs were similar prior to evaluation of outcomes.

RESULTS

396 patients (79.2%) were confirmed to have an ESBL-E BSI. ESBL gene family prevalence was as follows: blaCTX-M (n=370), blaSHV (n=16), blaOXY (n=12), and blaVEB (n=5). ESBL gene identification was not limited to Escherichia coli and Klebsiella species. In the IPW cohort, there was no difference in 30-day mortality or ESBL-E infection recurrence between the non-CTX-M and CTX-M groups (OR=.99, 95% CI 0.87-1.11; p=0.83) and (OR=1.10, 95% CI 0.85--1.42; p=0.47), respectively. In an exploratory analysis limited to the non-CTX-M group, 86% of the 21 patients receiving meropenem were alive on day 30; none of the 5 patients receiving piperacillin-tazobactam were alive on day 30.

CONCLUSIONS

Our findings suggest that non-CTX-M and CTX-M ESBL-producing Enterobacterales BSIs are equally concerning and associated with similar clinical outcomes. Meropenem may be associated with improved survival in patients with non-CTX-M ESBL-E BSIs, underscoring the potential benefit of comprehensive molecular diagnostics to enable early antibiotic optimization for patients with ESBL-E BSI, beyond just blaCTX-M genes.

Jamestown Canyon virus comes into view: understanding the threat from an underrecognized arbovirus

This review examines the epidemiology, ecology, and evolution of Jamestown Canyon virus (JCV) and highlights new findings from the literature to better understand the virus, the vectors driving its transmission, and its emergence as an agent of arboviral disease. We also reanalyze data from the Connecticut Arbovirus Surveillance Program which represents the largest dataset on JCV infection in mosquitoes. JCV is a member of the California serogroup of the genus Orthobunyavirus, family Peribunyaviridae, and is found throughout much of temperate North America. This segmented, negative-sense RNA virus evolves predominately by genetic drift punctuated by infrequent episodes of genetic reassortment among novel strains. It frequently infects humans within affected communities and occasionally causes febrile illness and neuroinvasive disease in people. Reported human cases are relatively rare but are on the rise during the last 20 yr, particularly within the northcentral and northeastern United States. JCV appears to overwinter and reemerge each season by transovarial or vertical transmission involving univoltine Aedes (Diptera: Culicidae) species, specifically members of the Aedes communis (de Geer) and Ae. stimulans (Walker) Groups. The virus is further amplified in a mosquito-deer transmission cycle involving a diversity of mammalophilic mosquito species. Despite progress in our understanding of this virus, many aspects of the vector biology, virology, and human disease remain poorly understood. Remaining questions and future directions of research are discussed.

Prevalence of Acinetobacter baumannii and Candida auris in Patients Receiving Mechanical Ventilation

Importance

To date, only 1 statewide prevalence survey has been performed for Acinetobacter baumannii (2009) in the US, and no statewide prevalence survey has been performed for Candida auris, making the current burden of these emerging pathogens unknown.

Objective

To determine the prevalence of A baumannii and C auris among patients receiving mechanical ventilation in Maryland.

Design, Setting, and Participants

The Maryland Multi-Drug Resistant Organism Prevention Collaborative performed a statewide cross-sectional point prevalence of patients receiving mechanical ventilation admitted to acute care hospitals (n = 33) and long-term care facilities (n = 18) between March 7, 2023, and June 8, 2023. Surveillance cultures (sputum, perianal, arm/leg, and axilla/groin) were obtained from all patients receiving mechanical ventilation. Sputum, perianal, and arm/leg cultures were tested for A baumannii and antibiotic susceptibility testing was performed. Axilla/groin cultures were tested by polymerase chain reaction for C auris.

Main Outcomes and Measures

Prevalence of A baumannii, carbapenem-resistant A baumannii (CRAB), and C auris. Prevalence was stratified by type of facility.

Results

All 51 eligible health care facilities (100%) participated in the survey. A total of 482 patients receiving mechanical ventilation were screened for A baumannii and 470 were screened for C auris. Among the 482 patients who had samples collected, 30.7% (148/482) grew A baumannii, 88 of the 148 (59.5%) of these A baumannii were CRAB, and C auris was identified in 31 of 470 (6.6%). Patients in long-term care facilities were more likely to be colonized with A baumannii (relative risk [RR], 7.66 [95% CI, 5.11-11.50], P < .001), CRAB (RR, 5.48 [95% CI, 3.38-8.91], P < .001), and C auris (RR, 1.97 [95% CI, 0.99-3.92], P = .05) compared with patients in acute care hospitals. Nine patients (29.0%) with cultures positive for C auris were previously unreported to the Maryland Department of Health.

Conclusions

A baumannii, carbapenem-resistant A baumannii, and C auris were common among patients receiving mechanical ventilation in both acute care hospitals and long-term care facilities. Both pathogens were significantly more common in long-term care facilities than in acute care hospitals. Patients receiving mechanical ventilation in long-term care facilities are a high-risk population for emerging pathogens, and surveillance and prevention efforts should be targeted to these facilities.

Fir (Abies balsamea) (Pinales: Pinaceae) needle essential oil enhances the knockdown activity of select insecticides

Because of the increased interest in plant essential oils (PEO) for both home pest control and personal bite protection, the ability of fir needle (Abies balsamea) oil to synergize the 1-h knockdown and 24-h toxicity of 9 different synthetic insecticides was evaluated. Fir needle oil strongly synergized knockdown of the neonicotinoids, clothianidin, and thiamethoxam (between 16- and 24-fold), as well as natural pyrethrins (12-fold), but had less effect with organophosphates and fipronil. For 24-h mortality, only pirimiphos-methyl was strongly synergized by fir needle oil pretreatment (18-fold). Chemical analysis and testing identified delta-3-carene is the most bioactive constituent, producing synergism similar to that of the whole oil. In fact, this constituent synergized the 24-h mortality of clothianidin to a higher degree than fir needle oil itself (4.9-fold vs. 2.4-fold). Synergism is unlikely to be mediated by effects on the nervous system, as fir needle oil caused no change in mosquito central nervous system firing at 100 ppm and did not synergize an inactive concentration of natural pyrethrins (10 nM). To better understand fir needle oil effects, we evaluated the ability of pretreatment with this oil to impact Aedes aegypti monooxygenase degradation of a model substrate, 7-ethoxycoumarin. Interestingly, both fir needle oil and delta-3-carene caused a significant increase in metabolic degradation of 7-ethoxycoumarin, perhaps indicating they upregulate oxidative metabolic processes. Such an action would explain why fir needle oil enhances knockdown, but not 24-h mortality for most of the insecticides studied here, whereas increased bioactivation would explain the synergism of pirimiphos-methyl toxicity.