Misdiagnosis of Clostridioides difficile Infections by Standard-of-Care Specimen Collection and Testing among Hospitalized Adults, Louisville, Kentucky, USA, 2019-20201.

Although Clostridioides difficile infection (CDI) incidence is high in the United States, standard-of-care (SOC) stool collection and testing practices might result in incidence overestimation or underestimation. We conducted diarrhea surveillance among inpatients >50 years of age in Louisville, Kentucky, USA, during October 14, 2019-October 13, 2020; concurrent SOC stool collection and CDI testing occurred independently. A study CDI case was nucleic acid amplification test‒/cytotoxicity neutralization assay‒positive or nucleic acid amplification test‒positive stool in a patient with pseudomembranous colitis. Study incidence was adjusted for hospitalization share and specimen collection rate and, in a sensitivity analysis, for diarrhea cases without study testing. SOC hospitalized CDI incidence was 121/100,000 population/year; study incidence was 154/100,000 population/year and, in sensitivity analysis, 202/100,000 population/year. Of 75 SOC CDI cases, 12 (16.0%) were not study diagnosed; of 109 study CDI cases, 44 (40.4%) were not SOC diagnosed. CDI incidence estimates based on SOC CDI testing are probably underestimated.

Association and predictive value of biomarkers with severe outcomes in hospitalized patients with SARS-CoV-2 infection.

This study analyzed the levels at admission of biomarkers for their association with and ability to predict risk of severe outcomes, including admission to the ICU, need for invasive mechanical ventilation (IMV), need for vasopressor use (VU), and in-hospital mortality (IHM) in 700 patients hospitalized with COVID-19. Biomarker data split by outcomes was compared using Mann-Whitney U tests; frequencies of biomarker values were compared using Chi-square tests and multivariable logistic regression analysis was performed to look at the impact of biomarkers by outcome. Patients that suffered IHM were more likely to have reduced platelet numbers and high blood urea nitrogen (BUN) levels among patients admitted to the ICU. Risk factors for mortality were related to hyper-coagulability (low platelet count and increased D-dimer) and decreased respiratory (PaO2/FiO2 ratio) and kidney function (BUN). Association with risks of other severe outcomes were as follows: ICU with hyper-inflammation (IL-6) and decreased respiratory function; IMV with low platelet count, abnormal neutrophil-lymphocyte ratio with reduced respiratory function, VU with inflammatory markers (IL-6), and low platelet count with respiratory function. Our studies confirmed the association of biomarkers of hematological, inflammatory, coagulation, pulmonary and kidney functions with disease severity. Whether these biomarkers have any mechanistic or causal role in the disease progress requires further investigation.

Electrocardiographic Features and Outcome: Correlations in 124 Hospitalized Patients With COVID-19 and Cardiovascular Events.

OBJECTIVES: Electrocardiographic (ECG) changes have been associated with coronavirus disease 2019 (COVID-19) severity. However, the progression of ECG findings in patients with COVID-19 has not been studied. The purpose of this study was to describe ECG features at different stages of COVID-19 cardiovascular (CV) events and to examine the effects of specific ECG parameters and cardiac-related biomarkers on clinical outcomes in COVID-19. DESIGN: Retrospective, cohort study. SETTING: Major tertiary-care medical centers and community hospitals in Louisville, KY. PARTICIPANTS: A total of 124 patients with COVID-19 and CV events during hospitalization. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twelve-lead ECG parameters, biomarkers of cardiac injuries, and clinical outcomes were analyzed with Spearman correlation coefficients and Kruskal-Wallis 1-way analysis of variance. Atrial fibrillation/atrial flutter was more frequent on the ECG obtained at the time of the CV event when compared with admission ECG (9.5% v 26.9%; p = 0.007). Sinus tachycardia was higher in the last available hospital ECG than the CV event ECG (37.5% v 20.4%; p = 0.031). Admission ECG-corrected QT interval was significantly associated with admission troponin levels (R = 0.52; p < 0.001). The last available hospital ECG showed nonsurvivors had longer QRS duration than survivors (114.6 v 91.2 ms; p = 0.026), and higher heart rate was associated with longer intensive care unit length of stay (Spearman ρ = 0.339; p = 0.032). CONCLUSIONS: In hospitalized patients with COVID-19 and CV events, ECGs at various stages of COVID-19 hospitalization showed significantly different features with dissimilar clinical outcome correlations.

Effectiveness of oseltamivir treatment on clinical failure in hospitalized patients with lower respiratory tract infection.

BACKGROUND: Influenza is associated with excess morbidity and mortality of individuals each year. Few therapies exist for treatment of influenza infection, and each require initiation as early as possible in the course of infection, making efficacy difficult to estimate in the hospitalized patient with lower respiratory tract infection. Using causal machine learning methods, we re-analyze data from a randomized trial of oseltamivir versus standard of care aimed at reducing clinical failure in hospitalized patients with lower respiratory tract infection during the influenza season. METHODS: This was a secondary analysis of the Rapid Empiric Treatment with Oseltamivir Study (RETOS). Conditional average treatment effects (CATE) and 95% confidence intervals were computed from causal forest including 85 clinical and demographic variables. RETOS was a multicenter, randomized, unblinded, trial of adult patients hospitalized with lower respiratory tract infections in Kentucky from 2009 through 2012. Adult hospitalized patients with lower respiratory tract infection were randomized to standard of care or standard of care plus oseltamivir as early as possible after hospital admission but within 24 h of enrollment. After randomization, oseltamivir was initiated in the treatment arm per package insert. The primary outcome was clinical failure, a composite measure including failure to reach clinical improvement within 7 days, transfer to intensive care 24 h after admission, or rehospitalization or death within 30 days. RESULTS: A total of 691 hospitalized patients with lower respiratory tract infections were included in the study. The only subgroup of patients with a statistically significant CATE was those with laboratory-confirmed influenza infection with a 26% lower risk of clinical failure when treated with oseltamivir (95% CI 3.2-48.0%). CONCLUSIONS: This study suggests that addition of oseltamivir to standard of care may decrease clinical failure in hospitalized patients with influenza-associated lower respiratory tract infection versus standard of care alone. These results are supportive of current recommendations to initiate antiviral treatment in hospitalized patients with confirmed or suspected influenza as soon as possible after admission. Trial registration Original trial: Clinical Trials.Gov; Rapid Empiric Treatment With Oseltamivir Study (RETOS) (RETOS); ClinicalTrials.gov Identifier: NCT01248715 https://clinicaltrials.gov/ct2/show/NCT01248715.

Outcomes and Risk Factors for Cardiovascular Events in Hospitalized COVID-19 Patients.

OBJECTIVE: To analyze outcomes and risk factors of cardiovascular events in a metropolitan coronavirus disease 2019 (COVID-19) database, and to perform a subgroup analysis in African American populations to determine whether outcomes and risk factors are influenced by race. DESIGN: Retrospective cohort analysis from March 9, 2020 to June 20, 2020. SETTING: Population-based study in Louisville, KY, USA. PARTICIPANTS: Seven hundred adult inpatients hospitalized with COVID-19. INTERVENTIONS: N/A. MEASUREMENTS AND MAIN RESULTS: This cohort consisted of 126 patients (18%) with cardiovascular events and 574 patients without cardiovascular events. Patients with cardiovascular events had a much higher mortality rate than those without cardiovascular events (45.2% v 8.7%, p < 0.001). There was no difference between African American and white patients regarding mortality (43.9% v 46.3%, p = 1) and length of stay for survivors (11 days v 9.5 days, p = 0.301). Multiple logistics regression analysis suggested that male, race, lower SaO2/FIO2, higher serum potassium, lower serum albumin, and number of cardiovascular comorbidities were highly associated with the occurrence of cardiovascular events in COVID-19 patients. Lower serum albumin and neoplastic and/or immune-compromised diseases were highly associated with cardiovascular events for African American COVID-19 patients. SaO2/FIO2 ratio and cardiovascular comorbidity count were significantly associated with cardiovascular events in white patients. CONCLUSIONS: Cardiovascular events were prevalent and associated with worse outcomes in hospitalized patients with COVID-19. Outcomes of cardiovascular events in African American and white COVID-19 patients were similar after propensity score matching analysis. There were common and unique risk factors for cardiovascular events in African American COVID-19 patients when compared with white patients.

Effectiveness of 13-Valent Pneumococcal Conjugate Vaccine Against Hospitalization for Community-Acquired Pneumonia in Older US Adults: A Test-Negative Design.

Background: Following universal recommendation for use of 13-valent pneumococcal conjugate vaccine (PCV13) in US adults aged ≥65 years in September 2014, we conducted the first real-world evaluation of PCV13 vaccine effectiveness (VE) against hospitalized vaccine-type community-acquired pneumonia (CAP) in this population. Methods: Using a test-negative design, we identified cases and controls from a population-based surveillance study of adults in Louisville, Kentucky, who were hospitalized with CAP. We analyzed a subset of CAP patients enrolled 1 April 2015 through 30 April 2016 who were aged ≥65 years and consented to have their pneumococcal vaccination history confirmed by health insurance records. Cases were defined as hospitalized CAP patients with PCV13 serotypes identified via culture or serotype-specific urinary antigen detection assay. Remaining CAP patients served as test-negative controls. Results: Of 2034 CAP hospitalizations, we identified PCV13 serotypes in 68 (3.3%) participants (ie, cases), of whom 6 of 68 (8.8%) had a positive blood culture. Cases were less likely to be immunocompromised (29.4% vs 46.4%, P = .02) and overweight or obese (41.2% vs 58.6%, P = .01) compared to controls, but were otherwise similar. Cases were less likely to have received PCV13 than controls (3/68 [4.4%] vs 285/1966 [14.5%]; unadjusted VE, 72.8% [95% confidence interval, 12.8%-91.5%]). No confounding was observed during adjustment for patient characteristics, including immunocompromised status, body mass index, and history of influenza and pneumococcal polysaccharide vaccination (adjusted VE range, 71.1%-73.3%). Conclusions: Our study is the first to demonstrate real-world effectiveness of PCV13 against vaccine-type CAP in adults aged ≥65 years following introduction into a national immunization program.

Elevated Blood Lead Levels by Length of Time From Resettlement to Health Screening in Kentucky Refugee Children.

OBJECTIVES: To examine elevated blood lead levels (EBLLs) in refugee children by postrelocation duration with control for several covariates. METHODS: We assessed EBLLs (≥ 5µg/dL) between 2012 and 2016 of children younger than 15 years (n = 1950) by the duration of resettlement to health screening by using logistic regression, with control for potential confounders (gender, region of birth, age of housing, and intestinal infestation) in a cross-sectional study. RESULTS: Prevalence of EBLLs was 11.2%. Length of time from resettlement to health screening was inversely associated with EBLLs (tertile 2 unadjusted odds ratio [OR] = 0.79; 95% confidence interval [CI] = 0.56, 1.12; tertile 3 OR = 0.62; 95% CI = 0.42, 0.90; tertile 2 adjusted odds ratio [AOR] = 0.62; 95% CI = 0.39, 0.97; tertile 3 AOR = 0.57; 95% CI = 0.34, 0.93). There was a significant interaction between intestinal infestation and age of housing (P < .003), indicating significant risk in the joint exposure of intestinal infestation (a pica proxy) and age of house. CONCLUSIONS: Elevated blood lead levels were reduced with increasing length of time of resettlement in unadjusted and adjusted models. Improved housing, early education, and effective safe-house inspections may be necessary to address EBLLs in refugees.

Infection Prevention and Control Core Practices: A Roadmap for Nursing Practice.

In 2017, the CDC released a set of Core Practices focusing on infection prevention and control relevant for care delivered in all settings. These eight Core Practices address foundational elements of practice and should be embedded into every aspect of nursing care and part of every nurse's professional development plan.

Adults Hospitalized With Pneumonia in the United States: Incidence, Epidemiology, and Mortality.

BACKGROUND: Understanding the burden of community-acquired pneumonia (CAP) is critical to allocate resources for prevention, management, and research. The objectives of this study were to define incidence, epidemiology, and mortality of adult patients hospitalized with CAP in the city of Louisville, and to estimate burden of CAP in the US adult population. METHODS: This was a prospective population-based cohort study of adult residents in Louisville, Kentucky, from 1 June 2014 to 31 May 2016. Consecutive hospitalized patients with CAP were enrolled at all adult hospitals in Louisville. The annual population-based CAP incidence was calculated. Geospatial epidemiology was used to define ecological associations among CAP and income level, race, and age. Mortality was evaluated during hospitalization and at 30 days, 6 months, and 1 year after hospitalization. RESULTS: During the 2-year study, from a Louisville population of 587499 adults, 186384 hospitalizations occurred. A total of 7449 unique patients hospitalized with CAP were documented. The annual age-adjusted incidence was 649 patients hospitalized with CAP per 100000 adults (95% confidence interval, 628.2-669.8), corresponding to 1591825 annual adult CAP hospitalizations in the United States. Clusters of CAP cases were found in areas with low-income and black/African American populations. Mortality during hospitalization was 6.5%, corresponding to 102821 annual deaths in the United States. Mortality at 30 days, 6 months, and 1 year was 13.0%, 23.4%, and 30.6%, respectively. CONCLUSIONS: The estimated US burden of CAP is substantial, with >1.5 million unique adults being hospitalized annually, 100000 deaths occurring during hospitalization, and approximately 1 of 3 patients hospitalized with CAP dying within 1 year.

Public reporting of health care-associated surveillance data: recommendations from the healthcare infection control practices advisory committee.

Health care-associated infection (HAI) rates are used as measures of a health care facility's quality of patient care. Recently, these outcomes have been used to publicly rank quality efforts and determine facility reimbursement. The value of comparing HAI rates among health care facilities is limited by many factors inherent to HAI surveillance, and incentives that reward low HAI rates can lead to unintended consequences that can compromise medical care surveillance efforts, such as the use of clinical adjudication panels to veto events that meet HAI surveillance definitions.The Healthcare Infection Control Practices Advisory Committee, a federal advisory committee that provides advice and guidance to the Centers for Disease Control and Prevention (CDC) and the Secretary of the Department of Health and Human Services about strategies for surveillance, prevention, and control of HAIs, assessed the challenges associated with using HAI surveillance data for external quality reporting, including the unintended consequences of clinician veto and clinical adjudication panels. Discussions with stakeholder liaisons and committee members were then used to formulate recommended standards for the use of HAI surveillance data for external facility assessment to ensure valid comparisons and to provide as level a playing field as possible.The final recommendations advocate for consistent, objective, and independent application of CDC HAI definitions with concomitant validation of HAIs and surveillance processes. The use of clinician veto and adjudication is discouraged.

Assisting the infection preventionist: Use of artificial intelligence for health care-associated infection surveillance.

BACKGROUND: Health care-associated infection (HAI) surveillance is vital for safety in health care settings. It helps identify infection risk factors, enhancing patient safety and quality improvement. However, HAI surveillance is complex, demanding specialized knowledge and resources. This study investigates the use of artificial intelligence (AI), particularly generative large language models, to improve HAI surveillance. METHODS: We assessed 2 AI agents, OpenAI's chatGPT plus (GPT-4) and a Mixtral 8×7b-based local model, for their ability to identify Central Line-Associated Bloodstream Infection (CLABSI) and Catheter-Associated Urinary Tract Infection (CAUTI) from 6 National Health Care Safety Network training scenarios. The complexity of these scenarios was analyzed, and responses were matched against expert opinions. RESULTS: Both AI models accurately identified CLABSI and CAUTI in all scenarios when given clear prompts. Challenges appeared with ambiguous prompts including Arabic numeral dates, abbreviations, and special characters, causing occasional inaccuracies in repeated tests. DISCUSSION: The study demonstrates AI's potential in accurately identifying HAIs like CLABSI and CAUTI. Clear, specific prompts are crucial for reliable AI responses, highlighting the need for human oversight in AI-assisted HAI surveillance. CONCLUSIONS: AI shows promise in enhancing HAI surveillance, potentially streamlining tasks, and freeing health care staff for patient-focused activities. Effective AI use requires user education and ongoing AI model refinement.

Knowledge and confidence gains after a COVID-19 vaccine continuing education program developed for nurse practitioners.

ABSTRACT: The COVID-19 pandemic has been marked by rapid innovation in vaccine development. Given that nurse practitioners (NPs) are often involved in vaccine counseling and administration, the American Association of Nurse Practitioners developed a continuing education (CE) series that covered COVID-19 vaccine development, recommendations, administration, and solutions for overcoming hesitancy. In 2020 and 2021, three separate live webinars were delivered; each webinar was updated with the latest vaccine recommendations and was then archived in an enduring format for up to 4 months. The goal of this study was to assess changes in preactivity and postactivity knowledge and confidence and to qualitatively report other learner outcomes. Across the three webinars, 3,580 unique learners who self-reported seeing patients eligible for COVID-19 vaccination completed at least one activity. Knowledge and competence improved from the preactivity to postactivity survey in all webinars, with the overall rates of correct answers increasing by 30% after webinar 1, 37% after webinar 2, and 28% after webinar 3 (all p < .001). Furthermore, mean confidence in learner's ability to address vaccine hesitancy improved across all three webinars (range, 31-32%; all p < .001). The majority of learners indicated that they planned to incorporate lessons from the activity into their clinical practice (range, 85-87%). In postactivity surveys, vaccine hesitancy was identified as an ongoing barrier by up to 33% of learners. In conclusion, this CE activity improved learner knowledge, competence, and confidence related to COVID-19 vaccination and underscores the importance of up-to-date CE targeted to NPs.

Epidemiology of Pneumococcal Pneumonia in Louisville, Kentucky, and Its Estimated Burden of Disease in the United States.

Streptococcus pneumoniae remains a primary pathogen in hospitalized patients with community-acquired pneumonia (CAP). The objective of this study was to define the epidemiology of pneumococcal pneumonia in Louisville, Kentucky, and to estimate the burden of pneumococcal pneumonia in the United States (US). This study was nested in a prospective population-based cohort study of all adult residents in Louisville, Kentucky, who were hospitalized with CAP from 1 June 2014 to 31 May 2016. In hospitalized patients with CAP, urinary antigen detection of 24 S. pneumoniae serotypes (UAD-24) was performed. The annual population-based pneumococcal pneumonia incidence was calculated. The distribution of S. pneumoniae serotypes was characterized. Ecological associations between pneumococcal pneumonia and income level, race, and age were defined. Mortality was evaluated during hospitalization and at 30 days, 6 months, and 1 year after hospitalization. Among the 5402 CAP patients with a UAD-24 test performed, 708 (13%) patients had pneumococcal pneumonia. The annual cumulative incidence was 93 pneumococcal pneumonia hospitalizations per 100,000 adults (95% CI = 91-95), corresponding to an estimated 226,696 annual pneumococcal pneumonia hospitalizations in the US. The most frequent serotypes were 19A (12%), 3 (11%), and 22F (11%). Clusters of cases were found in areas with low incomes and a higher proportion of Black or African American population. Pneumococcal pneumonia mortality was 3.7% during hospitalization, 8.2% at 30 days, 17.6% at 6 months, and 25.4% at 1 year after hospitalization. The burden of pneumococcal pneumonia in the US remains significant, with an estimate of more than 225,000 adults hospitalized annually, and approximately 1 out of 4 hospitalized adult patients dies within 1 year after hospitalization.

Community-Acquired Pneumonia in the Immunocompromised Host: Epidemiology and Outcomes.

Background: The epidemiology and outcomes of community-acquired pneumonia (CAP) in immunocompromised hosts (ICHs) are not well defined. The objective of this study was to define the epidemiology and outcomes of CAP in ICHs as compared with non-ICHs. Methods: This ancillary study included a prospective cohort of hospitalized adult Louisville residents with CAP from 1 June 2014 to 31 May 2016. An ICH was defined per the criteria of the Centers for Disease Control and Prevention. Geospatial epidemiology explored associations between ICHs hospitalized with CAP and income level, race, and age. Mortality for ICHs and non-ICHs was evaluated during hospitalization and 30 days, 6 months, and 1 year after hospitalization. Results: A total of 761 (10%) ICHs were identified among 7449 patients hospitalized with CAP. The most common immunocompromising medical conditions or treatments were advanced-stage cancer (53%), cancer chemotherapy (23%), and corticosteroid use (20%). Clusters of ICHs hospitalized with CAP were found in areas associated with low-income and Black or African American populations. Mortality by time point for ICHs vs non-ICHs was as follows: hospitalization, 9% vs 5%; 30 days, 24% vs 11%; 6 months, 44% vs 21%; and 1 year, 53% vs 27%, respectively. Conclusions: Approximately 1 in 10 hospitalized patients with CAP is immunocompromised, with advanced-stage cancer being the most frequent immunocompromising condition, as seen in half of all patients who are immunocompromised. Risk for hospitalization may be influenced by socioeconomic disparities and/or race. ICHs have a 2-fold increase in mortality as compared with non-ICHs.

Implementing strategies to prevent infections in acute-care settings.

This document introduces and explains common implementation concepts and frameworks relevant to healthcare epidemiology and infection prevention and control and can serve as a stand-alone guide or be paired with the "SHEA/IDSA/APIC Compendium of Strategies to Prevent Healthcare-Associated Infections in Acute Care Hospitals: 2022 Updates," which contain technical implementation guidance for specific healthcare-associated infections. This Compendium article focuses on broad behavioral and socio-adaptive concepts and suggests ways that infection prevention and control teams, healthcare epidemiologists, infection preventionists, and specialty groups may utilize them to deliver high-quality care. Implementation concepts, frameworks, and models can help bridge the "knowing-doing" gap, a term used to describe why practices in healthcare may diverge from those recommended according to evidence. It aims to guide the reader to think about implementation and to find resources suited for a specific setting and circumstances by describing strategies for implementation, including determinants and measurement, as well as the conceptual models and frameworks: 4Es, Behavior Change Wheel, CUSP, European and Mixed Methods, Getting to Outcomes, Model for Improvement, RE-AIM, REP, and Theoretical Domains.

Diagnosis of Respiratory Syncytial Virus in Adults Substantially Increases When Adding Sputum, Saliva, and Serology Testing to Nasopharyngeal Swab RT-PCR.

INTRODUCTION: Nearly all existing respiratory syncytial virus (RSV) incidence estimates are based on real-time polymerase chain reaction (RT-PCR) testing of nasal or nasopharyngeal (NP) swabs. Adding testing of additional specimen types to NP swab RT-PCR increases RSV detection. However, prior studies only made pairwise comparisons and the synergistic effect of adding multiple specimen types has not been quantified. We compared RSV diagnosis by NP swab RT-PCR alone versus NP swab plus saliva, sputum, and serology. METHODS: This was a prospective cohort study over two study periods (27 December 2021 to 1 April 2022 and 22 August 2022 to 11 November 2022) of patients aged ≥ 40 years hospitalized for acute respiratory illness (ARI) in Louisville, KY. NP swab, saliva, and sputum specimens were collected at enrollment and PCR tested (Luminex ARIES platform). Serology specimens were obtained at acute and convalescent timepoints (enrollment and 30-60-day visit). RSV detection rate was calculated for NP swab alone and for NP swab plus all other specimen type/test. RESULTS: Among 1766 patients enrolled, 100% had NP swab, 99% saliva, 34% sputum, and 21% paired serology specimens. RSV was diagnosed in 56 (3.2%) patients by NP swab alone, and in 109 (6.2%) patients by NP swab plus additional specimens, corresponding to a 1.95 times higher rate [95% confidence interval (CI) 1.62, 2.34]. Limiting the comparison to the 150 subjects with all four specimen types available (i.e., NP swab, saliva, sputum, and serology), there was a 2.60-fold increase (95% CI 1.31, 5.17) compared to NP swab alone (3.3% versus 8.7%). Sensitivities by specimen type were: NP swab 51%, saliva 70%, sputum 72%, and serology 79%. CONCLUSIONS: Diagnosis of RSV in adults was several-fold greater when additional specimen types were added to NP swab, even with a relatively low percentage of subjects with sputum and serology results available. Hospitalized RSV ARI burden estimates in adults based solely on NP swab RT-PCR should be adjusted for underestimation.

23-Valent Pneumococcal Polysaccharide Vaccination Does Not Prevent Community-Acquired Pneumonia Hospitalizations Due to Vaccine-Type Streptococcus pneumoniae.

Controversy exists regarding the clinical effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) for the prevention of serotype-specific community-acquired pneumonia (CAP). The objective of this study was to define the effectiveness of PPSV23 for the prevention of CAP hospitalizations due to vaccine-contained serotypes. This secondary analysis was a nested case-control, test-negative study design of adult patients hospitalized for CAP between 1 June 2014 and 31 March 2017. Cases included patients with CAP due to a S. pneumoniae serotype contained in the PPSV23. Urinary antigen detection of the 23 serotypes was performed. In the study, PPSV23 vaccination alone and no other pneumococcal vaccination was the primary exposure of interest. Vaccine effectiveness was calculated as (1-OR) × 100. Adjusted estimates were obtained from a logistic regression model that controlled for confounding variables. A total of 3686 patients were included in the analysis. The PPSV23 vaccination was documented in 608 (16%) patients, and the PPSV23-serotype CAP was detected in 48 (8%) PPSV23-vaccinated patients and in 288 (9%) non-vaccinated patients. Unadjusted vaccine effectiveness for preventing PPSV23-serotype CAP was 17% (95% CI: -13% to 40%). Adjusted estimates for preventing PPSV23-serotype CAP was 14% (95% CI: -17% to 38%). In this study, PPSV23 vaccination offered no protection against PPSV23-serotype CAP hospitalization in adults. This is the first PPSV23 vaccine effectiveness study from United States that utilized a urinary antigen detection assay as the main method for S. pneumoniae serotyping. This study highlights the need for more effective vaccines in the prevention of hospitalization due to S. pneumoniae CAP.