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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The burden of noninvasive group B Streptococcus (GBS) infections in adults is unknown. We determined population-based rates of hospitalization where invasive or noninvasive GBS infections were identified among US adults in a defined catchment area.Methods: We identified adults with clinical and laboratory-confirmed evidence of GBS infection from January 2014 through December 2016 from 6 hospitals in Louisville, Kentucky. Invasive disease was defined as GBS isolated from a normally sterile site.Results: Among 1076 adults with GBS infection, the median age was 52 years, 51% were male, and 89% had ≥1 chronic medical condition. The most prevalent infection sites were skin and soft tissue (39%), urinary tract (23%), bone and joint (16%), and bloodstream (11%). Forty percent of infections were polymicrobial. The annual incidence of GBS-associated hospitalization was 73 per 100 000 adults and 68 and 100 per 100 000 for patients aged 18-64 and ≥ 65 years, respectively. For every invasive GBS infection, 3.7 noninvasive infections occurred.Conclusions: Our population-based study outlines the full burden of GBS-associated hospitalization in adults and found incidence rates comparable to those of pneumococcal disease, where vaccines are recommended. Noninvasive disease was 3-4 times more common than invasive disease, suggesting that the GBS burden among adults is considerably greater than previously recognized. [ABSTRACT FROM AUTHOR]

Serotype 3 pneumococcal disease has not substantially declined at the population level after the routine introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into pediatric immunization programs across the globe. This epidemiological finding has generated debate regarding the effectiveness of PCV13 against serotype 3 disease. Evaluating PCV13 effectiveness against serotype 3 is especially critical in adults, where serotype 3 makes up an important amount of remaining pneumococcal disease. We performed a systematic review of the published literature to assess the direct effectiveness of PCV13 against serotype 3 community-acquired pneumonia (CAP) among adults. We then estimated overall vaccine effectiveness (VE) using a pooled analysis of the individual-level, raw data. Two published studies met inclusion criteria. One was a randomized controlled trial conducted in the Netherlands and published in 2014. The other was a recently-published case-control study conducted in Louisville, Kentucky that used a test-negative design (TND). We also identified a third TND study conducted in Argentina that was recently presented as a conference abstract but is not yet published. All three studies were conducted in adults aged ≥65 years. PCV13 VE against serotype 3 hospitalized CAP was 52.5% (95%CI: 6.2–75.9%) from the pooled analysis of individual-level data from all three studies. Results were similar if the unpublished estimate was excluded (serotype 3 VE = 53.6% [95%CI: 6.7–76.9%]). No heterogeneity was observed. Currently-available evidence, although limited to three studies, suggests that PCV13 provides direct protection against serotype 3 hospitalized CAP in adults aged ≥65 years. [ABSTRACT FROM AUTHOR]