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.

Persistent SARS-CoV-2 Infection in a Multiple Sclerosis Patient on Ocrelizumab: A Case Report.

A 44-year-old female patient with multiple sclerosis (MS) treated with ocrelizumab was hospitalized with SARS-CoV-2 pneumonia three times over the course of five months, eventually expiring. Viral sequencing of samples from her first and last admissions suggests a single persistent SARS-CoV-2 infection. We hypothesize that her immunocompromised state, due to MS treatment with an immunosuppressive monoclonal antibody, prevented her from achieving viral clearance.

Induction of interferon response by high viral loads at early stage infection may protect against severe outcomes in COVID-19 patients.

Key elements for viral pathogenesis include viral strains, viral load, co-infection, and host responses. Several studies analyzing these factors in the function of disease severity of have been published; however, no studies have shown how all of these factors interplay within a defined cohort. To address this important question, we sought to understand how these four key components interplay in a cohort of COVID-19 patients. We determined the viral loads and gene expression using high throughput sequencing and various virological methods. We found that viral loads in the upper respiratory tract in COVID-19 patients at an early phase of infection vary widely. While the majority of nasopharyngeal (NP) samples have a viral load lower than the limit of detection of infectious viruses, there are samples with an extraordinary amount of SARS-CoV-2 RNA and a high viral titer. No specific viral factors were identified that are associated with high viral loads. Host gene expression analysis showed that viral loads were strongly correlated with cellular antiviral responses. Interestingly, however, COVID-19 patients who experience mild symptoms have a higher viral load than those with severe complications, indicating that naso-pharyngeal viral load may not be a key factor of the clinical outcomes of COVID-19. The metagenomics analysis revealed that the microflora in the upper respiratory tract of COVID-19 patients with high viral loads were dominated by SARS-CoV-2, with a high degree of dysbiosis. Finally, we found a strong inverse correlation between upregulation of interferon responses and disease severity. Overall our study suggests that a high viral load in the upper respiratory tract may not be a critical factor for severe symptoms; rather, dampened antiviral responses may be a critical factor for a severe outcome from the infection.

The reliability of saliva for the detection of SARS-CoV-2 in symptomatic and asymptomatic patients: Insights on the diagnostic performance and utility for COVID-19 screening.

Current literature has focused on testing saliva in symptomatic patients, and little information is available regarding saliva performance in asymptomatic severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. We compared paired saliva and nasopharyngeal swabs (NPS) collected from 33 symptomatic and 12 asymptomatic known SARS-CoV-2-positive patients. Saliva had an overall sensitivity of 59%, a specificity of 95%, and a negative predictive value of 98%. Saliva demonstrated higher sensitivity in symptomatic (80%) vs. asymptomatic individuals (36%) (P = 0.006), and in high-risk (symptomatic, febrile and/or with comorbidities) (82%) vs. low-risk (asymptomatic, afebrile, and no comorbidities) (22%) patients (P = 0.0002). Cycle threshold (Ct) values in NPS specimens were higher in saliva-negative vs. saliva-positive cases (P = 0.02 and <0.001). Overall, these findings show that despite saliva's low sensitivity in asymptomatic SARS-CoV-2 infections, it can detect infections with lower Ct values and a potentially higher chance of viral transmission. Additional studies are warranted to fully evaluate saliva as a screening test for coronavirus disease-2019.

Pneumonia in older adults.

PURPOSE OF REVIEW: The purpose of this review is to address the relevant issues surrounding older adults with community-acquired pneumonia (CAP) today. RECENT FINDINGS: Approximately 1 million people >65 years have CAP in the US per year, which is more than previously reported (or realized). Older adults are vulnerable to the increasing prevalence of viral CAP, as the SARS-CoV-2 pandemic emphasizes, but pneumococcus is still the most common pathogen to cause CAP. Racial disparities continue to need to be addressed in order to improve early and late outcomes of older adults with CAP. SUMMARY: The epidemiology of CAP, specifically for older adults is changing. More recent pathogen incidence studies have included culture, as well as newer microbiological methods to determine etiology. Current disparities among disadvantaged populations, including African-Americans, result in more comorbidities which predisposes to more severe CAP. However, outcomes in the hospital between races tend to be similar, and outcomes between age groups tends to be worse for older compared to younger adults. Finally, the cost of CAP is significant compared to diabetes mellitus, myocardial infarction and stroke.

Surveillance testing reveals a significant proportion of hospitalized patients with SARS-CoV-2 are asymptomatic.

BACKGROUND: The proportion of positive patients admitted to acute-care hospitals for reasons other than coronavirus disease-19 (COVID-19) is unknown. These patients potentially put other patients and healthcare workers at risk of infection. OBJECTIVE: The objective of this study was to define the proportion of asymptomatic patients admitted with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Secondary objectives were to define the positivity rate, reasons for admission, and the geographic distribution in the region. METHODS: Universal surveillance testing for SARS-CoV-2 was performed on patients admitted to this hospital over a 12-week period from April 9, 2020 to July 1, 2020. Positive patients were categorized as either symptomatic or asymptomatic as defined by the 11 criteria per the Centers for Disease Control and Prevention. The positivity rate, proportion with and without symptoms, reasons for admission, and geographic distribution in the region were recorded. RESULTS: The positivity rate ranged from 0.8% to 6.2%. The proportion of asymptomatic patients with SARS-CoV-2 was 37%. Asymptomatic patients primarily presented to the hospital because of either trauma or labor. Some clusters in the region were identified of both symptomatic and asymptomatic patients. CONCLUSIONS: The proportion of asymptomatic patients admitted with SARS-CoV-2 was significant. Identifying and isolating asymptomatic patients likely prevented exposure and development of hospital-acquired COVID-19 cases among healthcare workers and other patients, supporting the universal surveillance of all admitted patients.