Risk factors associated with severe disease in respiratory syncytial virus infected children under 5 years of age.

Objective: To evaluate risk factors for severe disease in children under 59 months of age hospitalized with respiratory syncytial virus (RSV) infection. Study design: We prospectively enrolled 1,096 cases of laboratory confirmed RSV infection during three consecutive RSV seasons in 2015-2018. Potential risk factors for severe disease were retrieved through patient questionnaires and linkage to national health registries. Need for respiratory support (invasive ventilation, bi-level positive airway pressure, or continuous positive airway pressure), and length of stay exceeding 72 h were used as measures of disease severity. Associations were investigated using multivariable logistic regression analyses. Multiple imputation was used to avoid bias and inference induced by missing data. Results: Risk factors associated with a need for respiratory support included age younger than 3 months of age [aOR: 6.73 (95% CI 2.71-16.7)], having siblings [aOR: 1.65 (95% CI 1.05-2.59)] and comorbidity [aOR: 2.40 (95% CI 1.35-4.24)]. The length of hospital stay >72 h was significantly associated with being younger than 3 months of age [aOR: 3.52 (95% CI 1.65-7.54)], having siblings [aOR: 1.45 (95% CI 1.01-2.08)], and comorbidity [aOR: 2.18 (95% CI 1.31-3.61)]. Sub-group analysis of children younger than 6 months of age confirmed the association between both young age and having siblings and the need for respiratory support. Conclusion: In a large cohort of children <59 months hospitalized with RSV infection, young age, comorbidity, and having siblings were associated with more severe disease.

Evaluation of eleven rapid tests for detection of antibodies against SARS-CoV-2.

Objectives: SARS-CoV-2, causing COVID-19, has emerged to cause a human pandemic. Detection of SARS-CoV-2 in respiratory samples by using PCR is the standard laboratory diagnostic tool. Our aim was to perform a limited evaluation of the diagnostic performance and user-friendliness of eleven rapid tests for detection of antibodies against SARS-CoV-2. Methods: All participants were tested with PCR against SARS-CoV-2 at a clinical microbiology laboratory. Comparing with results from PCR tests, we evaluated the rapid tests' performances in three arms; 1) 20 hospitalized patients with PCR-confirmed COVID-19, 2) 23 recovered outpatients with former PCR-confirmed COVID-19, and 3) 49 participants with suspected COVID-19 presenting at a primary care emergency room. Results: All eleven tests detected antibodies in hospitalized COVID-19 patients, though with varying sensitivities. In former outpatients recovered from COVID-19, there were differences between tests in the immunoglobulin type G (IgG) sensitivity, with five tests having a sensitivity below 65%. In participants with suspected COVID-19 infection, the rapid tests had very low sensitivities. Most rapid tests were easy to perform and interpret. Conclusions: Rapid tests were not suited as stand-alone tests to detect present infection in a Norwegian primary care emergency room population. All the rapid tests were able to detect SARS-CoV-2 antibodies, although sensitivities varied and were generally higher in the study arm of more severely affected participants. Rapid tests with high IgG sensitivity (and specificity) may be useful for confirmation of past infection. An independent evaluation should be performed in the intended population before introducing a rapid test.

Stratification by interferon-γ release assay level predicts risk of incident TB.

INTRODUCTION: Targeted testing and treatment of latent TB infection (LTBI) are priorities on the global health agenda, but LTBI management remains challenging. We aimed to evaluate the prognostic value of the QuantiFERON TB-Gold (QFT) test for incident TB, focusing on the interferon (IFN)-γ level, when applied in routine practice in a low TB incidence setting. METHODS: In this large population-based prospective cohort, we linked QFT results in Norway (1 January 2009-30 June 2014) with national registry data (Norwegian Surveillance System for Infectious Diseases, Norwegian Prescription Database, Norwegian Patient Registry and Statistics Norway) to assess the prognostic value of QFT for incident TB. Participants were followed until 30 June 2016. We used restricted cubic splines to model non-linear relationships between IFN-γ levels and TB, and applied these findings to a competing risk model. RESULTS: The prospective analyses included 50 389 QFT results from 44 875 individuals, of whom 257 developed TB. Overall, 22% (n=9878) of QFT results were positive. TB risk increased with the IFN-γ level until a plateau level, above which further increase was not associated with additional prognostic information. The HRs for TB were 8.8 (95% CI 4.7 to 16.5), 19.2 (95% CI 11.6 to 31.6) and 31.3 (95% CI 19.8 to 49.5) times higher with IFN-γ levels of 0.35 to <1.00, 1.00 to <4.00 and >4.00 IU/mL, respectively, compared with negative tests (<0.35 IU/mL). CONCLUSIONS: Consistently, QFT demonstrates increased risk of incident TB with rising IFN-γ concentrations, indicating that IFN-γ levels may be used to guide targeted treatment of LTBI.