Lower respiratory tract infection bacterial

To investigate the value of apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), and ApoA1/B ratio in pathogenic diagnosis of chronic obstructive pulmonary disease (COPD) complicated by acute lower respiratory tract infection, assisting comprehensive disease assessment.

The study enrolled 171 COPD patients with acute lower respiratory tract infections, 35 COPD patients without acute lower respiratory tract infections, and 41 healthy controls. Correlation analysis and binary logistic regression were used to assess the roles of various factors in COPD with acute lower respiratory tract infections. Receiver operating characteristic (ROC) curves were plotted and area under curves (AUC) values were calculated to evaluate the predictive performance.

Infections were the cause of alterations in ApoA1, ApoB and ApoA1/B index. In correlation analysis for pathogenic diagnosis of COPD complicated by acute lower respiratory infections, age, ApoA1, ApoA1/B ratio, lymphocyte count (LYMPH), neutrophil count (NEUT), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and endotoxin were significantly correlated. For predicting COPD complicated by acute lower respiratory tract bacterial infection, ApoA1 had the highest area under the ROC curve (AUC: 0.889), with sensitivity and specificity of 82.9% and 83.9%, respectively. The combination of NEUT and ApoA1 improved the prediction efficacy (AUC: 0.909; sensitivity/specificity: 85.1%/85.7%).

ApoA1, ApoB, and ApoA1/B ratio are good indicators for predicting pathogens in COPD complicated by acute lower respiratory tract infection, especially ApoA1 which has high predictive value.

Correlations between SARS-CoV-2 and bacterial infections have mainly been studied in hospitals, and these studies have shown that such interactions may be lethal for many. In the context of community flora, less is known of the trends and consequences of viral infections relative to subsequent bacterial infections.

This study aims to explore the prevalence and characteristics of bacterial infections in the three months following SARS-CoV-2 infections, in a community, real-world setting.

In this retrospective cohort study, we compared patients who completed a polymerase chain reaction (PCR) test or an antigen test for SARS-CoV-2 during January 2022, the peak of the Omicron wave, and examined bacterial infections following the test. We searched these cases for diagnoses of the following four bacterial infections for three months following the test: Group A Streptococcus (GAS) pharyngitis, pneumonia, cellulitis, and urinary tract infections (UTI).

During January 2022, 267,931 patients tested positive and 261,909 tested negative for SARS-CoV-2. Test-positive compared to test-negative patients were significantly younger (42.5 years old vs. 48.5 years old, p < 0.001), smoked less, and had fewer comorbidities (including ischemic heart disease, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, and chronic renal failure). In the multivariable analysis, test-positive patients had an increased risk for GAS pharyngitis (adjusted odds ratio [aOR] = 1.25, 95% CI 1.14-1.38, p-value < 0.001) and pneumonia (aOR = 1.25, 95% CI 1.15-1.35, p-value < 0.001), a trend towards an increased prevalence of UTI (aOR = 1.05, 95% CI 0.99-1.12, p-value = 0.092), and lower risk for cellulitis (aOR = 0.92, 95% CI 0.86-0.99, p-value < 0.05).

A history of SARS-CoV-2 infection in the past three months increased susceptibility to respiratory tract bacterial infections and the prevalence of UTI.

Viral bronchiolitis is a common cause of acute respiratory failure requiring intubation for infants. Bacterial respiratory tract infections can occur with bronchiolitis, although their prevalence and impact on outcomes are unclear, especially with increased use of noninvasive respiratory support.

This was a single-center retrospective cohort study of children <2 years old requiring intubation in the emergency department for bronchiolitis from 2012 to 2017 who had viral testing plus a lower respiratory culture obtained. We evaluated the impact of bacterial codetection (positive respiratory culture plus moderate or many polymorphonuclear neutrophils on Gram stain) on mechanical ventilation (MV) duration and intensive care unit length of stay using multivariable gamma regression.

Of 149 patients enrolled, 52% had bacterial codetection. In adjusted analysis, patients with codetection had shorter MV duration [adjusted relative risk (aRR) 0.819, 95% confidence interval (CI): 0.69-0.98; marginal mean duration of 5.31 days (4.71-5.99) compared to 6.48 days (5.72-7.35) without codetection]. Patients with codetection had a shorter intensive care unit stay [aRR 0.806 (0.69-0.94); marginal mean length of stay 6.9 days (6.21-7.68) vs. 8.57 days (7.68-9.56) without codetection]. The association between codetection and duration of ventilation appears confined to those receiving earlier antibiotics (less than the median time) rather than later antibiotics [aRR 0.738 (0.56-0.95) for earlier vs. aRR 0.92 (0.70-1.18) for later].

Respiratory bacterial codetection is common and associated with shorter MV duration in infants requiring early intubation for bronchiolitis. Early antibiotics may contribute to these outcomes, but further multicenter studies are needed to understand the role of codetection and antibiotics on bronchiolitis outcomes.