Factors affecting the severity of respiratory infections: a hospital-based cross-sectional study.

BACKGROUND

Acute respiratory infections (ARIs) are a leading cause of global morbidity and mortality, with disease severity influenced by factors such as advanced age, underlying comorbidities, and pathogen type. This report analyzed the association between several clinical variables and disease severity.

METHODS

A hospital-based cross-sectional study was conducted from September 2023 to April 2024, with data collected from eight districts in Chongqing, China. The study included 1,638 patients with ARIs, including both severe and mild cases. Severe cases were identified using the qSOFA and APACHE II scores, while demographic and clinical data were obtained via questionnaires and hospital records. Pathogen detection was performed using real-time quantitative PCR. Data analysis was carried out using Stata 17.0, with multiple logistic regression models assessing the associations between clinical factors and disease severity.

RESULTS

Influenza A was the most prevalent pathogen, detected in 65.1% of severe cases and 32.9% of mild cases (P < 0.001). 42.0% (165/393) of severe cases had viral and bacterial co-infections, compared to 26.8% (334/1,245) of mild cases (P < 0.001). The most common pathogens in co-infections included influenza A and Streptococcus pneumoniae. Severe cases were more common in rural areas (28.8% vs. 18.1%, P < 0.001) and among older adults (≥ 60 years) (28.2% vs. 13.5%, P < 0.001). Clinical symptoms such as fever (61.8% vs. 40.9%, P < 0.001), cough (68.7% vs. 53.2%, P < 0.001), and dyspnea (34.8% vs. 15.1%, P < 0.001) were significantly more prevalent in severe cases. Logistic regression analysis showed that influenza A (OR: 4.52, 95% CI: 3.51-5.85), Streptococcus pneumoniae (OR: 1.54, 95% CI: 1.28-2.15), and pre-existing cardiovascular diseases (OR: 1.96, 95% CI: 1.28-2.99) were significantly associated with the development of severe outcomes.

CONCLUSIONS

This study underscores the complex interplay of factors influencing ARI severity, including pathogen type, co-infections, age, and underlying medical conditions. Early identification of high-risk patients, particularly those with bacterial co-infections and cardiovascular comorbidities, is essential for improving clinical outcomes in ARI patients. Targeted treatment and preventative strategies are needed to mitigate severe disease in vulnerable populations.

CLINICAL TRIAL NUMBER: Not applicable.