Evaluation of Inflammatory Markers and Clinical Outcomes in COVID-19 Patients with Concurrent Infection: A Comparative Cohort Analysis.

Background And Objectives: Co-infection with () in COVID-19 patients has emerged as a clinical challenge associated with increased morbidity and mortality. While both infections elicit systemic inflammation, the interplay between inflammatory markers, disease severity, and outcomes in patients with COVID-19 and concurrent infection remains poorly characterized. This study aimed to evaluate the inflammatory status and clinical outcomes of patients hospitalized with COVID-19, with and without co-infection, and to identify the inflammatory markers most predictive of severe disease.

Methods: We conducted a retrospective cohort study of 200 hospitalized adults with confirmed COVID-19, of whom 92 had laboratory-confirmed infection. Baseline demographic data, comorbidities, inflammatory markers (C-reactive protein [CRP], interleukin-6 [IL-6], ferritin, neutrophil-to-lymphocyte ratio [NLR], platelet count, albumin, and derived indices such as the CRP-to-Albumin Ratio [CAR] and Prognostic Nutritional Index [PNI]) were recorded. Clinical outcomes included ICU admission, need for mechanical ventilation, length of stay, and in-hospital mortality.

Results: Patients with COVID-19 and co-infection had significantly elevated inflammatory markers (CRP, IL-6, NLR) and higher CAR, alongside lower PNI, compared to those with COVID-19 alone ( < 0.001). Inflammatory indices correlated strongly with disease severity: elevated CAR and low PNI were associated with higher odds of ICU admission and mortality ( < 0.001). Multivariate analysis identified co-infection status, increased IL-6, and elevated CAR as independent predictors of severe outcomes.

Conclusions: co-infection in COVID-19 patients is associated with an intensified inflammatory response and worse clinical outcomes. Among the evaluated markers, CAR and PNI emerged as robust predictors of severe disease. Timely recognition of co-infection and use of targeted anti-inflammatory and supportive therapies may improve patient management. Future studies should expand on these findings to optimize care and guide therapeutic strategies.