Background: Viral pneumonia is a common complication of influenza like illness including COVID-19. Virus is the most common cause of pneumonia in children. While there are important cues in history, the laboratory examination that can help differentiate viral and bacterial causes. There are limited clinical manifestations to differentiate viral and co-infection bacterial and viral pneumonia.

Objective: To determine basic clinical manifestations and laboratory performed at bedside as predictors to differentiate viral and co-infection bacterial and viral pneumonia.

Materials and Methods: A retrospective study was conducted in pediatric patients with radiographic evidence of severe pneumonia and admitted in Nakornping Hospital, Chiang Mai, Thailand between October 2017 and April 2020. Multiplex real time polymerase chain reactions (PCRs) (RP-24-26) were used to identify the cause of the pneumonia. Demographic data and basic clinical predictors such as age, comorbidity, symptoms, and physical findings, and basic laboratory such as complete blood count were collected. Patients were divided into three groups, no infection detected, viral infection, and bacterial and viral co-infection. Polytomous logistic regression was performed to investigate predictors for type of infection. Area under the receiver operating characteristic curve (AuROC) and 95% confidence interval (CI) were further determined for a final model to differentiate type of infection.

Results: Two hundred eight cases participated in this study and included 122 males (58.7%). The etiology of pneumonia identified by RP-24-26, pathogen was detected among 166 cases (79.8%). A virus was detected in 141 cases (67.8%), co-infection was detected in 25 cases (12%), and no infection was detected in 42 cases (20.2%). The statistically significant predictor for viral pneumonia was cough, with an adjusted relative risk ratio (RRR) of 4.42 (1.41 to 13.82). The statistically significant predictors for co-infection were age 13 to 24 months and lymphocytes at 40.0% or greater with adj. RRR 14.28 (1.47 to 138.52), and 4.60 (1.24 to 17.04), respectively. Pneumonia patients with cough were 4.42 times more to have viral cause. Those with lymphocytes of 40.0% or greater were 4.60 times more to be co-infected with both virus and bacteria, especially in the age group 13 to 24 months compared with 1 to 12 months. The age group13 to 24 months, cough, and lymphocytes at 40.0% or greater were 74% (95% CI 0.66 to 0.82) correctly predicted to viral pneumonia.

Conclusion: Coughing is a predominant symptom for childhood pneumonia caused by virus. In addition, pneumonia patients age 13 to 24 months who have lymphocyte of more than 40% should start and continue antibiotics until complete course.

Keywords: Childhood pneumonia, Respiratory panel 24, Respiratory panel 26, Co-infection bacterial pneumonia, Predictor

DOI: doi.org/10.35755/jmedassocthai.2020.12.11568

Received 23 June 2020 | Revised 6 October 2020 | Accepted 8 October 2020