Is H3N2 Pneumonia Different from Other Community-Acquired Pneumonia?

Objective: To evaluate the clinical, laboratory, radiological, and demographic data of H3N2 pneumonia cases hospitalized to the Pulmonology Department during H3N2 pandemics and compare them with non-H3N2 community-acquired pneumonia (CAP) cases.
Methods: The study population consisted of all CAP cases hospitalized to our Pulmonology Department between December 2013 and February 2014 during the influenza outbreak. The patient files were evaluated for physical findings, laboratory data, radiological findings, and treatment and outcome of cases. H3N2 was diagnosed using polymerase chain reaction (PCR) analysis of throat swabs. The clinical, radiological, and laboratory findings of H3N2 pneumonia cases were compared with those of non-H3N2 pneumonia cases. Mann–Whitney U test, Chi-square test, Fisher’s exact test, and logistic regression analysis by the forward step wise method were used for statistical analyses. P value<0.05 was considered significant.
Results: During the H3N2 pandemic outbreak, 69 cases were diagnosed with CAP; 62 (89.8%) with non-H3N2 CAP, and 7 (10.2%) with H3N2 pneumonia. The demographic data, CURB-65, pneumonia severity index (PSI) scores, and clinical, radiological, and laboratory findings of the two groups were similar (p>0.05). The rates of treatment failure and/or transport to the intensive care unit with the need of invasive mechanical ventilation and mortality rates were also similar in both groups (p>0.05).
Conclusion: H3N2 pneumonia/viral pneumonia is a member of CAP. Although the number of H3N2 cases are extremely small to draw a conclusion, the results of this study highlight that the clinical, radiological, and laboratory findings of H3N2 pneumonia cases are not different from those of non-H3N2 CAP cases.