COVID-19 and H1N1 Influenza: Are They 2 Sides of the Same Coin?

Swine flu (H1N1) and Coronavirus diseases (COVID-19) have been compared in the past few months. Both pandemics sparked a worldwide major panic. Although both have some common symptoms and diagnoses, they are quite different in many aspects. The current study aimed to investigate the differences in clinical and viral behaviors between H1N1 Influenza and COVID-19 pneumonia.

This was a retrospective study of adult patients hospitalized with H1N1 influenza pneumonia between January 2019 and February 2020, and patients hospitalized with COVID-19 during the outbreak. A demographic and clinical characteristic of H1N1 influenza and COVID-19 patients were recorded. Both groups were compared-using an independent samples student t test for continuous variables and a chi-square test for categorical data-to identify significantly different parameters between the 2 diseases.

A total of 78 patients were included and divided into 2 groups: 33 patients (42.3%) with H1N1 and 45 patients (57.7%) with COVID-19. The mean age of the patients was 43.3 ± 10.6 years. Bronchial asthma was significantly higher among patients with H1N1, while diabetes mellitus was significantly higher among patients with COVID-19. Right lower lobe affection was significantly present among those with H1N1 than those with COVID (100% vs 0%). The monocytic count was significantly higher among those with H1N1 than COVID-19 (11.63 ± 1.50 vs 7.76 ± 1.68; P < 0.001). Respiratory rates of more than 22 c/min significantly increased in patients with HINI than in those with COVID-19 (18.2% vs 4.4%; P = 0.05). Mortality increased in patients with HINI than in those with COVID-19 (18.2% vs 6.7%). However, the difference did not reach statistical significance (P = 0.15).

Clinically, it is difficult to distinguish between H1N1 and COVID-19. Thus, a polymerase chain reaction is recommended for all patients suffering from influenza-like symptoms to rule out influenza A subtype H1N1 and/or SARS-CoV2.