Clinical characteristics of COVID-19 in Osaka, Japan: Comparison of the first-third waves with the fourth wave

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• The fourth wave of COVID-19 in Osaka Prefecture, Japan, resulted in a significant medical crisis.
• Previous waves (first-third) provide a baseline for comparison with the more severe fourth wave.

Purpose of the Study:

• To identify independent risk factors associated with moderate to severe COVID-19.
• To compare the severity and outcomes of COVID-19 patients between the first-third waves and the fourth wave in Osaka.

Main Methods:

• An observational, retrospective study was conducted.
• Data from 404 COVID-19 patients treated at the National Hospital Organization Kinki-Chuo Chest Medical Center were analyzed.
• Multivariate logistic regression was employed to determine risk factors for disease severity.

Main Results:

• Cardiovascular disease, fever, dyspnea, and elevated inflammatory biomarkers (C-reactive protein, lactate dehydrogenase, ferritin) were identified as independent risk factors for moderate to severe COVID-19.
• Increased levels of C-reactive protein, lactate dehydrogenase, and ferritin correlated with a higher risk of moderate to severe disease.
• The fourth wave exhibited higher overall disease severity compared to the first-third waves, with 14.3% of severe cases in the fourth wave unable to be transferred due to bed shortages.

Conclusions:

• Specific clinical indicators and inflammatory biomarkers are crucial for predicting moderate to severe COVID-19.
• The worsening severity during the fourth wave exacerbated the medical crisis in Osaka, highlighting challenges in patient management and resource allocation.
• While mortality rates did not significantly differ, the increased severity and bed shortages underscore the critical impact of viral surges on healthcare systems.