Japanese researchers studying functional decline among patients aged 80 years and older hospitalized for SARS-CoV-2 Omicron pneumonia find significantly higher rates of decline in those also infected with bacteria than in those with primary viral pneumonia 1 year later, though both groups had substantial levels of impairment.
The study, published yesterday in Influenza and Other Respiratory Viruses, was conducted at five Japanese hospitals and clinics from December 2021 to August 2022. Attending physicians calculated the difference in activities-of-daily-living (ADL) scores from hospital admission to release.
"During the period when the ancestral [SARS-CoV-2] strain, Alpha variant, and Delta variant were dominant, bacterial coinfection and secondary bacterial infection in patients with COVID-19 were low," the study authors wrote. "In the Omicron period, however, the pattern of pneumonia changed from primarily viral pneumonia to pneumonia mixed with bacteria, mainly aspiration pneumonia."
Early rehabilitation, treatment for Omicron
Of the 891 patients with pneumonia due to the SARS-CoV-2 Omicron variant, 303 had primary viral pneumonia and 326 patients had pneumonia mixed with bacteria (primarily aspiration pneumonia).
Among patients with primary viral pneumonia, 112 cases were sequenced as the Omicron BA.1 subvariant, 70 were BA.2, and 121 cases were BA.5. Among patients with pneumonia mixed with bacteria, 118 cases were caused by Omicron BA.1, 72 were BA.2, and 136 were BA.5. The proportion of subvariants and vaccination status was the same between the two groups.
Functional decline rates at hospital release were significantly higher in patients with primary viral pneumonia than in those with pneumonia mixed with bacteria (52.3% vs 40.3%).
It is necessary to consider early rehabilitation and treatment in elderly patients even when the predominant strain is the Omicron variant.
But by 1 year, 139 of 171 (81.3%) patients with pneumonia mixed with bacteria who experienced reduced physical function at hospital release still showed functional decline. In comparison, 20.5% of patients with primary viral pneumonia had functional decline at 1 year. Among the Omicron subvariant groups, functional decline rates at hospital release and 1 year later were similar in both pneumonia groups.
The researchers noted that the bacterial-coinfection group had higher rates of cerebrovascular disease and chronic kidney disease than those with primary viral pneumonia. "Thus, it is quite possible that comorbid conditions affect the physical functional decline in elderly COVID-19 patients with bacterial coinfection," they wrote.
Because functional decline during or after hospitalization is tied to adverse health outcomes, prolonged hospital stays, and more episodes of early hospital admission, the authors wrote, "it is necessary to consider early rehabilitation and treatment in elderly patients even when the predominant strain is the Omicron variant."