A new study from Italy has linked fewer household members and a higher number of nursing facility beds with more COVID-19 cases in people over age 80.

Italy is one of the countries hardest hit by the coronavirus. Researchers have proposed that this is due to its aging population and to large family groups that contribute to intergenerational transmission. But the new study contradicts the latter theory. 

Rather than regions with large family groups, the investigators’ model showed regions with fragmented families had more elders with COVID-19, wrote Giuseppe Liotta of the University of Rome, and colleagues. In addition, nursing home bed rates helped determine infection rates in older age groups, they reported. 

“Variables associated with social isolation are risk factors for an increase in the proportion of cases in Italian patients aged 80 years and older among the total number of cases,” concluded Liotta. 

The study was limited by the fact that age-specific infection rates were not available and the number of COVID-19 tests varied “enormously” by regions, the investigators reported.

Full findings were published Thursday in the journal PLOS ONE.