Long-term care facilities are by far the most common settings for norovirus outbreaks, dwarfing the number of outbreaks in hospitals, according to government data released Tuesday.

More than 2,000 outbreaks of norovirus originated in a long-term care facility between 2009 and 2012, the Centers for Disease Control and Prevention reported. Only about 120 outbreaks occurred in hospitals during those years.

The CDC report focused largely on outbreaks caused by contaminated food, because restaurants were the second most-common setting associated with outbreaks. There were nearly 575 outbreaks linked to contaminated restaurant food in the four-year study period. Another 150 outbreaks were linked to catering or banquet facility food.

However, poor food preparation practices are not behind the norovirus problem in nursing homes, the report showed. Only 12 long-term care outbreaks were food-related.

There are numerous other ways the highly contagious disease is transmitted, including person-to-person contact, the report stated. It is notoriously difficult to combat, given that it is resistant to common disinfectants, is infectious at very low doses, and people shed viral particles “copiously” even when asymptomatic.

The report did not offer explanations as to why long-term care facilities see so many more norovirus outbreaks than hospitals. The CDC had not returned a call from McKnight’s as of press time. However, norovirus is known to spread rapidly through “closed places”— it earned the nickname “the cruise ship disease” after several high-profile outbreaks at sea.

Norovirus also hits the elderly especially hard, with the majority of annual hospitalizations and deaths occurring among seniors and very young children. There were about 800 deaths due to norovirus between 2009 and 2012, according to the CDC report.