Quantifying the roles of vomiting, diarrhea, and residents vs. staff in norovirus transmission in U.S. nursing home outbreaks

Carly Adams; David Young; Paul A Gastañaduy; Prabasaj Paul; Zach Marsh; Aron J Hall; Benjamin A Lopman

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/707356 doi: bioRxiv preprint 81 virus', the majority of all norovirus outbreaks reported to the CDC occur in LTCFs [6] . While 82 norovirus gastroenteritis is generally mild and self-limiting, older nursing home residents are 83 vulnerable to infection leading to hospitalization and death [8] , with the vast majority of 84 norovirus-associated deaths in the U.S. occurring among persons aged 65 years and older [9] . 85 Norovirus is highly transmissible in nursing homes [10] [11] [12] , but there is no vaccine or 86 specific antiviral therapy available to prevent or treat norovirus infection. As a result, rapid 87 implementation of standard control measures is the mainstay for curtailing transmission [13] . 88 Identifying factors associated with norovirus transmission is critical to better understanding 89 disease spread and preventing additional cases. Individual-level risk factors for susceptibility to 90 norovirus infection or severe disease in nursing home outbreaks have been identified, including 91 resident mobility, dependency on staff assistance [14] , immunodeficiency [15] , and statin use 92 [16] . But because transmission of norovirus from one person to another cannot be directly