Household transmission of human metapneumovirus and seasonal coronavirus.

We analyzed data from a community-based acute respiratory illness study involving K-12 students and their families in southcentral Wisconsin and assessed household transmission of two common seasonal respiratory viruses - human metapneumovirus (HMPV) and human coronaviruses OC43 and HKU1 (HCOV). We found secondary infection rates of 12.2% (95% CI: 8.1%-17.4%) and 19.2% (95% CI: 13.8%-25.7%) for HMPV and HCOV, respectively. We performed individual- and family-level regression models and found that HMPV transmission was positively associated age of the index case (individual model:  = .016; family model:  = .004) and HCOV transmission was positively associated with household density (family model:  = .048). We also found that the age of the non-index case was negatively associated with transmission of both HMPV (individual model:  = .049) and HCOV (individual model:  = .041), but we attributed this to selection bias from the original study design. Understanding household transmission of common respiratory viruses like HMPV and HCOV may help to broaden our understanding of the overall disease burden and establish methods to prevent the spread of disease from low- to high-risk populations.