North Dakota experienced a cluster of severe respiratory illnesses in 2016 that included two deaths in a Fargo children's hospital, according to a new report from the CDC.
Here are nine things to know about the deadly infection cluster.
1. The infections were caused by human metapneumovirus. HMPV can cause upper and lower respiratory tract infections, including bronchiolitis and pneumonia.
2. The CDC got involved to identify possible risk factors for HMPV infection.
3. Six patients at the children's hospital were infected. Among them, five had underlying medical conditions, including premature birth, congenital heart disease, bronchopulmonary dysplasia, developmental delay and cerebral palsy.
4. Two of those six patients died. The four who survived were all American Indian children, while the two who died were not.
5. In addition to the six patients at the children's hospital, 11 additional pediatric patients were identified at three hospitals, and 27 adult patients were found from four hospitals.
6. Among the 11 additional pediatric patients, nine had underlying medical conditions. While one patient needed mechanical ventilation, none died.
7. For the 27 adult patients, all were white and all had underlying medical conditions like chronic lung disease or chronic heart disease. Nearly all (22) were current or previous smokers.
8. Three of the 27 adult patients died.
9. The report authors noted further study is needed "to understand the epidemiology of HMPV in the American Indian population." Additionally, they noted that "increased HMPV diagnostic testing could facilitate enhanced understanding of the clinical spectrum of illness, virus circulation, and populations at increased risk."