Risk for Severe COVID-19 Illness Among Teachers and Adults Living With School-Aged Children.

Background: Schools provide critical educational and health benefits to children, and reopening them facilitates parents', particularly mothers', return to work (1). Although children rarely have severe coronavirus disease 2019 (COVID-19) illness, they can transmit infection (2).

Objective: To determine the prevalence of risk factors for severe COVID-19 illness among teachers and adults living with school-aged children.

Methods and Findings: We analyzed nationally representative data from the 2018 National Health Interview Survey. We used the Centers for Disease Control and Prevention's criteria (3) to define “definite” and “possible” risk factors for severe COVID-19 illness, including differing severities of obesity, and tabulated their prevalence among 3 groups: employed adults other than teachers, adults employed as teachers, and adults living with school-aged (aged 5 to 17 years) children. We assessed differences in the prevalence of definite or possible risk factors among adults living with children according to the children's ages (5 to 10 years vs. 11 to 17 years), race/ethnicity, and family income using bivariate logistic regressions. Analyses were done with STATA/SE, version 16.1 (StataCorp), using weights and procedures that accounted for the survey's complex design.

The National Health Interview Survey sample included 14 097 adults representative of 150.3 million U.S. nonteacher workers; 592 adults representative of 5.8 million primary, secondary, and special education teachers; and 5682 adults representative of 69.7 million adults living with school-aged children.

Among teachers, 39.8% (weighted n = 2.32 million [95% CI, 1.98 to 2.66 million]) had definite and 50.6% (weighted n = 2.95 million) had definite or possible risk factors for severe COVID-19 illness (Table 1). Although only 0.7% had cancer, 27.9% had a body mass index (BMI) of 30 kg/m2 or greater, 4.2% had a BMI of 40 kg/m2 or greater, and 8.0% had a cardiac condition. The prevalence of most risk factors was similar among nonteacher workers, although more were smokers; 41.4% had any definite risk factors, and 55.8% had definite or possible risk factors.

Table 1. Risk Factors for Severe COVID-19 Illness Among Teachers* and Adults Living in a Household With School-Aged Children

Among the 69.74 million adults living with school-aged children, 41.0% (weighted n = 28.61 million [CI, 27.03 to 30.20 million]) had definite and 54.0% (weighted n = 37.7 million) had definite or possible risk factors, including 2.50 million who were older than 64 years, 4.67 million with heart disease, 4.84 million with type 2 diabetes, and more than 600 000 with cancer.

The prevalence of risk factors was similar among adults living with younger versus older children (Table 2). Adults living with children in low-income households were more likely to be at risk than those in higher-income households, as were those residing with Black children; adults living with Asian children or children of other races/ethnicities were at lowest risk.

Table 2. Increased Risk for Severe COVID-19 Illness Among Adults Living in a Household With School-Aged Children, by Children's Age, Children's Race/Ethnicity, and Family Income (

Discussion: About 40 million U.S. adults who work or live with school-aged children have definite or possible risk factors for severe COVID-19 illness, a number that excludes 4.4 million nonteachers working at schools and 1.6 million day care workers (Himmelstein DU. Unpublished data). Adults living with Black children and those living with children in low-income households are at especially high risk; teachers' risk seems similar to that of other working adults.

By mid-March 2020, 107 nations had closed schools to help contain the COVID-19 outbreak (4); many that have suppressed the virus are now reopening them. In-person instruction is preferable for children's educational and social development, and school closures may adversely affect children's mental health, food security, and safety (1). Moreover, children rarely develop severe COVID-19 disease. However, as our findings indicate, school leaders must weigh these undoubted benefits against the risk to the adults who care for children, particularly older children who commonly transmit the infection (younger children are about one third as likely to cause household spread) (2). Both the risks and benefits of schools reopening are likely larger for poor and Black families.

Our study has limitations. We could not identify school personnel other than teachers or day care workers in the National Health Interview Survey, nor could we identify some conditions identified as risk factors for severe COVID-19 illness, such as chronic kidney disease or thalassemia. Hence, our estimate of the number of adults at risk is likely too low. Our study data predated the COVID-19 pandemic, although substantial shifts in disease prevalence seem unlikely. Finally, different risk factors and different levels of obesity carry different levels of risk for severe COVID-19 illness (for example, a BMI ≥45 kg/m2 more than quintupled the risk for COVID-19–related death, whereas a BMI of 30 to 34 kg/m2 increased it by 26%) (5).

Our findings underscore the need for careful consideration of and preparation for school reopenings this fall. The resumption of face-to-face instruction is critical for children's development, health, and welfare. However, without adequate safeguards, reopening schools could put millions of vulnerable adults at risk for severe COVID-19 illness.