High Household Transmission Among Asymptomatic Contacts Across Pandemic Waves in Cincinnati, Ohio

COVID-19 and long COVID remain prevalent, with household transmission being an important mode of spread. To quantify household transmission of subclinical SARS-COV-2 infection and identify sociodemographic risk factors that may explain disparities in transmission, we conducted a case-ascertained antibody surveillance study of households in Cincinnati, Ohio.

A partnership was formed between the Cincinnati Health Department and Cincinnati Children's Hospital Medical Center. The Health Department identified cases of COVID-19. Infected individuals, along with their household contacts (n = 245), completed multiple questionnaires about symptoms, demographics, psychosocial (Adverse Childhood Experiences Scale and Everyday Discrimination Scale) and social risk factors, and conditions before and during the pandemic. In addition, they completed a non-fasting blood draw for IgG, IgM, IgA, and nucleocapsid protein serology testing.

Household contacts experienced few symptoms of COVID-19. However, according to the presence of the nucleocapsid protein, nearly 50% contracted the SARS-CoV-2 virus. This rate was similar by vaccination status but it was higher for household contacts who experienced high levels of early life adversity compared with those with lower levels.

Our results confirm the high transmission of subclinical disease among household contacts, which may vary due to psychosocial factors. This reinforces the importance of isolating cases to prevent transmission, regardless of vaccination status.