Study population and setting
In this study, an outbreak during a three-week family gathering of five households from four different states between July and August 2020 was investigated. The index case was a thirteen-year-old adolescent and had a known exposure in June 2020. Because of this exposure, the index case sought out testing four days after exposure and tested negative to a rapid antigen test. Detailed demographic characteristics, exposures, symptoms, close contacts, and outcomes were obtained from this family gathering and analyzed. Viral testing was completed among all those staying together during this period and antibody testing was completed on those who were not tested while symptomatic.
Summary of Main Findings
Attendees of the family gathering ranged in age from 9 to 72 years old. Overall, the outbreak directly affected the asymptomatic adolescent index case and 11 of the 19 family members. Of the 13 relatives of the index case who were staying together in a house during this period, 11 (84.6%) of them experienced symptoms and subsequently developed COVID-19. Three individuals, including the index case and her two brothers, tested positive for antibodies, suggesting earlier infection. While eight individuals reported participating in activities that may have increased their risk during this period, only the index case had confirmed contact with a known case. An additional six relatives visited, but did not stay, maintained physical distance, and remained outdoors. Of the four visiting relatives tested, all four tested negative by RT-PCR.
Nearly complete exposure, symptom, contacts, and testing data allow for a detailed investigation of this outbreak at a family gathering.
Because attendees of this family gathering did have contact with individuals outside of this group during this same period, an external source of transmission cannot be ruled out, though the evidence supports the hypothesis that the supposed index patient is in fact the source of the outbreak.
This investigation is a timely reminder, given the upcoming holiday season, of the potential for transmission between family members at planned gatherings where mask use and physical distancing are not utilized. Importantly, these results highlight that children and adolescents can serve as the source for outbreaks regardless of whether or not they have symptoms.
This review was posted on: 10 November 2020