Reports suggest that children aged ≥10 years can efficiently transmit SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (1,2). However, limited data are available on SARS-CoV-2 transmission from young children, particularly in child care settings (3). To better understand transmission from young children, contact tracing data collected from three COVID-19 outbreaks in child care facilities in Salt Lake County, Utah, during April 1–July 10, 2020, were retrospectively reviewed to explore attack rates and transmission patterns. A total of 184 persons, including 110 (60%) children had a known epidemiologic link to one of these three facilities. Among these persons, 31 confirmed COVID-19 cases occurred; 13 (42%) in children. Among pediatric patients with facility-associated confirmed COVID-19, all had mild or no symptoms. Twelve children acquired COVID-19 in child care facilities. Transmission was documented from these children to at least 12 (26%) of 46 nonfacility contacts (confirmed or probable cases). One parent was hospitalized. Transmission was observed from two of three children with confirmed, asymptomatic COVID-19. Detailed contact tracing data show that children can play a role in transmission from child care settings to household contacts. Having SARS-CoV-2 testing available, timely results, and testing of contacts of persons with COVID-19 in child care settings regardless of symptoms can help prevent transmission. CDC guidance for child care programs recommends the use of face masks, particularly among staff members, especially when children are too young to wear masks, along with hand hygiene, frequent cleaning and disinfecting of high-touch surfaces, and staying home when ill to reduce SARS-CoV-2 transmission (4).
Contact tracing* data collected during April 1–July 10, 2020 through Utah’s National Electronic Disease Surveillance System (EpiTrax) were used to retrospectively construct transmission chains from reported COVID-19 child care facility outbreaks, defined as two or more laboratory-confirmed COVID-19 cases within 14 days among staff members or attendees at the same facility. EpiTrax maintains records of epidemiologic linkage between index patients and contacts (defined as anyone who was within 6 feet of a person with COVID-19 for at least 15 minutes ≤2 days before the patient’s symptom onset) and captures data on demographic characteristics, symptoms, exposures, testing, and the monitoring/isolation period. A confirmed case was defined as receipt of a positive SARS-CoV-2 real-time reverse transcription–polymerase chain reaction (RT-PCR) test result. A probable case was an illness with COVID-19–compatible symptoms,† epidemiologically linked to the outbreak, but with no laboratory testing. For this report, the index case was defined as the first confirmed case identified in a person at the child care facility, and the primary case was defined as the earliest confirmed case linked to the outbreak. Pediatric patients were aged <18 years; adults were aged ≥18 years.
Persons with confirmed or probable child care facility–associated COVID-19 were required to isolate upon experiencing symptoms or receiving a positive SARS-CoV-2 test result. Contacts were required to quarantine for 14 days after contact with a person with a confirmed case. Facility attack rates were calculated by including patients with confirmed and probable facility-associated cases (including the index patient) in the numerator and all facility staff members and attendees in the denominator. Overall attack rates include facility-associated cases (including the index case) and nonfacility contact (household and nonhousehold) cases in the numerator and all facility staff members and attendees and nonfacility contacts in the denominator; the primary case and cases linked to the primary case are excluded.
During April 1–July 10, Salt Lake County identified 17 child care facilities (day care facilities and day camps for school-aged children; henceforth, facilities) with at least two confirmed COVID-19 cases within a 14-day period. This report describes outbreaks in three facilities that experienced possible transmission within the facility and had complete contact investigation information. A total of 184 persons, including 74 (40%) adults (median age = 30 years; range = 19–78 years) and 110 (60%) children (median age = 7 years; range = 0.2–16 years), had a known epidemiologic link to one of these three facilities with an outbreak; 54% were female and 40% were male. Among these persons, 31 confirmed COVID-19 cases occurred (Table 1); 18 (58%) cases occurred in adults and 13 (42%) in children. Among all contacts, nine confirmed and seven probable cases occurred; the remaining 146 contacts had either negative test results (50; 27%), were asymptomatic and were not tested (94; 51%) or had unknown symptoms and testing information (2; 1%).
Among the 101 facility staff members and attendees, 22 (22%) confirmed COVID-19 cases (10 adult and 12 pediatric) were identified (Table 2), accounting for 71% of the 31 confirmed cases; the remaining nine (29%) cases occurred in contacts of staff members or attendees. Among the 12 facility-associated pediatric patients with confirmed COVID-19, nine had mild symptoms, and three were asymptomatic. Among 83 contacts of these 12 pediatric patients, 46 (55%) were nonfacility contacts, including 12 (26%) who had confirmed (seven) and probable (five) COVID-19. Six of these cases occurred in mothers and three in siblings of the pediatric patients. Overall, 94 (58%) of 162 contacts of persons with facility-associated cases had no symptoms of COVID-19 and were not tested. Staff members at two of the facilities had a household contact with confirmed or probable COVID-19 and went to work while their household contact was symptomatic. These household contacts represented the primary cases in their respective outbreaks.