TABLE 3. Characteristics of 12 contacts who received positive SARS-CoV-2 test results and summary of evidence for school-associated transmission in five contacts across 20 elementary schools — Salt Lake County, Utah, December 3, 2020–January 31, 2021*.
| Positive contact ID | Index patient |
School contact† |
School-associated transmission |
Factors associated with transmission |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| School role | Symptoms reported | School role | Symptoms reported | Basis for exclusion of school-associated transmission |
School-associated transmission hypothesized | Close contact between patient and contact† | Contact sat <6 ft from index patient | Poor adherence to distancing, mask use, or neither at school |
|||
| Epidemiologic data | WGS data | Index patient | Contact | ||||||||
| I1 |
Student |
N |
Student |
N |
N |
NA |
Y |
Y |
Class |
Distancing |
Mask use, distancing |
| J2 |
Student |
N |
Student |
Y |
N |
NA |
Y |
Y |
Class |
Neither |
Mask use |
| X3 |
Student |
Y |
Student |
N |
N |
NA |
Y |
N |
Lunch |
Neither |
Distancing |
| AA4 |
Student |
Y |
Student |
N |
N |
NA |
Y |
Y |
Lunch |
Neither |
Neither |
| EE5 |
Student |
N |
Teacher |
Y |
N |
NA |
Y |
N |
Neither |
Neither |
Neither |
| A6 |
Student |
Y |
Student |
Y |
N |
Y |
N |
Y |
—§ |
— |
— |
| A7 |
Student |
Y |
Student |
N |
N |
Y |
N |
Y |
— |
— |
— |
| L8 |
Student |
N |
Student |
Y |
N |
Y |
N |
Y |
— |
— |
— |
| O9 |
Teacher |
N |
Student |
Y |
Y |
NA |
N |
Y |
— |
— |
— |
| T10 |
Student |
Y |
Student |
Y |
Y |
NA |
N |
Y |
— |
— |
— |
| RR11 |
Teacher |
Y |
Student |
Y |
Y |
NA |
N |
Y |
— |
— |
— |
| VV12 | Student | Y | Student | Y | Y | NA | N | Y | — | — | — |
Abbreviations: ID = identifier; Y = yes; N = no; NA = not available; WGS = whole genome sequencing.
* School-associated transmission was excluded by epidemiologic data if 1) the school contact had an illness onset (if symptomatic, symptom onset; if asymptomatic, first positive test date) before the last date of school exposure, or 2) a household member had an illness onset (if symptomatic, symptom onset; if asymptomatic, first positive test date) within 14 days of the positive school contact’s illness onset (if school contact was symptomatic) or before the last date of school exposure (if the school contact was asymptomatic). School-associated transmission was excluded by WGS data if the index patient isolate was found to be a different lineage from the positive school contact isolate.
† Persons were determined to be close contacts if they were <6 ft from the index patient for a cumulative total of ≥15 minutes during a 24-hour period at school. All other school contacts were students or staff members who were in contact with the index patient for a cumulative total of ≥15 minutes in a classroom, cafeteria, school bus, or recess space during an index patient’s infectious period.
§ Dashes indicate that data are not applicable.