To reduce introductions of COVID-19 into the United States, officials screened travelers from selected countries upon entry to the US and shared their contact information to states for monitoring.

This report summarizes the experience of California Department of Public Health (CDPH) with this traveler monitoring program. Findings suggest that monitoring travelers is labor-intensive and limited by incomplete information, volume of travelers, and potential for asymptomatic transmission. Health departments need to weigh the resources needed for monitoring against those needed for implementing mitigation activities during the COVID-19 pandemic.

Between February 3–March 17, 2020, CDPH processed 2,266 notifications of arriving travelers from China and Iran, representing 12,061 individual travelers. They processed a median of 39 notifications per day (range = 1–146), with a median of 23 individual records per notification (range = 1–250), equating to a median of 1,431 travelers per week.

Following resolution of identifiable and correctable errors, 11,574 (96%) records were assigned and sent to 51 of California’s 61 local health jurisdictions. The number of travelers in each affected jurisdiction ranged from 1 to 4,852.

Among the 11,574 California travelers processed by CDPH, 3 were matched by name and date of birth to 3 of 26,182 confirmed COVID-19 cases in California reported to CDPH through the California reportable disease system as of April 15.

CDPH staff members devoted an estimated 1,694 total person-hours (equivalent to six employees working full-time for 7 weeks) processing traveler notices and assigning travelers to local health jurisdictions; 576 (34%) of these person-hours occurred outside regular working hours.