What is already known about this topic?

To reduce introductions of COVID-19 into the U ited States, travelers from selected countries were screened upon entry, and their contact information forwarded to states for monitoring.

What is added by this report? During February 3–March 17, 2020, California received, corrected, and transmitted information on 11,574 travelers to local health jurisdictions for follow-up. Three travelers were matched to three of the 26,182 patients with COVID-19 reported to California by April 15.

What are the implications for public health practice? Monitoring travelers was 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.

The threat of introduction of coronaVirus disease 2019 (COVID-19) into the United States with the potential for community Transmission prompted U.S. federal officials in February 2020 to screen travelers from China, and later Iran, and collect and transmit their demographic and contact information to states for follow-up. During February 5–March 17, 2020, the California Department of Public Health (CDPH) received and transmitted contact information for 11,574 international travelers to 51 of 61 local health jurisdictions at a cost of 1,694 hours of CDPH personnel time. If resources permitted, local health jurisdictions contacted travelers, interviewed them, and oversaw 14 days of quarantine, self-monitoring, or both, based on CDC risk assessment criteria for COVID-19. Challenges encountered during follow-up included errors in the recording of contact information and variation in the availability of resources in local health jurisdictions to address the substantial workload. Among COVID-19 patients reported to CDPH, three matched persons previously reported as travelers to CDPH. Despite intensive effort, the traveler screening system did not effectively prevent introduction of COVID-19 into California. Effectiveness of COVID-19 screening and monitoring in travelers to California was limited by incomplete traveler information received by federal officials and transmitted to states, the number of travelers needing follow-up, and the potential for presymptomatic and asymptomatic Transmission. More efficient Methods of collecting and transmitting passenger data, including electronic provision of flight manifests by airlines to federal officials and flexible text-messaging tools, would help local health jurisdictions reach out to all at-risk travelers quickly, thereby facilitating timely tTesting, case identification, and contact investigations. State and local health departments should weigh the resources needed to implement incoming traveler monitoring against community mitigation activities, understanding that the priorities of each might shift during the COVID-19 pandemic.

Suggested citation for this article: Suggested citation for this article: Myers JF, Snyder RE, Porse CC, et al. Identification and Monitoring of International Travelers During the Initial Phase of an Outbreak of COVID-19 — California, February 3–March 17, 2020. MMWR Morb Mortal Wkly Rep. ePub: 11 May 2020. DOI: http://dx.doi.org/10.15585/mmwr.mm6919e4

mm6919e4-H.pdf