UC San Diego Health
Department of Family
Medicine and Public Health
200 West Arbor Drive
San Diego, CA 92103

Linda Hill, MD, MPH

Director, UCSD-SDSU Preventive
Medicine Residency Director,
Center for Human and Urban
Mobility
Director, Training Research and
Education for Driving Safety
Professor, Department of Family
Medicine and Public Health and
Department of Surgery School of
Medicine UC San Diego

San Diego, California, May 28, 2020
Alexander Eastman, MD, MPH
US Department of Homeland Security

Dear Dr. Eastman,
Greetings from San Diego. We are grateful for your visit to our region several
weeks ago and as follow-up would like to share with you the proposal discussed in
San Diego on May 9, 2020. We feel this proposal to screen for COVID-19
north of the border is crucial and timely, since despite the border closure,
120,000 unique U.S. Citizens and legal residents continue to cross north
weekly at San Ysidro Port of Entry alone. To minimize the COVID-19 impact on
the economy, we propose to implement a cohesive risk mitigation and testing
strategy that you will find detailed in the attachments.
This proposal has been vetted by key leadership at both our university and the
county. We feel both strategies can serve as a model for COVID-19 mitigation
along the southern border.

Sincerely,

Dr. Linda Hill

 .

Proposal to Identify and Mitigate
Transmission of COVID-19 North of the
US-Mexico Border
UC San Diego Health requests Department of Homeland Security support for a new
binational COVID-19 surveillance and risk mitigation effort to Detect disease, Assess
risk, Reduce transmission and Track binational cases at key Ports of Entry on the
California/Mexico border and Near-border worksites.
Situation: There is a long history of infectious disease risk mitigation at our international borders. Due to

the ability of COVID-19 to be spread by asymptomatic and pre-symptomatic individuals, and the sheer
scale of foot and vehicular traffic at the California/Mexico border, our current ability to detect and prevent
cross-border transmission of COVID-19 is severely limited.

Background on COVID-19 and the Border

San Diego county is home to San Ysidro, the busiest border crossing in the world, with 100,000-120,000
individuals crossing north daily, pre-COVID19; approximately one-third of crossers are pedestrians. The same
county houses the Otay Mesa Port of Entry (POE), the largest commercial crossing on the California-Mexico
border. Pre-COVID-19, approximately 2500 trucks a day, or more than 700,000 trucks annually, carrying more
than $20 billion in goods, passed through the northbound border crossing. Imperial County is just east of San
Diego County and the location of the Calexico Port of Entry, with approximately (pre-COVID-19) 25,000
individual crossers a day.
Despite border closure for non-essential travel, 40,000-60,000+ individuals are currently legally crossing the
border from Mexico to California each day at the San Ysidro border crossing alone. They are legal residents or
citizens of the US, and many an essential part of the regional economy and responsible for providing essential
services in the US. While it is currently unclear exactly what the COVID-19 prevalence is in the cities just south
of the California/US border, due to very limited testing being done in Mexico, it is clear by increasing death
rates and full hospitals, that their health system is being overwhelmed by this disease. Additionally, due to the
limited public health resources available in Mexico and lack of uniform enforcement of social distancing and
shelter-in-place orders, the situation in Baja Mexico is likely to get a lot worse before it improves.
The binational ramifications of this urgent public health emergency in Mexico are already being seen in San
Diego where healthcare facilities near the border are experiencing 10-20 times higher COVID test positivity
rates than regions further north from the border. This binational burden is also stretching south County

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 hospital resources close to the border, which is creating a ripple effect north as hospitals shift patients to
northern county hospitals to mitigate the pressure.
There is currently no specific screening for COVID-19 at the border. Customs and Border Patrol (CBP) report
that their border agents average 25 seconds with each crosser, in which time they can only determine if there
are critical health issues requiring engagement of the US Emergency Medical System. CBP is not able to
differentiate between asymptomatic and symptomatic travelers for risk assessment.
Known barriers to engaging people at the border include:
• Distrust in disclosing information to border workers.
• Concern about adding additional time delays if screening was introduced.
• Perceptions by crossers that self-identifying as sick may be grounds for denied entry into the US.
• Concerns about losing work.

Background on Worksites and COVID-19

Many local industries are being affected by COVID-19 -positive workers, who infect others in close working
conditions, leading to amplified absenteeism and reduced productivity. In a push to reopen businesses across
the county and restart the economy, we need to make sure businesses can open safely and stay open.
Worksites have a long history of implementing effective safety protocols, reducing injuries and other
morbidities. and implementation of infection safety protocols has already been done in some settings.
Many workers in San Diego live in Baja California and are essential to the local economy, as there are many San
Diegans who work in factories in Tijuana that may not have workplace standards that minimize the risk for
communicable disease. There are approximately 85,000 companies in San Diego (pre-COVID-19), with 1.3
million employees.
• The top employers are health care, education, biotech, US Navy and local government, including law
enforcement; additional major employers are casinos, SDG-E, General Dynamics, Qualcomm, General
Atomics, electronic assembly, farming, and manufacturing.
• Almost 60% are small businesses with <100 employees.

Screening programs, both on the US side of the border crossing and at
local worksites, are needed to effectively control the spread of COVID19 and safely improve the economic situation.
Border Testing Program: A screening program will create a mechanism for voluntary COVID-19 testing, just
north of three POE, providing the San Diego public health system with an opportunity to Detect disease, Assess

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 risk, Reduce transmission and Track binational cases, as well provide information and education about the
disease and how to mitigates risks and prevent transmission.
Worksite COVID-19 Safety Program: This prevention and screening program will help support the
implementation of evidenced-based COVID-19 protocols for physical distancing in the work environment, best
practices for cleaning and infection control; as well as periodic testing, and associated isolation and contact
tracing for those testing positive. The program will give San Diego the tools to implement a cohesive risk
mitigation and testing strategy in collaboration with large and small businesses in order to maximize the
productivity of workers and minimize COVID-19 impact on the economy all while maintaining a safe working
environment for employees and their families in this unique binational setting.
Both proposals are detailed below and should be considered adaptive, so that all parties have the opportunity
to check-in and adjust various aspects as needed in order to sustain efforts.
The project would be implemented in a phase approach:
1) Phase 1: implementation of screening at San Ysidro POE
2) Phase 2: Implementation of the program at OM and Calexico POE
3) Phase 3: Implementation of worksite program
Testing supplies will require close coordination between federal, county and UCSD agencies.

UC San Diego Health recommends the following approach for border
testing:
COVID-19 screening program north of the three border Ports of Entry will offer free COVID-19 testing stations
for both pedestrian and drive-through testing for crossers just after entering the US either on foot or in a
vehicle:
1) Use point of care (POC) testing, and send out PCR testing for those with negative POC; this will be
adjusted as the testing technology improves. Symptomatic individuals would be encouraged to selfisolate until testing results and accompanying advice received.
2) Advertise ‘link’ to enter information needed for testing during wait to get through official border;
3) Implement spacing mechanisms to keep pedestrian crossers appropriately distanced while waiting to
be tested;
4) Registration to include: preferred method for contacting client with results (required); city of residence;
purpose of entry to the US; city of main and contact information for preferred healthcare provider;
option to send results to health care providers (optional);
5) Where clients are unable to use phone app, testing station staff will enter information with verbal input
from clients;
6) Staff will be bilingual at all levels; staffing will include medical personnel at the appropriate level for
testing and advising.

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 7) Provide COVID-19 information to include
a. Current isolation regulations;
b. Methods for protection;
c. Symptoms of COVID-19;
d. Potential incentives for isolation and quarantine
e. Advice for management when symptomatic;
f. Management of contacts if tested positive.
8) Supply kit to include mask, hand sanitizer;
9) Obtain specimen into test kit, with bar code linked to phone app;
10) Deliver results to client upon processing by method preferred by client, if not give at point of care.
11) Provide for tracking and contact tracing, in conjunction with county public health efforts.
Resources needed for COVID-19 screening north of three Ports of Entry:
1) Staffing to screen up to 1000-4,000 people a day with resources based on the following levels of
screening across the 3 POE:
a. Bronze level screening: 1000/day
b. Silver level screening: 2000/day
c. Gold level screening: 4000/day
2) Testing: 1000-4,000 tests/day completed for rapid POC testing; additional lab-based PCR testing for
symptomatic individuals with negative POC results.
a. POC testing kits
b. Additional 20% transported to the lab
c. N.B. The COVID CARES ACT will be billed for testing based on guidance from the governmental
agencies involved.
3) Trailers for screening stations;
4) PPE for screening staff commensurate with type of test (self-collection would require less PPE, for
example, than administered testing);
5) Offices for tracking system, admin: will use existing space;
6) Signage upon border entry to advertise the service and encourage pre-registration in pedestrian
crossing terminal and in the SENTRI/regular car waiting lanes;
7) Development of written health education material available in multiple languages;
8) Database for tracking and transfer of data for contact tracing;
9) Security, concurrently providing traffic direction;
10) Tracking staff to inform of non-POC results, and coordinate isolation and contact tracing with County
system and companies.
11) Management to lead, supervise, and interface with involved government and non-governmental
agencies
Scalability: Based on resources and response to the program, the scope can be increased or decreased to
screen the following percentage of crossers, based on current crossing numbers.
• Bronze version: 1.3% of crossers
• Silver version: 2.6% of crossers

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 •

Gold version: 5.2% of crossers

UC San Diego Health recommends the following structure for a
Worksite testing program:
The Worksite program will provide technical support for companies based on the latest guidelines, tailored to
the type of workplace and each workplace will be tiered as either low or high risk based on size, number and
types of contact with the public, capacity for social isolation. The program will address:
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)

PPE
Social distancing
Cleaning
Education
Isolation and quarantine as appropriate
Follow-up for those testing positive (ensure patients knows how to connect to their preferred
provider/send results or offer UCSD ID COVID-19 telemedicine service as back-up, in addition to Epi
evaluation for close contact follow-up)
Link to county housing where appropriate.
COVID-19 testing program, linked to tracking system of county, isolation of worker, quarantine of
contacts
Testing periodicity will be based on tier from low to high risk, and based on changing incidence of
COVID-19 in the community.
Work with regulatory agencies to encourage voluntary or mandatory COVID-19 -prevention plans for all
companies and agencies, and explore paid COVID-19 -related leave programs.

Resources needed: Similar to the screening program, and based on resources, the program can provide scopes
of testing as follows. Each participating company would have repeat testing and support efforts, with the
periodicity based on company COVID-19 incidence and community COVID-19 levels.
• Bronze level: 10 companies a day, up to 500 tests/day
• Silver level: 20 companies a day, up to 1000 tests/day
• Gold level: 30 companies a day, up to 1500 tests/day
1) N.B. The COVID CARES ACT will be billed for testing based on guidance from the governmental agencies
involved.
2) Staffing to create best practices to date will guide protocol development and guidelines; this will be
done by project leadership.
3) Worksite outreach-workers to reach out to each company to help perform assessment and determine
level of risk they face, testing, PPE and/or educational needs. Staffing will include medical personnel at
the appropriate level for testing and advising.
4) Rapid POC testing; additional lab-based PCR testing for symptomatic individuals with negative POC
results.

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 a. POC testing kits
b. Additional 20% transported to the lab
c. N.B. The COVID CARES ACT will be billed for testing based on guidance from the governmental
agencies involved.
5) Tracking system database
6) Tracking of positives, with outreach and recommendations to workers and companies, and coordinate
isolation and contact tracing with County system and companies.
health.ucsd.edu

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