Between January 17 and September 13, more than 766,000 travelers were evaluated at 15 airports across the US.
Of that figure, just nine people went on to test positive for COVID-19, the Centers for Disease Control and Prevention (CDC) revealed on Thursday.
The findings suggest ‘most infected travelers [went] undetected by symptom-based screening at airports’ and were then able to unknowingly spread the virus within their communities.
A new CDC report looked at a screening program during which, from January 17 to September 13, more than 766,000 travelers were screened for coronavirus at 15 US airports. Pictured: A traveler is checked with a handheld thermometer at Los Angeles International Airport, June 24
About 300 people met criteria for additional evaluation and, out of 35 people who were tested for COVID-19, nine received positive results
The program began on January 17 when CDC officials began working with the Department of Homeland Security, to screen passengers arriving from Wuhan, China, which was the epicenter of the outbreak at the time.
Screening initially occurred at just Los Angeles International Airport, San Francisco International Airport and John F Kennedy International Airport in New York City.
However, on February 3, the strategy was expanded to included all passengers arriving from mainland China, whom were routed to one of 11 designated airports.
Over the next few weeks, numerous countries were added to the list including Iran, the Uk, Ireland, Brazil and 28 nations in the European Schengen Zone.
By May 28, screening had expanded to 15 airports. The remaining 12 included:
- Boston Logan International Airport – Boston, Massachusetts
- Dallas Fort Worth International Airport – Dallas, Texas
- Daniel K. Inouye International Airport – Honolulu, Hawaii
- Detroit Metropolitan Airport – Detroit, Michigan
- Fort Lauderdale-Hollywood International – Fort Lauderdale, Florida
- George Bush Intercontinental Airport – Houston, Texas
- Hartsfield-Jackson Atlanta International Airport – Atlanta, Georgia
- Miami International Airport – Miami, Florida
- Newark Liberty International Airport – Newark New Jersey
- O’Hare International Airport – Chicago, Illinois
- Seattle Tacoma International Airport – Seattle, Washington
- Washington Dulles International Airport – Dulles, Virginia
John F Kennedy International Airport screened the most passengers over the eight month period at 146,127, nearly 20 percent of all people who entered the US.
Meanwhile, Fort Lauderdale-Hollywood International screened the least amount at 6,582, only about 0.9 percent of all passengers.
Screening was a three-step process with the first step requiring US Customs and Border Protection to identify passengers who had been in a country that required screening over the last 14 days.
Secondly, health officials would conduct a temperature check and have passengers fill out a questionnaire asking if they experienced symptoms such as coughing or shortness of breath.
Lastly, any flagged travelers were additionally examined by on-site medical officer or referred to a local healthcare facility.
Regardless of symptoms, all passengers were given an information card advising them to stay home or in a hotel room and quarantine for 14 days.
Of 766,044 travelers who were screened only 298 – about 0.04 percent – met CDC criteria for referral.
More than 93 percent were referred because they signs or symptoms while the remaining seven percent had either been in the Hubei Province or had come into a contact with an infected person.
Nearly three-quarters of the people with symptoms reported a cough while the next most common symptom was a self-reported fever.
In total, 35 passengers were tested for coronavirus and nine people received positive results.
This means one in every 85,000 travelers screened were identified by the CDC’s program.
The CDC ended the airport screening program on September 14 and ‘has transitioned to enhancing communication with travelers to promote recommended preventive measures.’
This includes encouraging travelers to wear face covering on airplanes and urging testing pre- and post-travel.
Researchers add that this style of screening may miss many cases due to the high number of asymptomatic patients or passengers denying symptoms.
‘Because…infection and transmission can occur in the absence of symptoms and because the symptoms of COVID-19 are nonspecific, symptom-based screening programs are ineffective for case detection,’ the authors wrote.