CDC to expand disease surveillance at four major U.S. airports to include flu, RSV

The U.S. Centers for Disease Control and Prevention is expanding its infectious disease surveillance program at four major U.S. airports to more than 30 pathogens, including flu, RSV and other respiratory viruses.

The Traveller-based Genomic Surveillance program, led by CDC’s Travellers’ Health Branch, was introduced during the Covid-19 pandemic to detect new SARS-CoV-2 variants and other pathogens through nasal swab and wastewater sample collection from arriving international travellers at US airports.

“We have known that travellers are a very important population to consider for tracking new and emerging infections,” Dr. Cindy Friedman, who leads the CDC’s traveller genomic surveillance program and is the chief of the agency’s Travellers’ Health Branch, told CNN.

The program currently operates COVID-19 surveillance at seven major international airports in the United States. For a pilot program, it’s now expanding to test for more than 30 bacteria, antimicrobial resistance targets and viruses including influenza A and B, and respiratory syncytial virus, known as RSV, at Boston Logan International Airport, San Francisco International Airport, Dulles International Airport in Washington, D.C., and John F. Kennedy International Airport in New York.

The traveller surveillance program was introduced in 2021 when the CDC began collecting nasal swab samples from anonymous international travellers arriving at participating airports who volunteer to get swabbed.

“We started this as a concept. Could we get travellers to volunteer at the airport to give us a sample voluntarily when they came in from countries all over the globe?” Friedman said. “And could we get enough samples to then test and do genomic sequencing and know very quickly what was coming into our country.”

As of last month, the surveillance program has tested over 370,000 travellers through nasal swab sampling, with around 6,000 travellers volunteering weekly. The program has collected samples from travellers from more than 135 countries and has sequenced more than 14,000 samples for further analysis.

The wastewater program, which was introduced in August 2022, collects wastewater from a single plane using a custom-made collection device. Samples are then shipped to a laboratory for RT-PCR testing. If samples come back positive for a specific pathogen, such as COVID-19, they undergo whole genome sequencing to determine variants.

“One sample from an aircraft coming from a geographic destination afar can give us information potentially about 200 to 300 people that were on that plane,” according to Friedman.

Since the program’s inception, the agency has worked alongside Ginkgo Bioworks, a biotech company focused on building a global biosecurity infrastructure to empower governments, communities, and public health leaders to prevent, detect, and respond to a wide variety of biological threats.

Matthew McKnight, the general manager of biosecurity at Ginkgo Bioworks, adds that surveillance programs such as TGS are created in part to help prevent another health crisis, like the COVID-19 pandemic, from happening.

“The dream is that you’re running similar programs across the world in many, many places, so you get much earlier detection than if somebody shows up at a hospital of something emerging,” McKnight said. “The idea would be, how do you prevent a pandemic? You catch something really early, which allows you to put it into a vaccine manufacturing process much faster. Today we don’t have as much of that early warning as we want. And these are the first stages of it.”

Through wastewater testing and nasal swabbing, Friedman said, TGS has detected many COVID-19 variants entering the United States up to six weeks before they were officially reported nationwide, including Omicron BA.2, BA.3, XBB and BA.2.86. Now, she said, the program is focused on monitoring emerging respiratory viruses as cold and flu season ramps up.

Currently, the rate of COVID-19 hospitalizations remains steady with just over 15,700 hospital admissions per 100,000 people recorded for the week ending on October 28, according to CDC data. The number of Covid-19-related deaths also hasn’t seen a significant change in the last week, with just under 600 deaths reported.

Flu season is ticking up slightly throughout the country, but activity remains low, CDC data shows. For the week ending October 28, 189 cases of influenza were reported by public health laboratories, with 77 per cent of cases being influenza A, and 23 per cent being influenza B.

“We are interested in these fall respiratory pathogens,” Friedman said. “We want to able to sequence them, so we know the genomics of the strain.”

Friedman also highlights the importance of knowing whether strains of virus are changing and identifying what countries they are coming from.

“There are a lot of blind spots globally where there’s limited testing and monitoring,” she said. “In general, our focus is on airports that are international hubs, and have flights coming in from a broad array of international locations.”

CNN’s Deidre McPhillips contributed to this report.