Despite an official declaration of a pandemic last month, public health officials continue to track new variants of COVID-19. Experts at the U.S. Centers for Disease Control and Prevention (CDC) are monitoring samples from international travelers arriving in the U.S. as data collection slows down after pandemic measures were lifted.
this Voyager-based Genome Surveillance Programlaunched by CDC in late 2021, continues to operate at seven of the busiest international airports in the United States, including John F. Kennedy International Airport (JFK), Newark Liberty International Airport (EWR), San Francisco International Airport (SFO), Harbin Atlanta International Airport (ATL), Los Angeles International Airport (LAX), Seattle-Tacoma International Airport (SEA) and Washington Dulles International Airport (IAD).
Working with XpresCheck, a company originally known for operating airport spas but later getting involved in COVID-19 testing, CDC officials met with passengers from selected international flights after customs clearance. Officials asked passengers to voluntarily collect nasal swabs, which were then collected and tested by Ginkgo Bioworks, a CDC laboratory partner.
Dr. Cindy Friedman, chief of the CDC Traveler’s Health Division, emphasized the importance of the program for early detection and filling of global surveillance blind spots. With testing down in many countries, including the U.S., tracking passengers arriving from abroad has become an ideal way to monitor changes in the virus and global flows.Dr. Friedman took part in the program himself after returning from a trip abroad, highlighting the role of travelers as sentinels in getting valuable samples to the United States
“This project is critical to the early detection and filling of many blind spots in global surveillance. This is very important now as many countries, including the US, are reducing testing by as much as 90%. This is a critical part of biosecurity,” Dr. Friedman is quoted as time.
CDC officials select flights for testing each week based on global case trends. During the recent spike in cases in China and other parts of Asia, the project detected an increase in positive tests in the region before the number of cases peaked. The program often detects an increase in cases before it is reported in the news or in the public health community.
To date, more than 200,000 passengers have provided samples upon arrival in the U.S. Passengers provided anonymous information such as age, travel itinerary, and history of COVID-19 infection and vaccinations. They also provided two nasal swabs, one of which was added to the pooled sample and the other was stored for possible future testing.
If pooled samples test positive, a second sample is tested separately to identify positive cases in the pool. If new changes are found in the genetic sequence, a second sample will be sent to the CDC laboratory in Atlanta for further identification and addition to the agency’s ever-expanding database of SARS-CoV-2 sequences.
In 2021, the program detected the Omicron BA.2 and BA.3 variants, respectively, one week and six weeks ahead of reported cases in the United States.
While the program has received a significant number of willing volunteers to provide nasal swabs, maintaining that altruism may become more challenging as the urgency of the pandemic recedes. As a result, the CDC is ramping up its airport wastewater testing program as a potential screening method.
For about a year, the agency collected wastewater directly from the toilets of overseas flights at three to four airports, as well as from public drains at San Francisco International Airport. Preliminary tests showed that wastewater reflected the same variant identified by nasal swab testing, a finding supported by a similar study in Australia.
Wastewater screening promises to be a permanent pathogen screening tool that can be used to detect any emerging disease-causing agents, making it key to addressing future biological threats.
Health officials have stressed the importance of learning from the program’s success and making sure the lessons are not wasted, especially if precautionary measures are relaxed. After the coronavirus was first identified in China and new strains were detected in multiple countries, the implementation of anticipatory and proactive surveillance tools such as wastewater screening could greatly benefit the world in early 2020. This foresight can lead to the development of diagnostics, identification of outbreaks, and ultimately game-changing.
Published by Medicaldaily.com