When the next deadly disease epidemic strikes, government officials may be powerless at stopping its spread via airplane.
A recent University of California, Los Angeles (UCLA) study published in the scientific journal eLife says that airport screenings for infectious diseases miss anywhere from 50 to 75 percent of infected passengers.
According to the study, screening for fever upon arrival is effective at best only 70 percent of the time, though scientists say post-flight checks are still more effective than departure ones, as symptoms can further expose themselves during travel.
Last October, during the height of the Ebola scare, the FAA implemented such measures, requiring passengers from Ebola-infected countries to fly into one of five airports—New York John F. Kennedy, Newark, Washington Dulles, Atlanta, and Chicago O'Hare—where they would undergo mandatory screening.
The UCLA study, which examined Ebola, SARS, Marburg virus, swine flu, avian flu, and Middle East respiratory syndrome coronavirus (MERS), is especially pertinent in the wake of recent Ebola and measles scares.
The authors suggest that the detection rate is so low because because authorities rely on self-reported questionnaires, and passengers often lie about their exposure to diseases. Honesty could potentially cause a passenger to be detained. According to the paper, only a quarter of passengers truthfully reported their possible exposure to the 2009 influenza epidemic.
"We need to find ways to incentivize better self-reporting," UCLA graduate student researcher Katelyn Gostic told Infection Control Today.
Unfortunately, there is no simple infection test in the early stages of most epidemic-prone diseases with long incubation periods, and the study suggests that questionnaires, despite their rampant human error, are still the best early detection method we have. That's a finding libertarians should probably view as troubling, since high failure rates could spur government officials to enact harsh regulations against international travel the next time an epidemic breaks out.