If more people at airports would practice better personal hygiene — particularly keeping their hands clean — the spread of many contagious diseases could be slowed significantly, according to researchers from the Massachusetts Institute of Technology (MIT).
In a study published in the journal Risk Analysis, the researchers estimate that if just 60 percent of travelers passing through the world’s airports kept their hands clean, the risk of a potential infectious disease pandemic would decrease by almost 70 percent.
Even if that level of hand cleanliness were achieved in just 10 of the world’s leading airports, the risk would drop by 37 percent, say the researchers.
Currently, only about one in five travelers in airports have clean hands at any given moment, previous research has suggested.
The MIT study was published in late December, just before the coronavirus outbreak in Wuhan, China, although the study’s authors note that their findings would pertain to any kind of infectious viral disease.
“Airports, and airplanes, are highly infectious because they are close, confined areas with large, mobile populations,” said Christos Nicolaides, one of the study’s lead authors and a physicist at MIT, in a released statement. “Viruses are spread through bodily fluids, so keeping hands clean at major transport hubs is central to control spread.”
Key sites for contagion
As background information in the study points out, in past centuries contagious diseases spread slowly, particularly across continents. For example, the Black Death (or Great Plague) pandemic, which originated in China in 1334, took almost 15 years to reach Europe.
The most significant hindrance to the spread of diseases at that time was the lack of good transportation, although once an infectious disease reached a country, poor public hygiene and ineffective medical treatment meant it infected — and killed — a greater proportion of individuals than such diseases do now.
Today, of course, modern forms of transportation, particularly air travel, allow people to travel more often and across greater distances. In 2017, 4.1 billion individuals passed through airports, a number that is expected to reach 7.8 billion by 2036.
Airports, therefore, have acquired a key role in the spread of contagious diseases, especially viral diseases like the flu.
The first confirmed cases of the H1N1 (“swine flu”) virus, for example, were reported in Veracruz, Mexico, in April 2009. Within a few days, the infection had spread to the United States and Europe, and within two months, the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) had declared the disease a global pandemic.
H1N1 is estimated to have killed 300,000 people worldwide before the outbreak ended in August 2010.
For the current study, Nicolaides and his MIT colleagues wanted to assess the impact that hand hygiene in airports might have on reducing the global risk of epidemics like H1N1. To do that they used epidemiological modeling and data simulations that took into account a variety of factors, including the duration, distance and interconnections of international flights; how long passengers wait in airports; and typical ways that people interact with their physical surroundings and with each other.
Unfortunately, far too few people practice good hand hygiene in airports (or anywhere else). Yet airports are full of surfaces that may be contaminated with infectious germs, such as check-in kiosks, security checkpoint trays and restroom doorknobs.
“Seventy percent of the people who go to the toilet wash their hands afterwards,” notes Nicolaides. “The other 30 percent don’t. And of those that do, only 50 percent do it right.” (Experts recommend that to have clean hands, we must wash our hands with soap and water for at least 15 seconds.)
Using that finding that 30 percent of people fail to wash their hands in restrooms, combined with estimates of how many potentially contaminated surfaces airport travelers come into contact with, Nicolaides and his colleagues calculated that only about 20 percent of people in airports have clean hands at any given moment.
They then determined that if 30 percent of travelers could be prevailed upon to keep their hands clean while in airports — an additional 10 percent more than the current figure — the global spread of disease might be slowed by as much as 24 percent. And if the number of airport travelers with clean hands could reach 60 percent, the spread of disease might decelerate by as much as 69 percent.
The researchers also determined that 10 particular airports have an outsized effect on the spread of infectious diseases. They aren’t necessarily the highest-traffic airports, but they do provide direct connections with “mega-hub” airports, operate long-range in- and out-bound international flights, and are located at East-West connective points.
Those 10 airports are London’s Heathrow Airport, the Los Angeles International Airport, New York’s John F. Kennedy International Airport, the Paris Charles De Gaulle Airport, the Dubai International Airport, the Frankfurt Airport, the Hong Kong International Airport, the Beijing Capital International Airport, the San Francisco International Airport and the Amsterdam Airport Schiphol.
Focusing hand-washing strategies at these 10 airports alone could potentially slow down the spread of viruses by as much as 37 percent, the MIT researchers estimate.
Keep your hands clean
“Eliciting an increase in hand-hygiene is a challenge,” Nicolaides acknowledges, “but new approaches in education, awareness, and social-media nudges have proven to be effective in hand-washing engagement.”
One important strategy at airports, he says, would be to place handwashing sinks at convenient locations, including outside of restrooms. Airports should also assign staff to do more frequent cleaning of surfaces, he adds.
In the meantime, it’s up to each of us to keep our hands free of infectious germs, whether we’re in an airport or any other public place. That means washing our hands frequently. (Yes, you can use a hand sanitizer, but even without soap, washing is more effective.)
Here’s a reminder from the CDC on how to wash your hands effectively:
Wet your hands with clean, running water (warm or cold), turn off the tap, and apply soap.
Lather your hands by rubbing them together with the soap. Be sure to lather the backs of your hands, between your fingers, and under your nails.
Scrub your hands for at least 20 seconds. Need a timer? Hum the “Happy Birthday” song from beginning to end twice.
Rinse your hands well under clean, running water.
Dry your hands using a clean towel or air dry them.
FMI: You’ll find the MIT study on the Risk Analysis website.