In models of air transportation networks during the early stages of an outbreak, disease spread could be reduced by up to 38% with improved hand washing at 10 major airports.
During the peak of respiratory virus season it may be difficult to differentiate between novel coronavirus disease (COVID-19) and influenza. This is because both influenza and COVID-19 share symptoms like fever, cough, and runny nose. As a result, this problem may continue if COVID-19 becomes more prevalent in the United States.
In fact, on February 14, 2020, the US Centers for Disease Control and Prevention announced that public health labs in Los Angeles, San Francisco, Seattle, Chicago, and New York City would begin testing individuals with influenza-like symptoms for COVID-19.
The similar clinical characteristics could also present a challenge for airport screening programs. Airport screening for COVID-19 began at 3 major US airports on January 17, 2020, and has since expanded to other locations.
An additional challenge for airport screening programs is the asymptomatic period which individuals with COVID-19 experience. The first confirmed US case, for example, was in a traveler who did not have a fever at the time of his arrival at Seattle-Tacoma airport.
However, there is evidence that the virus, SARS-CoV-2, could persist on inanimate surfaces for up to 9 days.
There is one simple measure that could significantly mitigate the role of environmental contamination at airports in the spread of diseases. The investigators of a new study in Risk Analysis show that increased hand hygiene at just 10 major airports could reduce the risk of a hypothetical pandemic by up to 38%.
The study team, led by investigators from the University of Cyprus, sought to model the potential impact of hand hygiene behavioral changes on pandemic risk if such changes were implemented at critical points within the world air-transportation network.
“The air transportation system is the main channel of global disease spreading. In only couple of hours we can get from one part of the world to the other. At the same time airports facilitate the rapid spread of an epidemic since they are areas with high density of population at any given time and with limited capacity of hand washing,” study author Christos Nicolaides, PhD, told Contagion®.
The team developed a computational model which simulated the mobility of air travelers through the world’s 120 busiest airports and incorporated the spread of a hypothetical infectious disease.
The investigators then analyzed the power of the disease to spread under various scenarios, such as homogenous increased handwashing engagement at all airports or the increase of handwashing engagement at the most important airports.
As a baseline, around 20% of the airport population had “clean” hands at a given moment in time. In a scenario where all airports increased their level of hand cleanliness from 20% to 30%, a potential infectious disease could have a reduced impact of 24%. Increasing the level of hand cleanliness to 60% at all airports would reduce the potential disease spread by up to 69%.
In an intervention scenario where 10 airports that are critical to air travel infrastructure improved hand cleanliness, disease spread could be decreased by 8% to 37%.
“The current research can potentially shape the way policymakers design and implement strategic interventions based on promoting hand washing in airports, which could help hindering any infection within a confined geographical area during the early days of an outbreak, inhibiting its expansion as a pandemic,” study authors wrote.
It is too early to predict the impact of COVID-19 and where the disease will spread. However, this study highlights that in the early stages of outbreaks, tried and true methods of reducing transmission present a simple and effective way to substantially minimize the impact of a disease.
“It has been shown by other researchers that potential interventions like education, posters, public announcements, and perhaps improved access to hand-washing facilities are proven to be effective in increasing hand-washing engagement. The main setting of this research is hospitals, however one can argue that this evidence can be generalized in the case of a health emergency,” Nicolaides said.