Researchers Study Ways to Reduce the Spread of Infectious Diseases on Commercial Airliners

It has become second nature for the Daytona Beach Campus assistant professor of aerospace engineering and his PhD student Pierrot Derjany as part of research that could have a worldwide impact on reducing the spread of infectious diseases in congested places such as airplanes, airports and other gathering venues.

Recently published reports, which have received international attention, initially show that the way passengers board a plane and the size of the plane could have an impact on their health. Boarding planes in three sections from the front to the back, for example, may pose more of a risk, compared to randomly boarding a plane in two sections.

With billions of passengers passing through the world’s airports each year and the numbers rising, Namilae, the lead investigator on the ongoing studies, believes it’s important to find solutions.

“The research we are doing will affect people on a broad scale,” Namilae said.

Results from the research published in Physical Review E (S. Namilae, P. Derjany, A. Mubayi, M. Scotch and A. Srinivasan, Multiscale Model for Pedestrian and Infection Dynamics During Air Travel) were covered in about 40 international news outlets in four continents, including newspapers and magazines such as The Economist, Fox News, Economic Times, Navbharat Times, and India Today.

Derjany, 30, who also has two master’s degrees, including one in aerospace engineering from Embry-Riddle, is honored to be doing this type of research for his PhD.

 “Human life is priceless,” Derjany said. “I hope it will have an impact and be a breakthrough in the field.”

The concern over Ebola and plane travel dominated the airways in 2014 and 2015 with cases of people being diagnosed soon after flying commercially, putting an unknown number of people at risk.

In September 2014, a man who flew from Liberia to New Jersey was soon found to have Ebola marking the first case in the U.S. A nurse who cared for him also flew on two commercial flights shortly before she was diagnosed with the deadly virus.

But Namilae and Derjany’s research shows changing the way people board planes could reduce the transmission of such viruses.  They are also expanding their research to include analyzing pedestrian density and movement in areas such as ticketing and security; boarding at the gate and baggage claim. 

“We want to determine if there is anything we can do in terms of pedestrian flow that will reduce the spread of infection,” Namilae said.

The researchers are looking at various perimeters such as the size of waiting areas at the gate and how they are designed. The concern is real considering the International Air Transport Association predicts 7.2 billion passengers travelling in 2035, almost double the 3.8 billion air travelers in 2016. International passenger traffic rose 6.7 percent in 2016 compared to 2015, while domestic air travel rose 5.7 percent.

Namilae, the primary author on the two initial research papers that included professors from Arizona State University and Florida State University, studied the transmission of Ebola and other viruses using a multiscale, hybrid computer model. By applying mathematical models used in materials science such as molecular dynamics, passenger movement and boarding and deplaning was analyzed around a hypothetical infected passenger along with transmission rates and incubation periods for diseases.

The research, funded by a $240,000 National Science Foundation grant and also included touring various airports, found that the standard boarding scenario of passengers boarding a plane in three sections presented a 67 percent chance that more than 20 new air-travel-related infections could occur per month. The findings were based on data from the 2014 Ebola epidemic in Africa.

“Because of this pattern, the passageway is filled with passengers waiting to get to their seats, resulting in clustering,” the report states.

However, using a two-section strategy, which divides the plane into two sections and passengers randomly board, the risk is less because passengers may be in seats that are wider apart from each other which prevents clustering. The probability of 20 new air-travel related infections in this scenario drops to less than 40 percent.

The research found that smaller planes, like 50 seaters, would reduce the infection probability even further because of fewer passengers, a lower number of susceptible individuals within a given area and less time spent moving on the plane.

“These problems have inherent uncertainty, and significant computing capability is needed to address this uncertainty,” Namilae said.

In collaboration with professor Ashok Srinivasan of Florida State University, Namilae used the Blue Waters supercomputer at the National Center for Supercomputing Applications at the University of Illinois, Urbana-Champaign, which allows accessing 100,000 processors at a time.

Namilae and Derjany are gearing up to use the new Cray supercomputer at Embry-Riddle to understand how small changes in travel policies could also impact the spread of infectious diseases on a global scale. The studies include ensuring that any changes to reduce passenger contact doesn’t disrupt travel or cause an economic impact to airlines.

“We’re trying to find the best strategy so any changes don’t effect turn time, which is the amount of time the airplane spends on the ground loading and unloading passengers and cargo,” Derjany said.