A study recently published in Preventive Medicine shows a potential alternative that scientists have developed to replace the Ebola entry screen program that is in place at U.S. airports.
Within the US, there have been two imported cases and two locally contract cases in September and October 2014. Because of concern about how to prevent the virus from spreading worldwide, health experts developed an Ebola screening program for airports.
"This outbreak stimulated high-level discussions about how to prevent the global transmission and spread of Ebola," Sheldon Jacobson, a professor of computer science at the University of Illinois at Urbana-Champaign, said. "One strategy recommended by the World Health Organization required exit screening at airports for passengers who depart from countries with Ebola. Passengers with a high-risk exposure to or symptoms of Ebola are denied boarding under this approach.”
Because of how the disease progresses, health professionals decided that there must be exit as well as entry screening for international travelers.
"With exit screening from such countries, out of approximately 80,000 departing travelers from August to November 2014, none were reported as symptomatic with Ebola,” Jacobson said. “However, since the physical condition of a passenger can deteriorate during a long international flight, entry screening at destination countries was also instituted as an auxiliary precaution to prevent the entry of passengers with Ebola into their country."
The new approach uses social contact tracing to determine the risk level and spread of the disease. This will help experts create a more strategic system for locating potential Ebola cases.
"This alternative policy in regards to Ebola transmission incorporates a social contact tracing risk level, in addition to the current health risk level used by the [U.S. Centers for Disease Control and Prevention] CDC,” Jacobson said. “It requires additional passenger input data, taking into account not only a passenger's exposure to Ebola, but also the potential to conduct social contact tracing if they are not initially monitored or their movements are not initially restricted, yet later become ill with Ebola."
With a scenario-cost-based sensitivity analysis in addition to an expected cost-based optimization model analysis, scientists found that the CDC policy and the new alternative are comparable.
"Indeed, using a secondary risk level such as the potential footprint for social contact tracing level may be a useful consideration when the current CDC policy is evaluated," Jacobson said. "Although the implementation of the secondary risk level requires additional data collection costs and time, the potential societal and public health benefits may justify such expenditures and efforts."
As of January, Ebola has been connected to 28,639 cases as well as 11,316 deaths. Some experts believe this figure underestimates the 2014 outbreak that occurred in West Africa.