Efficacy of travel bans in disease containment largely unknown, study finds

Since the rapid outbreak of the novel coronavirus (COVID-19) on Wuhan, China, and beyond, numerous governments have restricted travel to and from China, but a new university-run study reminds one and all that the effectiveness of travel bans remains unknown.

While the World Health Organization (WHO) had previously warned nations against acting to ban or restrict travel to China, the United States and others notably bucked the suggestion, implementing bans alongside declarations of a public health emergency. Their decisions were spurred by the speedy infection of tens of thousands and the deaths of hundreds. Though most cases remain in China, there have been 15 reported infection in the United States and 25 countries have been affected in all.

Travel bans are nothing new, according to researchers at the University of Washington and Johns Hopkins University. There has been little research into their efficacy, though.

“Some of the evidence suggests that a travel ban may delay the arrival of an infectious disease in a country by days or weeks,” Nicole Errett, lead author and a lecturer in the UW Department of Environmental & Occupational Health Sciences in the School of Public Health, said. “However, there is very little evidence to suggest that a travel ban eliminates the risk of the disease crossing borders in the long term.”

Errett and her team delved into thousands of published articles to identify those directly addressing travel bans used to halt Ebola, SARS, MERS, and Zika. They left out one of the most common viruses — influenza — because the ineffectiveness of travel bans to halt its spread has already been well documented. The team found just six studies.

Those six studies stemmed from models and simulations, not actual post-ban data. As a result, the study authors have recommended research questions, partnerships, and study protocols be created before the next outbreak so that such data can be quickly gathered and assessed. Additional research is urgently needed to inform future policy decisions, they said.

“When assessing the need for, and validity of, a travel ban, given the limited evidence, it’s important to ask if it is the least restrictive measure that still protects the public’s health, and even if it is, we should be asking that question repeatedly, and often,” Lauren Sauer, co-author and an assistant professor of emergency medicine at Johns Hopkins University’s School of Medicine, said.