EpidemicsEffective screening of airline passengers arriving from areas of infectious disease outbreaks

Published 9 August 2013

New study shows that exit-screening at thirty-six airports would have assessed all air travelers at risk of transporting H1N1 out of Mexico at start of 2009 pandemic. Screening at 99 percent of the world’s international airports could have been forgone with negligible missed opportunities to prevent or delay the spread of disease. Screening at just eight airports worldwide would have led to the assessment of 90 percent of all at-risk air travelers.

Researchers have developed a simple new tool to help governments around the world decide whether to screen airplane passengers leaving or arriving from areas of infectious disease outbreaks.

The tool was developed by examining all international airplane traffic in the initial stages of the 2009 H1N1 pandemic.

A St. Michael’s Hospital release reports that researchers led by Dr. Kamran Khan of St. Michael’s Hospital in Toronto found that that a focused and coordinated approach to screening airplane passengers would generate the greatest public health benefits.

Furthermore, they found that screening travelers as they leave an area where an infectious disease outbreak is under way is far more efficient than screening passengers when they land at their final destination.

It is also much less disruptive to international travel and the global economy, they wrote in the May issue of the Bulletin of the World Health Organization.

After the 2003 SARS outbreak, 194 countries agreed to the International Health Regulations, a global treaty designed to prevent, protect against and control the spread of infectious disease without putting unnecessary restrictions on international travel and trade. Until now, it’s been unclear how governments should balance those competing demands.

Dr. Khan, an infectious disease physician and founder of BioDiaspora, uses global air traffic patterns to predict the international spread of infectious disease. This web-based technology has been used by numerous international agencies, including the U.S. Centers for Disease Control and Prevention (CDC), the European Center for Disease Prevention and Control, and the World Health Organization (WHO) to evaluate emerging infectious disease threats, including those during global mass gatherings such as the Olympics or the annual Hajj pilgrimage in Saudi Arabia.

Dr. Khan used his experience analyzing air traffic patterns to review the flights of the nearly 600,000 people who flew out of Mexico in May 2009, the start of the H1N1 pandemic. He found that exit screening would have caused the least disruption to international air traffic.

In fact, all air travelers at risk of H1N1 infection could have been assessed as they left one of Mexico’s thirty-six international airports. Exit screening at just six airports in Mexico coupled with entry screening at two airports in Asia (Shanghai and Tokyo) would have allowed for screening of about 90 percent of the at-risk travelers worldwide.

Assessing those same passengers when they landed at their destinations on direct flights out of Mexico would have been much more complicated and expensive because