The ease with which a man infected with extensively drug resistant tuberculosis (XDR TB) flew on several international flights exposes flaws in international public health systems. The asymptomatic US lawyer flew on two transatlantic flights and several European flights for his wedding and honeymoon.

It also led to an international search for passengers who may have been exposed to this almost incurable disease.

Local public health officials in the United States could not prevent him from travelling; the US Centers for Disease Control and Prevention (CDC) failed to contact him; a “no fly alert” did not prevent him from flying; and a border alert to detain him was ignored.

The good news, said Julie Gerberding, head of the CDC, was that the risk of transmission was low. The man was “smear negative,” with no detectable bacteria in his sputum.

Mario Raviglione, director of the Stop TB programme at the World Health Organization, told the BMJ that “if the International Health Regulations, 2006, had been in place, the relevant procedures outlined would have been followed correctly. [The regulations] will come into effect on 15 June worldwide and 17 July in the US [United …