This summer, two tourists from Taiwan set off alarm bells among global health authorities when they flew from Kaohsiung via Hong Kong to attend a relative's wedding in Nanjing.
The couple was infected with tuberculosis. The 55-year-old husband had multi-drug-resistant TB (MDR-TB), a less treatable strain of the disease.
Like common tuberculosis, the strain is spread through germs in the air. But it is resistant to at least two of the leading first-line drugs used to treat the disease, and its potential spread prompted warnings this month of a global tuberculosis crisis by lung disease experts.
The husband and wife were eventually traced in July by mainland authorities in Funing, and sent home. Although World Health Organisation guidelines suggest the risk of infection was minimal because the flight lasted less than eight hours, officials nevertheless tried to trace the passengers seated next to the infected couple.
The manhunt reflected a growing concern among global health bodies over the spread of the drug resistant strain of tuberculosis, a fear that multiplied last December, when research revealed cases of MDR-TB to be much more numerous than previously estimated.
It had been believed that 300,000 new cases of MDR-TB were appearing every year. Researchers from the WHO and the Centres for Disease Control and Prevention in the US revised the figure to 450,000.
