Guard must not be dropped in TB fight
Cases at a Sha Tin secondary school are a reminder that the disease has not gone away, and prompt diagnosis and infection control measures are key to safety
A time when tuberculosis killed more than 4,000 of their fellow residents a year is well within the living memory of many older Hongkongers. In those days the recent widely reported spread of the disease among six pupils and a teacher at a Sha Tin secondary school would have been a footnote to the daily news. But now it is a timely reminder that the eradication of TB remains a distant goal, although it is curable with a long course of antibiotics.
Hong Kong, a hub of travel and commerce, is a crossroads for travellers from five Asian countries among the seven responsible for 64 per cent of the world’s 10 million new cases of TB last year – China, the Philippines, Indonesia, India and Pakistan. The other two are South Africa and Nigeria. To be sure, with only 155 deaths last year, Hong Kong has been at the forefront of a global decline in mortalities of 2 per cent annually, brought about by infection control strategies and more effective drugs. The number of new cases in the city last year was roughly equal to the number of deaths a few decades ago. But, with 1.7 million deaths worldwide last year, TB remains a major public health issue concentrated in our region.
The global reduction in the incidence of TB needs to rise to 4-5 per cent to come remotely close to the goal of an end to the epidemic by 2030 as targeted under the sustainable development goals of the United Nations. The contagion detected at the Sha Tin school serves as a reminder of a lurking health threat commonly thought to have been seen off. Five pupils and a teacher were diagnosed with latent TB after a member of Form Four became ill following travel during the holiday period. All have since been cleared to return to school. Latent TB is symptomless, has a low risk of transmission and a one in 10 chance of becoming active later in life.
Hong Kong’s battle against the disease, beginning with the partially effective vaccination of newborns in 1952, is one of its post-war successes. Ironically, because of geography and the rising potential for cases to be imported, the city will become one of the last places that can safely drop its guard against it. Prompt diagnosis and infection control measures remain key to community safety.