Why Hong Kong lags behind Taiwan in the war against tuberculosis
Recent outbreak in city has exposed a flawed contact tracing system and preventive measures that are lacking
People who have been in close contact with tuberculosis patients should be screened and required to take preventive drugs, Taiwan experts said on Wednesday, as an outbreak at a school in Hong Kong sparked fears of a citywide epidemic.
Taiwan has extensive experience in dealing with the contagious disease and greatly reduced the infection rate in its population over the past decade.
In Hong Kong, eight people from Kiangsu-Chekiang College in Sha Tin recently contracted tuberculosis, with the school now screening 70 others for symptoms. As of Wednesday, all infected patients have recovered or are in stable condition.
The case has exposed a flawed contact tracing system in the city, with health authorities failing to identify early those who may be at risk of being infected.
The disease – also known as “white plague” in earlier eras when being diagnosed meant a virtual death sentence – was once the biggest killer in many Asian cities, including Hong Kong.
The World Health Organisation said a quarter of the planet’s population was infected with latent tuberculosis and about 15 per cent of these would become full-blown at some point, especially for people aged 65 or above.
This worrying trend is coupled with a growing number of drug-resistant tuberculosis cases, making treatment difficult.
In Hong Kong, the incidence rate of the disease was 65 people per 100,000 last year. In Taiwan, there was a significant drop from 72.5 people per 100,000 a decade ago to 43 last year, while the figure for Singapore was 44, according to WHO statistics.
“Taiwan’s experience in tuberculosis elimination and preventive control can serve as a valuable reference for health care authorities in Asia,” Dr Huang Yi-wen, chairman of the Taiwan Society of Tuberculosis and Lung Diseases, said.
A sound contact tracing system, screening programme and preventive treatment that cost the Taiwanese government HK$2 billion a year, have been key to successfully controlling tuberculosis, according to Dr Anita Chan Pei-chun from Taiwan’s Centres for Disease Control (CDC) under its Ministry of Health and Welfare.
Since 2006, Taiwan has had a system in place to trace people who have been exposed to the disease. These included individuals who have come into contact with a tuberculosis patient at home, in the office or at leisure.
Anyone with an eight-hour window of exposure to a patient within a day, or a cumulative 40-hour exposure in a week, is considered at risk.
With each tuberculosis patient diagnosed in Taiwan, about 12 to 15 close contacts are usually traced and notified. They are then screened and placed under preventive treatment. Through the programme, carers reach out to these people for follow-ups and deliver preventive drugs to their homes or workplace for free.
Experts fear return of Hong Kong’s No 1 killer, TB, amid rise in visitors from disease hotspots and drug resistance
Taiwan has also recently become the second place in the world after the United States to provide the preventive antibiotic Priftin to people with latent tuberculosis, shortening the traditional nine-month treatment period to three.
In comparison, Hong Kong typically only identifies and screens members in a patient’s household as high-risk individuals. Aside from them, only two to four other contacts are likely to be traced and contacted.
Those diagnosed with latent tuberculosis need to visit a public clinic daily on their own to take preventive pills over a nine-month period.
Data from the Department of Health suggested that only half complete the long treatment.
“If the contacts have to travel to a clinic every day for the pill, of course they feel reluctant to continue with the treatment. This is why in Taiwan we send carers to them,” Chan said in an interview in Taipei.
Dr Huang Yi-wen added that it was important to expand the network of contact tracing beyond the household of a patient.
“Those who spent time in entertainment activities with tuberculosis patients are the most difficult to trace, as they are usually reluctant to be identified,” Huang said. “Singing KTV, playing mahjong or drinking sessions are the easiest ways the disease can be transmitted.”
As a pre-emptive move, Taiwan authorities also carry out tuberculosis screenings regularly for the elderly in nursing homes, a group deemed most susceptible to the disease.
The island’s officials aim to push the incidence rate down to 10 in 100,000 people by 2035, in line with WHO’s strategy to end the world’s tuberculosis epidemic by that year, Chan said.
“Many people do not realise that tuberculosis is still with us and killing people. Any government that cares about the health conditions of the poor should enhance tuberculosis prevention, which is the most effective form of public health protection,” she added.
But Hong Kong specialist in cardiothoracic surgery, Dr Lee Tak-wai, said the disease was still a global health risk with a high prevalence in the city and on mainland China as it was difficult to eradicate because of difficulties in diagnosing and treating it.