A 12-year-old girl infected by a drug-resistant strain of tuberculosis was on Friday night under mandatory quarantine at a Hong Kong public hospital after skipping her treatment. The girl had been in medical isolation at Alice Ho Miu Ling Nethersole Hospital, in Tai Po, since Thursday, a Department of Health spokesman said. Doctors said the girl’s condition was under control. The quarantine was ordered after the girl, who had been getting regular treatment at a public clinic, stopped her medication and skipped medical visits, the spokesman said. She had been diagnosed with isoniazid-resistant tuberculosis (TB), a more common form of drug resistance in TB, which affects about 5 per cent of local TB patients, he added. “Treatment for isoniazid-resistant tuberculosis is shorter and easier compared with other types of multidrug resistance,” he said. “The patient should not suffer any major incident as long as he or she takes medication regularly.” Drug resistance in TB – a bacterial infection that mainly affects the lungs and can be fatal – has been a growing global public health threat. The World Health Organisation said recently that a quarter of the global population has been infected with latent TB and about 10 per cent will become full-blown cases at some point, especially people aged 65 or above. Last year in Hong Kong, more than 4,400 people were infected, 155 of them fatally. About 10 school outbreaks happen every year, according to the department. In 2012 and 2013, there were 26 and 21 cases of drug-resistant TB found, respectively. In general, about 1 per cent of TB cases in the city are resistant to more than one kind of drug, the so-called super-tuberculosis, said David Hui Shu-cheong, professor of respiratory medicine at Chinese University. The victims of such a bacteria have to go through treatment for up to 24 months, compared with just six months for patients with normal TB infections. The department did not respond to an inquiry on the number of mandatory quarantines ordered for TB patients. Why Hong Kong lags Taiwan in the war against tuberculosis It confirmed the girl’s condition only after media reports, and a spokesman said it would not announce subsequent TB infections. He said quarantine orders are made under the Prevention and Control of Disease Ordinance. A patients’ group criticised the department for withholding details about infections with TB, once one of the deadliest diseases in Hong Kong and other Asian cities, which still inspires a lingering fear among older residents. “It could create public panic ... if we don’t know more details about the infection,” Tsang Kin-ping from Hong Kong Patients’ Voice said. He urged the department to announce the area of the city affected and the transmissibility of the disease so locals could take precautions. Last month, a TB outbreak hit Kiangsu-Chekiang College in Sha Tin. Seven students and one teacher were infected and about 70 others were put under medical screening. Vice-principal of the school Lau Chi-ip said on Friday that a few more people were found to have contracted the disease but all of them were latent cases with low infectious ability. All of them have been going to school as usual, Lau said, except one student who was believed to be the source of the outbreak.