Over the centuries, few diseases have invoked such dread as leprosy. Even in English, the word leper means not just a victim of the disease but carries the wider connotation of being a pariah, outcast or one who is rejected by society. Today this tragic disease persists on the mainland - and will continue to do so, experts say, as long as discrimination against its victims continues.
Today is World Leprosy Day, which was established in the 1950s to highlight the plight of millions of people affected by a devastating and disfiguring illness. According to the World Health Organisation, more than 192,000 leprosy cases were registered worldwide in 2011. Most were in tropical Asia, South America and Africa, although America's National Institutes of Health says about 100 cases a year are reported in the US.
Leprosy, also called Hansen's disease, is caused by the Mycobacterium leprae bacterium. It first affects the skin, then nerves and muscles, and causes permanent disfigurement if not treated. It is not very contagious and has a long incubation period, making it difficult to know when and where it was contracted. It is more likely to strike children than adults, but can be effectively treated with multidrug therapy provided free by the World Health Organisation since the 1990s.
In China, leprosy victims were often permanently quarantined in the mountains. Some were even murdered - in some cases buried alive - such was the public's horror of the disease before effective drugs were developed in the 1940s. Today the national infection rate is less than one in 100,000, according to the Ministry of Health.
Most of the mainland's 6,000 active cases, those not declared cured, are found in poverty-stricken southwestern regions such as Yunnan, Guizhou and Sichuan, although some are still being treated in Guangdong.
Another 200,000 patients are considered cured but still require rehabilitation. Of these, 60 per cannot work due to their disability and 90 per cent are poor, according to the China Leprosy Association.
Dr Shen Jianping , a professor at the Nanjing-based National Centre for Leprosy Control administered by the China Centre of Disease Control and Prevention, said it would be hard for the mainland to meet a health ministry target set last year to reduce the number of active patients to 5,300 by 2015.
Shen said it would only be possible to reach the target if patients were identified in the early stages.
It is the stigma associated with the disease that is the greatest obstacle, Shen said, as it made patients far more reluctant to come forward.
"When doctors visit homes in remote Yunnan, Guizhou and Sichuan, to monitor the status of the disease, many residents don't co-operate," he said. "People don't want their neighbours to know they have leprosy.
"The fact that so many of them are scattered in remote areas in the mountains makes screening arduous."
Xu Xianfeng, a doctor who works at the Liangshan Leprosy Rehabilitation Centre in Sichuan, which is funded by Hong Kong-based charity RCHKS-Handa Projects International, said leprosy patients faced even greater prejudice and discrimination than people with HIV, the virus than can lead to Aids.
"Some cured leprosy victims can't find marriage partners," she said. "Leprosy casts a shadow long after it has been cured."
Xu said her project, which has provided medical aid and education for 315 patients and their families in nine villages in Liangshan prefecture since 2003, aims to develop "self care and self development" skills for patients and to campaign to eradicate the stigma.
"In the beginning, these patients did everything to shun our organisation, she said. "After suffering from leprosy and bad treatment from society for decades, the victims thought they should be kept away from normal people."
Shen said the mainland reported 1,300 new leprosy patients last year. The average age for new patients in coastal regions was 48, while in the hinterland it was 39, meaning that the epidemic was still at its peak in those regions.
Dr Dong Shumeng, president of Linglong Hospital in Kaiping, Guangdong, said the public's prejudice had "ebbed a bit" compared with five years ago. More volunteers were visiting the 53 rehabilitating patients at his hospital, and people showed less fear in public.