Scientists have conquered many diseases, but leprosy remains the unconquered frontier, mainly in Africa.
Modou Gaye sits on a hospital bed in Senegal, his left leg stretched the length of the mattress, the right one amputated below the knee.
Afflicted by recurrent yet mysterious sores, he had done the rounds of traditional practitioners and physicians who prescribed him various plants and potions but were unable to tell him he had leprosy.
"I didn't know anything about the disease," the 32-year-old street peddler from central Senegal tells AFP in his native language, Wolof.
Gaye's story typifies the experience of many patients who one day notice an innocuous, painless blemish on the skin, and later discover they have leprosy, a condition which is easy to combat yet which continues to cripple and exclude millions worldwide.
When Gaye was finally diagnosed the young father was lucky to receive care from the Hospital of the Order of Malta (HOM), a medical facility in the capital Dakar at the forefront of treatment of the disease.
But it was too late to save his right leg, the bone already too badly damaged.
Leprosy, transmitted most effectively in overcrowded conditions with poor sanitation, "afflicts the poorest, the most vulnerable", says Dr Charles Kinkpe, chief medical officer at HOM, which provides free care for the destitute.
"They often wait until the last minute to be seen," laments the orthopaedic surgeon. Yet the bacterial illness can be easily cured before it causes serious damage.
Multi-drug therapy (MDT), available free of charge through the World Health Organisation since the 1980s, consists of three antibiotics which together can cure patients in a few months.
But often those afflicted with leprosy do not know how to spot the signs early on and the disease takes an insidious hold, attacking nerve endings, destroying the ability to feel pain and injury.
Over 200,000 new cases a year
"They burn themselves holding a hot pan or injure their feet walking on glass, for example, and do not realise," Kinkpe told AFP.
Unable to sense these injuries, patients are susceptible to sores and infections which can eventually lead to the loss of fingers, hands, toes and feet, blindness and facial disfigurement.
"People with leprosy are isolated, kept remote -- people don't touch them. People say they are cursed," says Diemg Mas, a 33-year-old teacher who has been receiving treatment for nearly two years.
Women sometimes hide the illness for fear of being rejected by their husbands.
Organisations dealing with leprosy combat prejudice through eduction, hammering home the message that leprosy is not hereditary, nor a sign of a divine curse.
They point out that 95 percent of humans are actually naturally immune to what campaigners call the world's "least contagious communicable disease".
Treated in 1976 and cured permanently, 60-year-old Moustapha Seck stayed at HOM and now manufactures orthopaedic shoes for those crippled by leprosy.
"When they put them on, first they walk, then they dance with joy," he says proudly.
Between 200 and 300 new cases of leprosy are reported each year in Senegal but doctors believe that only a small proportion of patients are detected.
"If nothing is done we can expect an increase in prevalence," warns Professor Charles Badiane of HOM.
Considerable progress has been made in the fight against leprosy but it remains present in more than 100 countries in Africa, America, Asia and the Pacific.
World Leprosy Day -- a period of three days, in fact, aimed at raising awareness of the disease -- begins on Friday and organisers hope to communicate the message that, despite more than 200,000 new cases being detected in 2012, it can be eradicated.