Lead author Xiang-Yang Han, M.D., Ph.D., associate professor in Laboratory Medicine at The University of Texas M. D. Anderson Cancer Center, said that the new discovery holds importance as all cases of leprosy previously had been thought to be caused by a single species of bacterium.
"We have identified a second species of leprosy mycobacterium, and in identifying this killing organism we've better defined the disease that it causes, diffuse lepromatous leprosy (DLL)," Han said.
The new species Mycobacterium lepromatosis were discovered from 2 patients who died of (DLL).
A 53-year-old man, originally from Mexico, was admitted for treatment of extensive leg wounds. While undergoing antibiotic treatment and additional diagnostic testing the next day, he was stricken with high fever and shock. He died after 10 days in intensive care.
Analysis of autopsied tissue at the Phoenix hospital suggested a diagnosis of diffuse lepromatous leprosy, a form first described in Mexico in 1852.
Han said DLL uniquely attacks a patient's skin vasculature, blocking or impeding blood flow.
This leads to extensive skin death at late stage and may cause secondary infection and fatal shock.
The research team also analyzed samples from a similar lethal case of a 31-year-old man in 2002 with so much skin damage that he was first admitted to a hospital burn unit.
The study is published in the December issue of the American Journal of Clinical Pathology.