Analysis of the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis in four countries.

OBJECTIVES

To differentiate the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis and correlate them with geographic distribution and clinicopathologic features.

METHODS

Species-specific polymerase chain reactions were used to detect each bacillus in archived skin biopsy specimens from patients with leprosy from Brazil (n = 52), Malaysia (n = 31), Myanmar (n = 9), and Uganda (n = 4). Findings were correlated with clinical and pathologic data.

RESULTS

Etiologic species was detected in 46 of the 52 Brazilian patients, including 36 patients with M leprae, seven with M lepromatosis, and three with both bacilli. The seven patients with sole M lepromatosis all had tuberculoid leprosy, whereas only nine of the 36 patients infected with M leprae exhibited this type, and the rest were lepromatous (P < .001). All patients with dual infections had lepromatous leprosy. Of the nine patients from Myanmar, six were test positive: four with M leprae and two with M lepromatosis. Of the Malaysian and Ugandan patients, only M leprae was detected in 27 of the 31 Malaysians and two of the four Ugandans.

CONCLUSIONS

The leprosy agents vary in geographic distribution. Finding M lepromatosis in Brazil and Myanmar suggests wide existence of this newly discovered species. The leprosy manifestations likely vary with the etiologic agents.