Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan.
Clin Infect Dis. 2011 Mar 1;52(5):e127-32. doi: 10.1093/cid/ciq217.
Multidrug therapy has effectively reduced the number of leprosy cases in the world. However, the rate of reduction has decelerated over the years, giving early detection of Mycobacterium leprae and epidemiological study of relapse renewed relevance in attempts to eliminate the disease.
A molecular epidemiological survey for drug-resistant M. leprae was conducted in the central and highland regions of Vietnam. A total of 423 samples taken from patients, including 83 patients with new cases, 321 patients receiving treatment, and 19 patients with relapse, were studied for detection of M. leprae with mutations relating to drug resistance by sequencing the drug resistance determining region of the folP1, rpoB, and gyrA genes, which are responsible for dapsone, rifampicin, and ofloxacin resistance, respectively.
Nineteen mutations were found in the folP1 gene samples, and no mutations relating to drug resistance were found in either the rpoB or gyrA genes. Samples from patients with relapse showed folP1 mutation rates as high as 57%, and the mutation rates in samples from new and recent cases were <10%. Patients with relapse who had histories of treatment with dapsone monotherapy showed high mutation rates (78%), compared with patients with relapse who had previously only received multidrug therapy (33%).
Our study indicated high rates of dapsone resistance in patients with relapse, compared with patients with new and recent cases of leprosy. Moreover, it was observed that many of the patients with relapse who had dapsone-resistant mutations had histories of treatment with dapsone monotherapy.
多药疗法已有效减少了全球的麻风病病例数。然而，近年来减少速度有所放缓，因此，早期发现麻风分枝杆菌并对复发进行流行病学研究，对于消除该疾病具有重要意义。
在越南中部和高原地区进行了一项针对耐药麻风分枝杆菌的分子流行病学调查。共对 423 份来自患者的样本进行了研究，包括 83 例新发病例、321 例正在接受治疗的患者和 19 例复发患者。通过对负责达普司酮、利福平、氧氟沙星耐药的folP1、rpoB 和 gyrA 基因的耐药决定区进行测序，检测与耐药相关的突变。
在 folP1 基因样本中发现了 19 个突变，而 rpoB 或 gyrA 基因中未发现与耐药相关的突变。复发患者的 folP1 突变率高达 57%，新发病例和近期病例的突变率均<10%。曾接受过单药氨苯砜治疗的复发患者的突变率较高（78%），而仅接受过多药治疗的复发患者的突变率较低（33%）。
与新发病例和近期病例相比，本研究表明复发患者的氨苯砜耐药率较高。此外，还观察到许多携带氨苯砜耐药突变的复发患者曾接受过氨苯砜单药治疗。
