据世界卫生组织（WHO）估计，全世界约有1/3的人口感染了结核分枝杆菌。虽然结核病的发病率只有5%~10%，但由于感染人群庞大，所以结核病仍是致死率仅次于艾滋病的全球第2大感染性疾病，每年有超过200万人死于结核病。从目前的流行趋势来看，至2020年，结核病仍会居于全球最严重的10大疾病之列。经济和卫生资源不发达的地区，往往是结核病的高发区。亚洲主要发展中国家，如印度和中国2008年集中了全球35%以上的结核病病例。全世界发病率最高的地区是撒哈拉沙漠以南的非洲地区，由于人类免疫缺陷病毒（HIV）和结核分枝杆菌的共感染，结核病的发病率可达290/10万，是发达国家的100倍以上。分子流行病学研究表明，不同基因型的结核分枝杆菌在不同的国家和地区的流行，以及不同基因型菌株的致病性和传播力不尽相同。如细胞和动物模型都证实在东亚流行的北京基因型菌株比其他基因型菌株具有更高的毒力，能抑制宿主的免疫反应。本文综述了近年来在结核分枝杆菌进化分型与菌株致病性方面的研究成果。

According to World Health Qrganization (WHO)’s global tuberculosis control report, up to one-third of the global population is estimated to carry latent Mycobacterium tuberculosis （M.tb）infection. Although following M.tb infection, only 5 to 10% of immunocompetent individuals develop active tuberculosis （TB）, this disease remains a major health problem particularly in low-income developing countries, which currently causes over 2 million deaths annually and is predicted to be among the 10 leading causes of disease burden even in the year 2020. India, China, Pakistan and Indonesia together account for 50% of the global TB epidemic. In sub-Sahara Africa, because of high HIV prevalence the TB incidence reaches 290 per 100 000 which is a hundred times of developed countries. Molecular epidemiology studies have shown that diverse strains of different genotypes were prevalence in different regions such as the predominance of W-Beijing family, one of the most successful M.tb families, in countries of East Asia. The notion that some strains of a single genotype, such as the W-Beijing genotype, are more virulent than others is supported by results obtained with animal and cellular models. The inhibition of the host immune response by mycobacterial strains of the W-Beijing family has recently been confirmed in vivo. This review discusses the phylogenetic studies that have been made in discovering how certain M.tb has achieved its virulence as a successful pathogen.