Korma Workneh, Mihret Adane, Hussien Jemal, Anthony Richard, Lakew Mekuria, Aseffa Abraham
Institute of Biotechnology, Addis Ababa University, P.O. Box 62720, Addis Ababa, Ethiopia.
Armauer Hansen Research Institute, P.O.Box 1105, Addis Ababa, Ethiopia.
BMC Infect Dis. 2015 Oct 26;15:456. doi: 10.1186/s12879-015-1177-4.
In conjunction with the spread of HIV infection, tuberculosis (TB) remains a major cause of illness and death worldwide. The Ethiopian national report reveals that extra pulmonary tuberculosis is on the rise and that case detection rate is exceeding that of smear positive or negative cases in many parts of the country. Different studies indicated that host and/or pathogen related factors are associated with the rise of extra pulmonary cases. However, the reason for this is not clearly known in our setting.
Specimens were taken from clinically suspected extra pulmonary patients and confirmed by cytology, histopathology and culture. Deletion typing and Spoligotyping was utilized to identify the strains. The isolates were then assigned to lineage using conformal Bayesian network (rules model) algorithm and dendrograms were drawn using UPGMA methods. In addition, drug sensitivity test was done using the indirect proportion and 24 well plate methods.
Out of the 200 clinically suspected extra pulmonary tuberculosis patients, 106 (53 %) were between 15 and 35 years of age and 167 (83.5 %) were new while 33 (16.5 %) were retreatment cases. The culture yield was 29.5 % (59). Of these only one was M. bovis and 58 were M. tuberculosis strains with 31 different spoligotype patterns grouped into seven clusters. The largest cluster (ST53) comprised 12 (20.3 %) isolates. There was higher clustering of CAS isolates in TBLN than in any other form of extra pulmonary tuberculosis cases. Resistance to rifampicin was higher (22 %) than that for INH, STM and EMB (8.1 %, 5 % and 3 % respectively). Out of the 37 isolates tested for resistance, only 2 isolates were resistant for both STM and INH and no MDR strain was found.
There is an ongoing active recent transmission among extra pulmonary tuberculosis in the study areas as shown by the presence of clusters. Although no MDR case was observed, there is a risk of emergence of MDR as noted from the high proportion of resistance to rifampicin. Detailed study at population level is recommended to monitor its trend.
随着艾滋病毒感染的蔓延，结核病仍然是全球疾病和死亡的主要原因。埃塞俄比亚国家报告显示，肺外结核病正在增加，并且在该国许多地区病例检出率超过涂片阳性或阴性病例。不同研究表明，宿主和/或病原体相关因素与肺外病例的增加有关。然而，在我们的环境中，其原因尚不清楚。
从临床疑似肺外患者中采集标本，并通过细胞学、组织病理学和培养进行确诊。采用缺失分型和间隔寡核苷酸分型（Spoligotyping）来鉴定菌株。然后使用共形贝叶斯网络（规则模型）算法将分离株分配到谱系，并使用非加权组平均法（UPGMA）绘制树形图。此外，使用间接比例法和24孔板法进行药物敏感性试验。
在200例临床疑似肺外结核病患者中，106例（53%）年龄在15至35岁之间，167例（83.5%）为新发病例，33例（16.5%）为复治病例。培养阳性率为29.5%（59例）。其中仅1例为牛分枝杆菌，58例为结核分枝杆菌菌株，具有31种不同的间隔寡核苷酸分型模式，分为7个簇。最大的簇（ST53）包含12株（20.3%）分离株。与任何其他形式的肺外结核病例相比，支气管淋巴结结核（TBLN）中CAS分离株的聚类性更高。对利福平的耐药率（22%）高于异烟肼、链霉素和乙胺丁醇（分别为8.1%、5%和3%）。在37株进行耐药检测的分离株中，仅2株对链霉素和异烟肼均耐药，未发现耐多药菌株。
研究区域肺外结核病之间存在近期持续的活跃传播，如簇的存在所示。虽然未观察到耐多药病例，但鉴于对利福平的高耐药比例，存在出现耐多药的风险。建议在人群水平进行详细研究以监测其趋势。
