South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa.
PLoS One. 2006 Dec 20;1(1):e21. doi: 10.1371/journal.pone.0000021.
To evaluate the frequency and clinical significance of non-tuberculous mycobacteria (NTM) isolates among children investigated for pulmonary tuberculosis in a rural South African community.
Children were investigated for pulmonary tuberculosis as part of a tuberculosis vaccine surveillance program (2001-2005). The clinical features of children in whom NTM were isolated, from induced sputum or gastric lavage, were compared to those with culture-proven M. tuberculosis.
Mycobacterial culture demonstrated 114 NTM isolates from 109 of the 1,732 children investigated, a crude yield of 6% (95% CI 5-7). The comparative yield of positive NTM cultures from gastric lavage was 40% (95% CI 31-50), compared to 67% (95% CI 58-76) from induced sputum. 95% of children with NTM isolates were symptomatic. Two children were HIV-infected. By contrast, M. tuberculosis was isolated in 187 children, a crude yield of 11% (95% CI 9-12). Compared to those with culture-proven M. tuberculosis, children with NTM isolates were less likely to demonstrate acid-fast bacilli on direct smear microscopy (OR 0.19; 95% 0.0-0.76). Children with NTM were older (p<0.0001), and more likely to demonstrate constitutional symptoms (p = 0.001), including fever (p = 0.003) and loss of weight or failure to gain weight (p = 0.04), but less likely to demonstrate a strongly positive tuberculin skin test (p<0.0001) or radiological features consistent with pulmonary tuberculosis (p = 0.04).
NTM were isolated in 6% of all children investigated for pulmonary tuberculosis and in more than one third of those with a positive mycobacterial culture. NTM may complicate the diagnosis of PTB in regions that lack capacity for mycobacterial species identification. The association of NTM isolates with constitutional symptoms suggestive of host recognition requires further investigation.
评估南非农村社区中,在接受肺结核调查的儿童中分离出非结核分枝杆菌(NTM)的频率及其临床意义。
作为结核病疫苗监测计划的一部分(2001-2005 年),对儿童进行了肺结核调查。从诱导性痰或胃灌洗液中分离出 NTM 的儿童的临床特征与培养证实的结核分枝杆菌(M. tuberculosis)进行了比较。
从 1732 名接受调查的儿童中,分枝杆菌培养显示 114 株 NTM 分离株,粗发病率为 6%(95%CI 5-7)。胃灌洗液中阳性 NTM 培养的比较产量为 40%(95%CI 31-50),而诱导性痰中为 67%(95%CI 58-76)。95%的 NTM 分离株患儿有症状。两名儿童感染了 HIV。相比之下,187 名儿童中分离出结核分枝杆菌,粗发病率为 11%(95%CI 9-12)。与培养证实的结核分枝杆菌相比,NTM 分离株患儿直接涂片显微镜检查中发现抗酸杆菌的可能性较小(比值比 0.19;95%置信区间 0.0-0.76)。NTM 分离株患儿年龄较大(p<0.0001),更可能出现全身症状(p = 0.001),包括发热(p = 0.003)和体重减轻或体重未增加(p = 0.04),但结核菌素皮肤试验呈强阳性(p<0.0001)或影像学特征与肺结核一致(p = 0.04)的可能性较小。
在接受肺结核调查的所有儿童中,有 6%分离出 NTM,在培养阳性的儿童中,有超过三分之一分离出 NTM。在缺乏分枝杆菌种鉴定能力的地区,NTM 可能会使肺结核的诊断复杂化。NTM 分离株与提示宿主识别的全身症状之间的关联需要进一步研究。