Multidisciplinary Respiratory Medicine
多学科呼吸内科

Keywords: China, Infection, Nontuberculous mycobacterium
关键词：中国， 感染， 非结核分枝杆菌

Nontuberculous mycobacteria (NTM) diseases have been neglected in most of developing world [1]. With the global pandemic of HIV/AIDS and aging population, NTM have been increasingly associated with pulmonary diseases in humans [2]. In China, Mycobacterium tuberculosis (MTB) still causes the majority of pulmonary mycobacteria diseases. Nevertheless, in the last decade, the NTM isolation rate has shown an increasing trend in China [3,4]. Pulmonary NTM diseases may share clinical signs with TB, causing a clinical dilemma in early diagnosis and treatment. Delay or misdiagnosis of NTM diseases may worsen the disease and increase the mortality and economic burden of patients. In this study, we retrospectively investigated the diagnostic history and clinical characteristics of patients with pulmonary NTM
非结核分枝杆菌 （NTM） 疾病在大多数发展中国家被忽视 [1]。随着 HIV/AIDS 的全球流行和人口老龄化，NTM 与人类肺部疾病的相关性越来越高 [2]。在中国，结核分枝杆菌 （MTB） 仍然导致大多数肺分枝杆菌疾病。然而，在过去 10 年中，中国的 NTM 隔离率呈上升趋势 [3,4]。肺部 NTM 疾病可能与结核病有共同的临床症状，导致早期诊断和治疗的临床困境。NTM 疾病的延误或误诊可能会使疾病恶化并增加患者的死亡率和经济负担。在这项研究中，我们回顾性调查了肺 NTM 患者的诊断史和临床特征

diseases to better understand the factors related to the diagnostic delay in China.
疾病，以更好地了解与中国诊断延迟相关的因素。

This study was conducted in Shandong Province, which is the second largest province in China (population size, 96 million and 59% rural) and has approximately 40,000 new TB cases annually. Shandong Provincial Chest Hospital (SPCH) is the only provincial-level hospital specialized in TB (a referral hospital) and other lung infections, and networks 139 county/city-level TB clinics. Between January 1, 2007 and December 31, 2012, 91 patients were diagnosed with pulmonary NTM disease based on the American Thoracic Society/Infectious Disease Society of America (ATS) diagnostic criteria [5]. Multiple $(\ge =2)$$(\ge =2)$(≥=2)(\geq=2) sputum specimens from each patient were collected for Acid Fast Bacillus (AFB) test and mycobacterial culture at SPCH. Identification of mycobacteria species was first carried out at the ISO15189-certified SPCH TB reference laboratory by conventional biochemical tests, P-nitrobenzoic acid (PNB) and 2-Thiophene carboxylic acid hydrazide (TCH) testing following a standard protocol [6], and further
这项研究是在山东省进行的，山东省是中国第二大省份（人口规模为 9600 万，农村占 59%），每年约有 40,000 例新发结核病病例。山东省胸科医院 （SPCH） 是唯一一家专门治疗结核病和其他肺部感染的省级医院（转诊医院），并与 139 个县/市级结核病诊所建立了网络。2007年1月1日至2012年12月31日期间，根据美国胸科学会/美国传染病学会（American Thoracic Society/Infectious Disease Society of America， ATS）的诊断标准，91例患者被诊断为肺部NTM疾病[5]。收集每位患者的多个 $(\ge =2)$$(\ge =2)$(≥=2)(\geq=2) 痰标本用于抗酸芽孢杆菌 （AFB） 检测和 SPCH 分枝杆菌培养。分枝杆菌种类的鉴定首先在 ISO15189 认证的 SPCH TB 参考实验室通过常规生化测试、对硝基苯甲酸 （PNB） 和 2-硫代苯羧酸酰肼 （TCH） 测试进行，遵循标准方案 [6]，并进一步
identified by 16S rRNA gene sequence analysis (MicroSeq ID Microbial Indentification Software V2.0, PE Applied Biosystems) at the species level as previously described [7]. To minimize possible species identification error, DNA extraction and 16 S rRNA gene sequencing of each NTM isolate was independently conducted twice. Statistical analysis was carried out by using SPSS (IBM, USA). The study protocol was approved by the SPCH Institutional Review Board.
如前所述，通过物种水平的 16S rRNA 基因序列分析（MicroSeq ID 微生物鉴定软件 V2.0，PE Applied Biosystems）鉴定 [7]。为了最大限度地减少可能的物种鉴定错误，每个 NTM 分离株的 DNA 提取和 16 S rRNA 基因测序独立进行两次。使用 SPSS （IBM， USA） 进行统计分析。该研究方案已获得 SPCH 机构审查委员会的批准。

Over the six study years, a total of 91 patients (mean age $\pm \mathrm{SD},45.7\pm 16.2$$\pm \mathrm{SD},45.7\pm 16.2$+-SD,45.7+-16.2\pm \mathrm{SD}, 45.7 \pm 16.2 years; age range, $15-79$$15-79$15-7915-79 years; male, $73.6\mathrm{\%}$$73.6\mathrm{\%}$73.6%73.6 \% ) were identified with pulmonary NTM infection from 4541 patients with positive mycobacteria cultures at SPCH, indicating an overall NTM isolation rate of $2.0\mathrm{\%}$$2.0\mathrm{\%}$2.0%2.0 \% among all mycobacterial isolates, that did not show a significantly increasing or decreasing trend within the study period. The patients were predominantly male ( $73.6\mathrm{\%}$$73.6\mathrm{\%}$73.6%73.6 \% ) and adult ( $98.9\mathrm{\%}$$98.9\mathrm{\%}$98.9%98.9 \% older than 18 years; and $37.4\mathrm{\%}$$37.4\mathrm{\%}$37.4%37.4 \% from age group of $46-64$$46-64$46-6446-64 years) (Table 1). The diagnostic delay of NTM patients was defined as the period from the date of the patient’s first visit at the healthcare service to the date of diagnosis. Median diagnostic delay time for the 91 NTM patients was 84 days (range, $28-1,144$$28-1,144$28-1,14428-1,144 days), and it was not significantly associated with sex and age of NTM patients (Table 1). Patients living in rural areas showed a significantly longer diagnostic delay time than those in the urban areas
在六个研究年中，共有 91 名患者 （平均年龄 $\pm \mathrm{SD},45.7\pm 16.2$$\pm \mathrm{SD},45.7\pm 16.2$+-SD,45.7+-16.2\pm \mathrm{SD}, 45.7 \pm 16.2 岁;年龄范围， $15-79$$15-79$15-7915-79 岁;男性） $73.6\mathrm{\%}$$73.6\mathrm{\%}$73.6%73.6 \% 从 4541 例 SPCH 分枝杆菌培养阳性的患者中确定了肺部 NTM 感染，表明在所有分枝杆菌分离株 $2.0\mathrm{\%}$$2.0\mathrm{\%}$2.0%2.0 \% 中，总体 NTM 分离率在研究期间没有显示出显着增加或下降的趋势。患者主要是男性 （ $73.6\mathrm{\%}$$73.6\mathrm{\%}$73.6%73.6 \% ） 和成人 （ $98.9\mathrm{\%}$$98.9\mathrm{\%}$98.9%98.9 \% 18 岁以上;年龄 $37.4\mathrm{\%}$$37.4\mathrm{\%}$37.4%37.4 \% 组 $46-64$$46-64$46-6446-64 ） （表 1）。NTM 患者的诊断延迟定义为从患者首次就诊之日到诊断之日。91 例 NTM 患者的中位诊断延迟时间为 84 天 （范围， $28-1,144$$28-1,144$28-1,14428-1,144 天数），与 NTM 患者的性别和年龄无显著相关性 （表 1）。生活在农村地区的患者表现出的诊断延迟时间明显长于城市地区的患者

Table 1 Characteristics and diagnostic delay of 91 NTM patients
表 1 91 例 NTM 患者的特点和诊断延迟

(135 vs. 73 days, $\mathrm{p}<0.01$$\mathrm{p}<0.01$p < 0.01\mathrm{p}<0.01 ). Patients with a first visit at tertiary and secondary hospitals/clinics had significantly shorter delay time than those at primary hospitals/clinics (70 and 82 days respectively vs. 120 days, $\mathrm{p}<0.05$$\mathrm{p}<0.05$p < 0.05\mathrm{p}<0.05 ) (Table 1).
（135 天对 73 天）。 $\mathrm{p}<0.01$$\mathrm{p}<0.01$p < 0.01\mathrm{p}<0.01 在三级和二级医院/诊所首次就诊的患者延迟时间明显短于初级医院/诊所的患者（分别为 70 天和 82 天对 120 天）（ $\mathrm{p}<0.05$$\mathrm{p}<0.05$p < 0.05\mathrm{p}<0.05 表 1）。
All 91 NTM patients were HIV seronegative. Other comorbidities included diabetes (9.9%), cardiovascular diseases (13.2%), chronic obstructive pulmonary disease (COPD, 12.1%), and bronchiectasis (20.9%) (Table 2). Mycobacterium (M.) intracellulare infection accounted for 46.1% of these NTM diseases, following by M. chelonaeabscessus complex (28.6%), M. kansasii (12.1%), M. gordonae (5.5%), M. fortuitum (5.5%), M. asiaticum (1.1%), and M. farcinogenes (1.1%). In this study, a 79-year-old male patient was diagnosed with severe COPD, bronchiectasis, and pulmonary infection Positive results were shown in six consecutive sputum AFB smear tests. Mycobacterial culture and identification revealed isolation of M. farcinogenes. It is the second report of human infection and the first report of pulmonary $M$$M$MM. farcinogenes disease in humans [8].
所有 91 例 NTM 患者均为 HIV 血清阴性。其他合并症包括糖尿病 （9.9%）、心血管疾病 （13.2%）、慢性阻塞性肺病 （COPD， 12.1%） 和支气管扩张症 （20.9%）（表 2）。分枝杆菌 （M.） 细胞内感染占这些 NTM 疾病的 46.1%，其次是 M. chelonaeabscessus 复合体 （28.6%）、堪萨斯分枝杆菌 （12.1%）、戈登分枝杆菌 （5.5%）、偶发分枝杆菌 （5.5%）、亚洲分枝杆菌 （1.1%） 和法基因分枝杆菌 （1.1%）。在这项研究中，一名 79 岁的男性患者被诊断为严重 COPD、支气管扩张和肺部感染，连续 6 次痰 AFB 涂片检查显示阳性结果。分枝杆菌培养和鉴定揭示了 M. farcinogene 的分离。这是人类感染的第二例报告和肺部 $M$$M$MM 的第一次报告。人类 FARCINOGENES 病 [8]。

Our data suggest that the diagnosis of pulmonary NTM disease is significantly delayed in China, which is attributed to rural inhabitance, and limited access to higher-level healthcare and laboratory services (tertiary and secondary). In China, approximately $71.3\mathrm{\%}$$71.3\mathrm{\%}$71.3%71.3 \% of patients with active TB live in the resource-poor rural areas, where the mycobacteria culture and species identification tests are not routine testing for each TB or NTM suspect yet [8]. In our previous studies in Shandong, without species identification testing, NTM disease was often misdiagnosed as multidrug resistant TB (MDR-TB) and accounted for 30.7% of reported MDR-TB (due to natural resistance of NTM to anti-TB drugs) [4]. Approximately 4% of retreated TB cases were caused by NTM infections [4]. The 2010 Chinese National TB Surveillance Program has reported a NTM isolation rate of $22.9\mathrm{\%}$$22.9\mathrm{\%}$22.9%22.9 \% among 363 culture positive TB suspects [9]. This data strongly indicates that NTM infection has become a significant public health concern in China, which should not be neglected in disease control practice. The clinicians and public health professionals in primary care settings need to improve their awareness of this emerging disease. Mycobacteria culture and species identification tests need to be routine testing for each TB or NTM suspect.
我们的数据表明，中国肺 NTM 疾病的诊断明显延迟，这归因于农村居民，以及获得更高级别医疗保健和实验室服务（三级和二级）的机会有限。在中国，大约 $71.3\mathrm{\%}$$71.3\mathrm{\%}$71.3%71.3 \% 活动性结核病患者生活在资源匮乏的农村地区，分枝杆菌培养和种属鉴定检测还不是每个结核病或 NTM 疑似病例的常规检测 [8]。在我们之前在山东的研究中，在没有种属鉴定检测的情况下，NTM 疾病经常被误诊为耐多药结核病 （MDR-TB），占已报道的耐多药结核病的 30.7%（由于 NTM 对抗结核药物的自然耐药性）[4]。大约 4% 的复发结核病病例是由 NTM 感染引起的 [4]。2010 年中国国家结核病监测计划报道了 363 例培养阳性 TB 疑似患者的 NTM 分离率 $22.9\mathrm{\%}$$22.9\mathrm{\%}$22.9%22.9 \% [9]。这一数据有力地表明，NTM 感染已成为中国重大的公共卫生问题，在疾病控制实践中不应被忽视。初级保健机构的临床医生和公共卫生专业人员需要提高他们对这种新出现的疾病的认识。分枝杆菌培养和种属鉴定检测需要作为每个 TB 或 NTM 疑似患者的常规检测。
This study is a hospital-based surveillance study with a limited sample size, which aims to investigate the diagnostic delay caused by the healthcare system. There are definitely some other factors, such as patients’ comorbid diseases and environmental risks [10], also contributing to the delay of care, which need to be investigated in future studies.
本研究是一项样本量有限的医院监测研究，旨在调查医疗保健系统引起的诊断延迟。肯定还有一些其他因素，例如患者的合并症和环境风险 [10]，也会导致护理延迟，这些因素需要在未来的研究中进行调查。

Table 2 Clinical characteristics of patients infected with different NTM species
表 2 不同 NTM 种属感染患者的临床特征