Mavenyengwa Rooyen T, Shaduka Emma, Maposa Innocent
Department of Health Sciences, School of Health and Applied Sciences, Namibia University of Science and Technology, Private Bag 13388, Windhoek, Namibia.
Department of Medical Microbiology, University of Zimbabwe College of Health Sciences, P. O. Box A178, Harare, Zimbabwe.
Infect Dis Poverty. 2017 Jan 11;6(1):13. doi: 10.1186/s40249-016-0213-y.
Tuberculosis (TB) kills approximately two million people and infects around nine million worldwide annually. Its proper management, especially in resource-limited settings, has been hindered by the lack of rapid and easy-to-use diagnostic tests. Sputum smear microscopy remains the cheapest, readily available diagnostic method but it only identifies less than half of the patients with a HIV/TB co-infection because the bacilli would have disseminated from the lungs to other areas of the body. The fully automated Xpert® MTB/RIF assay is a promising innovation for diagnosing TB and detecting resistance to rifampicin. This study aimed to evaluate the use of Xpert® MTB/RIF assay and microscopy in the diagnosis of Mycobacterium tuberculosis in Namibia, by determining the disease's epidemiology and calculating the proportion of cases infected just with TB and those with a resistance to rifampicin among the total suspected cases of TB in the country.
This retrospective study analysed TB cases that were diagnosed using both the Xpert® MTB/RIF assay and microscopy. Data were collected from patient records from the Meditech laboratory information system of the Namibia Institute of Pathology for the time period of July 2012-April 2013. Data from 13 regions were collected.
The total number of specimens collected from patients with symptoms of pulmonary TB was 1 842. Of these, 594 (32.20%) were found to be positive for MTB by Xpert® MTB/RIF assay, out of which 443 (24.05%) were also found to be positive by microscopy. The remainder was negative. The male patients were more resistant to rifampicin when compared to the female patients.
Tuberculosis is widely distributed throughout Namibia, with slightly more males infected than females. Most TB patients are also co-infected with HIV. Both microscopy and Xpert® MTB/RIF assay are crucial for the diagnosis of TB in the country. Screening diagnostic efforts should focus on the sexually active HIV positive male population who could be the source of more RIF-resistant TB than females to prevent its spread.
结核病每年在全球导致约200万人死亡，感染约900万人。由于缺乏快速且易于使用的诊断测试，其合理管理，尤其是在资源有限的环境中，受到了阻碍。痰涂片显微镜检查仍然是最便宜、最容易获得的诊断方法，但它只能识别不到一半的艾滋病毒/结核病合并感染患者，因为杆菌已经从肺部扩散到身体的其他部位。全自动Xpert® MTB/RIF检测是诊断结核病和检测利福平耐药性的一项有前景的创新技术。本研究旨在通过确定该国结核病的流行病学情况，并计算该国结核病疑似病例中仅感染结核病的病例以及对利福平耐药的病例在总病例中所占的比例，来评估Xpert® MTB/RIF检测和显微镜检查在纳米比亚诊断结核分枝杆菌中的应用。
这项回顾性研究分析了同时使用Xpert® MTB/RIF检测和显微镜检查诊断的结核病病例。数据收集自纳米比亚病理研究所Meditech实验室信息系统2012年7月至2013年4月期间的患者记录。收集了13个地区的数据。
从有肺结核症状的患者中收集的标本总数为1842份。其中，594份（32.20%）通过Xpert® MTB/RIF检测被发现结核分枝杆菌呈阳性，其中443份（24.05%）通过显微镜检查也呈阳性。其余为阴性。与女性患者相比，男性患者对利福平的耐药性更强。
结核病在纳米比亚广泛分布，男性感染人数略多于女性。大多数结核病患者还合并感染了艾滋病毒。显微镜检查和Xpert® MTB/RIF检测对该国结核病的诊断都至关重要。筛查诊断工作应侧重于性活跃的艾滋病毒阳性男性人群，他们可能比利福平耐药结核病的女性来源更多，以防止其传播。
