Mtetwa Hlengiwe N, Amoah Isaac D, Kumari Sheena, Bux Faizal, Reddy Poovendhree
Institute for Water and Wastewater Technology (IWWT), Durban University of Technology, PO Box 1334, Durban, 4000, South Africa.
Department of Community Health Studies, Faculty of Health Sciences, Durban University of Technology, PO Box 1334, Durban, 4000, South Africa.
Heliyon. 2023 Jul 21;9(8):e18302. doi: 10.1016/j.heliyon.2023.e18302. eCollection 2023 Aug.
The spread of multidrug-resistant tuberculosis (MDR-TB) is a serious public health issue, particularly in developing nations. The current methods of monitoring drug-resistant TB (DR-TB) using clinical diagnoses and hospital records are insufficient due to limited healthcare access and underreporting. This study proposes using Wastewater-Based Epidemiology (WBE) to monitor DR-TB in six African countries (Ghana, Nigeria, Kenya, Uganda, Cameroon, and South Africa) and examines the impact of treated wastewater on the spread of TB drug-resistant genes in the environment. Using droplet-digital polymerase chain reaction (ddPCR), the study evaluated untreated and treated wastewater samples in selected African countries for TB surveillance. There was a statistically significant difference in concentrations of genes conferring resistance to TB drugs in wastewater samples from the selected countries (p-value<0.05); South African samples exhibited the highest concentrations of 4.3(±2,77), 4.8(±2.96), 4.4(±3,10) and 4.7(±3,39) log copies/ml for genes conferring resistance to first-line TB drugs (, , and respectively) in untreated wastewater. This may be attributed to the higher prevalence of TB/MDR-TB in SA compared to other African countries. Interestingly, genes conferring resistance to second-line TB drugs such as delamanid ( gene) and bedaquiline ( gene) were detected in relatively high concentrations (4.8(±3,67 and 3.2(±2,31 log copies/ml for ddn and respectively) in countries, such as Cameroon, where these drugs are not part of the MDR-TB treatment regimens, perhaps due to migration or the unapproved use of these drugs in the country. The gene encoding resistance to streptomycin ( gene) was abundant in all countries, perhaps due to the common use of this antibiotic for infections other than TB. These results highlight the need for additional surveillance and monitoring, such as WBE, to gather data at a community level. Combining WBE with the One Health strategy and current TB surveillance systems can help prevent the spread of DR-TB in populations.
耐多药结核病（MDR-TB）的传播是一个严重的公共卫生问题，在发展中国家尤为如此。由于医疗服务可及性有限和报告不足，目前利用临床诊断和医院记录监测耐药结核病（DR-TB）的方法并不充分。本研究提议采用基于废水的流行病学（WBE）方法，对六个非洲国家（加纳、尼日利亚、肯尼亚、乌干达、喀麦隆和南非）的耐多药结核病进行监测，并研究经处理的废水对环境中结核耐药基因传播的影响。该研究使用液滴数字聚合酶链反应（ddPCR），对选定非洲国家的未经处理和经处理的废水样本进行结核病监测评估。选定国家废水样本中赋予结核药物耐药性的基因浓度存在统计学显著差异（p值<0.05）；南非样本中，未经处理的废水中赋予一线结核药物耐药性的基因（分别为、、和）浓度最高，分别为4.3（±2.77）、4.8（±2.96）、4.4（±3.10）和4.7（±3.39） log拷贝/毫升。这可能归因于与其他非洲国家相比，南非结核病/耐多药结核病的患病率更高。有趣的是，在喀麦隆等国家，赋予二线结核药物（如地拉曼id（基因）和贝达喹啉（基因））耐药性的基因被检测到相对较高的浓度（ddn和分别为4.8（±3.67）和3.2（±2.31） log拷贝/毫升），而这些药物并非喀麦隆耐多药结核病治疗方案的一部分，这可能是由于这些药物在该国的迁移或未经批准的使用。编码对链霉素耐药性的基因（基因）在所有国家都很丰富，这可能是由于该抗生素常用于结核病以外的感染。这些结果凸显了需要开展额外的监测，如基于废水的流行病学监测，以便在社区层面收集数据。将基于废水的流行病学与“同一健康”战略及当前的结核病监测系统相结合，有助于防止耐多药结核病在人群中的传播。
