Belay Shegaw, Alemu Getaneh, Hailu Tadesse
Amhara National Regional State Health Bureau, Bahir Dar Health Science College, Bahir Dar, Ethiopia.
Departments of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
J Trop Med. 2023 Jun 26;2023:9697165. doi: 10.1155/2023/9697165. eCollection 2023.
Soil-transmitted helminths are parasitic nematodes found in the intestine. They are more prevalent in the tropics and subtropics, including Ethiopia. However, low-sensitive direct wet mount microscopy fails to detect soil-transmitted helminths among infected cases. Therefore, more sensitive and cost-effective diagnostic methods are urgently needed to minimize soil-transmitted helminthiasis morbidity.
This study aimed to compare and evaluate the performance of diagnostic methods for soil-transmitted helminths against the "gold" standard.
An institution-based cross-sectional study was conducted among 421 schoolchildren from May to July, 2022 in the Amhara Region. Study participants were selected using a systematic random sampling technique. Stool samples were processed via Kato-Katz, McMaster, and spontaneous tube sedimentation techniques. Data were entered into epi-data version 3.1 and analyzed using SPSS version 25. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated against the combined result as a "gold" standard. The strength of agreement between the diagnostic methods was determined by the Kappa value.
The overall prevalence of soil-transmitted helminths was 32.8% (95% CI: 28.2-37.8%) using a combination of methods. The detection rates of Kato-Katz, McMaster, and spontaneous tube sedimentation were 28.5% (95% CI: 24.2-33.2%), 30% (95% CI: 25.6-34.8%), and 30.5% (95% CI: 26.1-35.3%), respectively. Sensitivity and negative predictive values were 87.1% (95% CI: 80.2-92.3%) and 95.1% (95% CI: 92.6-96.8%) for Kato-Katz; 91.7% (95% CI: 85.6-95.6%) and 96.5% (95% CI: 94.1-98.0%) for McMaster; and 93.2% (95% CI: 87.5-96.8%) and 97.1% (95% CI: 94.7-98.4%) for spontaneous tube sedimentation. Kappa values of Kato-Katz, McMaster, and spontaneous tube sedimentation for the diagnosis of soil-transmitted helminths were 0.901, 0.937, and 0.948, respectively.
Kato-Katz, McMaster, and spontaneous tube sedimentation techniques had comparable sensitivity with almost perfect agreement for the detection of soil-transmitted helminths. Therefore, the spontaneous tube sedimentation technique can be used as an alternative diagnostic method for soil-transmitted helminth infections in endemic countries.
土源性蠕虫是寄生于肠道的寄生线虫。它们在包括埃塞俄比亚在内的热带和亚热带地区更为普遍。然而，低敏感性的直接涂片镜检法无法在感染病例中检测出土源性蠕虫。因此，迫切需要更敏感且具成本效益的诊断方法，以尽量减少土源性蠕虫病的发病率。
本研究旨在比较和评估针对土源性蠕虫的诊断方法与“金”标准的性能。
2022年5月至7月，在阿姆哈拉地区对421名学童开展了一项基于机构的横断面研究。研究参与者采用系统随机抽样技术选取。粪便样本通过改良加藤厚涂片法、麦克马斯特法和自然沉淀法进行处理。数据录入Epi-Data 3.1版本，并使用SPSS 25版本进行分析。以联合结果作为“金”标准，计算敏感性、特异性、阳性预测值和阴性预测值。诊断方法之间的一致性强度由kappa值确定。
采用多种方法联合检测，土源性蠕虫的总体患病率为32.8%（95%置信区间：28.2 - 37.8%）。改良加藤厚涂片法、麦克马斯特法和自然沉淀法的检出率分别为28.5%（95%置信区间：24.2 - 33.2%）、30%（95%置信区间：25.6 - 34.8%）和30.5%（95%置信区间：26.1 - 35.3%）。改良加藤厚涂片法的敏感性和阴性预测值分别为87.1%（95%置信区间：80.2 - 92.3%）和95.1%（95%置信区间：92.6 - 96.8%）；麦克马斯特法为91.7%（95%置信区间：85.6 - 95.6%）和96.5%（95%置信区间：94.1 - 98.0%）；自然沉淀法为93.2%（95%置信区间：87.5 - 9
