Infectious Diseases Ward, Mahosot Hospital, Vientiane, Lao People's Democratic Republic.
University of Basel, Basel, Switzerland.
Infect Dis Poverty. 2020 Sep 21;9(1):133. doi: 10.1186/s40249-020-00750-y.
Despite the high prevalence of strongyloidiasis in the Laotian population, Laotian hospitals still lack diagnostic capacity to appropriately diagnose Strongyloides stercoralis infections. This cross-sectional hospital-based study was conducted to assess the prevalence of Strongyloides stercoralis infection among hospitalized patients treated at Mahosot Hospital, the primary reference hospital of Lao People's Democratic Republic (Lao PDR), and to validate feasible methods for diagnosing S. stercoralis infection at hospital's laboratory.
Between September and December 2018, stool samples of 104 inpatients were investigated for S. stercoralis infection by wet smear, Baermann technique, Koga Agar plate culture (KAPC), and real-time detection polymerase chain reaction (RTD-PCR) at the Infectious Diseases Ward of the Mahosot Hospital in Vientiane. The sensitivity, the specificity, the negative predictive value (NPV) of each diagnostic test, as well as their combination(s) was calculated using a composite reference standard (CRS). The correlation of the different test methods was assessed by chi-square or Fisher's exact test. Cohen's kappa coefficient was used to assess the diagnostic agreement of the different test methods.
The overall prevalence of S. stercoralis infections among the study population was 33.4%. The cumulative infection prevalence statistically significantly increased from the lowest age group of 40 years and below (22.4%), to the medium (40.0%) and to the oldest age group of 61 year and above (72.7%)(P = 0.003). The cumulative infection prevalence of CRS was considerably higher in male (40.4%) compared to female patients (28.1%), but not statistically different (P = 0.184). The diagnostic sensitivity of Baermann technique, KAPC, RTD-PCR, and the combination of Baermann technique and KAPC were 60.0, 60.0, 74.3, and 77.1%, respectively. Only 13 patients (37.1%) of the total 35 S. stercoralis patients diagnosed with any technique had a simultaneously positive diagnostic test with Baermann, KAPC and RTD-PCR.
We identified Baermann technique and KAPC to be currently the most feasible and implementable standard methods for diagnosing S. stercoralis at a hospital setting such as Mahosot Hospital and provincial and district hospitals in Lao PDR and other low- and middle income countries in Southeast Asia.
This study was approved by the National Ethics Committee for Health Research in Lao PDR (reference no. 083/NECHR) and by the Ethics Committee Northwest and Central Switzerland (reference no. 2018-00594).
尽管老挝人群中 Strongyloides stercoralis 的患病率很高，但老挝医院仍然缺乏适当诊断 Strongyloides stercoralis 感染的诊断能力。本横断面医院为基础的研究旨在评估 Mahosot 医院住院患者中 Strongyloides stercoralis 感染的患病率，该医院是老挝人民民主共和国（老挝）的主要参考医院，并验证医院实验室诊断 S. stercoralis 感染的可行方法。
2018 年 9 月至 12 月，在万象 Mahosot 医院传染病病房，对 104 名住院患者的粪便样本进行 Strongyloides stercoralis 感染的湿涂片、巴氏技术、Koga 琼脂平板培养（KAPC）和实时检测聚合酶链反应（RTD-PCR）检测。使用复合参考标准（CRS）计算每种诊断试验的敏感性、特异性、阴性预测值（NPV）及其组合。通过卡方检验或 Fisher 精确检验评估不同检测方法的相关性。采用 Cohen's kappa 系数评估不同检测方法的诊断一致性。
研究人群中 Strongyloides stercoralis 感染的总体患病率为 33.4%。感染患病率从 40 岁及以下的最低年龄组（22.4%）到中等年龄组（40.0%）到 61 岁及以上的最老年组（72.7%）呈累积性显著增加（P=0.003）。男性（40.4%）的累积感染患病率明显高于女性患者（28.1%），但无统计学差异（P=0.184）。巴氏技术、KAPC、RTD-PCR 和巴氏技术与 KAPC 联合的诊断灵敏度分别为 60.0%、60.0%、74.3%和 77.1%。仅 35 例 S. stercoralis 患者中的 13 例（37.1%）在任何检测技术下同时具有巴氏、KAPC 和 RTD-PCR 的阳性诊断检测。
我们发现巴氏技术和 KAPC 是目前在 Mahosot 医院和老挝以及东南亚其他中低收入国家的省级和地区医院等医疗机构诊断 S. stercoralis 最可行和可实施的标准方法。
本研究得到老挝国家卫生研究伦理委员会（参考号 083/NECHR）和瑞士西北和中央伦理委员会（参考号 2018-00594）的批准。
