Rubaba O, Chimbari M J, Soko W, Manyangadze T, Mukaratirwa S
School of Nursing and Public Health, College of Health Science, University of KwaZulu-Natal, Durban, South Africa.
School of Nursing and Public Health, College of Health Science, University of KwaZulu-Natal, Durban, South Africa.
Acta Trop. 2018 Jun;182:161-165. doi: 10.1016/j.actatropica.2018.02.029. Epub 2018 Feb 24.
Circulating cathodic antigen (CCA) tests for schistosomiasis are fast and less complicated allowing making them good candidates for routine qualitative screening for schistosomiasis at point of care. The urine-CCA has been evaluated for detection of S. mansoni with promising results. Its specificity and consistency in detecting S. haematobium infection in different endemic regions has been variable. This study validated a rapid urine-CCA cassette test for qualitative detection of S. haematobium infection in an S. haematobium endemic area with low S. mansoni prevalence. Microscopic examination for the standard urine filtration technique was used to validate the commercially available urine-CCA cassette test (rapid medical diagnostics ). The validation was done in a sample of primary school pupils (n = 420) aged 10-15 years in schools in the Jozini Municipality, KZN. There was a relationship between infection intensity and a positive urine-CCA test. Using the urine filtration method as the gold standard, the prevalence for S. haematobium was 40%, the accuracy of the CCA kit was 54.8%, sensitivity was 68.1% while the specificity was 45.8%. The positive predictive value was 45.82% while the negative predictive value was 68.05%. Both the urine filtration and the urine-CCA methods detected heavy (≥50 eggs/10 mL urine) and light infections at statistically significant levels. The overall accuracy, sensitivity and specificity of the urine-CCA cassette test were low. The urine-CCA cassette test performed much better for heavy infections than low infections (p < 0.05) implying that the kit may not be suitable for low endemic areas.
用于血吸虫病的循环阴极抗原（CCA）检测快速且操作不太复杂，使其成为在护理点进行血吸虫病常规定性筛查的理想选择。尿CCA已被评估用于检测曼氏血吸虫，结果很有前景。其在不同流行地区检测埃及血吸虫感染的特异性和一致性存在差异。本研究在曼氏血吸虫流行率低的埃及血吸虫流行地区，验证了一种用于定性检测埃及血吸虫感染的快速尿CCA试纸条检测方法。采用标准尿过滤技术的显微镜检查来验证市售的尿CCA试纸条检测方法（快速医学诊断）。验证工作在夸祖鲁 - 纳塔尔省乔齐尼市各学校中10 - 15岁的420名小学生样本中进行。感染强度与尿CCA检测阳性之间存在关联。以尿过滤法作为金标准，埃及血吸虫的流行率为40%，CCA试剂盒的准确率为54.8%，灵敏度为68.1%，而特异性为45.8%。阳性预测值为45.82%，阴性预测值为68.05%。尿过滤法和尿CCA法在检测重度（≥50个虫卵/10 mL尿液）和轻度感染方面均具有统计学显著水平。尿CCA试纸条检测的总体准确率、灵敏度和特异性较低。尿CCA试纸条检测对重度感染的表现比对轻度感染好得多（p < 0.05），这意味着该试剂盒可能不适用于低流行地区。
