Abdul-Ghani Rashad, Mahdy Mohammed A K, Saif-Ali Reyadh, Alkubati Sameer A, Alqubaty Abdulhabib R, Al-Mikhlafy Abdullah A, Al-Eryani Samira M, Al-Mekhlafi Abdusalam M, Alhaj Ali
Tropical Disease Research Center, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana'a, Yemen.
Department of Parasitology, Faculty of Medicine and Health Sciences, Sana'a University, Sana'a, Yemen.
Malar J. 2016 Jun 21;15:327. doi: 10.1186/s12936-016-1372-9.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common genetic enzymopathy worldwide, is associated with an acute haemolytic anaemia in individuals exposed to primaquine. The present study aimed to determine G6PD deficiency among Yemeni children in malaria-endemic areas as well as to assess the performance of the CareStart™ G6PD rapid diagnostic test (RDT) for its detection.
A cross-sectional study recruiting 400 children from two rural districts in Hodeidah governorate was conducted. Socio-demographic data and blood samples were collected and G6PD deficiency was qualitatively detected in fresh blood in the field using the CareStart™ G6PD RDT, while the enzymatic assay was used to quantitatively measure enzyme activity. Performance of the CareStart™ G6PD RDT was assessed by calculating its sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) against the reference enzymatic assay.
The ranges of enzyme activity were 0.14-18.45 and 0.21-15.94 units/g haemoglobin (U/gHb) for males and females, respectively. However, adjusted male median G6PD activity was 5.0 U/gHb. Considering the adjusted male median as representing 100 % normal enzyme activity, the prevalence rates of G6PD deficiency were 12.0 and 2.3 % at the cut-off activities of ≤60 and ≤10 %, respectively. Multivariable analysis showed that gender, district of residence and consanguinity between parents were independent risk factors for G6PD deficiency at the cut-off activity of ≤30 % of normal. The CareStart™ G6PD RDT showed 100 % sensitivity and NPV for detecting G6PD deficiency at the cut-off activities of ≤10 and ≤20 % of normal activity compared to the reference enzymatic method. However, it showed specificity levels of 90.0 and 95.4 % as well as positive/deficient predictive values (PPVs) of 18.0 and 66.0 % at the cut-off activities of ≤10 and ≤20 %, respectively, compared to the reference method.
G6PD deficiency with enzyme activity of ≤60 % of normal is prevalent among 12.0 % of children residing in malaria-endemic areas of Hodeidah governorate, with 2.3 % having severe G6PD deficiency. Gender, district of residence and consanguinity between parents are significant independent predictors of G6PD deficiency at the cut-off activity of ≤30 % of normal among children in malaria-endemic areas of Hodeidah. The CareStart™ G6PD RDT proved reliable as a point-of-care test to screen for severely G6PD-deficient patients, with 100 % sensitivity and NPV, and it can be used for making clinical decisions prior to the administration of primaquine in malaria elimination strategies.
葡萄糖-6-磷酸脱氢酶（G6PD）缺乏症是全球最常见的遗传性酶病，与接触伯氨喹的个体发生急性溶血性贫血有关。本研究旨在确定疟疾流行地区也门儿童中的G6PD缺乏症，并评估CareStart™ G6PD快速诊断试验（RDT）用于检测该疾病的性能。
开展了一项横断面研究，从荷台达省的两个农村地区招募了400名儿童。收集了社会人口学数据和血样，在现场使用CareStart™ G6PD RDT对新鲜血液进行G6PD缺乏症的定性检测，同时采用酶法测定酶活性。通过计算CareStart™ G6PD RDT相对于参考酶法的灵敏度、特异性、阴性预测值（NPV）和阳性预测值（PPV）来评估其性能。
男性和女性的酶活性范围分别为0.14 - 18.45和0.21 - 15.94单位/克血红蛋白（U/gHb）。然而，校正后的男性G6PD活性中位数为5.0 U/gHb。将校正后的男性中位数视为代表100%正常酶活性，在截断活性分别为≤60%和≤10%时，G6PD缺乏症的患病率分别为12.0%和2.3%。多变量分析表明，在截断活性≤正常的30%时，性别、居住地区和父母之间的血缘关系是G6PD缺乏症的独立危险因素。与参考酶法相比，CareStart™ G6PD RDT在截断活性≤正常活性的10%和≤20%时，检测G6PD缺乏症的灵敏度和NPV均为100%。然而，与参考方法相比，在截断活性≤10%和≤20%时，其特异性水平分别为90.0%和95.4%，阳性/缺陷预测值（PPV）分别为18.0%和66.0%。
在荷台达省疟疾流行地区，12.0%的儿童存在酶活性≤正常60%的G6PD缺乏症，其中2.3%患有严重的G6PD缺乏症。在荷台达省疟疾流行地区的儿童中，在截断活性≤正常30%时，性别、居住地区和父母之间的血缘关系是G6PD缺乏症的重要独立预测因素。CareStart™ G6PD RDT被证明作为即时检测严重G6PD缺乏症患者的筛查工具是可靠的，灵敏度和NPV均为100%，可用于在疟疾消除策略中伯氨喹给药前做出临床决策。
