Supplementary Material for: Prevalence of Sickle Cell Trait and Reliability of Self-Reported Status among Expectant Parents in Nigeria: Implications for Targeted Newborn Screening

<i>Background/Aims:</i> Sickle cell disease (SCD) is a life-threatening, autosomal recessive blood disorder prevalent in sub-Saharan Africa. We identified the prevalence of sickle cell trait (SCT) among pregnant women and their male partners in Enugu State, Nigeria, and determined the accuracy of self-reported sickle cell status and its reliability for identifying high-risk newborns for targeted screening. <i>Methods:</i> We conducted a nested cohort study of expectant parents enrolled in the Healthy Beginning Initiative (HBI). The HBI is a cluster-randomized trial of a congregation-based approach designed to increase HIV testing. Participants completed a survey regarding self-awareness of their sickle cell genotype and consented to genotype screening by cellulose acetate electrophoresis. <i>Results:</i> SCT prevalence (HbAS) was 22% (746/3,371). Only 50% of participants provided an accurate self-report. Self-report accuracy was significantly different (p &lt; 0.0001) between individuals who reported having SCT or SCD (61% accuracy) versus those who reported not having SCT or SCD (86% accuracy). Demographic variables including gender, age, household size, employment, education, and home location were significantly associated with providing an accurate self-report. <i>Conclusions:</i> Low numbers of accurate parental self-reports, coupled with a high SCT prevalence in Nigeria, could limit the efficacy of targeted newborn screening. However, our data indicate that it is feasible to integrate sickle cell screening for pregnant women with existing, community-based health care programs developed by the President's Emergency Plan for AIDS Relief (PEPFAR), such as the HBI. Expanding screening programs could enable the development of targeted newborn screening based on maternal genotype that could identify all newborns with SCD in resource-limited settings.

【背景与研究目的】镰状细胞病（Sickle cell disease, SCD）是一种危及生命的常染色体隐性血液疾病，在撒哈拉以南非洲地区高发。本研究明确了尼日利亚埃努古州孕妇及其男性伴侣的镰状细胞特征（Sickle cell trait, SCT）患病率，并评估了自我报告镰状细胞状态的准确性，以及其用于识别需开展针对性筛查的高危新生儿的可靠性。【研究方法】本研究对纳入“健康起步计划（Healthy Beginning Initiative, HBI）”的待产父母开展了一项嵌套队列研究。该计划是一项以会众为基础的整群随机对照试验，旨在提升HIV检测覆盖率。所有参与者完成了关于自身镰状细胞基因型知晓情况的问卷调查，并同意通过醋酸纤维素电泳（cellulose acetate electrophoresis）法开展基因型筛查。【研究结果】镰状细胞特征（HbAS）的患病率为22%（746/3371）。仅有50%的参与者能准确报告自身镰状细胞状态。自我报告的准确性存在显著组间差异（p<0.0001）：自述患有镰状细胞特征或镰状细胞病的群体报告准确率为61%，而自述未患上述疾病的群体准确率达86%。包括性别、年龄、家庭规模、就业状况、受教育程度及居住地在内的人口统计学变量，均与自我报告的准确性存在显著关联。【研究结论】尼日利亚本地镰状细胞特征患病率较高，且父母的准确自我报告比例偏低，这可能会限制针对性新生儿筛查的实施效果。但本研究数据显示，将孕妇镰状细胞筛查与美国总统防治艾滋病紧急救援计划（President's Emergency Plan for AIDS Relief, PEPFAR）现有以社区为基础的医疗项目（如HBI）相结合是可行的。扩大筛查项目规模，可推动基于母体基因型的针对性新生儿筛查方案落地，从而在资源有限的环境中实现对所有镰状细胞病新生儿的精准识别。