Nnodu Obiageli E, Sopekan Alayo, Nnebe-Agumadu Uche, Ohiaeri Chinatu, Adeniran Adeyemi, Shedul Grace, Isa Hezekiah A, Owolabi Olumide, Chianumba Reuben I, Tanko Yohanna, Iyobosa Juliet H, Adekile Adekunle D, Olopade Olufunmilayo I, Piel Frédéric B
Sickle Cell Disease Desk, Non-Communicable Disease Unit, Federal Ministry of Health, Federal Secretariat, Abuja, Nigeria.
Sickle Cell Disease Desk, Non-Communicable Disease Unit, Federal Ministry of Health, Federal Secretariat, Abuja, Nigeria.
Lancet Haematol. 2020 Jul;7(7):e534-e540. doi: 10.1016/S2352-3026(20)30143-5.
Sickle cell disease is highly prevalent in sub-Saharan Africa, where it accounts for substantial morbidity and mortality. Newborn screening is paramount for early diagnosis and enrolment of affected children into a comprehensive care programme. Up to now, this strategy has been greatly impaired in resource-poor countries, because screening methods are technologically and financially intensive; affordable, reliable, and accurate methods are needed. We aimed to test the feasibility of implementing a sickle cell disease screening programme using innovative point-of-care test devices into existing immunisation programmes in primary health-care settings.
Building on a routine immunisation programme and using existing facilities and staff, we did a prospective feasibility study at five primary health-care centres within Gwagwalada Area Council, Abuja, Nigeria. We systematically screened for sickle cell disease consecutive newborn babies and infants younger than 9 months who presented to immunisation clinics at these five centres, using an ELISA-based point-of care test (HemoTypeSC). A subgroup of consecutive babies who presented to immunisation clinics at the primary health-care centres, whose mothers gave consent, were tested by the HemoTypeSC point-of-care test alongside a different immunoassay-based point-of-care test (SickleSCAN) and the gold standard test, high-performance liquid chromatography (HPLC).
Between July 14, 2017, and Sept 3, 2019, 3603 newborn babies and infants who presented for immunisation were screened for sickle cell disease at five primary health-care centres using the ELISA-based point-of-care test. We identified 51 (1%) children with sickle cell anaemia (HbSS), four (<1%) heterozygous for HbS and HbC (HbSC), 740 (21%) with sickle cell trait (HbAS), 34 (1%) heterozygous for HbA and HbC (HbAC), and 2774 (77%) with normal haemoglobin (HbAA). Of the 55 babies and infants with confirmed sickle cell disease, 41 (75%) were enrolled into a programme for free folic acid and penicillin, of whom 36 (88%) completed three visits over 9 months (median follow-up 226 days [IQR 198-357]). The head-to-head comparison between the two point-of-care tests and HPLC showed concordance between the three testing methods in screening 313 newborn babies, with a specificity of 100% with HemoTypeSC, 100% with SickleSCAN, and 100% by HPLC, and a sensitivity of 100% with HemoTypeSC, 100% with SickleSCAN, and 100% by HPLC.
Our pilot study shows that the integration of newborn screening into existing primary health-care immunisation programmes is feasible and can rapidly be implemented with limited resources. Point-of-care tests are reliable and accurate in newborn screening for sickle cell disease. This feasibility study bodes well for the care of patients with sickle cell disease in resource-poor countries.
Doris Duke Charitable Foundation, Imperial College London Wellcome Trust Centre for Global Health Research, and Richard and Susan Kiphart Family Foundation.
镰状细胞病在撒哈拉以南非洲地区高度流行，该病导致了大量的发病和死亡。新生儿筛查对于早期诊断以及让患病儿童纳入综合护理计划至关重要。到目前为止，在资源匮乏国家，这一策略受到了极大阻碍，因为筛查方法在技术和资金方面要求很高；需要经济实惠、可靠且准确的方法。我们旨在测试在初级卫生保健机构将创新的即时检测设备用于镰状细胞病筛查项目并纳入现有免疫计划的可行性。
基于常规免疫计划并利用现有设施和工作人员，我们在尼日利亚阿布贾瓜瓜拉达地区议会的五个初级卫生保健中心开展了一项前瞻性可行性研究。我们使用基于酶联免疫吸附测定的即时检测（HemoTypeSC），对到这五个中心的免疫诊所就诊的连续新生儿和9个月以下婴儿进行镰状细胞病的系统筛查。在初级卫生保健中心免疫诊所就诊且母亲同意的连续婴儿亚组，同时接受HemoTypeSC即时检测以及另一种基于免疫测定的即时检测（SickleSCAN）和金标准检测——高效液相色谱法（HPLC）。
在2017年7月14日至2019年9月3日期间，在五个初级卫生保健中心，使用基于酶联免疫吸附测定的即时检测对前来接种疫苗的3603名新生儿和婴儿进行了镰状细胞病筛查。我们确定了51名（1%）患有镰状细胞贫血（HbSS）的儿童，4名（<1%）HbS和HbC杂合子（HbSC），740名（21%）具有镰状细胞性状（HbAS），34名（1%）HbA和HbC杂合子（HbAC），以及2774名（77%）血红蛋白正常（HbAA）的儿童。在55名确诊为镰状细胞病的婴儿和儿童中，41名（75%）被纳入免费叶酸和青霉素项目，其中36名（88%）在9个月内完成了三次随访（中位随访时间226天[四分位间距198 - 357]）。两种即时检测与HPLC的直接比较显示，在对313名新生儿进行筛查时，三种检测方法结果一致，HemoTypeSC的特异性为100%，SickleSCAN的特异性为100%，HPLC的特异性为100%；HemoTypeSC的敏感性为100%，SickleSCAN的敏感性为100%，HPLC的敏感性为100%。
我们的试点研究表明，将新生儿筛查纳入现有的初级卫生保健免疫计划是可行的，并且可以在资源有限的情况下迅速实施。即时检测在新生儿镰状细胞病筛查中可靠且准确。这项可行性研究对资源匮乏国家的镰状细胞病患者护理而言是个好兆头。
多丽丝·杜克慈善基金会、伦敦帝国学院惠康信托全球健康研究中心以及理查德和苏珊·基法特家族基金会。
