Oni A O, Harrison T J
University Department of Medicine, Royal Free Hospital School of Medicine, London, United Kingdom.
J Med Virol. 1996 Jul;49(3):178-86. doi: 10.1002/(SICI)1096-9071(199607)49:3<178::AID-JMV4>3.0.CO;2-1.
A pilot survey of hepatitis C virus (HCV) infection in Nigeria was carried out on healthy adult blood donors and children of preschool age. Sixteen of 200 (8%) donors were positive for antibodies using a second generation enzyme-linked immunosorbent assay (ELISA) but all of the children were negative. Supplementary testing of the ELISA-positives using a recombinant immunoblot assay (RIBA-2) confirmed the presence of antibody in four and two others were indeterminate. Four of the anti-HCV-positive sera and one found positive by ELISA but which was negative by RIBA-2 were found to be positive for HCV RNA using reverse transcriptase-polymerase chain reaction (RT-PCR) and primers specific for the 5' untranslated region (5'UTR) of the HCV genome. The NS5 and core regions also were amplified and the PCR products from all three regions were sequenced. Sequences from the 5'UTR could be divided into two groups: one group comprised three isolates with greater than 95% sequence identity with published sequences of genotype 1 and the other comprised two isolates with greater than 93% sequence identity with genotype 4. Analysis of three sequences amplified from the NS5 region confirmed this assignment to genotypes 1 and 4. Pairwise comparisons of the NS5 region sequences with representatives of 1a, 1b, 1c (for the first group) and 4a-4h (for the second group) show the first group to include subtypes classifiable as 1a and a novel sequence and the second group to include a novel sequence within genotype 4. Sequence analysis of the core region was consistent with this interpretation. These data confirm the presence of at least two major HCV genotypes in Nigeria (genotypes 1 and 4) and we report two novel sequences which have been designated provisionally as genotypes 1d and 4i.
在尼日利亚，针对健康成年献血者和学龄前儿童开展了一项丙型肝炎病毒（HCV）感染的初步调查。采用第二代酶联免疫吸附测定（ELISA）法检测，200名献血者中有16名（8%）抗体呈阳性，但所有儿童检测结果均为阴性。对ELISA检测呈阳性者采用重组免疫印迹测定（RIBA-2）进行补充检测，结果证实4人存在抗体，另外2人结果不确定。使用逆转录聚合酶链反应（RT-PCR）及针对HCV基因组5'非翻译区（5'UTR）的特异性引物检测发现，4份抗-HCV阳性血清以及1份ELISA检测呈阳性但RIBA-2检测呈阴性的血清HCV RNA呈阳性。NS5区和核心区也进行了扩增，并对这三个区域的PCR产物进行了测序。5'UTR区的序列可分为两组：一组包含3个分离株，与已发表的1型基因型序列的序列同一性大于95%；另一组包含2个分离株，与4型基因型的序列同一性大于93%。对从NS5区扩增的3个序列进行分析，证实其分别属于1型和4型基因型。将NS5区序列与1a、1b、1c（第一组）和4a - 4h（第二组）的代表序列进行两两比较，结果显示第一组包括可分类为1a的亚型和一个新序列，第二组包括4型基因型内的一个新序列。核心区的序列分析与这一解释一致。这些数据证实尼日利亚至少存在两种主要的HCV基因型（1型和4型），并且我们报告了两个新序列，暂定为1d型和4i型。
