Damtie Debasu, Gelaw Aschalew, Wondimeneh Yitayih, Aleka Yetemwork, Kick Maryssa K, Tigabu Zemene, Sack Ulrich, Mekuria Zelalem H, Vlasova Anastasia N, Tessema Belay
Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
Department of Immunology and Molecular Biology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
Vaccines (Basel). 2024 Aug 1;12(8):866. doi: 10.3390/vaccines12080866.
: Globally, rotavirus (RV) A (RVA) is the most common cause of severe and sometimes fatal diarrhea in young children. It is also the major cause of acute gastroenteritis among children in Ethiopia. Currently, the WHO has prequalified four RVA vaccines for universal childhood immunization. Ethiopia introduced the monovalent Rotarix vaccine into its national immunization program in 2013. Since then, only a few studies on the burden and genotype distribution of RVA infection post-vaccine introduction have been conducted (mostly at sentinel surveillance sites). Therefore, this study aimed to assess RVA prevalence and genotype distribution among children under five years in Ethiopia (February 2021-December 2022). : This multi-center hospital-based cross-sectional study involved 537 diarrheic children under-five years old. Rotavirus A detection was conducted using a one-step reverse-transcriptase polymerase chain reaction (RT-PCR). Genotyping was conducted by Sanger sequencing of the VP7 (complete) and VP4 (partial) genes. Descriptive analysis and Pearson's chi-squared test were carried out using SPSS version 29. Phylogenetic analysis with 1000 bootstrap replicates was performed using MEGA version 11 software. Statistical significance was set at < 0.05 for all analyses. : The prevalence of RVA infection among diarrheic children was 17.5%. The most prevalent G-types identified were G3 (37%), the previously uncommon G12 (28%), and G1 (20%). The predominant P-types were P[8] (51%), P[6] (29%), and P[4] (14%). The three major G/P combinations observed were G3P[8] (32.8%), G12P[6] (28.4%), and G1P[8] (19.4%). Phylogenetic analysis revealed clustering of Ethiopian strains with the globally reported strains. Many strains exhibited amino acid differences in the VP4 (VP8* domain) and VP7 proteins compared to vaccine strains, potentially affecting virus neutralization. : Despite the high RVA vaccination rate, the prevalence of RVA infection remains significant among diarrheic children in Ethiopia. There is an observable shift in circulating RVA genotypes from G1 to G3, alongside the emergence of unusual G/P genotype combinations such as G9P[4]. Many of these circulating RVA strains have shown amino acid substitutions that may allow for neutralization escape. Therefore, further studies are warranted to comprehend the emergence of these unusual RVA strains and the diverse factors influencing the vaccine's diminished effectiveness in developing countries.
在全球范围内，A组轮状病毒（RVA）是幼儿严重腹泻甚至有时导致死亡的最常见原因。它也是埃塞俄比亚儿童急性胃肠炎的主要病因。目前，世界卫生组织已预认证四种RVA疫苗用于全球儿童免疫接种。埃塞俄比亚于2013年将单价Rotarix疫苗引入其国家免疫规划。自那时以来，仅开展了少数关于疫苗引入后RVA感染负担和基因型分布的研究（大多在哨点监测点）。因此，本研究旨在评估埃塞俄比亚5岁以下儿童中RVA的流行情况和基因型分布（2021年2月至2022年12月）。 这项基于医院的多中心横断面研究纳入了537名5岁以下腹泻儿童。使用一步法逆转录聚合酶链反应（RT-PCR）进行A组轮状病毒检测。通过对VP7（完整）和VP4（部分）基因进行桑格测序进行基因分型。使用SPSS 29版进行描述性分析和Pearson卡方检验。使用MEGA 11版软件进行1000次重复抽样的系统发育分析。所有分析的统计学显著性设定为<0.05。 A组轮状病毒感染在腹泻儿童中的患病率为17.5%。鉴定出的最常见G型为G3（37%）、以前不常见的G12（28%）和G1（20%）。主要的P型为P[8]（51%）、P[6]（29%）和P[4]（14%）。观察到的三种主要G/P组合为G3P[8]（32.8%）、G12P[6]（28.4%）和G1P[⑧]（19.4%）。系统发育分析显示埃塞俄比亚毒株与全球报告的毒株聚类。与疫苗毒株相比，许多毒株在VP4（VP⑧*结构域）和VP7蛋白中表现出氨基酸差异，这可能影响病毒中和。 尽管RVA疫苗接种率很高，但埃塞俄比亚腹泻儿童中RVA感染的患病率仍然很高。循环中的RVA基因型出现了从G1到G3的明显转变，同时出现了不寻常的G/P基因型组合，如G9P[4]。许多这些循环中的RVA毒株已显示出氨基酸替换，这可能导致中和逃逸。因此，有必要进一步开展研究，以了解这些不寻常RVA毒株的出现以及影响疫苗在发展中国家效力降低的多种因素。
