Abstract：
Globally, Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in children under 5 years old, with Pakistan having the highest rates of RVA-related morbidity and mortality. The current study aims to determine the genetic diversity of rotavirus and evaluate the impact of Rotarix-vaccine introduction on disease epidemiology in Pakistan. A total of 4749 children, hospitalized with acute gastroenteritis between 2018 and 2020, were tested at four hospitals in Lahore and Karachi. Of the total, 19.3% (918/4749) cases were tested positive for RVA antigen, with the positivity rate varying annually (2018 = 22.7%, 2019 = 14.4%, 2020 = 20.9%). Among RVA-positive children, 66.3% were under 1 year of age. Genotyping of 662 enzyme-linked immuno sorbent assay-positive samples revealed the predominant genotype as G9P[4] (21.4%), followed by G1P[8] (18.9%), G3P[8] (11.4%), G12P[6] (8.7%), G2P[4] (5.7%), G2P[6] (4.8%), and 10.8% had mixed genotypes. Among vaccinated children, genotypes G9P[4] and G12P[6] were more frequently detected, whereas a decline in G2P[4] was observed. Phylogenetic analysis confirmed the continued circulation of indigenous genotypes detected earlier in the country except G9 and P[6] strains. Our findings highlight the predominance of G9P[4] genotype after the vaccine introduction thus emphasizing continual surveillance to monitor the disease burden, viral diversity, and their impact on control of rotavirus gastroenteritis in children.
摘要：
全球范围内,A组轮状病毒（RVA）是5岁以下儿童急性胃肠炎的主要原因，巴基斯坦的RVA相关发病率和死亡率最高。本研究旨在确定轮状病毒的遗传多样性，并评估Rotarix疫苗引入对巴基斯坦疾病流行病学的影响。共有4749名儿童，2018年至2020年期间因急性胃肠炎住院，在拉合尔和卡拉奇的四家医院进行了测试。在总数中，19.3%(918/4749)例RVA抗原检测呈阳性,阳性率每年变化(2018年=22.7%，2019年=14.4%，2020年=20.9%）。在RVA阳性儿童中，66.3%的人年龄在1岁以下。662个酶联免疫吸附试验阳性样本的基因分型显示主要基因型为G9P[4]（21.4%），其次是G1P[8](18.9%)，G3P[8]（11.4%），G12P[6]（8.7%），G2P[4]（5.7%），G2P[6]（4.8%），10.8%为混合基因型。在接种疫苗的儿童中，基因型G9P[4]和G12P[6]检测频率更高，而观察到G2P[4]下降。系统发育分析证实，除G9和P[6]菌株外，该国较早检测到的土著基因型持续循环。我们的发现突出了疫苗引入后G9P[4]基因型的优势，因此强调持续监测以监测疾病负担，病毒多样性,以及它们对控制儿童轮状病毒胃肠炎的影响。
