Ningxia Center for Disease Control and Prevention, NO. 528 Shengli South Road, Yingchuan 750004, Ningxia Province, China.
Ningxia Center for Disease Control and Prevention, NO. 528 Shengli South Road, Yingchuan 750004, Ningxia Province, China.
Infect Genet Evol. 2023 Sep;113:105469. doi: 10.1016/j.meegid.2023.105469. Epub 2023 Jun 16.
Group A rotaviruses (RVA) are the primary pathogens of acute gastroenteritis. Currently, two live attenuated RVA vaccines, LLR and RotaTeq, have been introduced into mainland China but are not included in the national immunization program. Because of the unknown genetic evolution of group A rotavirus in an all-age population in Ningxia, China, we monitored the epidemiological characteristics and circulating genotypes of RVA as a reference for developing vaccine strategies.
We conducted seven years of consecutive surveillance of RVA based on stool samples from patients with acute gastroenteritis in sentinel hospitals in Ningxia, China, from 2015 to 2021. Reverse transcription quantitative polymerase chain reaction(RT-qPCR) was used to detect RVA in stool samples. Genotyping and phylogenetic analysis of VP7, VP4 and NSP4 genes were performed by reverse transcription-polymerase chain reaction(RT-PCR) and nucleotide sequence determination.
RVA was detected in 16.58% (1436/8662) of 8662 stool samples. The positive rates were 7.17% (201/2805) and 21.09% (1235/5857) in adults and children, respectively. The most affected age group was infants and children aged 12-23 months, with a positive rate of 29.53% (p < 0.05). A significant winter/spring seasonality was observed. 23.29% positive rate in 2020 was the highest in 7 years (p < 0.05). The region with the highest positive rate in the adult group was Yinchuan, and the children's group was Guyuan. A total of 9 genotype combinations were found to be distributed in Ningxia. The dominant genotype combinations in this region gradually changed from G9P[8]-E1, G3P[8]-E1, G1P[8]-E1 to G9P[8]-E1, G9P[8]-E2, and G3P[8]-E2 during these seven years. Rare strains (e.g., G9P[4]-E1, G3P[9]-E3 and G1P[8]-E2) were occasionally detected during the study.
During the study period, changes in the significant RVA circulating genotype combinations and the emergence of reassortment strains were observed, particularly the emergence and prevalence of G9P[8]-E2, G3P[8]-E2 reassortants in the region. These results indicate the importance of continuous monitoring of the molecular evolution and recombination characteristics of RVA, and should not be limited to G/P genotyping but should consider multi-gene fragment co-analysis and whole genome sequencing.
A 组轮状病毒（RVA）是急性胃肠炎的主要病原体。目前，两种活减毒 RVA 疫苗，LLR 和 RotaTeq，已引入中国大陆，但未纳入国家免疫规划。由于中国宁夏全年龄段人群 A 组轮状病毒的遗传进化尚不清楚，我们监测了 RVA 的流行病学特征和循环基因型，为制定疫苗策略提供参考。
我们对 2015 年至 2021 年宁夏哨点医院急性胃肠炎患者的粪便样本进行了连续 7 年的 RVA 监测。采用逆转录定量聚合酶链反应（RT-qPCR）检测粪便样本中的 RVA。采用逆转录-聚合酶链反应（RT-PCR）和核苷酸序列测定对 VP7、VP4 和 NSP4 基因进行基因分型和系统进化分析。
在 8662 份粪便样本中，检测到 RVA 阳性率为 16.58%（1436/8662）。成人和儿童的阳性率分别为 7.17%（201/2805）和 21.09%（1235/5857）。受影响最严重的年龄组是 12-23 个月的婴儿和儿童，阳性率为 29.53%（p<0.05）。观察到明显的冬春季季节性。2020 年 23.29%的阳性率是 7 年来最高的（p<0.05）。成人组阳性率最高的地区是银川，儿童组是固原。共发现 9 种基因型组合分布在宁夏。该地区优势基因型组合逐渐由 G9P[8]-E1、G3P[8]-E1、G1P[8]-E1 转变为 G9P[8]-E1、G9P[8]-E2 和 G3P[8]-E2。研究期间偶尔会检测到罕见株（如 G9P[4]-E1、G3P[9]-E3 和 G1P[8]-E2）。
在研究期间，观察到 RVA 循环基因型组合的显著变化和重组株的出现，特别是该地区 G9P[8]-E2、G3P[8]-E2 重组体的出现和流行。这些结果表明，需要持续监测 RVA 的分子进化和重组特征，不仅限于 G/P 基因分型，还应考虑多基因片段共分析和全基因组测序。
