Literature selection
A total of 9,281 articles were initially identified from online databases, along with 24 additional articles retrieved through manual searches of references and citations. After removing 1,026 duplicate records and excluding 227 articles that were published in minor journals, we selected 8,052 articles for title and abstract screening. Following this, 7,507 articles were excluded, leaving 545 for full-text review. Ultimately, 73 articles that met the inclusion criteria were selected for meta-analysis. Among these, 69 reported only on RV positivity rates, 3 exclusively reported on RV incidence, and 1 provided data on both RV positivity rate and incidence. Additionally, we included four articles on RV-related diarrhea incidence for qualitative description (Fig. 1). Of the 73 included articles, 19 were published in English, while 54 were in Chinese. A detailed description of the search strategy is provided in Supplementary Appendix 2, while details about the authors, publication year, study location (province), participant age, specimen type, diagnostic methods, sample size, and research outcomes are presented in Supplementary Appendices 4 and 5. The quality assessment of articles reporting RV positivity rates is presented in Supplementary Appendix 3.
Basic characteristics of included articles
The majority of RV infections were reported from hospitals. Of the included studies, 60 (82.2%) were hospital-based, while 13 (17.8%) used data from NNIDSS, A total of 34 (46.5%) articles reported only on RV testing, while 36 (49.3%) articles reported on testing for multiple pathogens, including RV, norovirus, and enteric adenovirus. Additionally, 66 (94%) articles reported on the clinical diagnostic criteria for RV-related diarrhea. In terms of the healthcare settings, 33 (47%) articles considered outpatients, 19 (27%) considered inpatients, 7 (10%) considered both outpatients and inpatients, and 11 (16%) had unspecified study population. Further details about the selected articles are available in Supplementary Appendix 4.
Incidence of RV-related diarrhea
Four population-based studies reported on the incidence of RV-related diarrhea in children under 5 years of age. Luo22 reported an average annual national incidence of 0.637 /1000 persons between 2005 and 2018. Ding et al.23 reported an incidence of 12.7 per 1,000 person-years in Zhongshan (Guangdong, China) from 2015 to 2021; Zhou et al.24 reported an incidence of 21.8 per 1000 person-years in Sanjiang (Guangxi, China) in 2013; and Chen et al.25 reported an incidence of 31.46 per 1000 person-years in Yuhuan (Zhejiang, China) from December 2016 to April 2017. Further details about these population-based studies are provided in Supplementary Appendix 5.
RV positivity rates
This meta-analysis involved a total 70 studies, which investigated the RV positivity rate, encompassing 605,466 pediatric diarrhea cases in China. The pooled RV detection rate for the under-5 age group was 24.7%. The highest RV prevalence occurred in children aged 1–2 y (36 studies, n = 101,419), with 36.4%(95% CI 31.5–41.3) RV positivity rate. RV positive rate showed a gradual decline among the older pediatric age groups, being 28.4% in 2–3 y-olds (27 studies), 21.4% (95% CI 15.8–27.1) in 3–4 y-olds, and 16.4%(95% CI12.4–20.5) in 4–5 y-olds. Hospitalized patients demonstrated a 24.1% RV positivity rate and the outpatient cohorts exhibited a 22.2% (95% CI 17.5–27.0) RV positivity rate. Studies encompassing both inpatients and outpatient settings recorded the highest pooled RV prevalence of 28.5%. A pooled analysis of 56 studies (n = 115,330 cases) demonstrated a pooled RV positivity rate of 27.3%(95% CI 24.2–30.3) before the marketing authorization of the RotaTeq® vaccine in 2018. In contrast, pooled analysis of 25 studies (n = 803,286 cases) revealed a significant reduction in the RV positivity rate (21.5%) (95% CI 17.0–25.9) following RotaTeq® licensure. A pooled analysis of 46 pre-COVID 19 studies (n = 316,968 cases) revealed an RV positivity rate of 28.8%. In contrast, analysis of 5 post-pandemic studies (n = 33,936 cases) showed a marked reduction in the RV positivity rate (22.5%, 95% CI 12.7–32.2). A total of 18 studies conducted in winter showing the highest pooled positivity rates of 39.3%. Spring and autumn exhibited comparable RV positivity rates (25.1% and 24.2%), while summer (17 studies) recorded the lowest point at 12.9%(95% CI 7.9–18.0). The RV prevalence for east, north, south and central part of China were shown in Fig. 2. Geographical stratification showed that Northeast China (3 studies) had the highest RV positivity rates (29.7%,95% CI 4.8–54.5), followed by Central China (27.9%, 95% CI15.8–39.9), South China (27.5%, 95% CI 10.1–44.8), and Southwest China (27.4%, 95% CI 19.4–35.4), which demonstrated similar prevalence patterns (I2 ≥ 98.6%, p < 0.0001). Notably, East China (22 studies) showed the lowest regional RV prevalence (19.9%, 95% CI 16.4–23.5) despite contributing the largest sample (n = 218,660). Low-income regions exhibited the highest RV detection rate (32.2%,95% CI 26.7–37.7), followed by the middle-income (24.4%, 95% CI 19.0–29.8) and high-income (20.5%,95% CI17.3–23.6) regions (Tables 1 and 2).
Prevalence of different RV genotypes
The prevalence of RV G9 genotype (24 studies) was estimated to be 69.6%(95% CI 60.6–78.5), while that of the RV G3 and G1 genotype was 10.7% and 7.0% respectively. The prevalence of the RV P8 genotype (24 studies) was 82.1%(95% CI 74.5–89.7). Among the G-P genotypes, G9P[8] (22 studies) exhibited the highest prevalence, at 71.7%(95% CI 64.9–78.6). The G3P[8] and G1P[8] genotypes exhibited prevalence at 9.5% and 6.2% respectively (Table 3). The prevalence of G9P[8] rose from 50.3%(95% CI 26.8–73.8) in 2013 to 93.6% (95% CI 87.4–99.9) in 2020, emerging as the dominant circulating genotype in China (Supplementary Appendix 6).
Publication bias
Egger’s test revealed no significant publication bias among the 70 included studies (0.21; 95% CI 0.15–0.26, p = 0.067). Funnel plots illustrating the RV positivity distribution are provided in Supplementary Appendix 7.
