Abstract：
Noroviruses are the leading cause of acute gastroenteritis in all age groups globally. The problem is magnified in developing countries including Africa. These viruses are highly prevalent with high genetic diversity and fast evolution rates. With this dynamicity, there are no recent review in the past five years in Africa. Therefore, this review and meta-analysis aimed to assess the prevalence and genetic diversity of noroviruses in Africa and tried to address the change in the prevalence and genetic diverisity the virus has been observed in Africa and in the world.
Twenty-one studies for the pooled prevalence, and 11 out of the 21 studies for genetic characterization of norovirus were included. Studies conducted since 2006, among symptomatic cases of all age groups in Africa, conducted with any study design, used molecular diagnostic methods and reported since 2015, were included and considered for the main meta-analysis. PubMed, Cochrane Library, and Google Scholar were searched to obtain the studies. The quality the studies was assessed using the JBI assessment tool. Data from studies reporting both asymptomatic and symptomatic cases, that did not meet the inclusion criteria were reviewed and included as discussion points. Data was entered to excel and imported to STATA 2011 to compute the prevalence and genetic diversity. Heterogeneity was checked using I2 test statistics followed by subgroup and sensitivity analysis. Publication bias was assessed using a funnel plot and eggers test that was followed by trim and fill analysis.
The pooled prevalence of norovirus was 20.2% (95% CI: 15.91, 24.4). The highest (36.3%) prevalence was reported in Ghana. Genogroup II noroviruses were dominant and reported as 89.5% (95% CI: 87.8, 96). The highest and lowest prevalence of this genogroup were reported in Ethiopia (98.3%), and in Burkina Faso (72.4%), respectively. Diversified genotypes had been identified with an overall prevalence of GII. 4 NoV (50.8%) which was followed by GII.6, GII.17, GI.3 and GII.2 with a pooled prevalence of 7.7, 5.1, 4.6, and 4.2%, respectively.
The overall pooled prevalence of norovirus was high in Africa with the dominance of genogroup II and GII.4 genotype. This prevalence is comparable with some reviews done in the same time frame around the world. However, in Africa, an in increasing trained of pooled prevalence had been reported through time. Likewise, a variable distribution of non-GII.4 norovirus genotypes were reported as compared to those studies done in the world of the same time frame, and those previous reviews done in Africa. Therefore, continuous surveillance is required in Africa to support future interventions and vaccine programs.
Twenty-one studies for the pooled prevalence, and 11 out of the 21 studies for genetic characterization of norovirus were included. Studies conducted since 2006, among symptomatic cases of all age groups in Africa, conducted with any study design, used molecular diagnostic methods and reported since 2015, were included and considered for the main meta-analysis. PubMed, Cochrane Library, and Google Scholar were searched to obtain the studies. The quality the studies was assessed using the JBI assessment tool. Data from studies reporting both asymptomatic and symptomatic cases, that did not meet the inclusion criteria were reviewed and included as discussion points. Data was entered to excel and imported to STATA 2011 to compute the prevalence and genetic diversity. Heterogeneity was checked using I2 test statistics followed by subgroup and sensitivity analysis. Publication bias was assessed using a funnel plot and eggers test that was followed by trim and fill analysis.
The pooled prevalence of norovirus was 20.2% (95% CI: 15.91, 24.4). The highest (36.3%) prevalence was reported in Ghana. Genogroup II noroviruses were dominant and reported as 89.5% (95% CI: 87.8, 96). The highest and lowest prevalence of this genogroup were reported in Ethiopia (98.3%), and in Burkina Faso (72.4%), respectively. Diversified genotypes had been identified with an overall prevalence of GII. 4 NoV (50.8%) which was followed by GII.6, GII.17, GI.3 and GII.2 with a pooled prevalence of 7.7, 5.1, 4.6, and 4.2%, respectively.
The overall pooled prevalence of norovirus was high in Africa with the dominance of genogroup II and GII.4 genotype. This prevalence is comparable with some reviews done in the same time frame around the world. However, in Africa, an in increasing trained of pooled prevalence had been reported through time. Likewise, a variable distribution of non-GII.4 norovirus genotypes were reported as compared to those studies done in the world of the same time frame, and those previous reviews done in Africa. Therefore, continuous surveillance is required in Africa to support future interventions and vaccine programs.
摘要：
诺罗病毒是全球所有年龄组急性胃肠炎的主要原因。这个问题在包括非洲在内的发展中国家更加突出。这些病毒非常普遍，具有高遗传多样性和快速进化速率。有了这种动态性，在过去的五年中，非洲没有最近的审查。因此,本综述和荟萃分析旨在评估非洲诺如病毒的患病率和遗传多样性,并试图解决非洲和世界上观察到的病毒患病率和遗传多样性的变化.
21项汇总患病率研究，21项诺如病毒基因特征研究中的11项被纳入。自2006年以来，在非洲所有年龄组的症状病例中进行了研究，进行任何研究设计，使用分子诊断方法,并自2015年以来报道,纳入并考虑进行主要荟萃分析.PubMed,科克伦图书馆,和谷歌学者被搜索以获得这些研究。使用JBI评估工具评估研究的质量。报告无症状和有症状病例的研究数据，对不符合纳入标准的项目进行了审查，并作为讨论要点。数据被输入到Excel并输入到STATA2011，以计算患病率和遗传多样性。使用I2检验统计量检查异质性，然后进行亚组和敏感性分析。使用漏斗图和蛋鸡测试评估出版偏倚，然后进行修剪和填充分析。
诺如病毒的合并流行率为20.2%（95%CI：15.91，24.4）。据报道，加纳的患病率最高（36.3％）。II型基因型诺如病毒占优势，报告为89.5%(95%CI:87.8,96)。埃塞俄比亚报告了该基因组的最高和最低患病率（98.3％），在布基纳法索（72.4%），分别。已鉴定出多样化的基因型与GII的总体患病率。第4期（50.8%），其次是GII.6、GII.17、GI.3和GII.2，合并患病率分别为7.7、5.1、4.6和4.2%，分别。
在非洲，诺如病毒的总体合并流行率很高，以基因群II和GII.4基因型为主。这种流行率与世界各地在同一时间框架内进行的一些评论相当。然而,在非洲,随着时间的推移，据报道，接受培训的合并患病率不断增加。同样，据报道，与在同一时间范围内进行的研究相比，非GII.4诺如病毒基因型的分布不同，以及以前在非洲进行的评论。因此,非洲需要持续监测,以支持未来的干预措施和疫苗计划.
21项汇总患病率研究，21项诺如病毒基因特征研究中的11项被纳入。自2006年以来，在非洲所有年龄组的症状病例中进行了研究，进行任何研究设计，使用分子诊断方法,并自2015年以来报道,纳入并考虑进行主要荟萃分析.PubMed,科克伦图书馆,和谷歌学者被搜索以获得这些研究。使用JBI评估工具评估研究的质量。报告无症状和有症状病例的研究数据，对不符合纳入标准的项目进行了审查，并作为讨论要点。数据被输入到Excel并输入到STATA2011，以计算患病率和遗传多样性。使用I2检验统计量检查异质性，然后进行亚组和敏感性分析。使用漏斗图和蛋鸡测试评估出版偏倚，然后进行修剪和填充分析。
诺如病毒的合并流行率为20.2%（95%CI：15.91，24.4）。据报道，加纳的患病率最高（36.3％）。II型基因型诺如病毒占优势，报告为89.5%(95%CI:87.8,96)。埃塞俄比亚报告了该基因组的最高和最低患病率（98.3％），在布基纳法索（72.4%），分别。已鉴定出多样化的基因型与GII的总体患病率。第4期（50.8%），其次是GII.6、GII.17、GI.3和GII.2，合并患病率分别为7.7、5.1、4.6和4.2%，分别。
在非洲，诺如病毒的总体合并流行率很高，以基因群II和GII.4基因型为主。这种流行率与世界各地在同一时间框架内进行的一些评论相当。然而,在非洲,随着时间的推移，据报道，接受培训的合并患病率不断增加。同样，据报道，与在同一时间范围内进行的研究相比，非GII.4诺如病毒基因型的分布不同，以及以前在非洲进行的评论。因此,非洲需要持续监测,以支持未来的干预措施和疫苗计划.
