Department of Biochemistry, Faculty of Science, The University of Yaoundé 1, Yaoundé, Cameroon.
Department of Microbiology, Faculty of Science, The University of Yaoundé 1, Yaoundé, Cameroon.
BMC Infect Dis. 2021 Jun 28;21(1):614. doi: 10.1186/s12879-021-06318-x.
Despite the global roll-out of rotavirus vaccines (RotaTeq/Rotarix / ROTAVAC/Rotasiil), mortality and morbidity due to group A rotavirus (RVA) remains high in sub-Saharan Africa, causing 104,000 deaths and 600,000 hospitalizations yearly. In Cameroon, Rotarix™ was introduced in March 2014, but, routine laboratory diagnosis of rotavirus infection is not yet a common practice, and vaccine effectiveness studies to determine the impact of vaccine introduction have not been done. Thus, studies examining RVA prevalence post vaccine introduction are needed. The study aim was to determine RVA prevalence in severe diarrhoea cases in Littoral region, Cameroon and investigate the role of other diarrheagenic pathogens in RVA-positive cases.
We carried out a study among hospitalized children < 5 years of age, presenting with acute gastroenteritis in selected hospitals of the Littoral region of Cameroon, from May 2015 to April 2016. Diarrheic stool samples and socio-demographic data including immunization and breastfeeding status were collected from these participating children. Samples were screened by ELISA (ProSpecT™ Rotavirus) for detection of RVA antigen and by gel-based RT-PCR for detection of the VP6 gene. Co-infection was assessed by multiplexed molecular detection of diarrheal pathogens using the Luminex xTAG GPP assay.
The ELISA assay detected RVA antigen in 54.6% (71/130) of specimens, with 45, positive by VP6 RT-PCR and 54, positive using Luminex xTAG GPP. Luminex GPP was able to detect all 45 VP6 RT-PCR positive samples. Co-infections were found in 63.0% (34/54) of Luminex positive RVA infections, with Shigella (35.3%; 12/34) and ETEC (29.4%; 10/34) detected frequently. Of the 71 ELISA positive RVA cases, 57.8% (41/71) were fully vaccinated, receiving two doses of Rotarix.
This study provides insight on RVA prevalence in Cameroon, which could be useful for post-vaccine epidemiological studies, highlights higher than expected RVA prevalence in vaccinated children hospitalized for diarrhoea and provides the trend of RVA co-infection with other enteric pathogens. RVA genotyping is needed to determine circulating rotavirus genotypes in Cameroon, including those causing disease in vaccinated children.
尽管全球已推出轮状病毒疫苗（Rotateq/Rotarix/ROTAVAC/Rotasiil），但撒哈拉以南非洲地区由 A 组轮状病毒（RVA）引起的死亡率和发病率仍然很高，每年导致 10.4 万人死亡和 60 万人住院。在喀麦隆，Rotarix™于 2014 年 3 月推出，但轮状病毒感染的常规实验室诊断尚未成为常见做法，也尚未开展疫苗有效性研究以确定疫苗推出的影响。因此，需要研究接种疫苗后 RVA 的流行情况。本研究旨在确定喀麦隆滨海地区严重腹泻病例中 RVA 的流行情况，并调查其他致腹泻病原体在 RVA 阳性病例中的作用。
我们于 2015 年 5 月至 2016 年 4 月期间在喀麦隆滨海地区的选定医院对 5 岁以下住院的急性肠胃炎患儿进行了一项研究。从这些参与的患儿中收集腹泻粪便样本和社会人口统计学数据，包括免疫接种和母乳喂养状况。使用 ELISA（ProSpecT™轮状病毒）检测 RVA 抗原，使用凝胶基 RT-PCR 检测 VP6 基因，对样本进行筛查。使用 Luminex xTAG GPP 检测腹泻病原体的多重分子检测评估合并感染。
ELISA 检测法在 71/130 份标本中检测到 RVA 抗原，45 份标本 VP6 RT-PCR 阳性，54 份标本 Luminex xTAG GPP 阳性。Luminex GPP 能够检测到所有 45 份 VP6 RT-PCR 阳性样本。在 54 份 Luminex 阳性的 RVA 感染中发现合并感染，其中志贺氏菌（35.3%；12/34）和肠产毒性大肠杆菌（29.4%；10/34）检出率较高。在 71 例 ELISA 阳性的 RVA 病例中，57.8%（41/71）完全接种疫苗，接受了 2 剂 Rotarix。
本研究提供了喀麦隆 RVA 流行情况的见解，这对于疫苗接种后流行病学研究可能有用，突出了接种疫苗的儿童因腹泻住院的 RVA 流行率高于预期，并提供了 RVA 与其他肠道病原体合并感染的趋势。需要对 RVA 进行基因分型，以确定喀麦隆的轮状病毒基因型，包括导致接种疫苗儿童发病的基因型。
