Mutua Maurine Mumo, Kathiiko Cyrus, Wachira Mary N, Muriithi Betty, Nyangao James, Khamadi Samoel A, Komoto Satoshi, Morita Kouichi, Ichinose Yoshio, Wandera Ernest A
Institute of Tropical Medicine, Nagasaki University-Kenya Medical Research Institute, Nairobi, Kenya.
KEMRI Graduate School of Health, Nairobi, Kenya.
Trop Med Health. 2025 Apr 27;53(1):60. doi: 10.1186/s41182-025-00716-6.
Rotavirus, norovirus, adenovirus (type 40/41) and astrovirus are the most significant viral etiological agents of acute gastroenteritis in young children globally. Kenya introduced the rotavirus vaccine into her National Immunization Program in July 2014, which has led to a significant decline in the prevalence of rotavirus. We sought to assess the impact of rotavirus vaccination on the epidemiological trends of other diarrhea-associated enteric viruses across different regions in Kenya.
Using conventional and multiplex RT-PCR, we analyzed a total of 716 fecal samples for adenovirus, astrovirus and norovirus from children aged below 5 years presenting with acute gastroenteritis but tested negative for rotavirus at Mbita Sub-County Referral Hospital in Western Kenya and Kiambu County Referral Hospital in Central Kenya before (2011-2013) and after (2019-2020) rotavirus vaccine introduction.
Following the rotavirus vaccine introduction, there was no significant difference in norovirus and astrovirus prevalence post-vaccine introduction in both Central (norovirus- 5.4% vs 5.9%; astrovirus- 2% vs 2.4%) and Western Kenya (norovirus- 2% vs 3%; astrovirus 3.3% vs 5.9%). Although the prevalence of adenovirus increased substantially in Western Kenya (9% vs 12.4%), there was a significant decrease in adenovirus in Central Kenya (17%, vs 6%, p = 0.007). Before the introduction of the rotavirus vaccine, a large proportion of adenovirus cases occurred at 6-8 months in Central Kenya and 12-23 months in Western Kenya, while norovirus prevalence was highest at 12-23 months in Central and 3-5 months in Western Kenya. Astrovirus infections in Central Kenya were predominantly among children aged 12-23 months, both before and after the vaccine. Following vaccine introduction, a large proportion of adenovirus cases occurred among children aged 12-23 months in both regions. Norovirus peaked at 12-23 months in Central Kenya and showed dual peaks at 3-5 and 9-11 months in Western Kenya. Astrovirus infections in Western Kenya shifted from peaks at 6-8 and 24-59 months pre-vaccine to 9-11 months post-vaccine.
Our data demonstrate the burden and changing epidemiology of enteric viruses in Western and Central Kenya and underscores the need for continued monitoring to guide the design and implementation of appropriate public health interventions.
轮状病毒、诺如病毒、腺病毒（40/41型）和星状病毒是全球幼儿急性胃肠炎最重要的病毒病原体。肯尼亚于2014年7月将轮状病毒疫苗纳入其国家免疫规划，这导致轮状病毒的流行率显著下降。我们试图评估轮状病毒疫苗接种对肯尼亚不同地区其他腹泻相关肠道病毒流行病学趋势的影响。
我们使用常规和多重逆转录聚合酶链反应（RT-PCR），对肯尼亚西部姆比塔县转诊医院和中部肯尼亚基安布县转诊医院5岁以下患有急性胃肠炎但轮状病毒检测呈阴性的儿童，在引入轮状病毒疫苗之前（2011 - 2013年）和之后（2019 - 2020年）的716份粪便样本进行了腺病毒、星状病毒和诺如病毒分析。
引入轮状病毒疫苗后，中部（诺如病毒 - 5.4%对5.9%；星状病毒 - 2%对2.4%）和肯尼亚西部（诺如病毒 - 2%对3%；星状病毒3.3%对5.9%）疫苗引入后诺如病毒和星状病毒的流行率没有显著差异。虽然肯尼亚西部腺病毒的流行率大幅上升（9%对12.4%），但肯尼亚中部腺病毒显著下降（17%对6%，p = 0.007）。在引入轮状病毒疫苗之前，肯尼亚中部很大一部分腺病毒病例发生在6 - 8个月，肯尼亚西部发生在12 - 23个月，而诺如病毒流行率在中部12 - 23个月最高，在西部3 - 5个月最高。在疫苗接种前后，肯尼亚中部星状病毒感染主要发生在12 - 23个月的儿童中。引入疫苗后，两个地区很大一部分腺病毒病例发生在12 - 23个月的儿童中。肯尼亚中部诺如病毒在12 - 23个月达到峰值，在肯尼亚西部在3 - 5个月和9 - 11个月出现双峰。肯尼亚西部星状病毒感染从疫苗接种前6 - 8个月和24 - 59个月的峰值转移到疫苗接种后的9 - 11个月。
我们的数据证明了肯尼亚西部和中部肠道病毒的负担和流行病学变化，并强调需要持续监测以指导适当公共卫生干预措施的设计和实施。
