Tayachew Adamu, Mekuria Zelalem, Shure Wolde, Arimide Dawit Assefa, Gebeyehu Ayele, Berkesa Tsegaye, Gonta Melaku, Teka Gizaw, Kebede Mandefro, Melese Daniel, Wossen Mesfin, Abte Melkamu, Hailu Mesay, Berhe Nega, Medstrand Patrik, Kebede Nigatu
Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
Addis Ababa University, Aklilu Lemma Institute of Pathobiology, Addis Ababa, Ethiopia.
BMC Infect Dis. 2025 Jul 24;25(1):941. doi: 10.1186/s12879-025-11330-6.
Data in Ethiopia on the epidemiology of Respiratory Syncytial Virus (RSV) and subtypes among influenza-like illness (ILI) and severe acute respiratory infections (SARI) cases is limited. Here, we assessed the epidemiology of RSV and its subtypes among the pediatric and adult ILI /SARI cases in Ethiopia.
We conducted prospective, multicenter facility-based study from May 2023 to April 2024. Respiratory swab specimens, epidemiological and clinical data were collected from participants of all age groups, and both hospitalized and non-hospitalized individuals who met the World Health Organization (WHO) case definition for ILI/SARI and provided informed consent. Laboratory investigation was performed using reverse transcription polymerase chain reaction (RT-PCR). Data were analyzed using SPSS V29. Descriptive statistics were used to summarize frequencies and ratios, and multivariable logistic regression model was employed to assess factors associated with RSV positivity.
In total, 4170 participants were enrolled, the majority (57.9%) of whom were cases from children under five and SARI (76.5%). RSV was detected in 654 cases (15.7%; 95% CI: 14.6-16.8). RSV subtyping was carried out for 475 (72.6%) of 654 RSV positive samples. The finding revealed that both RSV-A and RSV-B subtypes were co-circulating in Ethiopia, with predominance of RSV-B (68.8%). Age group, season and timing of sample collection were factors independently associated with RSV positivity. Accordingly, children aged < 2 years (AOR: 8.20, 95% CI: 3.57-18.81) and 2-4 years (AOR: 5.01, 95% CI: 2.15-11.67), autumn (AOR: 5.89, 95% CI: 3.79-9.17) and winter (AOR: 3.27, 95% CI: 2.07-5.16) seasons, and case whose samples were collected within three days of symptom onset (AOR: 1.76, 95% CI: 1.09-2.84) were significantly associated with RSV positivity.
The study provides evidence of RSV circulation among ILI/SARI cases in Ethiopia. It also revealed that RSV-B was the predominant subtype circulating in the country. The age-specific and temporal patterns of RSV positivity identified in this study contribute to the understanding of RSV and its subtypes epidemiology in Ethiopia. The findings provide valuable evidence to inform implementation of RSV vaccine introduction programs, particularly targeting high-risk populations during periods of peak transmission. Future research focusing on RSV genomic analysis and disease burden is needed to better understand RSV viral evolution, transmission dynamics and public health impacts in Ethiopia.
埃塞俄比亚关于呼吸道合胞病毒（RSV）及其在流感样疾病（ILI）和严重急性呼吸道感染（SARI）病例中的亚型流行病学数据有限。在此，我们评估了埃塞俄比亚儿科和成人ILI/SARI病例中RSV及其亚型的流行病学情况。
我们于2023年5月至2024年4月进行了一项前瞻性、多中心的基于医疗机构的研究。从所有年龄组的参与者以及符合世界卫生组织（WHO）ILI/SARI病例定义并提供知情同意的住院和非住院个体中收集呼吸道拭子标本、流行病学和临床数据。使用逆转录聚合酶链反应（RT-PCR）进行实验室检测。使用SPSS V29对数据进行分析。描述性统计用于总结频率和比率，多变量逻辑回归模型用于评估与RSV阳性相关的因素。
总共招募了4170名参与者，其中大多数（57.9%）是5岁以下儿童的病例和SARI（76.5%）。在654例病例中检测到RSV（15.7%；95%CI：14.6 - 16.8）。对654份RSV阳性样本中的475份（72.6%）进行了RSV亚型分型。结果显示，RSV - A和RSV - B亚型在埃塞俄比亚共同流行，以RSV - B为主（68.8%）。年龄组、季节和样本采集时间是与RSV阳性独立相关的因素。因此，年龄<2岁（调整后比值比[AOR]：8.20，95%CI：3.57 - 18.81）和2 - 四岁（AOR：5.01，95%CI：2.15 - 11.67）的儿童、秋季（AOR：5.89，95%CI：3.79 - 9.17）和冬季（AOR：3.27，95%CI：2.07 - 5.16）季节以及症状出现后三天内采集样本的病例（AOR：1.76，95%CI：1.09 - 2.84）与RSV阳性显著相关。
该研究提供了埃塞俄比亚ILI/SARI病例中RSV流行的证据。它还表明RSV - B是该国流行的主要亚型。本研究中确定的RSV阳性的年龄特异性和时间模式有助于了解埃塞俄比亚RSV及其亚型的流行病学。这些发现为实施RSV疫苗引入计划提供了有价值的证据，特别是针对传播高峰期的高危人群。未来需要针对RSV基因组分析和疾病负担的研究，以更好地了解埃塞俄比亚RSV病毒的进化、传播动态和公共卫生影响。
