Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
BMC Infect Dis. 2024 Oct 9;24(1):1127. doi: 10.1186/s12879-024-10061-4.
The COVID-19 disease requires accurate diagnosis to effectively manage infection rates and disease progression. The study aims to assess the relationship between vaccination status and RT-PCR cycle threshold (Ct) values by comparing clinical, RDT and RT-PCR results.
A total of 453 suspected COVID-19 cases were included in this study. Nasopharyngeal swabs were collected for both RDT and RT-PCR testing, with RDTs conducted on-site and RT-PCR at the Ethiopian Public Health Institute (EPHI) genomics laboratory. Detailed clinical, RDT, and RT-PCR results were analyzed. Data analysis included descriptive statistics, cross-tabulation, and Chi-Square tests to investigate the connections between diagnostic outcomes and vaccination status, with a focusing on Ct values.
RDT results showed 34.0% negative and 65.8% positive, while RT-PCR results indicated 35.8% negative and 64.2% positive cases. The discrepancies between RDT and RT-PCR results emphasize the importance of thorough testing. No significant association was found between vaccination status and viral load, as indicated by Ct values. Among RT-PCR positive cases, 49.8% had been vaccinated, suggesting challenges in interpreting results among vaccinated individuals. Further analysis revealed that vaccination (first or second dose) had minimal impact on Ct values, indicating limited influence of vaccination status on viral load dynamics in infected individuals.
The study highlights the significant differences between RDT and RT-PCR outcomes, underscoring the need for a comprehensive testing approach. Additionally, the findings suggest that vaccination status does not significantly impact RT-PCR Ct values, complicating the interpretation of diagnostic results in vaccinated individuals, especially in breakthrough infections and potential false positives.
COVID-19 疾病需要准确诊断，以有效管理感染率和疾病进展。本研究旨在通过比较临床、RDT 和 RT-PCR 结果来评估疫苗接种状态与 RT-PCR 循环阈值（Ct）值之间的关系。
本研究共纳入 453 例疑似 COVID-19 病例。采集鼻咽拭子进行 RDT 和 RT-PCR 检测，RDT 在现场进行，RT-PCR 在埃塞俄比亚公共卫生研究所（EPHI）基因组学实验室进行。详细分析了临床、RDT 和 RT-PCR 结果。数据分析包括描述性统计、交叉表和卡方检验，以调查诊断结果与疫苗接种状态之间的关系，重点关注 Ct 值。
RDT 结果显示 34.0%为阴性，65.8%为阳性，而 RT-PCR 结果显示 35.8%为阴性，64.2%为阳性。RDT 和 RT-PCR 结果之间的差异强调了彻底检测的重要性。Ct 值表明，疫苗接种状态与病毒载量之间没有显著关联。在 RT-PCR 阳性病例中，49.8%已接种疫苗，表明在接种疫苗的个体中解释结果存在挑战。进一步分析表明，接种疫苗（第一剂或第二剂）对 Ct 值的影响很小，表明接种状态对感染个体中病毒载量动态的影响有限。
本研究强调了 RDT 和 RT-PCR 结果之间的显著差异，突出了需要全面的检测方法。此外，研究结果表明，疫苗接种状态不会显著影响 RT-PCR Ct 值，这使得在接种疫苗的个体中解释诊断结果变得复杂，尤其是在突破性感染和潜在的假阳性病例中。
