From the *Department of Pediatrics, Fukushima Medical University, Fukushima; and †Department of Pediatrics, Fukushima South Aizu Hospital, South Aizu, Japan.
Pediatr Infect Dis J. 2014 Jul;33(7):e168-72. doi: 10.1097/INF.0000000000000266.
The objective of this study was to estimate the efficacy of the neuraminidase (NA) inhibitors (NAIs) oseltamivir and zanamivir for decreasing viral load and to investigate whether NAI treatment decreases viral susceptibility to NAIs over time in children with influenza B virus infection.
Of 27 patients with influenza B virus infection, 8 and 9 were treated with oseltamivir and zanamivir, respectively, whereas 10 received no NAI. Nasal aspiration samples, collected every morning until negative antigen results in 2 consecutive samples were observed, were subjected to viral load measurements by quantitative real-time reverse transcription polymerase chain reaction and viral susceptibility to NAI by NA inhibition assays.
Viral load decreased in both the oseltamivir and zanamivir groups by day 2 but increased in the no-NAI treatment group. Viral load in the oseltamivir and zanamivir groups on day 5 was 2.6% and 9.2% of that on day 0, respectively, whereas it was 26.4% in the no-NAI treatment group. Mean 50% inhibitory concentration (IC50) values of oseltamivir and zanamivir in the no-NAI treatment group were 5.0-6.6 and 1.3-1.8 nM, respectively. Mean IC50 values of oseltamivir and zanamivir in patients treated with oseltamivir and zanamivir were 3.9-8.8 and 1.3-1.8 nM, respectively. No major decrease in viral susceptibility to NAIs was observed during or after NAI treatment.
NAI treatment was effective for inhibiting viral replication during the early days of illness and did not decrease viral susceptibility to NAIs in patients with influenza B virus infection.
本研究旨在评估神经氨酸酶（NA）抑制剂（NAIs）奥司他韦和扎那米韦降低病毒载量的疗效，并探讨 NAIs 治疗是否会随着时间的推移降低乙型流感病毒感染患儿对 NAIs 的病毒易感性。
在 27 例乙型流感病毒感染患者中，8 例和 9 例分别接受了奥司他韦和扎那米韦治疗，而 10 例未接受 NAI 治疗。每天早上采集鼻抽吸样本，直到连续 2 个样本的抗原检测结果均为阴性，通过实时定量逆转录聚合酶链反应测量病毒载量，并通过 NA 抑制试验测量病毒对 NAI 的敏感性。
奥司他韦和扎那米韦组的病毒载量在第 2 天均下降，但未接受 NAI 治疗组的病毒载量增加。奥司他韦和扎那米韦组第 5 天的病毒载量分别为第 0 天的 2.6%和 9.2%，而未接受 NAI 治疗组的病毒载量为第 0 天的 26.4%。未接受 NAI 治疗组奥司他韦和扎那米韦的半数抑制浓度（IC50）值分别为 5.0-6.6 和 1.3-1.8 nM。奥司他韦和扎那米韦治疗患者的奥司他韦和扎那米韦的 IC50 值分别为 3.9-8.8 和 1.3-1.8 nM。在 NAI 治疗期间或之后，未观察到病毒对 NAIs 的敏感性明显下降。
NAI 治疗可有效抑制疾病早期的病毒复制，且不会降低乙型流感病毒感染患者对 NAIs 的病毒易感性。
