Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences (The First Department of Internal Medicine), Fukuoka, Japan.
Japan Physicians Association, Tokyo, Japan.
Influenza Other Respir Viruses. 2024 Nov;18(11):e70042. doi: 10.1111/irv.70042.
Clinical data on patients infected with influenza B Victoria (BV) after the approval of baloxavir is lacking.
This observational study of the Japanese 2023-2024 influenza season analyzed data from 25 outpatients with A(H1N1)pdm09, 36 with A(H3N2), and 65 with BV. Viral samples were collected before and after administering an antiviral (70 patients received baloxavir and 56 received a neuraminidase inhibitor), on days 1, 5, and 10. Isolated viruses after culturing were amplified using RT-PCR and sequenced to detect mutations of concern, including acidic protein (PA)-amino acid (AA) E23X/I38X for influenza A and M34X/I38X for BV. Fever and symptoms were tracked via self-reporting diaries.
No PA-AA-substituted virus was detected from 126 pre-treatment samples. In the baloxavir cohort, one (7.1%, 1/14) PA I38F-substituted A(H1N1)pdm09 and two (11.1%, 2/18) PA I38T-substituted A(H3N2) viruses were isolated on day 5 but not on day 10. No (0%, 0/37) PA-AA-substituted BV was detected on day 5 or after. The virus isolation rate on day 5 was higher among patients with BV than with influenza A in both baloxavir (35.1% vs. 14.3% for A(H1N1)pdm09 and 16.7% for A(H3N2)) and oseltamivir-treated patients (44.4% vs. 0% for A(H1N1)pdm09 and 33.3% for A(H3N2)). Patients with PA-AA-substituted influenza A after baloxavir administration did not have longer fever duration than those without virus isolation or with wild-type virus on day 5, for both A(H1N1)pdm09 and A(H3N2).
Baloxavir-resistant variants were not detected in influenza BV before treatment, as with A. The emergence of PA-AA-substituted influenza A after baloxavir administration was temporal and did not cause prolonged symptoms. No baloxavir-resistant BV variants were observed after baloxavir administration.
在批准巴洛沙韦后，缺乏关于感染乙型流感维多利亚（BV）的患者的临床数据。
本项针对日本 2023-2024 年流感季节的观察性研究分析了 25 例 A（H1N1）pdm09、36 例 A（H3N2）和 65 例 BV 门诊患者的数据。在使用抗病毒药物（70 例患者接受巴洛沙韦，56 例接受神经氨酸酶抑制剂）治疗前、治疗后第 1、5 和 10 天采集病毒样本。通过 RT-PCR 扩增培养后的分离病毒，并对其进行测序以检测相关突变，包括流感 A 的酸性蛋白（PA）-氨基酸（AA）E23X/I38X 和 BV 的 M34X/I38X。通过自我报告的日记跟踪发热和症状。
在 126 份治疗前样本中未检测到 PA-AA 取代病毒。在巴洛沙韦组中，1 例（7.1%，1/14）A（H1N1）pdm09 的 PA I38F 取代和 2 例（11.1%，2/18）A（H3N2）的 PA I38T 取代病毒于第 5 天分离，但第 10 天未分离。在第 5 天或之后未检测到（0%，0/37）BV 的 PA-AA 取代。在巴洛沙韦治疗的患者中，BV 患者的第 5 天病毒分离率高于流感 A，A（H1N1）pdm09 为 35.1%，A（H3N2）为 16.7%，而在奥司他韦治疗的患者中，A（H1N1）pdm09 为 44.4%，A（H3N2）为 33.3%。与未分离病毒或第 5 天野生型病毒的患者相比，接受巴洛沙韦治疗后出现 PA-AA 取代流感 A 的患者发热持续时间没有更长，无论是 A（H1N1）pdm09 还是 A（H3N2）。
在治疗前，与 A 型流感一样，未在 BV 中检测到对巴洛沙韦耐药的变异体。在接受巴洛沙韦治疗后，流感 A 的 PA-AA 取代是暂时的，不会导致症状延长。在接受巴洛沙韦治疗后，未观察到对巴洛沙韦耐药的 BV 变异体。
