Ricerca Clinica, Fukuoka, Japan.
Biostatistics Center, Shionogi & Co., Ltd, Osaka, Japan.
Influenza Other Respir Viruses. 2024 May;18(5):e13302. doi: 10.1111/irv.13302.
The transmission of influenza virus in households, especially by children, is a major route of infection. Prior studies suggest that timely antiviral treatment of ill cases may reduce infection in household contacts. The aim of the study was to compare the effects of oseltamivir (OTV) and baloxavir marboxil (BXM) treatment of index cases on the secondary attack rate (SAR) of influenza within household.
A post hoc analysis was done in BLOCKSTONE trial-a placebo-controlled, double-blinded post-exposure prophylaxis of BXM. Data were derived from the laboratory-confirmed index cases' household contacts who received placebo in the trial and also from household members who did not participate in the trial but completed illness questionnaires. To assess the SAR of household members, multivariate analyses adjusted for factors including age, vaccination status, and household size were performed and compared between contacts of index cases treated with BXM or OTV.
In total, 185 index cases (116 treated with BXM and 69 treated with OTV) and 410 household contacts (201 from trial, 209 by questionnaire) were included. The Poisson regression modeling showed that the SAR in household contacts of index cases treated with BXM and OTV was 10.8% and 18.5%, respectively; the adjusted relative reduction in SAR was 41.8% (95% confidence interval: 1.0%-65.7%, p = 0.0456) greater with BXM than OTV. Similar reductions were found in contacts from the trial and those included by questionnaire.
BXM treatment of index cases appeared to result in a greater reduction in secondary household transmission than OTV treatment.
流感病毒在家中传播，尤其是儿童，是主要的感染途径。先前的研究表明，及时对病例进行抗病毒治疗可能会降低家庭接触者的感染率。本研究旨在比较奥司他韦（OTV）和巴洛沙韦（BXM）治疗病例对家庭内流感二次攻击率（SAR）的影响。
对 BLOCKSTONE 试验的事后分析-一种对 BXM 的安慰剂对照、双盲、暴露后预防。数据来自于接受试验安慰剂的确诊病例的家庭接触者，以及未参加试验但完成疾病问卷的家庭接触者。为了评估家庭接触者的 SAR，对包括年龄、疫苗接种状况和家庭规模在内的因素进行了多变量分析，并比较了 BXM 或 OTV 治疗的病例接触者的 SAR。
共有 185 例病例（116 例用 BXM 治疗，69 例用 OTV 治疗）和 410 名家庭接触者（201 名来自试验，209 名通过问卷）纳入研究。泊松回归模型显示，BXM 和 OTV 治疗的病例家庭接触者的 SAR 分别为 10.8%和 18.5%；BXM 治疗的 SAR 相对降低 41.8%（95%置信区间：1.0%-65.7%，p=0.0456），比 OTV 更显著。在来自试验的接触者和通过问卷纳入的接触者中均发现了类似的降低。
与 OTV 治疗相比，BXM 治疗病例似乎导致家庭二次传播的减少更为显著。
