Yamada Takahiro, Yamada Takashi, Morikawa Mamoru, Cho Kazutoshi, Endo Toshiaki, Sato Sawako Seto, Saito Tsuyoshi, Sengoku Kazuo, Minakami Hisanori
Department of Obstetrics and Gynecology, Hokkaido University Graduate School of Medicine Department of Obstetrics and Gynecology, Sapporo, Japan.
J Obstet Gynaecol Res. 2012 Jan;38(1):130-6. doi: 10.1111/j.1447-0756.2011.01644.x. Epub 2011 Sep 28.
No maternal mortality from pandemic (H1N1) 2009 occurred in Japan. However, the reasons for this lack of maternal deaths remain unknown. This study was performed to investigate how many pregnant women were infected, how many women took antiviral drugs for prophylaxis or treatment, and the rate of vaccination effectiveness.
A questionnaire study was given to 20500 postpartum women before leaving obstetric facilities between December 2009 and May 2010 in Hokkaido, asking about antiviral drugs, vaccination, and infection with pandemic (H1N1) 2009.
Approximately one-third (n=7535) of women given the questionnaires responded. Of these, 268 women (3.5%) indicated that they had contracted influenza. 353 (4.7%) women took antiviral drugs for prophylaxis after close contact with an infected person and 140 (39.7%) of 353 women finally contracted influenza during or after prophylaxis with antiviral drugs, accounting for 52.2% (140/268) of all patients. 229 (85.4%) of 268 patients took antiviral drug for treatment and 6 (2.2%) needed hospitalization, but not mechanical ventilation or intensive care unit. 196 of 268 (73.1%) patients were already infected before the availability of a vaccine. Among 7328 candidates for vaccination, 4921 (67.2%) were vaccinated. Infection occurred in 0.22% (11/4921) and 2.1% (50/2407) of vaccinated and non-vaccinated women, respectively.
Frequent use of antiviral drugs for prophylaxis and treatment may partially explain the low infection rate and no maternal mortality from pandemic (H1N1) 2009 in Japan. Vaccination reduced infection by 89% in pregnant Japanese women.
日本未出现2009年甲型H1N1流感大流行导致的孕产妇死亡病例。然而，孕产妇死亡病例缺失的原因尚不清楚。本研究旨在调查有多少孕妇受到感染、多少女性使用抗病毒药物进行预防或治疗以及疫苗接种的有效率。
2009年12月至2010年5月期间，在北海道，对20500名产后女性在离开产科机构前进行问卷调查，询问有关抗病毒药物、疫苗接种以及2009年甲型H1N1流感感染情况。
约三分之一（n = 7535）的女性对问卷进行了回复。其中，268名女性（3.5%）表示感染了流感。353名（4.7%）女性在与感染者密切接触后服用抗病毒药物进行预防，在服用抗病毒药物预防期间或之后，353名女性中有140名（39.7%）最终感染了流感，占所有患者的52.2%（140/268）。268名患者中有229名（85.4%）服用抗病毒药物进行治疗，6名（2.2%）需要住院治疗，但无需机械通气或入住重症监护病房。268名患者中有196名（73.1%）在疫苗可用之前就已感染。在7328名疫苗接种候选者中，4921名（67.2%）接种了疫苗。接种疫苗和未接种疫苗的女性中，感染率分别为0.22%（11/4921）和2.1%（50/2407）。
频繁使用抗病毒药物进行预防和治疗可能部分解释了日本2009年甲型H1N1流感感染率低且无孕产妇死亡的原因。疫苗接种使日本孕妇的感染率降低了89%。
