Department of Health. Generalitat of Catalonia. Barcelona, Spain.
PLoS One. 2012;7(2):e31339. doi: 10.1371/journal.pone.0031339. Epub 2012 Feb 15.
Even though hepatitis A mass vaccination effectiveness is high, outbreaks continue to occur. The aim of this study was to investigate the association between duration and characteristics of hepatitis A outbreaks. Hepatitis A (HA) outbreaks reported between 1991 and 2007 were studied. An outbreak was defined as ≥2 epidemiologically-linked cases with ≥1 case laboratory-confirmed by detection of HA immunoglobulin M (IgM) antibodies. Relationships between explanatory variables and outbreak duration were assessed by logistic regression. During the study period, 268 outbreaks (rate 2.45 per million persons-year) and 1396 cases (rate 1.28 per 10(5) persons-year) were reported. Factors associated with shorter duration were time to intervention (OR = 0.96; 95% CI: 0.94-0.98) and school setting (OR = 0.39; 95% CI: 0.16-0.92). In person-to-person transmission outbreaks only time to intervention was associated with shorter outbreak duration (OR = 0.96; 95% CI: 0.95-0.98). The only variables associated with shorter outbreak duration were early administration of IG or vaccine and a school setting. Timely reporting HA outbreaks was associated with outbreak duration. Making confirmed HA infections statutory reportable for clinical laboratories could diminish outbreak duration.
尽管甲型肝炎大规模疫苗接种效果很高，但疫情仍在持续发生。本研究旨在探讨甲型肝炎疫情持续时间和特征之间的关系。研究了 1991 年至 2007 年期间报告的甲型肝炎（HA）疫情。疫情定义为≥2 例具有≥1 例通过检测 HA 免疫球蛋白 M（IgM）抗体确证的流行病学相关病例。通过逻辑回归评估解释变量与疫情持续时间之间的关系。研究期间报告了 268 起疫情（发病率为每百万人每年 2.45 例）和 1396 例病例（发病率为每 105 人每年 1.28 例）。与持续时间较短相关的因素包括干预时间（OR=0.96；95%CI：0.94-0.98）和学校环境（OR=0.39；95%CI：0.16-0.92）。在人际传播疫情中，只有干预时间与疫情持续时间较短有关（OR=0.96；95%CI：0.95-0.98）。与疫情持续时间较短相关的唯一变量是及早使用免疫球蛋白或疫苗和学校环境。及时报告甲型肝炎疫情与疫情持续时间有关。将确诊的甲型肝炎感染作为临床实验室的法定报告病例，可能会缩短疫情持续时间。
