Centre for Infectious Disease Research in Zambia, Lusaka Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia.
Clin Infect Dis. 2016 May 1;62 Suppl 2(Suppl 2):S175-82. doi: 10.1093/cid/civ1206.
Diarrhea is the third leading cause of child death in Zambia. Up to one-third of diarrhea cases resulting in hospitalization and/or death are caused by vaccine-preventable rotavirus. In January 2012, Zambia initiated a pilot introduction of the Rotarix live, oral rotavirus vaccine in all public health facilities in Lusaka Province.
Between July 2012 and October 2013, we conducted a case-control study at 6 public sector sites to estimate rotavirus vaccine effectiveness (VE) in age-eligible children presenting with diarrhea. We computed the odds of having received at least 1 dose of Rotarix among children whose stool was positive for rotavirus antigen (cases) and children whose stool was negative (controls). We adjusted the resulting odds ratio (OR) for patient age, calendar month of presentation, and clinical site, and expressed VE as (1 - adjusted OR) × 100.
A total of 91 rotavirus-positive cases and 298 rotavirus-negative controls who had under-5 card-confirmed vaccination status and were ≥6 months of age were included in the case-control analysis. Among rotavirus-positive children who were age-eligible to be vaccinated, 20% were hospitalized. Against rotavirus diarrhea of all severity, the adjusted 2-dose VE was 26% (95% confidence interval [CI], -30% to 58%) among children ≥6 months of age. VE against hospitalized children ≥6 months of age was 56% (95% CI, -34% to 86%).
We observed a higher point estimate for VE against increased severity of illness compared with milder disease, but were not powered to detect a low level of VE against milder disease.
腹泻是赞比亚导致儿童死亡的第三大原因。多达三分之一因住院和/或死亡的腹泻病例是由可通过疫苗预防的轮状病毒引起的。2012 年 1 月，赞比亚在卢萨卡省所有公共卫生机构启动了罗特律克斯活、口服轮状病毒疫苗的试点引进。
在 2012 年 7 月至 2013 年 10 月期间，我们在 6 个公立部门地点进行了一项病例对照研究，以评估适合年龄的患有腹泻症状的儿童中罗特律克斯疫苗的有效性 (VE)。我们计算了轮状病毒抗原阳性（病例）和轮状病毒抗原阴性（对照）儿童中至少接受过 1 剂罗特律克斯的儿童的优势比 (OR)。我们调整了由此产生的比值比 (OR)，以适应患者年龄、就诊的日历月份和临床地点，并将 VE 表示为 (1 - 调整后的 OR) × 100。
共有 91 例轮状病毒阳性病例和 298 例轮状病毒阴性对照者符合 5 岁以下卡片确认的疫苗接种状态且年龄在 6 个月以上，纳入病例对照分析。在适合接种疫苗的轮状病毒阳性儿童中，20%住院。针对所有严重程度的轮状病毒腹泻，≥6 个月儿童的 2 剂 VE 调整后为 26%（95%置信区间 [CI]，-30%至 58%）。≥6 个月儿童的住院 VE 为 56%（95% CI，-34%至 86%）。
与轻度疾病相比，我们观察到针对疾病严重程度增加的 VE 更高的点估计值，但没有足够的能力来检测针对轻度疾病的低水平 VE。
