Caroça Cristina, Vicente Vera, Campelo Paula, Chasqueira Maria, Caria Helena, Silva Susana, Paixão Paulo, Paço João
Otolaryngology Department, NOVA Medical School/Faculty of Medical Sciences, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 130, 1169-056, Lisboa, Portugal.
Hospital CUF Infante Santo, Avenida Infante Santo, 34, 6°, 1350-079, Lisboa, Portugal.
BMC Public Health. 2017 Feb 1;17(1):146. doi: 10.1186/s12889-017-4077-2.
Rubella infection can affect several organs and cause birth defects that are responsible for congenital rubella syndrome (CRS). Congenital hearing loss is the most common symptom of this syndrome, occurring in approximately 60% of CRS cases. Worldwide, over 100 000 babies are born with CRS every year. There is no specific treatment for rubella, but the disease is preventable by vaccination. Since 1969, the rubella vaccine has been implemented in many countries, but in Africa, only a few countries routinely immunize against rubella. The aim of this study was to estimate the rate of infection from the wild-type rubella virus in São Tomé and Príncipe by determining rubella seroprevalence with a DBS method. The goal of this study was to reinforce the need for implementation of the rubella vaccine in this country. As secondary objectives, the validation of a DBS method was first attempted and an association between seroprevalence and hearing loss was assessed.
We collected samples from individuals observed during humanitarian missions in São Tomé and Príncipe. All individuals underwent an audiometric evaluation, and a drop of blood was collected for the dried blood spot (DBS). We define two groups: the case group (individuals with unilateral or bilateral hearing loss (HL)) and the control group (individuals with two normal ears). Patients were excluded if they suffered from conductive HL, if they showed evidence of possible causes of HL, if they had developmental delay or if they refused to participate in the study.
Among the 315 subjects, we found 64.1% individuals with IgG for the rubella virus, 32.1% without immunity for the rubella virus and 3.8% who were borderline. In the control group, 62.6% were positive for the rubella IgG, whereas in the case group, 72% were positive. Analyzing both groups, with ages ranging from 2 to 14 years of age and from 15 to 35 years of age, we found a seroprevalence of 50.3% to rubella in the younger group and 82.1% in the older group, with a significant difference between cases and control group noted within the younger patients (p = 0.025).
Rubella is a disease that can be prevented. Rubella infections are still very common in São Tomé and Príncipe, and women of child-bearing age are still at risk for rubella infection during pregnancy, justifying the urgency of vaccination against rubella. A statistically significant association between the group of children under 14 years of age with HL and immunity for rubella was observed in this country, although this study did not allow us to establish a cause-effect relationship between rubella infection and SNHL.
风疹感染可累及多个器官并导致出生缺陷，进而引发先天性风疹综合征（CRS）。先天性听力损失是该综合征最常见的症状，约60%的CRS病例会出现此症状。全球每年有超过10万名婴儿患有CRS。风疹尚无特效治疗方法，但可通过接种疫苗预防。自1969年以来，许多国家已实施风疹疫苗接种，但在非洲，只有少数国家常规接种风疹疫苗。本研究的目的是通过采用干血斑（DBS）法测定风疹血清阳性率，估算圣多美和普林西比野生型风疹病毒的感染率。本研究的目标是强化该国实施风疹疫苗接种的必要性。作为次要目标，首次尝试验证DBS方法，并评估血清阳性率与听力损失之间的关联。
我们从在圣多美和普林西比人道主义任务期间观察到的个体中采集样本。所有个体均接受听力评估，并采集一滴血用于干血斑检测。我们定义了两组：病例组（单侧或双侧听力损失（HL）的个体）和对照组（双耳正常的个体）。如果患者患有传导性HL、有HL可能病因的证据、有发育迟缓或拒绝参与研究，则将其排除。
在315名受试者中，我们发现64.1%的个体风疹病毒IgG阳性，32.1%对风疹病毒无免疫力，3.8%处于临界状态。对照组中，62.6%的风疹IgG呈阳性，而病例组中这一比例为72%。分析年龄在2至14岁和15至35岁的两组人群，我们发现较年轻组的风疹血清阳性率为50.3%，较年长组为82.1%，较年轻患者的病例组与对照组之间存在显著差异（p = 0.025）。
风疹是一种可预防的疾病。风疹感染在圣多美和普林西比仍然非常常见，育龄妇女在孕期仍有感染风疹的风险，这证明了接种风疹疫苗的紧迫性。尽管本研究无法让我们确定风疹感染与感音神经性听力损失（SNHL）之间的因果关系，但在该国观察到14岁以下HL儿童组与风疹免疫力之间存在统计学上的显著关联。
