Valenzuela M T, Vega J, Leal I, Vicente M, Young V, Vera L, Fasce R, Ramírez E
Organización Panamericana de la Salud, Instituto de Salud Pública, Santiago de Chile, Chile.
Rev Med Chil. 1999 Mar;127(3):359-65.
Results of clinical and epidemiological studies confirm that no cases of measles have occurred in Chile since 1993. However, since covering of vaccination programs do not exceed 95%, an immunological surveillance for this disease is warranted.
To know the immune status against measles and rubella in the Chilean population.
A serological census of a representative sample of communities with high (90% or more) or low immunization coverings was performed. Four sub samples along the country were selected: 122 children aged 18 months of age (stratum A), 1,276 children attending the first years of basic school (stratum B), 899 teenagers in their last high school year (stratum C) and 399 women attending a family planning clinic (stratum D). IgG antibodies against measles and rubella were measured using ELISA and hemagglutination inhibition techniques, respectively.
Antibodies against measles and rubella were found in 96% and 94% of study subjects. No differences in these titres were found between different strata or communities with high or low vaccination covering. There is a high percentage of positive antibodies against measles among children of 18 months of age and a high percentage of antibodies against rubella among teenagers and women in family planning. Only 3% of the sample had not received any vaccine at the moment of the study.
The high prevalence of antibodies against rubella allows to conclude that it is not necessary to consider this antigen in the next vaccination campaign. Due to the high prevalence of antibodies against measles, only the population older than 20 years old should be affected by the disease if this virus enters the country.
临床和流行病学研究结果证实，自1993年以来智利未出现过麻疹病例。然而，由于疫苗接种计划的覆盖率未超过95%，因此有必要对该疾病进行免疫监测。
了解智利人群对麻疹和风疹的免疫状况。
对免疫覆盖率高（90%或更高）或低的社区的代表性样本进行血清学普查。在全国范围内选取了四个子样本：122名18个月大的儿童（A层）、1276名接受小学低年级教育的儿童（B层）、899名高中最后一年的青少年（C层）和399名在计划生育诊所就诊的女性（D层）。分别使用酶联免疫吸附测定法（ELISA）和血凝抑制技术检测针对麻疹和风疹的IgG抗体。
在96%的研究对象中发现了针对麻疹的抗体，在94%的研究对象中发现了针对风疹的抗体。在不同阶层或疫苗接种覆盖率高或低的社区之间，这些抗体滴度没有差异。18个月大的儿童中针对麻疹的抗体阳性率很高，青少年和计划生育诊所的女性中针对风疹的抗体阳性率很高。在研究时，只有3%的样本未接种过任何疫苗。
风疹抗体的高流行率表明在下一次疫苗接种活动中无需考虑该抗原。由于麻疹抗体的高流行率，如果该病毒进入该国，只有20岁以上的人群会感染该疾病。
