IMMUNITY COVERAGE AGAINST MEASLES, RUBELL A AND PAROTITIS VIRUSES IN A JUVENILE POPULATION IN LEON (SPAIN)

BACKGROUND: The immunity coverage, seroprevalence of IgG antibodies ag ainst infeCtiOn by measles, rubella and parotiditis viruses in a juven ile population (50.398 children) was studied. METHODS: Systematic samp ling was performed among children from 5-14 years of age who had under gone clinical analysis in the health care area of Leon. The hypothesis of sampling was the most unfavorable (p = q = 0,5) and the size of th e sample of 600 children. Information was collected on vaccination sta te, previous history of disease and place of residence. The presence/a bsence of IgG antibodies was investigated by a commercial immunoenzyma tic technique (EIA-Stat Measles, Mumps, Rubella, Whittaker Bioproducts (R), USA). RESULTS: Sixty percent of the children studied had IgG anti bodies against the three virus, 27 % against two and 9 % against only one with absence of antibodies against the three virus in 3 %. The ser oprotection observed was significantly higher (p < 0.05) for measles ( 87 % +/- 3 %) that for the other two diseases (rubella 80 % +/- 3 % an d parotiditis 77 % +/- 3 %). In the group of children with previous hi story of measles and parotiditis a higher percentage of antibodies (p < 0.01) was observed than in the group with previous history of vaccin ation (measles: 94 % versus 84 %, parotiditis: 90 % versus 75 %). No d ifference was observed in the case of rubella. CONCLUSIONS: Vaccinatio n is still the principal conditioning factor of the state of immunity of the juvenile population in Leon in relation with the diseases studi ed (measles, rubella, parotiditis). The place of residence (rural or u rban) did not condition different immunity coverage in the sample stud ied. The susceptibility of infection for some of these virus continues to be high: measles 13 %, rubella 20 % and parotiditis 23 %).