[Varicella and parvovirus B19 immunity among pregnant women in Gijón, Spain]

Background: We aimed at determining the inmunological status regarding varicella and parvovirus B19 in pregnant women in Gijón, Spain, and its correlation with several clinical and epidemiological parameters.
Patients and method: Blood samples taken during the first trimester of pregnancy in the area of Gijón were analysed to determine the immunological status with respect to varicella and parvovirus B19. The study included 2 groups: 99 non-European (all tested for both varicella and parvovirus) and 2,188 Europeans (406 were randomly selected for varicella test and 287 for parvovirus test). All patients underwent a clinical-epidemiological survey.
Results: With regard to varicella, while 89% of pregnant women aged 14 to 35 years displayed immunity, this percentage reached 100% in those older than 35 years. Sensitivity was 73.8%, specificity 74.4%, positive predictive value 96.6% and negative predictive value was 22.6%. As for parvovirus B19, immunity was observed in 59.9% of Europeans and 67.7% of non-Europeans, without significant differences in the analysed parameters.
Conclusions: Susceptibility to infection by varicella among pregnant women younger than 36 years reaches 10% in Gijón. Clinical surveys are useful to avoid a pre-vaccination serological study in an already immune population. Just over one third of these pregnant women are susceptible to infection by parvovirus B19.