Influência da síndrome respiratória aguda grave no parto prematuro e baixo peso ao nascer no estado do Ceará : estudo INFLUEN-SA Brasil

Abstract

INTRODUCTION: Vaccination against influenza in pregnant women has been shown to reduce the number of premature births. Studies show that seasonal influenza in Ceará, a semiarid region in Brazil, occurs 2 to 3 months before the South and Southeast. Despite this, all of Brazil is subject to the same vaccination schedule. Therefore, pregnant women and their fetuses are inadequately protected against influenza in tropical and equatorial regions of Brazil. OBJECTIVE: We will test the hypothesis that the current national influenza vaccination policy in the state of Ceará, in the months of April and May, using the Southern Hemisphere vaccine, inadequately protects against the harmful maternal-fetal effects of low birth weight characterized by weight less than 2500 grams and prematurity characterized by birth with less than 37 weeks. METHODS: The study was designed to describe and analyze the historic series of severe acute respiratory infection cases registered in the state of Ceará, Brazil in the period from 2013 to 2018. These data are part of the INFLUEN-SA Brazil study. RESULTS: 3297 cases of SARS were recorded, of which 1600 were men (49%). There were 145 (4%) records of pregnant women, and only 134 had a confirmed diagnosis of SARS. Of these 134, 43 (32%) had SARS due to Influenza; 11 (8%) by other viruses or etiologic agents; and 80 (60%) with unspecified cause. Of the 43 confirmed records of influenza SARS, 18 (42%) were diagnosed as subtype A H1N1; 14 (33%) of them were subtyped as A H3 / seasonal; 3 (7%) were diagnosed as subtype A without subtype; 8 (19%) was subtyped as influenza B; and 3 (7%) were type A, but without subtype determination. Children with low birth weight and premature births were associated with SARS during pregnancy (N = 61), 2,879.1 ± 783.57 g (P = 0.019; Mann-Whitney test) and 16 (27%) (P = 0.025; Test Chi-Square) compared to control pregnancies (N = 122), 3,195.6 ± 572.61 g 10 (13%), respectively. In the evaluation of the unadjusted Odds Ratio, we observed that the increase in birth weight, the mother's education, the previous pregnancy and the number of weeks of gestation significantly reduced the risk of association with the group of children. On the other hand, the increase in preterm care and the absence of a doctor at birth increased the associated risk in the children from mothers with severe acute respiratory infection.