Ocorrência do estreptococo do grupo B em gestantes de baixo e alto risco obstétrico em Manaus/AM

Abstract

Streptococcus agalactiae or β-hemolytic Streptococcus Group B Lancefield is responsible for the occurrence of urinary tract infection, abortion, prematurity, chorioamnionitis, puerperal endometritis and early neonatal sepsis with a high mortality, especially among premature infants. The rate of colonization, the incidence of perinatal complications caused by EGB, the unquestioned effectiveness of intervention and the shortage of national works that reveal the Brazilian reality, justify this study that can generate and expand knowledge. In this sense, the objective of the present work was to investigate the colonization by Group B Streptococcus (GBS) of pregnant women who used the prenatal unity of the Balbina Mestrinho State Hospital Maternity, ManausAM, pregnant service unit of low risk obstetric and reference to high risk obstetric. To this end, 174 were studied pregnant women who were between the 35th and 37th weeks of pregnancy, confirmed by ultrasound or by the first day of last the period, met in the period from April to November 2012. During the prenatal query were collected demographic, socioeconomic information, previous obstetric history and sexual activity, as well as data from the actual pregnancy and vaginal and anorectal specimens were collected for bacteriological and molecular tests. Bacteriological examination was conducted the cultivation, which in the case of positivity to the streptococcus was submitted to taxonomic identification. The clinical samples with Streptococcus isolates were subjected to analyses of DNA detection by PCR. For the purposes of analysis of the results, as the proposed objectives, the colonization by EGB was determined when one or more of the diagnostic methods (cultivation, or PCR "in house") in any of the samples collected (vaginal and anorectal), provided a positivity to the EGB. For analysis of the quantitative variables were calculated the percentages of occurrence of events. For the analysis of sensitivity and specificity of diagnostic methods, as well as their positive and negative predictive values were used type 2 x 2 contingency tables. Were also calculated the respective confidence intervals at 95% (95%) and comparison of proportions, the test Chi Square (X2) Pearson, and the impossibility of implementation, we used the exact test Fisher. Among the results obtained are distinguished colonization rate by cultivation of 51.02% and 69.39% by PCR, with the latter provided a magnification of 18.37%. At the vagina cultivation method, such as collection site, it was more efficient than anorectal, although at 17.33% colonization have been obtained only in the anorectal samples. The characterization of high and low risk did not translate into a risk factor for colonization, although that was higher in high-risk pregnancies. In this series, the occurrence of urinary tract infections was statistically significant protective factor for colonization by EGB.