613 Vaginal carriage of haemophilus influenzae in a non-pregnant reproductive-age population

Abstract

Haemophilus influenzae (Hi) is an emerging cause of early onset neonatal sepsis, but mechanisms of transmission are not well understood. We aimed to evaluate the prevalence of vaginal carriage of Hi in reproductive age women as a first step in assessing the role of peripartum vertical transmission in neonatal Hi disease. We performed a secondary analysis of stored vaginal lavage specimens from nonpregnant reproductive-age women. After extraction of bacterial genomic DNA, samples were tested for the presence of the gene encoding Haemophilus protein d (hpd) by quantitative real-time polymerase chain reaction (PCR) using validated primers and probe. PCR for the V3-V4 region of the 16S rRNA gene was performed as a positive control to assess sample quality. Samples with a cycle threshold (CT) value < 35 were defined as positive. Sanger sequencing confirmed the presence of hpd. We compared demographic and behavioral characteristics of women with and without vaginal carriage of Hi. Chi-square, Fisher’s exact, Mann-Whitney and t-test were used with p<0.05 set as the level of statistical significance. 415 samples were available for analysis. 315 (75.9%) had sufficient bacterial DNA present and were included in the analysis. Of these, 14 (4.4%) were positive for hpd. There were no demographic or behavioral differences between the women with Hi vaginal carriage and those without (Table 1). There was no difference in history of bacterial vaginosis, vaginal microbiome community state type, or presence of Group B Streptococcus (GBS) in women with and without vaginal carriage of Hi (Table 2). Haemophilus influenzae was present in vaginal lavage specimens of 4.4% of this cohort. Hi presence was unrelated to clinical or demographic characteristics, though the relatively small number of positive samples may have limited power to detect such differences. Further studies should assess for the presence of this possible perinatal pathogen in pregnant women and the rate of transmission to neonates.View Large Image Figure ViewerDownload Hi-res image Download (PPT)