ORIGINAL ARTICLE Maternal and neonatal colonization in Bangladesh: prevalences, etiologies and risk factors GJ Chan 1 , JK Modak 2 , AA Mahmud 3 , AH Baqui 1 , RE Black 1 and SK Saha 2 OBJECTIVE: To estimate the prevalence of maternal colonizers in South Asia and their potential to colonize the umbilicus, an important precondition causing neonatal sepsis. STUDY DESIGN: We conducted a cross-sectional study at a maternity center in Dhaka with 1219 pregnant women and a subset of 152 newborns from 15 January to 31 October 2011. During labor, study paramedics collected vaginal swabs for bacterial culture and rectal swabs for Group B Streptococcus (GBS) testing. Community health workers collected neonatal umbilical swabs. Log-binomial regression models were used to estimate risk ratios. RESULT: In all, 454 women (37.2%, 95% confidence interval (CI) 34.5 to 40.0%) were colonized. The most common organisms isolated were Staphylococcus aureus, Non-GBS and GBS. A total of 94 women (7.7%, 95% CI 6.2 to 9.2%) were colonized with GBS. The risk of GBS umbilical colonization was higher (RR ¼ 12.98, 95% CI 3.97 to 42.64) among newborns of mothers with GBS colonization. CONCLUSION: Newborns of mothers colonized with GBS are at higher risk of developing umbilical colonization. Journal of Perinatology (2013) 33, 971–976; doi:10.1038/jp.2013.99; published online 29 August 2013 Keywords: maternal and neonatal colonization; etiologies; risk factors; Bangladesh INTRODUCTION Common colonizers of the maternal reproductive tract are associated with early-onset neonatal sepsis. 1 In Bangladesh during the first week of life, the incidence of clinical sepsis defined by the WHO (World Health Organization) Young Infants criteria for very severe disease 2 was 13.4% with a case fatality of 10.2%. 3 Studies in South Asia have examined the prevalence of maternal colonization, although there have been no studies in Bangladesh. 4–12 Maternal recto-vaginal colonization with Group B Streptococcus (GBS) is associated with early-onset GBS neonatal sepsis in the United States. 13,14 However, based on the limited data, it appears that Group B Streptococcal sepsis in newborns is uncommon in South Asia. 15 Not much is known about the prevalence of this organism in maternal recto-vaginal colonization, hereafter referred to as maternal colonization, in this setting. We know that newborns come in direct contact with bacterial flora in the vaginal canal and perineum during labor and delivery, in which case newborns may acquire infections through the mouth, the umbilicus or a crack in the skin. Furthermore, ascending infections from the mother to the fetus may occur during labor, when colonized organisms from the maternal perineum spread through the vaginal canal to the placenta, and into the once-sterile amniotic fluid. 16 The amniotic fluid, which bathes the neonate, also circulates through the neonate’s lungs and intestinal tract, which are potential hot spots for bacterial translocation. 13,17 We conducted this study to determine the prevalences and etiologies of maternal colonization, to understand the factors associated with maternal colonization, to estimate the risk of neonatal umbilical colonization associated with maternal coloni- zation and to describe neonatal umbilical colonization patterns during the first 7 days of life. METHODS To determine the prevalence of maternal colonization during labor and the characteristics associated with colonization, we conducted a cross- sectional study at a maternity center in Dhaka, Bangladesh with 1219 pregnant women from 15 January 2011 to 31 October 2011. We followed a subgroup of 152 newborns (newborns who delivered vaginally during the last 2 months of the study) to determine neonatal colonization patterns. Pregnant women presenting to the maternity center were screened for eligibility. Our inclusion criteria were women of 30 gestational weeks or later who planned to deliver at the maternity center. Women who presented with obstructed labor, hemorrhage, severe pre-eclampsia or fetal distress were excluded to facilitate their need for urgent care. Women who used antibiotics or steroids within 2 weeks of labor were also excluded from the study. Data collected Trained study paramedics collected vaginal and rectal swabs to measure maternal bacterial colonization during labor. Women with a positive bacterial vaginal culture (Staphylococcus aureus, Non-GBS species, GBS, Klebsiella pneumoniae, Escherichia coli, Staphylococcus, Pseudomonas or Acinetobacter) or positive GBS rectal culture were classified as colonized. Trained community health workers collected umbilical swabs from newborns within 12 h after birth and on the seventh day of life. Study staff interviewed the enrolled women to collect demographic data on maternal age; maternal education; antenatal care provider type; receipt of tetanus toxoid during antenatal care visits; type of housing materials for the women’s roof, wall and floor; source of water supply; sanitation facility; household number; household number under 5 years; number of rooms where household members sleep; neonatal sex; gestational age and birth weight. Month of birth was used to determine seasonality: summer (March to May), rainy (June to September) and winter (October to February). 1 Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; 2 Department of Microbiology, Bangladesh Institute of Child Health, Dhaka Shishu Hospital, Dhaka, Bangladesh and 3 Centre for Child and Adolescent Health, International Center for Diarrheal Disease Research Bangladesh, Dhaka, Bangladesh. Correspondence: Dr GJ Chan, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA. E-mail: grace.chan@childrens.harvard.edu Received 8 March 2013; revised 24 May 2013; accepted 8 July 2013; published online 29 August 2013 Journal of Perinatology (2013) 33, 971–976 & 2013 Nature America, Inc. All rights reserved 0743-8346/13 www.nature.com/jp