N Medugu1, K C Iregbu1, R E Parker2, J Plemmons2, P Singh2, L I Audu3, E Efetie4, H D Davies5, S D Manning6. 1. Department of Medical Microbiology and Parasitology, National Hospital Abuja, Abuja, Nigeria. 2. Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA. 3. Department of Paediatrics, National Hospital Abuja, Abuja, Nigeria. 4. Department of Obstetrics and Gynaecology, National Hospital Abuja, Abuja, Nigeria. 5. Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE, USA. 6. Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA. Electronic address: mannin71@msu.edu.
Abstract
OBJECTIVES: Because few studies have been conducted on group B Streptococcus (GBS) in Nigeria, we sought to estimate GBS colonization and transmission frequencies for 500 women and their newborns and identify risk factors for both outcomes. METHODS: GBS strains were characterized for antibiotic susceptibilities, capsule (cps) genotype, pilus island profile and multilocus sequence type (ST). RESULTS: In all, 171 (34.2%) mothers and 95 (19.0%) of their newborns were colonized with GBS; the vertical transmission rate was 48.5%. One newborn developed early-onset disease, yielding an incidence of 2.0 cases per 1000 live births (95% CI 0.50-7.30). Rectal maternal colonization (OR 26.6; 95% CI 13.69-51.58) and prolonged rupture of membranes (OR 4.2; 95% CI 1.03-17.17) were associated with neonatal colonization, whereas prolonged membrane rupture (OR 3.4; 95% CI 1.04-11.39) and young maternal age (OR 2.0; 95% CI 1.22-3.39) were associated with maternal colonization. Women reporting four or more intrapartum vaginal examinations (OR 6.1; 95% CI 3.41-10.93) and douching (OR 3.7; 95% CI 2.26-6.11) were also more likely to be colonized. Twelve STs were identified among 35 mother-baby pairs with evidence of transmission; strains of cpsV ST-19 (n = 9; 25.7%) and cpsIII ST-182 (n = 7; 20.0%) predominated. CONCLUSIONS: These data demonstrate high rates of colonization and transmission in a population that does not use antibiotics to prevent neonatal infections, a strategy that should be considered in the future.
OBJECTIVES: Because few studies have been conducted on group B Streptococcus (GBS) in Nigeria, we sought to estimate GBS colonization and transmission frequencies for 500 women and their newborns and identify risk factors for both outcomes. METHODS:GBS strains were characterized for antibiotic susceptibilities, capsule (cps) genotype, pilus island profile and multilocus sequence type (ST). RESULTS: In all, 171 (34.2%) mothers and 95 (19.0%) of their newborns were colonized with GBS; the vertical transmission rate was 48.5%. One newborn developed early-onset disease, yielding an incidence of 2.0 cases per 1000 live births (95% CI 0.50-7.30). Rectal maternal colonization (OR 26.6; 95% CI 13.69-51.58) and prolonged rupture of membranes (OR 4.2; 95% CI 1.03-17.17) were associated with neonatal colonization, whereas prolonged membrane rupture (OR 3.4; 95% CI 1.04-11.39) and young maternal age (OR 2.0; 95% CI 1.22-3.39) were associated with maternal colonization. Women reporting four or more intrapartum vaginal examinations (OR 6.1; 95% CI 3.41-10.93) and douching (OR 3.7; 95% CI 2.26-6.11) were also more likely to be colonized. Twelve STs were identified among 35 mother-baby pairs with evidence of transmission; strains of cpsV ST-19 (n = 9; 25.7%) and cpsIII ST-182 (n = 7; 20.0%) predominated. CONCLUSIONS: These data demonstrate high rates of colonization and transmission in a population that does not use antibiotics to prevent neonatal infections, a strategy that should be considered in the future.