Early acquisition and high nasopharyngeal co-colonisation by <it>Streptococcus pneumoniae </it>and three respiratory pathogens amongst Gambian new-borns and infants

• Main Authors: Bottomley Christian, Barer Michael R, Kwambana Brenda A, Adegbola Richard A, Antonio Martin
• Format: Article
• Language: English
• Published: BMC 2011-06-01
• Series: BMC Infectious Diseases
• Subjects: Nasopharyngeal; PCR; respiratory pathogens
• Online Access: http://www.biomedcentral.com/1471-2334/11/175

<p>Abstract</p> <p>Background</p> <p>Although <it>Haemophilus influenzae type b </it>(Hib), <it>Staphylococcus aureus </it>and <it>Moraxella catarrhalis </it>are important causes of invasive and mucosal bacterial disease among children, co-carriage with <it>Streptococcus pneumoniae </it>during infancy has not been determined in West Africa.</p> <p>Methods</p> <p>Species specific PCR was applied to detect each microbe using purified genomic DNA from 498 nasopharyngeal (NP) swabs collected from 30 Gambian neonates every two weeks from 0 to 6 months and bi-monthly up to 12 months.</p> <p>Results</p> <p>All infants carried <it>S. pneumoniae, H. influenzae </it>and <it>M. catarrhalis </it>at several time points during infancy. S.<it>pneumoniae </it>co-colonized the infant nasopharynx with at least one other pathogen nine out of ten times. There was early colonization of the newborns and neonates, the average times to first detection were 5, 7, 3 and 14 weeks for <it>S. pneumoniae, H. influenzae, M. catarrhalis </it>and <it>S. aureus </it>respectively. The prevalence of <it>S. pneumoniae, H. influenzae </it>and <it>M. catarrhalis </it>increased among the neonates and exceeded 80% by 13, 15 and 23 weeks respectively. In contrast, the prevalence of <it>S. aureus </it>decreased from 50% among the newborns to 20% amongst nine-week old neonates. <it>S. pneumoniae </it>appeared to have a strong positive association with <it>H. influenzae </it>(OR 5.03; 95% CI 3.02, 8.39; p < 0.01) <it>and M. catarrhalis </it>(OR 2.20; 95% CI 1.29; p < 0.01) but it was negatively associated with <it>S. aureus </it>(OR 0.53; 95% CI 0.30, 0.94; p = 0.03).</p> <p>Conclusion</p> <p>This study shows early acquisition and high co-carriage of three important respiratory pathogens with <it>S. pneumoniae </it>in the nasopharyngeal mucosa among Gambian neonates and infants. This has important potential implications for the aetiology of respiratory polymicrobial infections, biofilm formation and vaccine strategies.</p>