BACKGROUND: The first step in a bacterial disease is the establishment of nasopharyngeal carriage. METHODS: We conducted a birth cohort study to identify factors associated with colonization in healthy children and evaluate the serotype distributions and resistances of Streptococcus pneumoniae/Haemophilus influenzae. Nasopharyngeal cultures were obtained from 349 subjects at 5 time points coinciding with health checkups (4, 7, 10, 18 and 36 months). RESULTS: A total of 551 S. pneumoniae (penicillin resistance rate: 46.3%) and 301 H. influenzae (ampicillin resistance rate: 44.5%) isolates were obtained from 1654 samples. In this study, 47.5% and 60.9% of S. pneumoniae isolates were included in the serotypes of 7- and 13-valent pneumococcal conjugate vaccines, respectively. Analyzing by Cox proportional hazards models, cohabiting older sibling(s) attending day-care (hazard ratios: 2.064-3.518, P < 0.001) and an early start of day-care attendance by the subjects themselves (2.259-2.439, P < 0.001) were associated with a higher risk of early colonization regardless of their susceptibility. Recent exposure to antimicrobials was also significantly associated with increased risk of colonization (odds ratios: 2.032-2.999, P < 0.001) but not with resistance rates. This data indicated that introduction of appropriate antimicrobial usage in areas of overuse of antimicrobials could contribute to lower colonization of S. pneumoniae/H. influenzae, resulting in a decrease in the absolute number of resistant isolates. CONCLUSIONS: Strategies to control transmission at day-care centers or from older sibling(s) as well as appropriate use of antimicrobials are essential for reducing colonization and the absolute number of resistant isolates.
BACKGROUND: The first step in a bacterial disease is the establishment of nasopharyngeal carriage. METHODS: We conducted a birth cohort study to identify factors associated with colonization in healthy children and evaluate the serotype distributions and resistances of Streptococcus pneumoniae/Haemophilus influenzae. Nasopharyngeal cultures were obtained from 349 subjects at 5 time points coinciding with health checkups (4, 7, 10, 18 and 36 months). RESULTS: A total of 551 S. pneumoniae (penicillin resistance rate: 46.3%) and 301 H. influenzae (ampicillin resistance rate: 44.5%) isolates were obtained from 1654 samples. In this study, 47.5% and 60.9% of S. pneumoniae isolates were included in the serotypes of 7- and 13-valent pneumococcal conjugate vaccines, respectively. Analyzing by Cox proportional hazards models, cohabiting older sibling(s) attending day-care (hazard ratios: 2.064-3.518, P < 0.001) and an early start of day-care attendance by the subjects themselves (2.259-2.439, P < 0.001) were associated with a higher risk of early colonization regardless of their susceptibility. Recent exposure to antimicrobials was also significantly associated with increased risk of colonization (odds ratios: 2.032-2.999, P < 0.001) but not with resistance rates. This data indicated that introduction of appropriate antimicrobial usage in areas of overuse of antimicrobials could contribute to lower colonization of S. pneumoniae/H. influenzae, resulting in a decrease in the absolute number of resistant isolates. CONCLUSIONS: Strategies to control transmission at day-care centers or from older sibling(s) as well as appropriate use of antimicrobials are essential for reducing colonization and the absolute number of resistant isolates.
Authors: Miwako Kobayashi; Laura M Conklin; Godfrey Bigogo; Geofrey Jagero; Lee Hampton; Katherine E Fleming-Dutra; Muthoni Junghae; Maria da Gloria Carvalho; Fabiana Pimenta; Bernard Beall; Thomas Taylor; Kayla F Laserson; John Vulule; Chris Van Beneden; Lindsay Kim; Daniel R Feikin; Cynthia G Whitney; Robert F Breiman Journal: BMC Infect Dis Date: 2017-01-05 Impact factor: 3.090
Authors: Amanda Jane Leach; Christine Wigger; Ross Andrews; Mark Chatfield; Heidi Smith-Vaughan; Peter Stanley Morris Journal: BMC Pediatr Date: 2014-08-11 Impact factor: 2.125