[Study of nasopharyngeal colonization by Streptococcus pneumoniae and its antibiotics resistance in healthy children less than 2 years of age in the Marrakech region (Morocco)].

The healthy carrier of Streptococcus pneumoniae (S. pneumoniae) has been studied very little at the national level. With the emergence of antibiotic-resistant strains worldwide, and the emergence of new serotypes, an epidemiological survey is needed before the vaccine can be introduced in Morocco. This study's objective was to determine the prevalence and risk factors of pneumococcal nasopharyngeal carriage in children less than 2 years of age in the Marrakech region and to assess the antibiotic susceptibility of the isolates and the serotypes present prior to the introduction of the conjugate pneumococcal vaccine. From 2008 to 2009, 660 nasopharyngeal samples were collected on children under 2 years of age during scheduled visits to dispensaries for routine immunization in the Marrakech region. S. pneumoniae carriage was found in 45.8% of children. Of the 660 samples, 302 strains were isolated. The percentage of pneumococcal strains with reduced susceptibility to penicillin (PRSP) was 34.7%. Among these strains, 87.1% showed low-level resistance and 12.9% high-level resistance. Resistance to amoxicillin was found in 3.3% of the strains and no strains were resistant to cefotaxime. Several risk factors for pneumococcal carriage were identified, the main ones being breastfeeding less than 2 months, the presence of more than one sibling, passive smoking, and low socioeconomic level. The most frequent serotypes were 19F, 6, 14, 23, 18, and 9. The study of the vaccine serotype distribution showed that the theoretical vaccine coverage of the 7 valent vaccines was at 57% for all the isolates. These data show the frequency and the risk factors on nasopharyngeal carriage, and report the status of penicillin resistance of strains carrying children less than 2 years of age in the Marrakech region. The fluctuation of circulating serotypes at the national level underscores the importance of epidemiological surveillance carried out before the introduction of the heptavalent vaccine in Morocco.

Bouskraoui M ，Soraa N ，Zahlane K ，Arsalane L ，Doit C ，Mariani P ，Bingen E ... -  《-》

A cross-sectional survey of the prevalence of Streptococcus pneumoniae nasopharyngeal carriage in Belgian infants attending day care centres.

Malfroot A ，Verhaegen J ，Dubru JM ，Van Kerschaver E ，Leyman S ... -  《CLINICAL MICROBIOLOGY AND INFECTION》

[Nasopharyngeal carriage, antibiotic susceptibility and serotyping of Streptococcus pneumoniae and Haemophilus influenzae in children attending day care centers].

The aim of this study was to investigate the nasal carriage of Streptococcus pneumoniae (SP) and Haemophilus influenzae (HI) in children. Nasal samples were swabbed from children 3 months to 3 years of age, between December 2006 and April 2007, in 10 day-care centers in Dijon. Three hundred and eighty-five children, 22.7 ± 8.4 months, were included. All were vaccinated against H1 and 92% had received at least one dose of PCV7 vaccine. HI colonization (55%) was associated with young age and concomitant pneumococcal carriage (52.4% vs. 39%). Amoxicillin/clavulanate and cefotaxime resistance rates were 17% and 0.5%. Pneumococcal carriage (48%) was increased in case of prior hospitalization. The rate of PDSP, 50%, was increased in case of recent infection (91% vs. 81%), previous antibiotherapy (64% vs. 41%), and decreased if PCV7 was completed (40.2% vs. 61,8%). There was no resistance to amoxicillin. The erythromycin resistance rate was 50.5%. 15% of the strains were vaccinal serotypes. Thirty-six and 41% of the strains were related and non-related to vaccine serotypes. Twenty-four and 11.6% of the strains were serotypes 19A and 6A respectively. Over the last 10 years the global antibiotic resistance in children decreased for SP (22.9%) but nasal colonization remained stable due to the increase of some serotypes, such as 19A, most often resistant to antibiotics. The vaccine effectiveness against HI is optimal since no HIb serotypes were detected; resistance to betalactam is currently due equally to enzymatic mechanism and alteration of protein binding penicillin.

Chavanet P ，Atale A ，Mahy S ，Neuwirth C ，Varon E ，Dabernat H ，Portier H ... -  《-》

Nasopharyngeal carriage of Streptococcus pneumoniae in Taiwan before and after the introduction of a conjugate vaccine.

The heptavalent pneumococcal conjugate vaccine was introduced in Taiwan in October 2005. To evaluate the effect of the vaccination, we conducted an active, prospective, large-scale, long-term, and multicenter study to assess the prevalence of nasopharyngeal Streptococcus pneumoniae carriage in Taiwanese children. This study was performed at three tertiary teaching hospitals in northern, central, and southern Taiwan. Questionnaires provided demographic, family/household, and medical history data. Pneumococcal isolates were tested for their susceptibility to various antimicrobial agents and serotypes. In addition, influenza virus and Staphylococcus aureus were recovered from nasopharyngeal and nasal swabs, respectively. Between July 2005 and July 2008, 857 pneumococcal strains were recovered from a total of 6057 children aged >2 months to 5 years (carriage rate, 14.1%). Carriage rates differed geographically and varied with subject age. In a multivariate analysis, having at least one sibling, attendance at day-care centers, a history of otitis media, and history of upper respiratory tract infection in the previous 2 weeks were each associated with a higher risk of pneumococcal colonization of the nasopharynx. Staphylococcus aureus nasal colonization was inversely associated with nasopharyngeal carriage of pneumococcus (p=0.000; odds ratio [OR]: 0.48; 95% CI: 0.39-0.58). Daycare attendance was the only risk factor for carriage of penicillin non-susceptible S. pneumoniae (OR: 2.37; 95% CI: 1.22-4.88). Although vaccination rates rose from 2005 to 2008, no concomitant decrease in S. pneumoniae carriage occurred. The rate of penicillin resistance among S. pneumoniae isolates was 92.8% (using the meningitis criteria). The prevalence of cefotaxime resistance (21.6%) was higher than that of penicillin (6.9%; non-meningitis criteria). Slightly more than half (57.4%) of the isolates belonged to strains covered by the heptavalent pneumococcal conjugate vaccine when both vaccine and vaccine-related serotypes were included. Although vaccination rates rose from 2005 to 2008, no concomitant decrease occurred in S. pneumoniae carriage. Interaction between S. aureus and S. pneumoniae may influence vaccination efficacy. These findings provide baseline data to further compare pneumococcal carriage rates and antibiotic resistance patterns in Taiwanese children as vaccination rates continue to increase.

Kuo CY ，Hwang KP ，Hsieh YC ，Cheng CH ，Huang FL ，Shen YH ，Huang YC ，Chiu CH ，Chen PY ，Lin TY ... -  《-》

Impact of pneumococcal conjugate vaccine and of reduction of antibiotic use on nasopharyngeal carriage of nonsusceptible pneumococci in children with acute otitis media.

Cohen R ，Levy C ，de La Rocque F ，Gelbert N ，Wollner A ，Fritzell B ，Bonnet E ，Tetelboum R ，Varon E ... -  《PEDIATRIC INFECTIOUS DISEASE JOURNAL》