Data on the prevalence of pneumooccal nasopharyngeal carriage and its risk factors among adolescents are scarce. The aim of this study was to provide such information. A cross-sectional, population-based prospective study was conducted. Participants were 1013 adolescents (age range 10-19 years) randomly recruited in 22 public schools. Those schools were randomly chosen among 307 public schools from 11 Sanitary Districts of Salvador, Brazil. Nasopharyngeal samples were assessed by standard procedures to recover and identify Streptococcus pneumoniae. Data on potential risk factors were gathered by confidential interview based on a standardized questionnaire. Pneumococci were recovered from 8.2 % [83/1013, 95 % confidence interval (CI) 6.6-10.0]. By stepwise logistic regression, pneumococcal colonization was independently associated with younger age [odds ratio (OR) 0.85, 95 % CI 0.77-0.94, P50.001], being male (OR 1.78, 95 % CI 1.11-2.85, P50.02), exposure to passive smoke in the household (OR 1.76, 95 % CI 1.10-2.79, P50.02), having an upper respiratory infection during recruitment (OR 2.67, 95 % CI 1.67-4.28, P,0.001) and having a history involving an episode of acute asthma during the last year (OR 2.89, 95 % CI 1.18-7.08, P50.03). The estimated probability of pneumococcal colonization decreased with age (x 2 for trend58.52, P50.003). These findings provide tools for increasing the use of prevention strategies for pneumococcal diseases, such as pneumococcal vaccination among asthmatic patients and public health measures to stop smoking. INTRODUCTIONThe incidence of invasive pneumococcal disease is highest among children and the elderly (CDC, 1997). However, respiratory infections are an important cause of morbidity and mortality among adolescents (Benguigui, 1992). Among children, Streptococcus pneumoniae is a major causative agent of such infections (Heiskanen-Kosma et al., 1998). The nasopharynx is known to be the main ecological reservoir of S. pneumoniae, from where it can give rise to disease after extending to other areas of the respiratory tract or penetrating normally sterile body fluids (Austrian, 1986). Although nasopharyngeal isolates are not useful for predicting the causative agent of invasive disease in individuals, they reflect epidemiological aspects of pneumococcal disease in the community (Brueggemann et al., 2003).Studies conducted over the last decades have gradually revealed the connection between pneumococcal carriage, and mucosal and invasive infections caused by the (Inostroza et al., 1998). Thus, we estimated that 900 participants would be sufficient to detect a prevalence and the respective 95 % confidence interval (CI) of nasopharyngeal colonization ranging from 8-12 % (point prevalence510 %, 2 % error). We assumed a 12 % refusal to participate, so the sample size was established as 1000 participants. Demographic, clinical and epidemiological data were collected by a standardized questionnaire.Bacteriological data. Two trained biochemists collected nasopharyngeal specimens by rotat...

Surveillance of nasopharyngeal pneumococcus has proven to be a valuable tool for the monitoring of antibiotic resistance. We reviewed the latest information on colonization rate and penicillin resistance by making a MEDLINE search, using the terms "nasopharyngeal carriage" and "Streptococcus pneumoniae". Out of 225 articles found, data from 109 recent publications (89% from 1996-2003) were analyzed. Data were reported from 41 countries of six continents. Individuals under the age of five (64.3%) or 10 years (85.7%) were enrolled, including children attending day-care centers (32.1%) or orphanages (3.6%), and healthy individuals (78.6%) or sick patients (43.6%); biological samples were collected mainly by nasopharyngeal swabs (89.3%). The highest colonization rates were reported from Africa (85-87.2%), where several authors did not find high rates of penicillin resistance. On the other hand, studies conducted in North and Central America reported high-level penicillin resistance at rates of approximately 20-30%. Great variation in the rates of pneumococcal colonization and penicillin resistance were observed within regions or continents. There were also considerable differences in similar populations located in different areas of the same country. Data regarding pneumococcal colonization and penicillin resistance are not available from most countries. We also examined the use of antibiotics to treat pneumococcal infections.

The aim of this study was to describe the frequency of antimicrobial-resistance and serotypes of nasopharyngeal pneumococcal isolates from adolescents. Clinical data and nasopharyngeal specimens for culture were collected from 1,013 adolescents as a part of a population-based study. A total of 83 isolates of Streptococcus pneumoniae were identified (8.2%). Seventy-four of the 83 isolates were serotyped. The median age of the 83 adolescents colonized by pneumococci was 14 years (mean 14 +/- 2.2 yrs); 55.4% were males. Intermediate resistance to penicillin was detected in 7.2% (6/83). No strain showed high resistance to penicillin. All isolates were susceptible to clindamycin, chloramphenicol, rifampin, and vancomycin; 37.3%, 18.1%, and 4.8% were resistant to trimethoprim-sulfamethoxazole, tetracycline, and erythromycin, respectively. The most frequent serotypes (5-10% of strains each) were 6B, 6A, 23F, and 18C among 28 serotypes/serogroups identified; 18.9% of the strains were nontypeable (NT). Intermediate resistance to penicillin was detected in serotypes 6B, 14, and NT. The rate of resistance to penicillin of nasopharyngeal isolates is low considering data from other studies about invasive strains recovered from children in Brazil. Serotype patterns are similar, except for type 14, which was unusually infrequent.