Prevalence and risk factors for nasopharyngeal carriage of Streptococcus pneumoniae among adolescents.

Data on the prevalence of pneumococcal 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, P=0.001], being male (OR 1.78, 95 % CI 1.11-2.85, P=0.02), exposure to passive smoke in the household (OR 1.76, 95 % CI 1.10-2.79, P=0.02), 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, P=0.03). The estimated probability of pneumococcal colonization decreased with age (chi(2) for trend=8.52, P=0.003). 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.

Antimicrobial resistance and serotypes of nasopharyngeal strains of Streptococcus pneumoniae in Brazilian adolescents.

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.

Community acquired Pneumonia among pediatric outpatients in Salvador, northeast Brazil, with emphasis on the role of pneumococcus

Pneumonia is one of the leading causes of hospitalization and death among children in developing counties,, and mortality due to pneumoniae has been associated with S. pneumoniae infection. This investigation was designed to describe the antimicrobial susceptibility and serotype patterns of pneumococcal strains recovered from the blood of children with community-acquired pneumonia (CAP) and to acess the clinical findings of pneumococcal bacteremic patients with pneumonia. In a 26 month prospective study, blood cultures were obtained as often as possible from children(<16 years of age) diagnosed with CAP in two emergency rooms. Antimicrobial drug susceptibility tests and serotyping were performed when pneumococcus was identified. We studied 3,431 cases and cultured blood samples from 65.5 percent of those. Pneumococcus was recovered from 0.8 percent of the blood samples. The differences in age, somnolence, wheezing and hospitalization among children with and without pneumococcal bacteremia were statistically significant. Pneumococcal bacteremia was age-related (mean 1.63 +1.55; median 0.92) and associated with somnolence and hospitalization among children with CAP. One strain was recovered from pleural fluid. Penicillin resistance was detected in 21.0 percent(4/19) of the strains at an intermediate level, whereas 63.0 percent of the strains were resistant to trimethoprim-sulfamethoxazole. The most common serotypes were 14 and 6B, and these serotypes included the resistant strains. Eight of our 18 isolates from blood were of types included in the heptavalent conjugate pneumococcal vaccine, recently licensed in the USA.