prevalence of streptococcus pneumoniae carriage among healthy children in Yemen

ABSTRACT

Elevated nasopharyngeal carriage rates of Streptococcus pneumoniae is an important epidemiological factor in the incidence of clinical infections caused by this microorganism. This study was aimed to determine the carriage rate of S pneumoniae among healthy children in Sana'a, Yemen, the antibiotic susceptibility of the isolates, risk factors predisposing to the colonization by this microorganism, and serotype the isolates of S pneumoniae. From January 2006 to June 2006, 602 nasophanygeal swabs from children were collected. A standard questionnaire for collecting information about risk factors for predisposing S pneumoniae carriage was filled for each child. Carriage was defined by positive cultures for S pneumoniae. The isolates identified as S pneumoniaee based on colony morphology, Gram staining, type of haemolysis on blood agar, optchin sensitivity, bile solubility and serotyping was done by using commercial antisera. Sensitivity to antibiotic for S. pneumoniaee was determined using standard Kirby Bauer technique. During the six months of the study, 602 children met the study criteria for collection nasopharyngeal swabs and were free from current upper respiratory tract infections. They were 365 [60.6%] males and 237 [39.4%] females. The crude prevalence rate of S pneumoniae was 5.6%, the male specific prevalence rate was 6% and the female specific prevalence rate was 5.1%. There were significant effect between S pneumoniae carriage and nose bleeding [OR=2.5, CI=1-6, X2=4.7, pv=0.02] and with tonsillectomy [OR=2.3, CI=0.8-6.8, X2=2.9 pv=0.08], and hospital visit [OR=4.1, CI=1.9-8.6, X2=17.4, and pv> 0.0001.]. 30 of the 32 isolates S pneumoniae were distributed among six different serotypes. 9 [30%] belonged to serotype 5. Serotype 19 count 7 [23.3%], and serotypes 1, 15 and 22 count 6 [20%] and 4 [13%], 2 [6.6%] respectively. S pneumoniae isolated in the present study was tested against 11 different antimicrobial agents, 93.3% of the isolates were resistant to penicillin, 93.3% to gentamycin. 33.3% to chloramphenicol, and 20% to co-trimoxazol and 0% to erythromycin. Multi-resistant S pneumoniae was occurring; the most predominant drug resistance pattern was of three antibiotics [73.3%]. We conclude that, the rate of carriages and frequency of different types of S pneumoniae strains are similar to that reported in Middle East countries. However multi and single drugs resistance were higher than those reported in developed and developing countries