Oro-Pharyngeal Carriage And Antimicrobial Susceptibility Of Streptococcus Pneumoniae From Healthy Children

摘要

Objectives: Streptococcus pneumoniae causes acute otitis media, pneumonia, meningitis and bacteraemia. This study aimed to determine the prevalence of Streptococcus pneumoniae oropharyngeal carriage in healthy children and the antimicrobial susceptibility in a daycare nursery and a government-managed orphanage in Kuala Lumpur during 2010.Methods: Throat swabs were obtained from 36 children of daycare nursery (open community) and from 84 orphans from orphanage (closed community) those did not receive any pneumococcal vaccine. Children were between births to 6 years of age. Antibiotic susceptibility of isolated strains was determined using disk diffusion method and Etest? (minimum inhibitory concentration). Results: Overall prevalence of Streptococcus pneumoniae of the children was 1.7% (2 out of 120). Prevalence of the bacteria in open community was 5.6% (2 out of 36) and no positive cases were recorded in orphanage (closed community, (p=0.161). Prevalence was 15.4% (2 out of 13) in children aged below 2 years in the open community. There was no association was found to exist between Streptococcus pneumoniae carriage with age (p=0.432) and gender (p=0.418). Serotyping showed serotype 11F for one isolate, while the other was non-typable. Both isolates were susceptible to penicillin, azithromycin, ceftriaxone and vancomycin. The serotype 11F isolate was susceptible while the non-typable isolate was resistant to erythromycin.Conclusions: The results demonstrated low prevalence of Streptococcus pneumoniae in healthy children. These findings may complement other studies to explore further risk factors for colonisation, antimicrobial susceptibility and serotype distribution of Streptococcus pneumoniae to help for the planning of immunization strategies. Introduction Streptococcus pneumoniae (S. pneumoniae) causes acute otitis media, pneumonia, meningitis and bacteraemia. It is one of the major causes of respiratory tract disease in children, with mortality worldwide estimated at 700,000 to 1 million annually in children aged less than 5 years.1 The incidence of invasive pneumococcal bacteraemia in children less than 5 years in Malaysia was estimated at least 750 cases annually with 2% mortality.2 Hospital-based studies on pneumococcal infection in Malaysia have shown pneumonia to be the most common clinical presentation, with the highest morbidity and mortality in children below two years of age.3,4,5 Colonisation of the upper respiratory tract is the prerequisite for the development of infection and invasive pneumococcal disease. Epidemiology studies in western countries had shown a significant correlation between invasive pneumococcal disease in children with identification of asymptomatic carrier of S. pneumoniae in the pharynx.6,7 During pneumococcal outbreaks in day care centres, the corresponding pathogen strain was found up to 86% of the healthy children in the same centre.6 The link between S. pneumoniae colonisation and pneumococcal disease were reviewed by Bogaert et al,8 with the peak incidence of colonisation found during the first three years of life.Recent years resistance of S. pneumoniae strains in this country has been increased due to frequent use of antibiotics especially penicillin3,4,9,10,11, and macrolides.12,13 High prevalence of antibiotic-resistant strains was found among healthy young children.14,15 The aim of this study was to determine the prevalence and antimicrobial susceptibility of S. pneumoniae isolates from the oropharynx of healthy children of day-care nursery and orphanage. Materials and Methods This cross-sectional study was conducted in the daycare nursery of Universiti Kebangsaan Malaysia Medical Centre (UKMMC) and Tengku Budriah Orphanage, Jalan Yaakob Latif, Kuala Lumpur in April 2010. This research was approved by the Research and Ethical Committee of UKMMC. Informed consent was taken from parents or guardians of each child to take part in this study. The Director of the Department of Social