Decreased Streptococcus pneumoniae susceptibility to oral antibiotics among children in rural Vietnam: a community study

Background: Streptococcus pneumoniae is the most significant bacterial cause of community-acquired pneumonia among children under five years worldwide. Updated resistance information of S. pneumoniae among children is essential to adjust the recommendations for empirical treatment of community-acquired pneumonia, which will have immense implications for local and global health. This study investigated the prevalence of antibiotic resistance in isolated strains of S. pneumoniae and relationship with antibiotic use and demographic factors of children under five in rural Vietnam in 2007. Methods: In Bavi district, 847 children 6 to 60 months were selected from 847 households. The main child-caregivers in the households were interviewed weekly using structured questionnaires to collect information of daily illness symptoms and drug use for the selected child over a four-week period (from March through June 2007). In the 3(rd) week, the children were invited for a clinical examination and to collect nasopharyngeal samples for S. pneumoniae identification. Etest and disk diffusion were used to test antibiotic susceptibility. Results: Of 818 participating children, 258 (32%) had ongoing respiratory infections, 421 (52%) carried S. pneumoniae, and 477 (58%) had used antibiotics within the previous three weeks. Of the 421 isolates, 95% were resistant to at least one antibiotic (401/421). Resistance to co-trimoxazole, tetracycline, phenoxymethylpenicillin, erythromycin and ciprofloxacin was 78%, 75%, 75%, 70% and 28%, respectively. Low resistance was noted for amoxicillin (4%), benzylpenicillin (4%), and cefotaxime (2%). The intermediate resistance to amoxicillin was 32%. Multidrug-resistance was seen in 60%. The most common pattern was co-resistance to co-trimoxazole, tetracycline and erythromycin. The proportion of children carrying resistant bacteria was higher among the children who had used antibiotics in the previous three weeks. Conclusions: Resistance to commonly used antibiotics and multidrug-resistance of S. pneumoniae in the area is remarkably high. High-dose amoxicillin is the only investigated oral antibiotic that can possibly be used for treatment of community-acquired pneumococcal infections. Strategies to promote appropriate prescribing and dispensing of effective antibiotics should be immediately implemented for the benefit of local and global health.