The association between antibiotic use in the community and nasopharyngeal carriage of antibiotic-resistant Streptococcus pneumoniae in Bedouin children.

BACKGROUND: The objective of the study was to evaluate whether the increase in antibiotic-resistant Streptococcus pneumoniae carriage was associated with antibiotic use in the community in children in Southern Israel. METHODS: All the prescriptions given to Bedouin children <5 years old enlisted in 2 sentinel primary pediatric clinics treating approximately 20% of the Bedouin pediatric population of this age range were recorded, from 1998 to 2005. Nasopharyngeal pneumococcal isolates obtained during the same period from healthy children <5 years old were collected and antibiotic susceptibility was determined. RESULTS: A total of 1488 of 1927 (77.7%) cultures were positive for S. pneumoniae. The proportion of S. pneumoniae with penicillin minimal inhibitory concentration > or = 1.0 microg/mL increased from 8% to 21% (P < 0.01); resistance to clindamycin from 9% to 22%; resistance to erythromycin from 13% to 30%; resistance to tetracycline from 13% to 31%; and multidrug resistance from 16% to 30%. The total annual antibiotic prescription rates decreased by 19%, from 3867 to 3191 prescriptions per 1000 children (P < 0.001). This was mainly the result of a reduction in amoxicillin +/- clavulanate prescriptions (from 3046 to 2582; P < 0.001). Oral cephalosporin, erythromycin and penicillin prescription rates decreased significantly as well (P < 0.001) whereas azithromycin prescription rates increased significantly (P < 0.001). CONCLUSIONS: We suggest that the increased carriage of S. pneumoniae resistant to multiple antibiotics is possibly associated to the increased azithromycin consumption. Reduction of total antibiotic use may not be sufficient as long as antibiotics with high potential to promote multidrug resistance, given their pharmacokinetics and pharmacodynamics characteristics, are widely used.

Seasonality of antibiotic-resistant streptococcus pneumoniae that causes acute otitis media: a clue for an antibiotic-restriction policy?

BACKGROUND: It is unclear whether reducing antibiotic prescriptions can reduce rates of resistance once resistance becomes prevalent. We attempted to determine whether reduced antibiotic consumption, which is observed yearly in children during the warm season, is associated with a reduction in antibiotic resistance in pneumococcal acute otitis media (AOM). METHODS: Antibiotic prescriptions and resistance were measured prospectively during 1999-2003 in 2 demographically distinct populations: Jewish and Bedouin children (aged <5 years) in southern Israel. Associations were assessed using seasonally clustered logistic regression models. RESULTS: The study included 236,466 prescriptions and 3609 pneumococcal isolates. Prescription rates decreased during the warm months by 36% and 15% in Jewish and Bedouin children, respectively (P < .001 for the season). Among Jewish children, higher resistance rates were observed during the cold than the warm months (P < .001 for each antibiotic). This difference remained significant after adjustment for age, ethnic group, study year, history of antibiotic use, and serotype. The difference was not observed in Bedouin children. CONCLUSIONS: Rapid seasonal decline in resistant AOM-causing pneumococci occurred only in Jewish children, among whom a marked prescribing seasonality was noted, and not in Bedouin children, among whom prescription was less seasonal. The rapid seasonal decrease in resistance associated with markedly reduced antibiotic use suggests that drug-resistant pneumococci may pay a fitness cost.