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.
Dagan
Ron
R
Pediatric Infectious Disease Unit, Soroka University Medical Center, Israel. rdagan@bgu.ac.il
Barkai
Galia
G
Givon-Lavi
Noga
N
Sharf
Amir Z
AZ
Vardy
Daniel
D
Cohen
Ted
T
Lipsitch
Marc
M
Greenberg
David
D
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D006801:Humans; D007557:Israel / Q000453:epidemiology / Q000208:ethnology; D016015:Logistic Models; D008826:Microbial Sensitivity Tests; D015999:Multivariate Analysis; D010033:Otitis Media / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D011446:Prospective Studies; D012621:Seasons; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000254:growth & development
D000900:Anti-Bacterial Agents