Streptococcus pneumoniae antibiotic resistance in Northern Territory children in day care

Background: There is evidence that the rapid rise in Streptococcus pneumoniae (SP) antimicrobial resistance seen in other countries may have commenced in Australia. Streptococcus pneumoniae carriage and resistance levels are described for urban Northern Territory children in day care. Methods: A prospective cohort study was conducted of 250 children in nine Darwin day care centres between 24 March and 15 September 1997. Each fortnight nasopharyngeal swabs were collected from children, and parents were interviewed about medications administered. Results: Streptococcus pneumoniae was detected in 52% (1028/1974) of all nasopharyngeal swabs. Streptococcus pneumoniae was isolated from 92% (231/250) of children at some time. Penicillin resistance was found in 30% (312/1028) of isolates using a screening test. Of these, 256 (82%) had resistance confirmed by E-test. Two hundred and one (20% of all isolates) had intermediate penicillin resistance and 55 (5% of all isolates) had high level resistance. Ceftriaxone resistance was found in 19% of children's first isolates. Resistance to other antibiotics was also common: co-trimoxazole 45%, erythromycin 17%, tetracycline 17% and chloramphenicol 13%. A total of 17% (172/1028) of the isolates were multiresistant. The average fortnightly proportion of children given antibiotics was 16% (405/2476). Conclusions: Levels of intermediate and high level penicillin resistance in this day care population are consistent with previous data from the Northern Territory, and considerably higher than the rest of Australia. The national trend of increasing pencillin resistance is likely to continue.