A significant increase in antimicrobial resistance among pneumococci causing invasive disease in New Zealand.
OBJECTIVE
To review the prevalence of antibiotic resistance and the distribution of capsular types among pneumococci from invasive disease in New Zealand from 1995 through 1997.


METHODS
Pneumococci isolated from sterile sites that were referred to the Institute of Environmental Science and Research (ESR) were tested for antimicrobial susceptibility and capsular type.


RESULTS
A total of 994 pneumococci were referred by 27 hospital and community laboratories. Almost 74% of the isolates were from patients aged < 15 years or > or = 60 years. The majority (88.2%) of the isolates were from blood cultures. In 1997, cefotaxime-resistant pneumococci were confirmed for the first time from invasive disease in New Zealand. Over the three years, 6.0% of the pneumococci were penicillin-nonsusceptible (MIC > or = 0.12 mg/L) and 3.7% were cefotaxime-nonsusceptible (MIC > or = 1 mg/L). Penicillin nonsusceptibility increased significantly from 1.9% in 1995 to 6.2% in 1996 and 9.9% in 1997. Similarly, cefotaxime nonsusceptibility increased from 0.6% in 1995 to 3.5% in 1996 and 6.9% in 1997. In descending order of frequency, the ten most common capsular types were 14, 19, 6, 9, 1, 4, 18, 7, 23, and 3. Eighty-three percent of the penicillin-nonsusceptible pneumococci belonged to serotypes 9V, 19A, 19F, 23F, 14 and 6B and 90% belonged to serotypes included in the 23-valent vaccine.


CONCLUSIONS
The increasing prevalence of antimicrobial resistance among pneumococci highlights the need for continued surveillance and for effective measures to prevent pneumococcal infections.
D000293:Adolescent; D000328:Adult; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009520:New Zealand; D010403:Penicillin Resistance; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification