Changes in rates of antibiotic resistance in invasive isolates
of S. pneumoniae
To date, there are 3582 cases in the database, with
new cases accumulating at a rate of 65-70 per month. Rates of
antibiotic resistance over time are shown in Figure 1. Antibiotic
resistance is increasing for all classes of antibiotics other
than trimethoprim sulfamethoxazole. Most significantly, while
resistance to penicillin appeared to be stabilizing between 1998
and 2001, it has recently started to increase again. Macrolide
resistance has increased from 4% to 18% in association with the
increasing use of newer macrolides.
In the overall analysis, resistance to flouroquinolones
remains low, although concentrated in older adults. However, as
with the trends currently seen across the country, resistance
to flouroquinolones are decreasing in the last two years of surveillance.
Although hypothesized that this may be due to the use of the newer
drugs in the class, a mechanism for this observed trend has yet
to be determined.
Figure 1: Rate of antimicrobial resistance in S. pneumoniae
Figure 2: Fluoroquinolone-Resistant Pneumococci in Adults
[Click here to access
PowerPoint file containing the above graphs.]