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.]