Table 2.
Percentages of CRE Infections Treated With an intravenous Polymyxin or a New Anti-CRE Agent
| CRE Infections | CRE Infections Expected to Be Treated With New Agentb | ||||
|---|---|---|---|---|---|
| Estimates of Numbers of CRE Infectionsa | Number | Treated With Polymyxin, %c | Treated With New Agent, %d | Number | Treated With New Agent, %d |
| Middle estimate | 34 000 | 28% | 23% | 22 950 | 35% |
| High estimate | 49 000 | 19%e | 16%e | 34 055 | 23% |
| Low estimate | 19 000 | 50%f | 42%f | 12 825 | 62% |
Abbreviations: CRE, carbapenem-resistant Enterobacteriaceae.
aIn our primary calculation of percentages of CRE infections treated with a polymyxin or a new anti-CRE agent, we used the middle-range DIRECT-AB estimate of 34 000 CRE infections per year in the United States [2]. To define ranges of CRE infections treated by various agents, we used high- and low-range DIRECT-AB estimates of 49 000 and 19 000 CRE infections per year, respectively.
bNew anti-CRE agents of interest were ceftazidme-avibactam, meropenem-vaborbactam, and plazomcin. The maximum number of CRE that would be anticipated to be treated with a new anti-CRE agent was defined as follows: (total number of CRE infections) × 0.675.
cPercentages shown in this column were calculated using a numerator of 9437 CRE infections that were estimated to be treated with an intravenous polymyxin from February 2018 to January 2019 (9437/34 000 = 28%, 9437/49 000 = 19%, 9437/19 000 = 50%).
dPercentages shown in this column were calculated using a numerator of 7941 CRE infections that were estimated to be treated with ceftazidime-avibactam, meropenem-vaborbactam, or plazomicin from February 2018 to January 2019.
eThese data signify that as few as 19% and 16% of CRE infections in the United States from February 2018 to January 2019 were treated with an intravenous polymyxin or new agent, respectively. Percentages define the lower limit of the range, and they are not designed to add up to 100%.
fThese data signify that as many as 50% and 42% of CRE infections in the United States from February 2018 to January 2019 were treated with an intravenous polymyxin or new agent, respectively. Percentages define the upper limit of the range, and they are not designed to add up to 100%.