National (not including the territories) distribution of Clostridium difficile strain types among adults diagnosed with health care–associated C. difficile infection from 2009 to 2015*
| NAP strain | Year; no. (%) of patients | p value† | Trend‡ | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 2009 n = 379 | 2010 n = 352 | 2011 n = 384 | 2012 n = 388 | 2013 n = 412 | 2014 n = 385 | 2015 n = 390 | |||
| NAP1 | 178 (47.0) | 173 (49.1) | 142 (37.0) | 149 (38.4) | 148 (35.9) | 110 (28.6) | 111 (28.5) | < 0.001 | ↓ |
| NAP2 | 48 (12.7) | 16 (4.5) | 12 (3.1) | 14 (3.6) | 7 (1.7) | 5 (1.3) | 11 (2.8) | < 0.001 | ↓ |
| NAP3 | 0 (0.0) | 1 (0.3) | 0 (0.0) | 0 (0.0) | 1 (0.2) | 2 (0.5) | 0 (0.0) | Not tested | |
| NAP4 | 33 (8.7) | 39 (11.1) | 66 (17.2) | 44 (11.3) | 60 (14.6) | 69 (17.9) | 72 (18.5) | < 0.001 | ↑ |
| NAP5 | 1 (0.3) | 1 (0.3) | 1 (0.3) | 0 (0.0) | 1 (0.2) | 1 (0.3) | 0 (0.0) | Not tested | |
| NAP6 | 14 (3.7) | 10 (2.8) | 17 (4.4) | 22 (5.7) | 17 (4.1) | 18 (4.7) | 26 (6.7) | 0.03 | ↑ |
| NAP7 | 2 (0.5) | 12 (3.4) | 6 (1.6) | 6 (1.5) | 12 (2.9) | 11 (2.9) | 9 (2.3) | Not tested | |
| NAP8 | 5 (1.3) | 1 (0.3) | 4 (1.0) | 0 (0.0) | 1 (0.2) | 1 (0.3) | 1 (0.3) | Not tested | |
| NAP9 | 1 (0.3) | 3 (0.9) | 0 (0.0) | 1 (0.3) | 3 (0.7) | 2 (0.5) | 4 (1.0) | Not tested | |
| NAP10 | 9 (2.4) | 8 (2.3) | 16 (4.2) | 22 (5.7) | 19 (4.6) | 11 (2.9) | 14 (3.6) | Not tested | |
| NAP11 | 4 (1.1) | 6 (1.7) | 16 (4.2) | 23 (5.9) | 21 (5.1) | 52 (13.5) | 36 (9.2) | < 0.001 | ↑ |
| NAP12 | 5 (1.3) | 7 (2.0) | 14 (3.6) | 13 (3.4) | 10 (2.4) | 13 (3.4) | 9 (2.3) | Not tested | |