TABLE 1.
Serotype distribution of 1845 Streptococcus pneumoniae isolates from the biennial Taiwan Surveillance of Antimicrobial Resistance (TSAR) program, 2002–2018.
| Serotype |
No. (%) of isolates |
|||||||||
| 2002 | 2004 | 2006 | 2008 | 2010 | 2012 | 2014 | 2016 | 2018 | Total | |
| n = 320 | n = 316 | n = 302 | n = 289 | n = 196 | n = 116 | n = 118 | n = 99 | n = 89 | n = 1845 | |
| PCV7 | ||||||||||
| 19F | 58 (18.1) | 66 (20.9) | 56 (18.5) | 62 (21.4) | 31 (15.8) | 19 (16.4) | 24 (20.3) | 10 (10.1) | 11 (12.4) | 337 (18.3) |
| 23F | 88 (27.5) | 65 (20.6) | 54 (17.9) | 40 (13.8) | 27 (13.8) | 9 (7.8) | 5 (4.2) | 3 (3.0) | 1 (1.1) | 292 (15.8) |
| 6B | 31 (9.7) | 46 (14.6) | 45 (14.9) | 41 (14.2) | 30 (15.3) | 8 (6.9) | 5 (4.2) | 2 (2.0) | 2 (2.2) | 210 (11.4) |
| 14 | 28 (8.8) | 36 (11.4) | 29 (9.6) | 21 (7.3) | 12 (6.1) | 5 (4.3) | 2 (1.7) | 3 (3.0) | 0 (0) | 136 (7.4) |
| 9V | 8 (2.5) | 9 (2.8) | 7 (2.3) | 14 (4.8) | 3 (1.5) | 1 (0.9) | 0 (0) | 0 (0) | 0 (0) | 42 (2.2) |
| 4 | 1 (0.3) | 0 (0) | 2 (0.7) | 1 (0.3) | 1 (0.5) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 5 (0.3) |
| PCV7 total | 214 (66.9) | 222 (70.3) | 193 (63.9) | 179 (61.9) | 104 (53.1) | 42 (36.2) | 36 (30.5) | 18 (18.2) | 14 (15.7) | 1022 (55.4) |
| PCV13 | ||||||||||
| 3 | 28 (8.8) | 18 (5.7) | 18 (6.0) | 19 (6.6) | 19 (9.7) | 13 (11.2) | 6 (5.1) | 5 (5.1) | 3 (3.4) | 129 (6.9) |
| 5 | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (0.5) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (0.05) |
| 19A | 0 (0) | 1 (0.3) | 2 (0.7) | 9 (3.1) | 21 (10.7) | 24 (20.7) | 23 (19.5) | 13 (13.1) | 9 (10.1) | 102 (5.5) |
| 6A | 2 (0.6) | 5 (1.6) | 10 (3.3) | 7 (2.4) | 8 (4.1) | 2 (1.7) | 12 (10.1) | 8(8.1)c | 2 (2.2) | 56 (3.0) |
| PCV13 total | 244 (76.3) | 246 (77.8) | 223 (73.8) | 214 (74.0) | 153 (78.1) | 81 (69.8) | 77 (65.2) | 44 (44.4) | 28 (31.5) | 1310 (71.0) |
| PPV23 | ||||||||||
| 15B | 3 (0.9) | 11 (3.5) | 9 (3.0) | 13 (4.5) | 8 (4.1) | 7 (6.0) | 3 (2.5) | 3 (3.0) | 7 (7.9) | 64 (3.5) |
| 11A | 10 (3.1) | 4 (1.3) | 8 (2.6) | 7 (2.4) | 1 (0.5) | 1 (0.9) | 1 (0.8) | 7 (7.1) | 5 (5.6) | 44 (2.4) |
| 10A | 1 (0.3) | 4 (1.3) | 4 (1.3) | 2 (0.7) | 0 (0) | 1 (0.9) | 1 (0.8) | 1 (1.0) | 0 (0) | 14 (0.7) |
| 20 | 4 (1.3) | 3 (0.9) | 0 (0) | 1 (0.3) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 8 (0.4) |
| 22F/Aa | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 2 (1.0) | 0 (0) | 1 (0.8) | 0 (0) | 0 (0) | 3 (0.2) |
| 17F | 1 (0.3) | 0 (0) | 2 (0.7) | 2 (0.7) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 5 (0.3) |
| PPV23-onlyb | 19 (5.9) | 22 (7.0) | 23 (7.6) | 25 (8.7) | 11 (5.6) | 9 (7.8) | 6 (5.1) | 11 (11.1) | 12 (13.4) | 138 (7.5) |
| PPV23 total | 261 (81.6) | 263 (83.2) | 236 (78.1) | 232 (80.3) | 156 (79.6) | 88 (75.9) | 71 (60.2) | 47 (47.5) | 38 (42.7) | 1392 (75.4) |
| NVT (non-vaccine type) | ||||||||||
| 15A | 1 (0.3) | 4 (1.3) | 3 (1.0) | 1 (0.3) | 2 (1.0) | 5 (4.3) | 12 (10.2) | 20 (20.0) | 16 (18.0) | 64 (3.5) |
| 23A | 1 (0.3) | 2 (0.6) | 8 (2.6) | 9 (3.1) | 5 (2.6) | 5 (4.3) | 7 (5.9) | 5 (5.1) | 14 (15.7) | 56 (3.0) |
| 15C | 3 (0.9) | 2 (0.6) | 3 (1.0) | 6 (2.1) | 2 (1.0) | 2 (1.7) | 4 (3.4) | 5 (5.1) | 2 (2.2) | 29 (1.6) |
| 35B | 2 (0.6) | 3 (0.9) | 0 (0) | 3 (1.0) | 1 (0.5) | 1 (0.9) | 2 (1.7) | 6 (6.1) | 7 (7.9) | 25 (1.4) |
| 34 | 3 (0.9) | 1 (0.3) | 5 (1.7) | 5 (1.7) | 1 (0.5) | 1 (0.9) | 1 (0.8) | 2 (2.0) | 6 (6.7) | 25 (1.4) |
| 13 | 5 (1.6) | 1 (0.3) | 5 (1.7) | 2 (0.7) | 2 (1.0) | 2 (1.7) | 0 (0) | 0 (0) | 0 (0) | 17 (0.9) |
| 35A | 4 (1.3) | 4 (1.3) | 3 (1.0) | 2 (0.7) | 3 (1.5) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 16 (0.9) |
| 22 non-F/A | 3 (0.9) | 3 (0.9) | 3 (1.0) | 3 (1.0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 12 (0.7) |
| Others | 15 (4.7) | 14 (4.4) | 8 (2.6) | 4 (1.4) | 5 (2.6) | 5 (4.3) | 3 (2.5) | 0 (0) | 1 (1.1) | 55 (3.0) |
| NVT total | 37 (11.6) | 34 (10.8) | 38 (12.6) | 35 (12.1) | 21 (10.7) | 21 (18.1) | 29 (24.6) | 38 (38.4) | 46 (51.7) | 299 (16.2) |
| Non-typeablec | 20 (6.3) | 14 (4.4) | 18 (6.0) | 15 (5.2) | 11 (5.6) | 5 (4.3) | 6 (5.1) | 6 (6.1) | 3 (3.4) | 98 (5.3) |
aPPV23 vaccine includes serotype 22F, which is not differentiated from 22A in this study due to its low prevalence. bPPV23-only serotypes refer to 15B, 11A, 10A, 17F, 20, and 22F/A. cSome of the non-typeable isolates might be non-pneumococcal streptococci (Scholz et al., 2012; Sadowy and Hryniewicz, 2020).