Table 1.
Antibiotic susceptibility data from 409 clinical isolates of Neisseria gonorrhoeae from Hanoi, Vietnam in 2017–2019. Mean zone diameters of inhibition and interpretive categories are presented for each antibiotic
| Antibiotics | Mean Zone of Inhibition Diameter, mm (SD) | |||
|
2017 (n = 112) |
2018 (n = 135) |
2019 (n = 162) |
p value* | |
| Penicillin | 22.0 (11.9) | 20.9 (10.2) | 20.3 (10.5) | 0.16 |
| Tetracycline | 22.8 (9.6) | 21.7 (9.0) | 24.6 (8.2) | < 0.01 |
| Ciprofloxacina | 10 (6–10) | 6 (6–16) | 11 (6–17) | 0.17 |
| Spectinomycin | 30.3 (3.3) | 26.5 (3.3) | 27.1 (3.7) | < 0.01 |
| Azithromycin | 34.6 (4.4) | 31.6 (3.8) | 32.7 (4.0) | < 0.01 |
| Ceftriaxone | 43.0 (4.1) | 40.5 (3.6) | 41.1 (3.8) | < 0.01 |
| Cefixime | 37.5 (5.0) | 35.5 (4.3) | 36.3 (4.1) | < 0.01 |
| Interpretive Categories,b n (%) | ||||
| 2017 | 2018 | 2019 | p value | |
| Penicillin (n = 408) | 0.01 | |||
| Susceptible | 0 (0%) | 0 (0%) | 0 (0%) | |
| Intermediate | 59 (52.7%) | 50 (37.0%) | 56 (34.6%) | |
| Resistant | 53 (47.3%) | 85 (63.0%) | 106 (65.4%) | |
| Tetracycline (n = 409) | 0.02 | |||
| Susceptible | 0 (0%) | 1 (0.7%) | 2 (1.2%) | |
| Intermediate | 21 (18.8%) | 12 (8.9%) | 36 (22.2%) | |
| Resistant | 91 (81.3%) | 122 (90.4%) | 124 (76.5%) | |
| Ciprofloxacin (n = 408) | 0.24 | |||
| Susceptible | 0 (0%) | 0 (0%) | 2 (1.2%) | |
| Intermediate | 0 (0%) | 1 (0.7%) | 3 (1.9%) | |
| Resistant | 111 (100%) | 134 (99.3%) | 157 (96.9%) | |
| Spectinomycin (n = 409) | – | |||
| Susceptible | 112 (100%) | 135 (100%) | 162 (100%) | |
| Intermediate | 0 (0%) | 0 (0%) | 0 (0%) | |
| Resistant | 0 (0%) | 0 (0%) | 0 (0%) | |
| Azithromycin (n = 407) | < 0.01 | |||
| Non-resistant | 94 (84.7%) | 72 (53.3%) | 119 (73.9%) | |
| Resistant | 17 (15.3%) | 63 (46.7%) | 42 (26.1%) | |
| Cefixime (n = 406) | 0.31 | |||
| Susceptible | 110 (98.2%) | 125 (94.7%) | 158 (97.5%) | |
| Non-susceptible | 2 (1.8%) | 7 (5.7%) | 4 (2.5%) | |
| Ceftriaxone (n = 408) | 0.78 | |||
| Susceptible | 112 (100%) | 133 (99.3%) | 160 (98.8%) | |
| Non-susceptible | 0 (0%) | 1 (0.7%) | 2 (1.2%) | |
*p value from Kruskal-Wallis test for means and Chi-square or Fisher’s Exact tests for susceptibility categories
aMedian (Interquartile range)
b Interpretive categories (except for azithromycin) were defined according to the Clinical and Laboratory Standards Institute (CLSI) protocol [14]. For azithromycin, interpretive criteria were defined according to the Centers for Disease Control Neisseria Reference Laboratory [15]