Table 2.
Epidemiological factors associated with any ciprofloxacin resistance (CIP) vs. only tetracycline resistance (TET) among 135 patients with resistant infections.
| Any CIP resistance (n = 49) | Only TET resistance (n = 83) | |||||
|---|---|---|---|---|---|---|
| Characteristicsa | No. | (%) | No. | (%) | OR (95% CI)b | p-valuec |
| Age (years) | ||||||
| 0–40 (n = 83) | 31 | (37.4) | 52 | (62.5) | 1.0 | – |
| ≥41 (n = 48) | 18 | (37.5) | 30 | (62.5) | 1.0 (0.48, 2.10) | 0.99 |
| Sex | ||||||
| Male (n = 65) | 23 | (35.4) | 42 | (64.6) | 1.0 | – |
| Female (n = 59) | 23 | (39.0) | 36 | (61.0) | 1.2 (0.41, 1.78) | 0.85 |
| Residence type | ||||||
| Rural (n = 48) | 18 | (37.5) | 30 | (37.5) | 1.0 | – |
| Urban (n = 70) | 25 | (35.7) | 45 | (64.3) | 0.9 (0.43, 1.98) | 0.84 |
| Season | ||||||
| Winter, spring (n = 39) | 12 | (30.8) | 27 | (69.2) | 1.0 | – |
| Summer, fall (n = 93) | 37 | (39.8) | 56 | (60.2) | 1.5 (0.67, 3.30) | 0.33 |
| Any travel in the past month | ||||||
| No (n = 49) | 13 | (26.5) | 36 | (73.5) | 1.0 | – |
| Yes (n = 41) | 21 | (51.2) | 20 | (48.8) | 2.9 (1.20, 7.02) | 0.02 |
| Type of travel in the past month | ||||||
| None (n = 49) | 13 | (26.5) | 36 | (73.5) | 1.0 | – |
| Domestic (n = 19) | 4 | (21.1) | 15 | (79.0) | – | 0.76 |
| International (n = 21) | 17 | (81.0) | 4 | (19.1) | – | <0.0001 |
| Type of drinking water | ||||||
| Municipal, bottled (n = 67) | 25 | (37.3) | 42 | (62.7) | 1.0 | – |
| Any well water (n = 20) | 5 | (25.0) | 15 | (75.0) | – | 0.42 |
| Poultry consumption | ||||||
| No (n = 16) | 4 | (40.0) | 6 | (60.0) | – | – |
| Yes (n = 115) | 24 | (35.3) | 44 | (64.7) | – | 0.77 |
| Contact with livestock | ||||||
| No (n = 79) | 31 | (39.2) | 48 | (60.8) | – | – |
| Yes (n = 11) | 1 | (9.1) | 10 | (90.9) | – | 0.09 |
| Hospitalized | ||||||
| No (n = 85) | 27 | (31.8) | 58 | (68.2) | 1.0 | – |
| Yes (n = 26) | 14 | (53.9) | 12 | (46.2) | 2.5 (1.02, 6.14) | 0.04 |
| Multivariate analysisd | Adjusted OR (95% CI) | p-value | ||||
| Age | 1.0 (0.98, 1.02) | 0.87 | ||||
| Female | 0.5 (0.17, 1.40) | 0.18 | ||||
| Urban residence | 1.0 (0.33, 2.83) | 0.95 | ||||
| Summer or fall infection | 3.7 (1.03, 13.47) | 0.04 | ||||
| International travel only | 14.9 (4.00, 55.57) | <0.0001 | ||||
| Hospitalized | 3.0 (0.78, 11.19) | 0.11 | ||||
| Well water | 0.6 (0.16, 2.26) | 0.44 | ||||
| Livestock contact | 0.2 (0.02, 2.25) | 0.21 | ||||
Number of isolates may not add up to the total for some variables due to missing data; percentages were calculated using the number with each characteristic as the denominator.
95% confidence interval for the odds ratio (OR). ORs were calculated for ciprofloxacin resistance relative to tetracycline resistance.
The Fisher's Exact test was used for variables with fewer than 5 in one cell; no ORs could be calculated.
Multivariate results were generated using forward stepwise logistic regression while controlling for variables with p-values ≤ 0.2 in the univariate analysis as well as potential confounders. A base model consisted of the following variables: age (continuous), female sex, urban residence, season (fall and summer), and international travel. Each additional variable was added separately to the base model. The Homer and Lemeshow Goodness-of-Fit test (p > 0.05) was examined to ensure support for each model. Adjusted ORs were calculated and the Wald Chi-Square test was used to determine significance with 95% Wald Confidence Limits.