Table 3.
Details of Patients Recruited to the 3 Treatment Groupsa
| Variable | Doxycycline (7 d) (n = 72) | Doxycycline (3 d) (n = 72) | Azithromycin (3 d) (n = 72) | All Patients (n = 216) |
|---|---|---|---|---|
| Clinical and laboratory features | ||||
| Age, median (IQR), y | 28.5 (21–43) | 29.0 (21–40) | 31.5 (24–42) | 30 (22–41) |
| Female sex, No. (%) | 33 (45.8) | 30 (41.7) | 28 (38.9) | 91 (42.1) |
| Duration of illness, median (IQR), d | 8 (7–10) | 9 (7–10) | 8 (7–10) | 8 (7–10) |
| Fever ≥37.5°C at admission, No. (%) | 61 (84.7) | 64 (88.9) | 68 (94.4) | 193 (89.4) |
| Admission tympanic temperature, mean (95% CI), °C | 38.6 (38.3–38.8) | 38.4 (38.2–38.6) | 38.6 (38.4–38.8) | 38.5 (38.4–38.7) |
| PCR- or serology-confirmed Rickettsia typhi , No. (%)b | 55 (76.4) | 54 (75.0) | 49 (68.1) | 158 (73.2) |
| Serology-confirmed R. typhi, No. (%) | 53/70c (75.7) | 56/72 (77.8) | 51/70 (72.9) | 160/212 (75.5) |
| PCR-confirmed R. typhi, No. (%)b | 20/71 (28.2) | 18/69 (26.1) | 15/71 (21.1) | 53/211 (25.1) |
| No PCR or serologic evidence of R. typhi, No. (%) | 17 (23.6) | 18 (25.0) | 23 (31.9) | 58 (26.9) |
| R. typhi bacteremia, median (IQR), copies/μL whole blood | 3 (2–6) (n = 17)c | 3 (2–4) (n = 15) | 3 (2–4) (n = 13) | 3 (2–6) (n = 45) |
| PCR- or serology-confirmed O. tsutsugamushi, No. (%) | 0/69 | 5/69 (7.3) | 2/69 (2.9) | 7/207 (3.4) |
| PCR-confirmed O. tsutsugamushi, No. (%) | 0/71 | 4/69 (5.8) | 2/71 (2.8) | 6/211 (2.8) |
| Other confirmed diagnoses, No. (%) | 6/72 (8.3) | 2/72 (2.8) | 3/72 (4.2) | 11/216 (5.1) |
| No diagnosis made, No. (%) | 12/72 (16.7) | 11/72 (15.3) | 18/72 (25.0) | 41/216 (19.0) |
| CRP, median (IQR), mg/L | 40.8 (22.8–94.5) (n = 66)c | 34.2 (14.0–95.2) (n = 63) | 35.7 (19.0–59.4) (n = 68) | 37.6 (18.5–83.3) (n = 197) |
| Antibiotic dosages | ||||
| Total doxycycline doses administered, median (range), No.d | 15 (2–17) | 7 (4–21) | 0 (0–15) | … |
| Total duration of doxycycline treatment, median (range), dd | 7 (1–8) | 3.5 (2–10) | 0 (0–7) | … |
| Doxycycline dosage, mean (95% CI), mg/kg body weight dose per 100-mg dose | 1.83 (1.75–1.92) | 1.83 (1.76- 1.91) | 1.84 (1.77–1.92) (n = 14)c | … |
| Total doxycycline dose, mean (95% CI), mg/kg body weightd | 27.5 (26.0–29.0) | 14.0 (13.1–15.0) | 4.5 (2.3–6.7) | … |
| Total azithromycin doses administered, median (range), No. | 0 | 0 | 4 (4–4) | … |
| Total duration of azithromycin treatment, median (range), d | 0 | 0 | 3 (3–3) | … |
| Azithromycin dosage, mean (95% CI), mg/kg body weight dose per 250-mg dose | 0 | 0 | 4.60 (4.42–4.79) | … |
| Total azithromycin dose, mean (95% CI), mg/kg body weight | … | … | 18.9 (18.1–19.6) | … |
| Outcome | ||||
| Patients withdrawing, No. (%) | 1/72 (1.4) | 1/72 (1.4) | 1/72 (1.4) | 3/216 (1.4) |
| Patients vomiting loading dose within 1 h, No. (%) | 5/66 (7.6) | 5/64 (7.8) | 2/62 (3.2) | 12/192 (6.3) |
| Patients with mild adverse events, excluding headache, No. (%)e | 26/36 (72) | 17/37 (46) | 16/30 (53) | 59/103 (57) |
| Duration of patient follow-up, median (range), d | 190 (2–666) | 319 (4–411) | 224 (2–420) | 208 (2–666) |
| Patients returning with fever after admission, No. (%) | 7 (9.7) | 9 (12.5) | 10 (13.9) | 26 (12.0) |
Abbreviations: CI, confidence interval; CRP, C-reactive protein; IQR, interquartile range; PCR, polymerase chain reaction.
aAntibiotic batch numbers were as follows: Vibramycin (Pfizer), 0658105B, 0558103B, 0758103C, 0558103D, 0558101C, and 0458102B; Zithromax (Pfizer), 914640271, 814360231, 614646251, 616046261, 516645351, 714641322, 514645351, 214642178, 514665081, 014640091, and 516645351.
bWithout culture or PCR evidence of dual pathogens.
cDenominators are provided for variables with missing values.
dIncluding doxycycline given to those with treatment failure.
eMahosot Hospital patients only.