Table 1.
Efficacy of oseltamivir treatment of immunocompetent and immunosuppressed BALB/c mice inoculated with a lethal dose of influenza BR/08 virus.
| Oseltamivir dose (mg/kg/d)a | No. of treatment days | No. of surviving mice/total no. of mice (%) | Mean day to death ± SD | Mean weight loss (% ± SD) on dpi:b | Lung virus titer (mean ± SD) (log10QTCID50/ml) on dpi:c | ||||
|---|---|---|---|---|---|---|---|---|---|
| 6 | 10 | 14 | 6 | 10 | 14 | ||||
| Immunocompetent mice | |||||||||
| 0 | 8 | 0/5 (0) | 8.6 ± 0.9 | 25.7 ± 1.3 | NA | NA | 3.5 ± 0.0 | NA | NA |
| 20 | 8 | 4/5 (80) | 18.6 ± 5.4* | 17.4 ± 0.9 | 14.6 ± 2.0 | 3.1 ± 0.9 | 2.5 ± 0.7 | < | < |
| Immunosuppressed mice | |||||||||
| 0 | 8 | 0/5 (0) | 7.4 ± 0.9 | 21.2 ± 2.6 | NA | NA | 2.6 ± 1.2 | NA | NA |
| 20 | 8 | 0/5 (0) | 9.5 ± 1.6* | 13.6 ± 1.9 | 17.9 ± 1.2 | NA | 3.5 ± 0.0 | 4.1 ± 0.4 | 4.5 ± 0.1 |
| 20 | 16 | 1/5 (20) | 13.8 ± 4.4* | 11.9 ± 1.5 | 19.8 ± 2.2 | 24.8 ± 1.5 | 3.2 ± 0.4 | 3.5 ± 0.0 | < |
Oseltamivir was administered by oral gavage at a dose of 20 mg/kg/day (0.1 mL/mouse) twice daily for 8 (immunocompetent mice) or for 8 or16 (immunosuppressed mice) days. Control (virus-inoculated, untreated) mice received sterile water.
Loss of weight was calculated for each mouse as a percentage of its weight on day 0.
Virus titers were determined in the lungs of mice (n = 3/group/time-point) at 6, 10, and 14 dpi by TCID50 assays in MDCK cells.
, virus not detected by the TCID50 assay (detection limit was 1.0 log10TCID50/mL).
P < 0.01 for comparisons of untreated and oseltamivir-treated mice inoculated with BR/08 virus by one-way ANOVA with Bonferroni’s multiple comparison post-test. NA, not applicable (all mice in the group died).