The clinical effectiveness of oseltamivir in mild cases of pandemic influenza A H1N1 2009 infection.

BACKGROUND

Oseltamivir is widely used for the treatment of influenza infection, but data on its effectiveness in treating infections with pandemic influenza A H1N1 2009 are scarce. Therefore, we compared the effectiveness of oseltamivir and routine symptomatic treatment in pandemic influenza A H1N1 2009 infection.

METHODS

Between August and October 2009, among laboratory confirmed influenza cases who were aged over 15 y with no underlying disease, 90 patients with oseltamivir treatment and 72 patients with symptomatic treatment were evaluated by telephone interviews to compare clinical outcomes. No patient was hospitalized. The primary end-point was the duration of illness. We also assessed the time to attain a sense of well-being and the time to return to normal activity.

RESULTS

There was no statistically significant difference in the duration of illness between the oseltamivir-treated group and the symptomatic treatment group (mean duration after the start of treatment, 6.50 ± 3.75 days vs 7.04 ± 3.75 days). There was also no statistically significant difference between the 2 groups in the time to a sense of well-being (1.70 ± 1.57 days vs 2.00 ± 2.12 days) and to return to normal activity (7.13 ± 2.61 days vs 7.58 ± 2.71 days). The complication rate was very low (only 2 cases of mild pneumonia in oseltamivir recipients) and no significant difference was found between the 2 groups (p = 0.50).

CONCLUSIONS

Oral oseltamivir treatment does not significantly reduce the duration of illness or influenza-related complications in mild pandemic influenza A H1N1 2009 virus infection in previously healthy adults.