A study published in the Journal of Infectious Diseases indicates that treatment with oseltamivir significantly reduces mortality in patients with influenza A/H5N1, even when given late in the course of illness.
In humans, influenza A/H5N1 is associated with severe disease and a high mortality rate. The multinational observational study, which is the largest-ever analysis of confirmed influenza A/H5N1 cases, showed a survival rate of 50 percent in patients who received oseltamivir within six to eight days after the onset of their influenza symptoms, compared with 29 percent in patients who did not begin antiviral treatment during the same time period. In addition, these data, collected from 308 A/H5N1 patients occurring between 1997 and 2009 in 12 countries, showed oseltamivir was even more effective when treatment was started soon after symptom onset, with approximately 80 percent of patients surviving when oseltamivir was administered within two days of symptom onset compared to 20 percent survival for those who were untreated.
Professor Wiku Adisasmito from the University of Indonesia and lead author notes, "This important study highlights a new finding, that even delayed treatment with oseltamivir offers benefits. Clearly early treatment is what clinicians should aim to initiate and retain a high index of suspicion, but if presentation or diagnosis is delayed, treatment should still be started with oseltamivir. This study also highlights the benefits of the aggregation of data derived from many cases from multiple sites."