Analysis of Patient Records Shows Results of H5N1 Flu Drug

(Agricultural Research Service, USDA)

An analysis of clinical records stored in a registry of patients from various countries who contracted the influenza A/H5N1 (Avian flu) virus, shows that treatment with the drug oseltamivir reduces mortality in patients with the disease, even when given late in the course of illness. The findings were published in the Journal of Infectious Diseases.

The investigators analyzed records in the Avian Flu Registry, a global database collecting detailed information on clinical presentation, treatment, and course of human influenza A/H5N1 from 12 countries. It is designed as a collaborative study involving members of the international scientific and medical communities, and funded by a contract from Hoffmann-La Roche. The Registry is operated by Outcome Sciences Inc. in Cambridge, Massachusetts that says it contains information on nearly 70% of World Health Organization confirmed cases of H5N1.

The multinational observational study, which Outcome Sciences says is the largest-ever analysis of confirmed influenza A/H5N1 cases, showed a survival rate of 50 percent in patients who received oseltamivir (marketed under the name Tamiflu) 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.

These data, collected from 308 A/H5N1 patients occurring between 1997 and 2009 in 12 countries, also showed oseltamivir was more effective when treatment started soon after the onset of symptoms, Some 80 percent of patients survived when oseltamivir was administered within two days of symptom onset compared to 20 percent survival for those who were untreated.