Bird flu patients who get early treatment with the antiviral drug Tamiflu have the best chances of surviving, but steroid treatments can do more harm than good, the World Health Organisation (WHO) said on Friday.

The United Nations agency was reporting on the preliminary conclusions of international experts who met last month in Turkey to compare notes on treatments, including the attempt by doctors in some countries to use steroids.

“Corticosteroid therapy has failed so far to show effectiveness,” the WHO warned in a statement. “Prolonged or high dose corticosteroids can result in serious adverse events.”

Frederick Hayden of WHO’s global influenza programme said some doctors, notably in Vietnam and Indonesia, had administered steroids to try to save quickly deteriorating bird flu patients. Eight of nine had died, he said, citing published research.

“A concern is some treatment is of unsubstantiated value and in some instances may be doing more harm than good,” he told Reuters.

The WHO reaffirmed that early treatment with Tamiflu, made by Swiss-based Roche and known generically as oseltamivir, was useful in reducing death from the H5N1 virus. Giving it to people with advanced symptoms was also “warranted”.

“Data presented gave strong support that early treatment makes a difference,” Hayden said, citing data from Egypt where 20 of 34 bird flu patients have survived to date.

“Unfortunately the problem is many patients are coming in late with shortness of breath and progressive symptoms that would indicate advanced viral pneumonia,” he said.

While bird flu is mainly a disease in animals, experts fear it could mutate into a form that can be spread easily among people, triggering a possible pandemic.

Some 291 people have been infected with the disease, including 172 who have died, according to the agency.

Tamiflu may also be used at a two-fold higher dosage and possibly in combination with an older class of drugs known as amantadine, the WHO said, in line with previous recommendations.

But such decisions should be made on a case-by-case basis, especially in patients with pneumonia or progressive disease.

Combining Tamiflu with amantadine may be especially useful in countries where the virus is susceptible to amantadine.

These countries include China and parts of Europe and Africa where a particular H5N1 subvirus or “clade” has spread, causing human cases since January 2006, according to Hayden. He cited Turkey, Egypt and Azerbaijan.

Antibiotics should only be given if there is good reason to suspect the patient has a bacterial complication to pneumonia - according to the WHO. Antibiotics should not be given preventively, due to possible resistance and side effects.