U.S. Tries New Treatment for West Nile Infection

Tuesday, September 9, 2003

WASHINGTON (Reuters) - U.S. researchers said on Monday they were trying out a new treatment for West Nile virus infection, using antibodies from Israelis who have survived infection.

The approach, called passive immunization, is experimental but may offer short-term protection to people most at risk of serious complications of the virus, which include encephalitis brain inflammation.

West Nile virus, first reported in the United States in 1999, has infected more than 2,500 people and killed 47 this year, according to the U.S. Centers for Disease Control and Prevention.

"West Nile virus has emerged as a problem in the United States again this year, and public health officials are particularly concerned because the disease appears to be spreading more quickly and more widely than last year," National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci said in a statement.

"Currently, clinicians can provide only supportive care for patients infected with WNV," he added. "We hope that the results from this study will ultimately give physicians and their patients a useful treatment option."

West Nile virus has been reported for half a century in Africa and more recently in southern Europe. There is no good treatment but most infected people show only very mild symptoms and often no symptoms at all.

The NIAID-led researchers use a product taken from blood serum from Israeli volunteers who have been exposed to the virus for decades. The hope is that antibodies their bodies have produced to fight off the virus will help sick patients in the trial.

Israeli biopharmaceuticals company Omrix has developed a product using these antibodies, called immunoglobulins.

The researchers will be looking for 100 patients at 35 hospitals being treated for life-threatening West Nile infections.

The virus affects birds, horses and other animals and is transmitted by mosquitoes. It has spread across most of the United States and into Canada and possibly Mexico.