Reuters Health Information (2004-09-10): Interferon may treat flavivirus-induced encephalitis
Interferon may treat flavivirus-induced encephalitis
Last Updated: 2004-09-10 12:07:30 -0400 (Reuters Health)
NEW YORK (Reuters Health) - The results of a pilot
study suggest that early initiation of interferon (IFN)-alfa2b may
reduce the severity and duration of neurologic complications of
meningoencephalitis due to St. Louis encephalitis (SLE) virus.
IFN-alfa2b has demonstrated in vitro activity against at least three
members of the Flaviviridae family: hepatitis C virus, Japanese
encephalitis virus, and West Nile virus, Dr. James J. Rahal from New
York Hospital Queens in Flushing and colleagues note in the September
15th issue of The Journal of Infectious Diseases. These viruses are
structurally and genetically related to SLE virus.
During an outbreak of severe SLE viral meningoencephalitis in
Louisiana in the summer of 2001, Dr. Rahal's team treated 15 patients
with confirmed SLE virus infection with IFN-alfa2b. They compared the
clinical course and laboratory results of these patients with that of
17 infected untreated patients.
Treated patients initially received 3 million units of IFN-alfa2b
intravenously, followed by 3 million units administered subcutaneously
12 hours later and then every 24 hours for 14 days.
After the first week of hospitalization, significantly fewer treated
than untreated patients had persistent quadriplegia, quadriparesis, or
respiratory insufficiency (2 of 15 treated vs 11 of 17 untreated
After the second week of hospitalization, these complications were
present in only 1 of the 15 treated patients compared with 5 of the 17
In this pilot study, IFN-alfa2b therapy for CNS infection due to SLE
was well tolerated, except for the development of transient neutropenia
and/or mild hepatitis noted in 11 patients.
"There are currently no effective treatments for St. Louis or West
Nile encephalitis," Dr. Rahal told Reuters Health. "Our results suggest
that interferon is a possible treatment for [these] infections and we
are now doing a more definitive double-blinded trial this year against
West Nile virus," he added.
J Infect Dis 2004;190:1084-1087.