A mysterious disease that killed 23 people and infected 50 others in Bangladesh last month was encephalitis, a statement of the health ministry said on Sunday.
"The disease is caused by a virus closely related to Nipah and Hendra viruses that cause deadly encephalitis," it said.
Bangladesh sent samples to the US Center for Disease Control (CDC) in Atlanta for analysis after local laboratories failed to clearly identify the disease, which many suspected was bird flu.