West Nile virus has killed 13 people in Greece, health authorities say.

The Hellenic Centre for Disease Control and Prevention said Thursday that 13 people died with laboratory confirmed West Nile as of Wednesday. There have been 143 people who have become ill, including 39 hospitalized and eight still in intensive care.

One of the fatalities was an elderly patient with underlying diseases, the agency said.

West Nile virus is carried by mosquitoes and often presents no symptoms.

In a small number of cases, the virus can cause fatal inflammation of the brain (encephalitis) or of the membranes covering the brain or spinal cord (meningitis) that can lead to paralysis, coma and possibly death.

Cases were recorded in early August in Central Macedonia, northern Greece — the first time the infection has been documented in humans in Greece, researchers reported in the Aug. 26 issue of Eurosurveillance, Europe's journal on infectious disease epidemiology.

Greek authorities have banned blood donations in affected areas.

On Tuesday, Romania reported its first cases of West Nile virus, including two deaths and at least five other hospitalizations for West Nile infection.

In Canada, 42 people have died from the virus since 2002. With files from The Associated Press