Five people in Greece have contracted the West Nile virus, which is carried by mosquitoes, according the Center for Disease Control and Prevention (KEELPNO).
The first case reported this year in Greece was on Sunday, when a pensioner in Palaio Faliro, southern Athens, was taken ill. Another resident of a nearby district was confirmed as carrying the disease the next day.
However, KEELPNO says three more cases had been confirmed by Thursday evening. They were in Elliniko, Palaio Faliro and Piraeus, all neighbourhoods of southern Athens.
KEELPNO said that it expects more cases in this part of the capital, which has never been considered a high risk area for West Nile virus, to appear over the next few days.
The West Nile virus, which can cause encephalitis, was discovered in 1937 in Uganda. Sporadic cases of the disease in humans have occurred in Europe since the 1960s. It was first detected in Greece in 2010, when 262 people contracted the disease, 35 of whom died.