Speaking to Hina on Tuesday, dr. Iva Pem Novosel of the HZJZ said the institute was on the alert and cautioned protection from mosquito bites.
The virus is transmitted by mosquitoes which get infected by sucking the blood of infected birds or horses.
Pem Novosel said seven cases were reported in Croatia last year and all were treated successfully.
According to the European Centre for Disease Prevention and Control, there are 149 cases recorded in Europe at the moment, of which 30 in European Union countries. Cases have been reported in Hungary, Austria, Macedonia as well as 63 in Serbia, where four people have died.
Pem Novosel said the virus could be expected in Croatia as well because of the high temperatures, highlighting the importance of prevention.