As the European Union grapples with the arrival of bird flu, Greece says two people suspected of having the virus have been placed in quarantine. Initial tests came back negative, but a further round of samples have been ordered. This two days after the country confirmed the deadly strain of the virus had been found in three dead swans.Europe is on high alert, with news over the weekend that the H5N1 strain of bird flu has been found in Italy and Bulgaria. Slovenia is also testing a sample taken from a swan. European officials have been trying to ease concern, stressing that no human cases have been confirmed so far in the EU. They say while H5N1 has killed at least 88 people in Asia and the Middle East, and measures to stop it spreading are essential, human to human transmission has never been detected anywhere.