TWO of south-west Victoria's largest nursing homes have been hit by a highly-contagious gastroenteritis outbreak.A total of 22 residents at Hamilton's Birches centre and 20 at Warrnambool's Lyndoch have been quarantined in their rooms to isolate the virus which has raged since early last week. Affected staff were sent home and visitors restricted.By late yesterday management at both centres was confident the worst was over and predicted the all-clear would come by Thursday.Half of the Birches residents plus 35 staff at the centre and Hamilton base hospital were struck down.The hospital also treated six inpatients who developed symptoms. Three were still in hospital yesterday. Lyndoch and Birches each had 13 elderly residents still in quarantine yesterday afternoon. They will be cleared when free of symptoms for 48 hours."It is well and truly contained," Lyndoch CEO Rhys Boyle said."We expect the outbreak will be short and sharp." Western District Health Services CEO Jim Fletcher, who manages the Birches centre, said: "We believe we are at the tail end.""This was a highly-contagious virus which required stringent controls."Eight Lyndoch staff with symptoms were told to stay home for 48 hours. Staff movement into the quarantined Audrey Prider Centre and Tomlinson wing has been restricted.The gastro followed a more widespread outbreak of influenza in September which affected more than 50 residents and 46 staff at Lyndoch."We learnt a lot from that outbreak and were able to quickly minimise the exposure to gastro," Mr Boyle said."With 20 out of 200 patients affected our percentage is not as bad as some other centres I have heard about."We isolated the ill residents in their rooms and restricted staff and visitor movements."Management of Terang's Mount View Aged Care Centre and the Koroit aged care centre were on high alert yesterday. "As soon as we heard about Lyndoch we implemented extra precautions and infectious control procedures," Koroit manager Pam Gunther said.Warrnambool's medical officer Dr John Philpot said the situation was part of general gastro outbreaks in the community."I don't know specific numbers but it's not an abnormal outbreak," he said. Department of Human Services spokesman Bram Alexander said all nursing centres and hospitals followed strict procedures to control gastro outbreaks."The cornerstone of prevention for everybody is good hygiene in washing your hands after going to the toilet and handling pets," he said.