The Government might not have to slaughter tens of thousands more birds despite tests revealing the bird flu virus in duck excrement. A source confirmed yesterday 'a few duck excrement samples' from among the 1,200 checked had tested positive for the H5 virus. But evidence of H5 does not necessarily mean the deadly H5N1 strain is present and tests had so far proved negative, the source said. The H5-contaminated excrement was found among the 1,800 samples removed from markets and farms after the slaughter of 1.5 million chickens. 'A few samples have had H5 virus. We still have to do a lot of work to confirm whether it is H5N1 and also where the samples came from,' the source said. The Government would decide the next step, including whether another slaughter was necessary, only after full results were available, probably next week. One major factor was that the disease was transmitted among ducks and geese totally differently from the way it spread among chickens, the source said. 'When the virus is found among chickens, it can spread very rapidly. Therefore, we had to kill all the chickens after we found it. 'The public shouldn't be too worried, even if the virus has been found in some duck excrement samples. Ducks and geese are intermittent carriers of the virus. What's most important is the way we handle it and overall hygiene conditions,' he said. There are estimated to be 50,000 ducks in 73 SAR farms.