Care homes afflicted by Covid-19 are being hit with a three patient limit for testing.The refusal to keep tabs on the status of care home residents means those with coronavirus cannot be separated from those who do not - leading to fears over the loss of many more lives.The revelation casts grave doubt on First Minister Nicola Sturgeon’s pledge at the daily briefing on Monday to produce “robust and reliable” data on the numbers of people catching the virus among Scotland’s 33,000 nursing home population.The reality is that any data on numbers of new infections and the death rate among old people who catch Covid-19 will be guesswork.One concerned son was told by the Ancaster House care home in Crieff, Perthshire, that testing had stopped