Public Health England has said the risk of cat owners contracting tuberculosis is "very low" after two people developed the disease after coming into contact with a cat.
Professor Dilys Morgan told ITV News, "Something strange has happened in this instance".
"We don't know exactly what's happened but I don't think that we can read too much into it, that it is an increasing trend," she added.
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A 14-year-old girl was declared dead at the property before an eight-year-old boy and seven-year-old girl died in hospital.
TV presenter Keith Chegwin has died aged 60 following a "long-term battle with a progressive lung condition", his family said.