A salmonella outbreak affecting at least 23 victims has forced the Heartlands Hospital in Birmingham to close down eight wards as a leading public health lawyer calls for a probe into what caused the infection.
The Heart of England NHS Foundation Trust has confirmed that four of its staff and 19 patients have tested positive for a common strain of salmonella.
Amandeep Dhillon, a leading public health lawyer, has called for an investigation into the outbreak.
Mr Dhillon said the "unusual" outbreak, which has left eight people in a stable condition at Birmingham's Heartlands Hospital, might provide lessons to help prevent future outbreaks.
"Attention will then need to turn to identifying the cause of the infection. This will be essential to provide victims and their loved ones with the answers they will want as to what caused their illness," Mr Dhillon said.
Symptoms of salmonella include diarrhoea, stomach cramps and sometimes vomiting and fever.