Concerned: Permanent Secretary for Health, Welfare & Food Carrie Yau says health officers are working hard to trace the source of infection.

The Hospital Authority and the Centre for Health Protection are jointly investigating a necrotising enterocolitis cluster in Queen Mary Hospital��s Neonatal Intensive Care Unit.

Eight premature babies developed symptoms between June 12 and 18. One died on June 13 while the other seven are still being treated in isolation. They are in stable condition.

Permanent Secretary for Health, Welfare & Food Carrie Yau said health officers are working hard to trace the source of infection.

Upon notification of the outbreak Friday, officers worked with hospital officials to heighten infection control measures and launch epidemiological investigations.

From June 18, new neonatal unit admissions have been suspended. The Hospital Authority has informed all public hospitals of the incident and is closely monitoring the situation. So far, there is no similar incident in other public hospitals.

The illness is a common complication seen in premature and low-birth weight infants. It can be due to many causes, and infection may be a contributing factor in some cases.