The Centre for Health Protection said today the recent deaths of four girls with acute febrile illness were unrelated.

Announcing the findings of investigations into the deaths of the girls, aged three, six, seven and nine, who died August 11 to September 3, the centre's controller Dr Thomas Tsang said they died of fulminant sepsis, acute myocarditis, acute viral encephalitis and post infectious encephalitis.

Extensive tests were conducted by the centre, the Hospital Authority, the University of Hong Kong and the Chinese University. He said the combination of epidemiological, clinical and microbiological evidence did not support a common microbial agent or source.

Isolated incidents

The cases were not clustered in a single geographical area and the girls attended different schools and shared no common activity, while detailed epidemiological investigations found no common exposures. All family and school contacts had no similar illnesses and no secondary spread was evident.

"The most likely conclusion is that the cases were sporadic and unrelated, and there was no increase in the number of such deaths," he said.

Up to 20 children aged nine or below died from primary infective causes in Hong Kong each year from 2004-07. The major causes of death were sepsis, encephalitis or encephalopathy, pneumonia, and myocarditis.

Vigilance advised

Dr Tsang reminded parents and child carers to supervise children and ensure they observe good personal hygiene to minimise the chance of infection. Children with acute febrile illness should not attend school until two days after abatement of the fever.

If a child has a fever, parents should closely observe their condition for signs of more serious disease, such as persistent high fever not responding to medication, severe vomiting, decreased level of consciousness, breathing difficulties and convulsions. Consult a doctor immediately in such cases.