Hong Kong authorities have declared an outbreak of scarlet fever following the second death of a child from the disease in the past month, and a record number of cases so far this year.

Of particular concern is that the bacterium responsible for scarlet fever appears to have mutated and become more resistant to antibiotics used to treat the disease.

The outbreak is troubling given Hong Kong's history of epidemics.

A 2003 outbreak of severe acute respiratory syndrome, SARS, claimed several hundred lives.

Several outbreaks of swine flu have also occurred in the city.

The Hang Seng index HSI went into a tailspin at the time of the SARS epidemic.

Air travel has also suffered during previous disease outbreaks.

Victims of scarlet fever generally suffer from a red rash, sore throat and fever. Serious complications can develop if the disease is untreated, including rheumatic fever, which can lead to joint pain and heart damage.