The Centre for Health Protection has confirmed a second screwworm infestation for the year, this time involving a 93-year-old Sai Wan Ho woman.  

The woman has no recent travel history. In February, wounds on her right foot worsened and maggots were later found. She has been admitted to Pamela Youde Nethersole Eastern Hospital and is now in a stable condition.

Screwworms, or Chrysomya bezziana, eat dead or living tissue, often burrowing deep into wounds. This can cause tissue damage, secondary invasion - and sometimes death.

There were four screwworm infestations reported last year, eight in 2004 and nine in 2003.

To avoid screwworm infestations:

* All wounds should be treated immediately, and properly cleaned and dressed;

* Use window screens to keep flies out;

* Observe good personal and environmental hygiene;