The Centre for Health Protection has received four more reports of fungal corneal infection (keratitis) since early March, involving three men and a woman aged 17 to 43.

It brings the total number affected to 27 since the infection was first reported last May. Twenty-five patients claimed they were users of B&L ReNu multipurpose contact lens solution. The manufacturer has voluntarily suspended sales.

In the US 109 cases of fungal keratitis are under investigation, and 28 patients are soft contact lens users. Twenty-six use the B&L solution. Of the 75 affected in Singapore, 56 also used the solution.

Contact lens users should:

* wash hands before handling contact lenses and accessories;

* get regular check-ups by optometrists or ophthalmologists and follow their directions and replacement schedule. Do not wear lenses for longer than recommended;

* practise proper lens cleaning and care regimes. Both sides must be rubbed with the fingers for 20 seconds and rinsed thoroughly before soaking overnight in multi-purpose solution. Rinse the lenses with saline solution before wearing them next time;

* the multi-purpose solution in the lens storage case must be changed everyday even if the lenses are not used daily;

* contact lens solutions should be capped properly after use;

* discard contact lens solutions a month after opening;

* storage cases should be cleaned, rinsed and dried after each use to avoid micro-organism growth and contamination;

* lenses, solutions and accessories should be stored in a cool and dry place;

* disinfect the case weekly by soaking in just-boiled water for 10 minutes;

* replace case every three months;

* disposable lenses must not be used beyond their recommended disposal period;

* do not wet your lens with saliva, bottled water or tap water; and,

* remove the contact lens whenever you feel discomfort or redness and seek advice from optometrists or ophthalmologists. Seek medical advice promptly if symptoms persist.