TOMORROW has been designated Tampon Alert Day by the Toxic Shock Syndrome Information Service, to draw attention to this rare but potentially serious illness. Forty cases of toxic shock syndrome occur each year in the UK, of whom about three die. Although associated with forgetting to remove tampons, the disorder can affect anyone - men, women or children - and is caused by toxin-producing strains of the bacterium staphylococcus aureus. Symptoms include a flu-like illness, sudden high fever, vomiting, diarrhoea, rash, pain, dizziness and disorientation. Write to: TSSIS, 24-28 Bloomsbury Way, London WC1A 2PX. Phone 071-404 2120.