Shares in Tristel surged on Tuesday after the company raised its full-year guidance again after a stronger-than-expected fourth quarter. The AIM-listed company, which makes infection prevention, contamination control and hygiene products, said that the "strong momentum" seen in underlying trade in both March and April is now estimated to continue through its June year-end and beyond.A further acceleration in revenue growth is expected to result in a pre-tax profit before share-based payments for the year ending June 30th of at least £1.75m.This compares with an adjusted pre-tax profit of £0.48m the year before and is well ahead of numerous targets already set out by Tristel earlier in the year, the most recent being £1.5m.Tristel works in three main markets: Human Healthcare, Animal Healthcare and Contamination Control.Chief Executive Paul Swinney said the company is experiencing a rise in sales in all three areas."The pace of growth is higher than previously anticipated and with margins also improving and costs stable, the impact on the bottom line is both significant and immediate."The stock was up 22.5% at 78.98p by 08:22.BC