SEXUAL contact has replaced injection drug use as the chief cause of HIV/Aids transmission in Bermuda.

But speaking in the week before World Aids Day, Chief Medical Officer Dr. John Cann said young people needed to be aware that the statistic did not mean that sharing needles was any safer than in the past.

"In the beginning, 90 per cent of people of our Aids cases were due to injection drug use," Dr. Cann said yesterday.

"But as of the first quarter of 2004, 38.9 per cent of the cumulative total of Aids cases ? 191 cases ? were due to injection drug use."

The proportion of cases of people infected through unprotected sex is rising and those infected through heterosexual sex now make up 26.8 per cent of the total.

"The real message we want to get across is that people should try to make sure they know who they are having sex with and their sexual history," Dr. Cann said.

"The pattern has changed dramatically, but the key thing to remember is that the pattern could change again. We still have younger people who may not be aware of the risks they are taking if they share a needle. We have to keep reminding people and remaining vigilant."

Earlier this year, the Bermuda Police Service warned that heroin use was on the increase and needle use was moving back into fashion, leading to a greater risk of spreading the HIV virus.

Hundreds of lives were lost in Bermuda as a result of needle-sharing during the 1980s and 1990s, but many local drug users turned to smoking and snorting as Aids awareness grew.

More complete Aids statistics will be announced before World Aids Day, which is next Wednesday, December 1, Dr. Cann said.

The most recently released data on HIV/Aids cases show that 483 cases had been reported on the island through October 2003. Three out of four of those infected were men.

There will be a slew of events to mark World Aids Day, including a red ribbon campaign, an awareness campaign and a service at Hamilton's Anglican Cathedral next Wednesday at 7 p.m.

There will also be ceremonies around trees planted in memory of Aids victims both at Camden and at Bermuda College.

This week saw the release of , based on the findings of the World Health Organisation (WHO) and the Joint United Nations Programme on HIV/Aids (UNAIDS). The report said the Caribbean region ? which included Bermuda in the survey ? was the second most-affected region in the world and there were five countries (the Bahamas, Belize, Guyana, Haiti and Trinidad & Tobago) where HIV rate exceeded two per cent of the population.