There has been a 15% increase in the number of new cases of HIV and AIDs across Lancashire.
In 2011 there were 93 new cases across the county, compared with 81 in 2010.
The figures, which have been compiled in a report for the Centre of Public Health at Liverpool John Moors University also show that 56% of the new cases were men exposed through having sex with men.
And 35.5% of the cases were heterosexual.
The figures show in 2011 there were 14 cases in Preston, six cases in South Ribble and two cases in Chorley.
The highest number of cases was Blackpool with 24 cases and both Lancaster and the Ribble Valley has just one new cases in 2011.
The data also shows that 18% of the new cases were in those aged 50-years-old and over.
In the North West there were 789 new cases reported in 2011, representing a 7% increase from 2010, when there were 735 new cases.
Of these 44% were cases of men exposed through having sex with men and 41% were heterosexual cases.
Jim McVeigh, co-author of the report said: “The rise in new cases of HIV in Lancashire is of real concern, contributing to a total of 911 HIV positive individuals from across the county receiving treatment and care in 2011.
“Eighteen percent of new infections were in the age category of 50 and over.
“While the majority of sexual health and HIV prevention work has focussed on the young, it is clear that these messages are equally important to older adults.
“It is a real concern to us at the Centre of Public Health as to how we can better target our message to the over 50s age group.”
Mr McVeigh added: “Individuals who are starting new relationships in later life, need to be aware of the risks of sexually transmitted infections, including HIV.
“We would urge these people to take precautions with new partners to protect themselves against HIV and STIs.”
Jane Harris, lead author of the report, said: “HIV diagnosis is no longer a death sentence.
“However, caring for the needs of older people will present new challenges and this, coupled with an overall increas in new HIV cases show we cannot get complacent.
“Investment in prevention and innovations in treatment are vital to ensuring the best possible health outcomes.”
In total, there were 6,993 people in the North West living with HIV in 2011, a six per cent increase on 2010 and the highest total ever recorded.