LONDON, Sept 27 (Reuters) - Around one in six new cases of HIV diagnosed in Europe are in people over the age of 50, health officials said on Wednesday, showing a need to raise awareness and tailor testing programs to older generations.

A study by researchers at the European Centre for Disease Prevention and Control (ECDC) found steady growth over the past 12 years in rates of new HIV cases in older people in the region.

The over 50s were also more likely than younger people to have advanced HIV, the study found, and to have contracted it via heterosexual sex.

“Our findings suggest a new direction in which the HIV epidemic is evolving. This potentially is a result of older people’s low awareness of HIV and how it is transmitted,” said Lara Tavoschi, who led the research at the ECDC and published it in The Lancet HIV journal.

She said a perception of older people being at lower risk of HIV is shared by some health workers and can mean HIV-related services are focused toward people under 50.

“Our findings illustrate a clear need to provide comprehensive HIV prevention programs, including education, access to condoms, better testing opportunities and treatment targeted toward older adults across Europe,” Tavoschi said.

Almost 37 million people worldwide have the human immunodeficiency virus that causes AIDS.

The majority of cases are in poorer regions such as Africa, where access to testing, prevention and treatment measures has been more limited, but the HIV epidemic has also proved stubborn in wealthy regions like Europe.

The ECDC study analyzed new HIV cases in the 28 EU countries plus Iceland, Liechtenstein and Norway from 2004-2015. It found that more than 54,000 over 50s were diagnosed with HIV during that time, compared to 312,500 cases in people aged 15 to 49.

The rate of diagnosis in older people increased in 16 European countries, including Britain, Belgium, Germany and Ireland. By 2015, it found, rates of HIV among over 50s were highest in Estonia, Latvia, Malta and Portugal.