A charity has branded sex education in schools as 'not fit for purpose' following the publication of new figures on sexually transmitted infections (STI) in East Anglia.

Concern has been raised after the number of new diagnoses of gonorrhoea in the region increased by almost a quarter in 2013, compared with 2012.

Calls have been made to improve sexual health awareness and education after new figures from Public Health England revealed a 23pc increase in gonorrhoea cases last year in the region - higher than the national average - from 703 to 865

The total number of STIs diagnosed in Anglia and Essex in 2013 decreased by 1pc last year from 26,006 in 2012 to 25,798 in 2013.

Cases of chlamydia increased by 1pc, the number of herpes diagnoses rose by 6pc, and genital warts cases increased by 1pc over the last year in East Anglia. Cases of syphilis decreased by 6pc.

Adam Wilkinson, regional manager for the Terrence Higgins Trust in the East of England, said: 'It is concerning to see such a marked increase in rates of gonorrhoea in Anglia and Essex, which suggests that the safer sex message isn't getting through to everyone. This is a further reminder that the current approach to sex education in schools is not fit for purpose, leaving too many young people unprepared for the pressures of modern relationships.

'Taught properly, sex and relationships education has been shown to delay sexual activity, reduce the number of sexual partners, and increase the use of condoms and other contraception. Young people will continue to bear the brunt of sexual ill health until we have a high-quality programme of sex and relationships education taught in all schools.'

There were 446,253 STIs diagnosed in England in 2013, according to Public Health England data, close to the number diagnosed in 2012 (448,775 cases). Chlamydia was the most common STI, making up 47pc of all diagnoses, while gonorrhoea diagnoses saw a large rise, up 15pc from 2012 to 2013 (29,291).

Catherine Lowndes, consultant scientist in Public Health England's STI surveillance team, said: 'Sustained efforts to encourage people to regularly get checked for STIs means we are now finding and treating more infections, which is good news. Nevertheless these data show too many people are still getting STIs each year, especially young adults and gay men.

'Investment in promoting good sexual health awareness, contraception and condom use, and STI testing is vital, as is ongoing investment in easy to access sexual health services that meet the needs of local populations. Not only will this help bring down STI rates but abortion rates and under 18 conceptions as well.'

People can significantly reduce their risk of catching or passing on an STI by consistently and correctly using condoms until all partners have had a sexual health screen, by reducing the number of sexual partners, and by avoiding overlapping sexual relationships.

The Terrence Higgins Trust recently launched a campaign with the Sex Education Forum to encourage politicians to make sex and relationships education a statutory part of the curriculum for all schools in England.