Cases of 'untreatable gonorrhoea' soar by 25 per cent 21,000 cases of gonorrhoea were diagnosed in 2011 Health Protection Agency has warned the STI is becoming more resistant to treatment Gonorrhoea is spread during unprotected sex Cases of 'untreatable gonorrhoea' have soared 25 per cent in a year, as experts warn the disease is becoming more resistant to treatment. More than 20,000 new cases of the sexually-transmitted infection were diagnosed in 2011. The spike has led to the launch of a new campaign to tackle the growing threat in England and Wales in a bid to reverse the trend. Health experts are hoping the first Gonorrhoea Resistance Action Plan will increase awareness of the disease, which is the second most common bacterial STI in England. The plan, established by the Health Protection Agency, will monitor the global problem of increasing resistance over the last 10 years. It comes after the 2011 data revealed up to a third of reported cases were repeat gonorrhoea infections. Over a third of cases were in men who have sex with men, up from around a quarter in 2010. Professor Cathy Ison, lead author of the Grasp campaign, said: 'Ensuring treatment resistant gonorrhoea strains do not persist and spread remains a major public health concern. The Grasp action plan raises awareness of this important issue and sets out practical, measurable actions to extend the useful life of the current recommended therapies in England and Wales. Neisseria gonorrhoeae, the bacterium responsible for the sexually transmitted infection gonorrhoea Gonorrhoea is treated with a single dose of antibiotics which are at least 95 per cent effective, according to the NHS. However, if left untreated it can lead to pelvic inflammatory disease or infertility. In England and Wales, the risk of gonorrhoea resistance developing in current first-line therapies (ceftriaxone and azithromycin) fell slightly for the first time in five years in 2011. However, cases of treatment failure have now been reported globally and, with no new antimicrobial agents in the pipeline, Professor Sally Davies, England's Chief Medical Officer, recently advised government to add the threat of infection resistance to frontline antibiotics to the civil emergencies risk register. Prof Davies said: 'We have seen a worrying rise in cases of drug resistant gonorrhoea over the last decade. 'Antimicrobial resistance to common drugs will increasingly threaten our ability to tackle infections and the Health Protection Agency's work is vital to addressing this threat.'