Among patients being treated for gonorrhoea last year, tetracycline resistance rose from 49 per cent to 60 per cent of isolates, while ciprofloxacin resistance increased from 54 per cent to 69 per cent
New evidence into drug resistance in the bacterium that causes one of the most common sexually transmitted infections (STIs) reinforces why older antibiotics should not be routinely used, a new report has found.
Publishing its latest surveillance report on antimicrobial resistance (AMR) in Neisseria gonorrhoeae, the Health Protection Surveillance Centre (HPSC) said that resistance to several older antibiotics in fighting the infection increased last year.
Tetracycline resistance rose from 49 per cent to 60 per cent of isolates between 2024 and 2025, while ciprofloxacin resistance increased from 54 per cent to 69 per cent.
Production of β-lactamase, a marker of penicillin resistance, increased from 25 per cent of isolates in 2024 to 35 per cent in 2025.
Reduced susceptibility to azithromycin remained broadly stable last year, identified in 26 per cent of isolates compared with 28 per cent in 2024.
In a statement, the HPSC said: “These findings reinforce why older antibiotics are no longer routinely recommended for the treatment of gonorrhoea and underscore the importance of continued antimicrobial resistance monitoring.”
Newly published figures show that, in the first six months of this year, there were 2,798 new cases of gonorrhoea reported in Ireland, an increase of 166 or 6.3 per cent on the same period in 2025.
Gonorrhoea remains the second most common STI in the country, with over 88 per cent of cases in the first half of this year found in men.
Drug-resistant gonorrhoea has become an increasing concern globally in recent years, with the US Centers for Disease Control and Prevention (CDC) warning that the bacteria that cause the infection has grown resistant to nearly every drug ever used to treat it.
“Monitoring antimicrobial resistance in gonorrhoea is a vital component of Ireland’s public health surveillance system,” added the HPSC in its statement.
“The data collected help ensure that treatment recommendations remain effective and support early detection of any emerging resistance trends. Continued surveillance, laboratory testing, and collaboration with clinical services remain essential to protecting public health.
“Ireland contributes data annually to the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP), allowing comparison of national trends with those observed across Europe and supporting coordinated international responses to antimicrobial resistance.”
As part of efforts to contain the spread of the infection, last year the UK’s National Health Service began offering the Meningitis B vaccine to at-risk men, with studies then suggesting it could help prevent the disease by up to 40 per cent.
However, a new trial in Australia, published in the New England Journal of Medicine earlier this month, found no significant difference in gonorrhoea infections between men who were given the vaccine and those who were not.
The UK Health Security Agency said its own studies would provide ‘more robust data’ and is not recommending any immediate changes.
The MenB vaccine – which provides up to 88 per cent protection against the bacteria that cause Meningitis B – is available in Ireland under the HSE Primary Childhood Immunisation Programme for all babies born on or after October 1, 2016. It is administered in multiple doses at two, four, and 12 months.
