High levels of antibiotic-resistant Mycoplasma genitalium have been detected across Queensland, and the authors of a study warn the number of difficult-to-treat cases are set to increase.

Levels of macrolide-resistant M. genitalium have reached 62% across the state, according to the retrospective audit of nearly 500 samples sent by clinicians for PCR testing between 2013 and 2017.

The pathogen, which causes urethritis and can lead to pelvic inflammatory disease, cervicitis and preterm delivery, has been shown in other studies to carry high rates of macrolide resistance — about 50% — in urban Sydney and Melbourne.

However, the latest data exceeds these estimates, with lead author Dr Emma Sweeney (PhD), from the University of Queensland, saying researchers were stunned by the high numbers.