Cases of a strain of gonorrhoea impervious to an antibiotic have almost tripled in six months, the latest report from the National Alert System for Critical Antimicrobial Resistance (CARAlert) reveals.
The result was a “warning shot across the bow” for doctors and public health officials fighting antibiotic resistance, CARAlert’s senior medical adviser said.
A total of 742 reports of critically resistant bacteria were collected by the early-warning system from 65 laboratories nationwide between April and September last year, a 75 per cent rise on the 423 cases reported in the same period during 2016.
A spike in the number of reports of Neisseria gonorrhoeae, a bacterial strain responsible for gonorrhoea that is resistant to the antibiotic azithromycin, accounted for most of the overall increase.
Alerts for the strain rose by 182 per cent, from 121 to 342, according to the report released on Tuesday by the Australian Commission on Safety and Quality in Health Care.
Gonorrhoea that is not susceptible to azithromycin is now the most frequently reported “critical antimicrobial resistance” (CAR) bacterium that cannot be treated with, or is a major threat to, last-line antibiotics. CAR bacteria have been dubbed “super-superbugs”.
N. gonorrhoeae accounted for 47 per cent of all reports over the six-month period.
Victoria and NSW accounted for the bulk of N. gonorrhoeae cases, with 160 and 120 reports respectively.
A dual antibiotic treatment (ceftriaxone and azithromycin) for gonorrhoea was introduced in Australia in 2014 as part of a strategy to delay the rise of a strain resistant to the first-line antimicrobial ceftriaxone.
The strategy appeared to be working, with few reports of the strain being resistant to ceftriaxone, but the move has triggered a rise in azithromycin non-susceptible N. gonorrhoeae, John Turnidge, senior medical adviser for the commission’s antimicrobial surveillance system, said.
“Within a few months, we saw a little cluster in South Australia and then Victoria, and then it seemed to pop up everywhere.”
Ceftriaxone is still effective against N. gonorrhoeae, but the results were “a warning shot across the bow”, Professor Turnidge said.
“It’s getting harder to treat illnesses with effective antibiotics.
“The risk is: ‘Are the [antimicrobial] treatments we are using going to survive?’ ”
Untreatable gonorrhoea could lead to infertility in women, Professor Turnidge said.
“That’s what we’re trying to prevent in the end: mass infertility,” he said.
A separate report released by the Kirby Institute in November revealed the number of Australians diagnosed with gonorrhoea had increased by 63 per cent in the previous five years, particularly among men and heterosexual city-dwellers.
The super-superbug was still responsible for only a small percentage of all gonorrhoea cases, but it was clear the strain was spreading, he said.
Overprescribing antibiotics was certainly fuelling the rise of the highly multi-drug resistant infections, as were poor hygiene and lax infection control in hospitals and nursing homes.
The second most commonly reported CAR was a type of bacteria called carbepenemase-producing Enterobacteriaceae (CPE), with 307 notifications.
More than half (53 per cent) of CARs were detected from patients in the community, rather than in hospital or aged-care facilities.
Victoria had the highest number of CARs reports (35 per cent) followed by NSW (28 per cent) and Queensland (25 per cent).
Other CARs remain at very low levels, suggesting they had not established a foothold in Australia.
The flourishing of the so-called super-superbugs and antibiotic-resistant bacteria bolstered the need for national and global monitoring systems such as CARAlert – funded by the federal government since it was established in 2016 – and strategies aimed at slowing their spread, the report’s authors said.
“We need to know which resistant bacteria are emerging so as to be best prepared to respond to outbreaks if and when they happen,” Professor Turnidge said.
“CARAlert is an incredibly powerful tool, because it gives unprecedented and timely information to public health authorities and clinicians.”