NSW Health officials are concerned about a serious outbreak of the gut infection caused by shigella among gay men in the state.
Notifications of shigellosis in 2016 have exceeded 150 and are already on par with the total number of cases presented in 2015.
A number of cases this year have already resulted in hospitalisation and there is concern that the outbreak could worsen as people with mild symptoms may not see their doctor and so remain infectious for longer, spreading the infection further.
People with weakened immune systems, such as people with HIV, can experience a more severe illness resulting in hospitalisation.
ACON CEO Nicolas Parkhill says infection takes place when tiny particles of contaminated faeces enter the mouth.
“This can happen through sexual contact such as rimming, by getting infected faeces on your fingers and then touching your mouth or by putting contaminated objects like food, pens and cigarettes into your mouth,” he says.
ACON is working with the NSW Ministry of Health to ensure that gay men are aware of the risk and how they can help prevent it from spreading.
Areas of Sydney that have seen particular rises in cases of shigella include parts of the inner city as well as western and northern Sydney.
NSW Health Medical Epidemiologist Dr Christine Selvey said there had been more than 150 shigellosis notifications in NSW in the first half of 2016.
“However, it is likely the notifications are just the tip of the iceberg as many people sick with shigellosis will recover without seeing their doctor or getting tested.”
Dr Selvey noted a quarter of these men also reported experiencing a second infection around the same time, such as sexually transmitted infections like gonorrhoea and chlamydia, or other gastrointestinal infections like giardia.
“These reports of co-infections are three times higher than usual,” she said.
“The most effective way of reducing the risk of contracting shigellosis is to wash hands thoroughly after any sexual activity, after touching equipment like used condoms and sex toys, after going to the toilet, and before handling food.”
Treatment of Shigella infection with antibiotics clears the bacteria and so makes a person non-infectious after a few days. Without antibiotics, some people can remain infectious for weeks after their diarrhoea has stopped.
Parkhill says gay men should also avoid sex while they have symptoms and for at least seven days after the symptoms clear.