What Is Shigella? The STI That Some Don't Even Know They Have

The symptoms caused by this bacteria are all too easy to mistake for something else.
Close-up of Shigella sonnei​, the bacteria that causes shigella
Shigella sonnei, the bacteria that causes shigella. Photo: Alamy Stock Photo

It may sound like a Nigella Lawson-inspired drag queen, but Shigella is no joke – it’s an STI that some people don’t even realise they’ve had. Because it causes diarrhoea, stomach cramps and fever, it's easy to mistake this nasty gut infection for food poisoning, but it's actually caused by bacteria found in faeces. Shigella is also incredibly infectious and only needs a tiny amount of bacteria to spread, so if you're into rimming and/or anal sex, you should definitely make yourself aware of it.


In January, the UK Health Security Agency (UKHSA) put out a press release warning of a rise in Shigella cases, "mainly among gay, bisexual and other men who have sex with men (MSM)" – though it can be caught by anyone regardless of gender or sexual orientation. The UKSHA said it had detected 47 cases of an especially drug-resistant strain of Shigella in the last four months, a sharp spike from just 16 detected cases in the 17-month period before that.

Though the UKSHA didn't say as much, it's highly likely that these figures are just the tip of the iceberg because not everyone who catches Shigella will necessarily seek treatment or be accurately diagnosed. Ian Howley, CEO of the health and wellbeing charity LGBT HERO, says more than 5,000 people have accessed Shigella information on their website in the last six months, which is an increase of 93 percent. 

"During the peak of the pandemic, a lot of MSM refrained from partaking in sexual activity including group sex – a setting where Shigella is likely to be transmitted at a higher rate," Howley tells VICE. "But since the lifting of restrictions, people have slowly got back to pre-pandemic sexual activity. This is probably why we're seeing a rise in Shigella cases among queer men."


MSM who enjoy group sex, dark rooms and cruising are more susceptible to Shigella because of how it spreads. "You can catch Shigella from getting very small amounts of poo in your mouth, and this can happen from rimming someone, fingering or giving oral sex to someone after they have anally penetrated [topped] someone else," the UKHSA’s Mateo Prochazka tells VICE. "People who go to dark rooms, private sex clubs or cruising spots might engage in sex with multiple new sexual partners, increasing the risk of exposure to Shigella."

If you've caught Shigella, you'll probably know within one to four days of being exposed to it. The typical symptoms – diarrhoea, stomach cramps and fever – tend to clear up within a week, though the UKHSA notes that "some individuals need hospitalisation and require intravenous antibiotic treatment" to get rid of it.

Kyle, a 34-year-old gay man from London who asked to remain anonymous because of his job, tells VICE his own experiences of Shigella were at times "debilitating".  Kyle is "pretty sure" he has caught it four times in the last year, each time after having sex with multiple partners at a gay sauna or orgy

"For me, it was always worse than having another STI like gonorrhoea because the symptoms themselves are more awful," he says. "It feels like you actually are quite sick. Because you have diarrhoea lots of times a day, really uncomfortable bloating and really bad stomach aches, you're going to need time off work, which isn't really the case with something like gonorrhoea."


Joseph, a 30-year-old gay man from London who also asked to remain anonymous, says these symptoms "felt relentless" when he caught Shigella from rimming someone last July. "I woke up feeling well enough to go to the gym, but a few hours later I was violently sick and started having diarrhoea. I couldn't keep anything down," he recalls. "Then for the next 48 hours, I was basically either being sick or shitting myself."

At this point, Joseph finally stopped vomiting, but the chronic diarrhoea continued for another six days. "I was drinking one pint of water with a hydration sachet a day – that was all I could manage," he says. "I wasn't eating, I wasn't drinking anything else, I wasn't even watching TV because I was just completely out of it with a pretty bad fever and a very bad stomach. To this day, I can't even remember what I did during those six days except for lie on the bathroom floor for most of the day and night."

Both Kyle and Joseph went to their GP with their symptoms, but struggled to get an accurate diagnosis. Joseph suspected all along that he had caught Shigella, and tried saying this to his GP, but only had it confirmed when he went back a month later "with severe IBS symptoms that were just so unusual for me". Eventually his GP called him to apologise for not spotting it sooner.

Joseph's experience is echoed by Kyle, who was only prescribed antibiotics on one of the four occasions he visited a GP.  "Most of the time they didn't seem to realise what I was talking about," he says. "I would say, 'I think it could be Shigella', but they'd just say: 'Hmm, have you been in any countries where you've been drinking unclean water?'" 


Kyle says part of the problem was the inherent awkwardness of discussing an intimate sexual health problem with a GP. "I found it quite difficult in that situation to say, 'Well, basically I sucked someone's dick after it had been in someone's arse without a condom. And that's why I think I have Shigella'," he says.

For this reason, Ian Howley of LGBT Hero recommends visiting your local sexual health clinic if you suspect you have it.  "Lots of GPs may not be aware of Shigella or may not think about it unless you bring it up," he says. "A GUM clinic is better prepared to address the symptoms and you may feel more comfortable talking about it with them." 

Dr Alan McOwan of 56 Dean Street, a sexual health clinic in Soho, says you should definitely seek medical advice if "you notice blood and/or mucus in the diarrhoea, develop a fever or the symptoms last longer than a week".

The easiest way to minimise your risk of contracting Shigella is to avoid rimming, fisting and engaging in oral sex straight after anal sex. "But if you enjoy those sexual activities, that's just not realistic, is it?" acknowledges Howley. With this in mind, he says paying close attention to your personal hygiene is the best policy. 

"Make sure you clean your arse thoroughly after using the toilet, clean your cock after condomless sex, and wash your hands after fisting," he says. "And remember you don't need to engage in sexual activity to contract Shigella, because it can also be transmitted from skin-to-skin contact. Washing your hands regularly is really so important."

Thankfully, after two years of fending off COVID, we’re all well used to this by now. We just need to apply the same stringent standards to other parts of our anatomy. 

For more information about Shigella, visit the LGBT HERO website.