Sexually transmitted enteric infections – flushing out the facts.

Every year on the urgent care course there are a couple of topics that really get our delegates thinking– those ‘unknown unknowns’ that are both a bit surprising and slightly scary (when you think about how many others there may be...). On this year’s course, Sexually Transmitted Enteric Infections (STEI’s) were the Urgent Care bombshell, and an important DEN for many of us. 

Thankfully, the British Association of Sexual Health and HIV (BASHH) released the first ever National Guideline for the Management of STEI last year. This guidance was released in response to increasing rates of STEI and the emergence of multidrug resistant strains, and it includes plenty of learning points for us in primary care. 

So, what are STEIs, and what do we need to know about them? 

STEIs are enteric infections, spread by sexual contact, that cause intestinal inflammation. Anyone participating in activities involving oral-anal contact may be at risk, but STEI are most common in men who have sex with men (MSM). They can be caused by a wide range of different organisms, most of which aren’t just passed by sexual contact, so even when detected in a stool sample can easily be misattributed. Symptoms are also diverse, as they depend on the part of the gut infected, including hepatitis, enteritis, proctocolitis and proctitis. 

Because of the wide variety of symptoms and causative organisms, alongside increasing rates of STEI, BASHH now recommends adults, particularly MSM or others at risk, should have a sexual history taken when presenting with acute gastroenteritis. This should include sexual contacts and practices (particularly those that facilitate faeco-oral transmission), HIV status, recreational drug use, recent travel and occupation. 

What should we then do if we suspect an STEI? 

Unsurprisingly, our initial management involves assessing the patient as usual – including asking ourselves “does this patient need admission?” e.g. for sepsis, dehydration, or peritonitis.  Oral rehydration salts are recommended, anti-motility agents should be avoided, and we can advise about general measures to reduce the risk of spread. Notifiable diseases should be reported as usual. 

Specific advice if we suspect a STEI includes:

• Send stool samples early – this should include stool PCR testing for bacteria and parasites, ideally sent at the first contact. 
• Advise patients to abstain from sex for 7 days after diarrhoea has resolved.
• Refer on to sexual health services – where comprehensive STI testing, contact tracing and counselling can be undertaken. 

Because patients with STEIs are at increased risk of other STIs, this onward referral part really is key. England has just set the unenviable record of the highest number of annual gonorrhoea diagnoses since records began, with rates of gonorrhoea and syphilis both doubling in the past decade, so suspected cases of STEI should be seen as an opportunity for general sexual health promotion and risk reduction. 

Specific management of individual infections, including treatment of contacts, will largely depend on which pathogen is detected. Organism-specific management is discussed in detail in the guideline; however, a key message is that most bacterial infections can be managed conservatively. The consensus from the authors is that there is little role for empirical antibiotics, which should be reserved for those who are unwell and hospitalised. 

BASHH have also provided a useful patient information leaflet, which, if this topic was as new to you as it was to me, is well worth a read. 

As with so many diagnoses, we simply won’t make them if we don’t even consider them. So, when you next diagnose acute gastroenteritis, perhaps ask yourself ‘could this be a sexually transmitted enteric infection?’ Patients might not volunteer those relevant details unless prompted, so asking the right questions ensures not only an accurate diagnosis and treatment, but the all-important onward referral to sexual health services too.