The worrying rise of sexually transmitted gut infections in men who have sex with men

The article’s lead author, Dr. Ferric C. Feng, professor of microbiology, laboratory medicine and pathology at the University of Washington School of Medicine, writes that the “[global] emergence of several multidrug resistant gut pathogens and the potential for crossover transmission among different at-risk populations underscores the importance of prompt diagnosis, appropriate treatment, and the need to consider community-level education and testing.”

The authors of the article drew particular attention to infections like Shigella and Campylobacter among men who have sex with men. The sexual transmission of enteric infections (STEIs) among this group has been reported and recognised since the 1960s. The “public health response to these infections and identification and identification of transmission networks fall between the traditional groupings of sexually transmitted and foodborne diseases.”

Some infections, such as Shigella and Campylobacter, can be transmitted sexually or through contaminated food.

The article’s authors were initially concerned that having HIV or being on the drugs used to prevent or control HIV might increase the chance of catching these infections. However, there appears to be no increase in the rate of transmission of pathogens affecting HIV-positive or HIV negative men.

Rather, sexual behaviour seems to be the driving force behind the transmission of these infections. Oral-anal contact, or rimming, is the primary way these infections are passed on. Recent cultural changes make these kinds of behaviours more likely.

Sexual encounters with new partners are easily made through online dating and hookup sites and apps. Genital and genito-oral transmission is also helped by the decline in use of contraceptive barriers like condoms, as quick and effective treatments for infections like Chlamydia and Gonorrhoea become more readily available. Chemsex also plays a role in lowering inhibitions.

Men who have sex with men are more likely to contract these infections, tend to be younger, urban, and travel internationally. They also tend to have wider sexual networks.

People who are homeless, live in unsanitary conditions, and who exchange sex for money are also at more risk, as well as people who are immunocompromised.

• Hepatitis A: A highly contagious viral liver infection spread through contaminated food or water or close contact.
  • Common symptoms: Extreme unwellness, fatigue, nausea, abdominal pain, dark urine, jaundice, and low-grade fever.
• Campylobacter: A bacterial infection often contracted from undercooked poultry or contaminated water.
  • Common symptoms: Diarrhoea (sometimes bloody), fever, stomach cramps, nausea, and vomiting.
• E.Coli: A group of bacteria, some strains of which cause gastrointestinal illness through contaminated food or water.
  • Common symptoms: Watery or bloody diarrhoea, stomach cramps, low-grade fever, and vomiting.
• Salmonella: A bacterial infection commonly spread through contaminated food, especially raw meat and eggs.
  • Common symptoms: Diarrhoea, fever, stomach cramps, nausea, vomiting, and headache.
• Shigella: A bacterial infection of the intestines spread via contaminated food, water, or person-to-person contact.
  • Common symptoms: Bloody or mucus-filled diarrhoea, fever, stomach cramps, and nausea.
• Entamoeba histolytica: A parasitic infection acquired through contaminated food or water, especially in tropical regions.
  • Common symptoms: Diarrhoea, stomach pain, cramping; severe cases may cause bloody stools and liver abscesses.
• Giardia: A parasitic infection of the small intestine, often spread through contaminated water.
  • Common symptoms: Scanty, watery or greasy stools, bloating, gas, stomach cramps, fatigue, and weight loss.
• Strongyloides: A parasitic worm infection acquired through contact with contaminated soil.
  • Common symptoms: Itchy rash, abdominal pain, diarrhoea, bloating, and cough; severe cases can be life-threatening in immunocompromised individuals.
• Cryptosporidium: A microscopic parasite causing diarrheal illness, especially in the immunocompromised, often spread through contaminated water.
  • Common symptoms: Watery diarrhoea, stomach cramps, nausea, and sometimes fever.
• Cystoisospora: An intestinal parasite causing infection mainly in tropical regions.
  • Common symptoms: Watery diarrhoea, abdominal cramps, nausea, vomiting, fever, and loss of appetite.
• Microsporidia: A group of parasitic fungi-like organisms that infect various tissues, especially in immunocompromised individuals.
  • Common symptoms: Diarrhoea, weight loss, and systemic symptoms depending on the organ affected.

STEIs are becoming increasingly difficult to treat and can persist for extended periods. Fang and his colleagues also note that many of these gut infections have become increasingly resistant to drugs in recent years. International travel has also made it easier for these infections to break free from national barriers, where they may have been isolated in the past.

Responses to STEIs have been hampered because they aren’t clearly defined as a single, specific infection. Treatment and prevention initiatives tend to focus on traditional STIs, like Gonorrhoea and Syphilis.

Health professionals may not seek the sexual history of people with these gut infections during consultations.

This article has been medically reviewed by Dr. Steve Chapman, 27/11/2025.

STEIs can have serious consequences if they’re not treated properly. Talk to your healthcare provider if you’re experiencing any of the symptoms listed above.

If you’re worried about STIs, Better2Know can help. Book a sexual health test at a clinic near you by clicking the button below.