A concerning trend in sexually transmitted infections has emerged globally, including in Ghana, as a gut pathogen known as Shigella bacteria is increasingly being spread through sexual contact. Historically, Shigella has been transmitted through contaminated food or water during travel and among young children in daycare. However, since the turn of the century, it has emerged as a sexually transmitted infection, particularly among gay, bisexual, and other men who have sex with men.
According to the US Centers for Disease Control and Prevention (CDC), roughly 450,000 people acquire shigellosis each year in the United States, which can lead to dysentery. The CDC has found that among nearly 17,000 Shigella isolates, versions that were extensively drug-resistant rose from 2011 to 2023. In 2011, isolates resistant to five commonly used antibiotics made up 0 percent of the samples, but by 2023, they made up 8.5 percent.
Molecular biologist Shangxin Yang from the University of California, Los Angeles, reports that hospital workers are now seeing roughly one case of extensively drug-resistant Shigella a month, compared to just one case all year in 2022. This represents a significant increase in the spread of the infection. The CDC has also noted that more than a third of patients with extensively drug-resistant shigellosis were hospitalized, and nearly half of those with known HIV status had HIV.
The UK Health Security Agency has warned that while most cases of Shigella resolve without treatment, more severe cases do require treatment, and the options available are becoming limited. In 2025, 86 percent of Shigella sonnei samples and 94 percent of Shigella flexneri samples tested by UKHSA researchers showed resistance to antibiotics. These are the two most commonly spread strains through sexual contact among gay, bisexual, and other men who have sex with men in England.
Researchers have identified that the emergence of drug-resistant Shigella infections is linked to the treatment of other sexually transmitted infections. For example, when the UK's national treatment guidelines stopped recommending the use of azithromycin to treat gonorrhea infections, the emergence of azithromycin resistance in Shigella slowed down. This suggests that treating other STIs may be a risk factor for drug-resistant Shigella infections.
To prevent Shigella infection from sex, the California Department of Public Health advises not having sex with someone who has had diarrhea in the last two weeks, using barriers during oral and anal sex, and washing up before and after sex. Anyone who suspects they may have Shigella should get tested and seek treatment if necessary. Clinicians should also be asking patients with dysentery about sexual transmission and giving advice accordingly.
The increasing trend of sexually transmitted Shigella infections highlights the need for awareness and action. According to epidemiologist Naeemah Logan from the CDC, this is a broader global pattern, and it is essential to address the issue to prevent further spread. Geneticist Kate Baker from the University of Cambridge emphasizes that many men who have sex with men are unaware of the serious and increasing risk posed by sexually transmitted Shigella.
Key points
- Shigella bacteria are increasingly being spread through sexual contact, particularly among gay, bisexual, and other men who have sex with men.
- The infection is becoming difficult to treat due to its growing resistance to antibiotics.
- Awareness and preventive measures, such as using barriers during sex and getting tested, are crucial to preventing the spread of the infection.
