Certain strains of the Shigella bacterium, which can cause diarrhea, vomiting, fever, and abdominal pain, have moved to the forefront of the public health agenda in the US and the UK due to both their increased spread through sexual contact and their development of resistance to antibiotics.
Typically transmitted through the consumption of contaminated water and food or close contact in environments with poor hygiene, the bacterium has also become more visible among sexually transmitted infections in recent years. Experts are particularly concerned that strains circulating within certain sexual contact networks are resistant to multiple antibiotics.
INCREASE IN RESISTANT STRAINS
According to data from the US Centers for Disease Control and Prevention (CDC), approximately 450 thousand people contract a Shigella infection in the country each year. In a study by the CDC examining nearly 17 thousand samples collected between 2011 and 2023, a significant increase was detected in the proportion of strains considered resistant to five commonly used antibiotics.
While no bacteria falling into this group were encountered in the study in 2011, the rate rose to 8.5 percent by 2023. The fact that the majority of individuals with resistant infections were adult men and that a significant portion of patients had not recently traveled abroad were among the findings indicating that the spread is not solely travel-related.
We are seeing the bacteria essentially exploding in the community.
According to CDC data, more than one-third of patients who contracted extensively drug-resistant infections were hospitalized. Although most infections resolve within about a week without requiring antibiotic treatment, the decrease in treatment options for severe cases poses a risk.
Studies in the UK point to a similar picture. According to research published in The Lancet Infectious Diseases, for which Kate Baker from the University of Cambridge was the senior author, the annual growth rate of Shigella spread associated with sexual contact between 2015 and 2020 was 15 percent higher compared to spread originating from travel, food, or daycare centers.
The UK Health Security Agency (UKHSA) also announced that antibiotic resistance was detected in 86 percent of Shigella sonnei bacteria and 94 percent of Shigella flexneri bacteria in samples examined in 2025. The agency also emphasizes that these rates do not mean the bacteria are resistant to all antibiotics.
MODES OF TRANSMISSION AND PREVENTION
Shigella is transmitted when bacteria in the stool of an infected person reach the mouth area of another person. This can occur through contaminated food or water, failure to wash hands sufficiently, or the transfer of fecal-borne bacteria to the mouth area during sexual contact. The bacterium is highly contagious; in some cases, the entry of even a very small number of bacteria into the body can lead to an infection.
Symptoms of the disease include severe diarrhea, vomiting, fever, and abdominal pain. In some cases, severe outcomes such as bloody diarrhea, serious dehydration, bloodstream infection, shock, and neurological complications can develop. Children under the age of five, those traveling to regions with inadequate hygiene conditions, homeless individuals, and individuals in certain sexual contact networks are counted among the risk groups.
Scientists are also investigating why the development of resistance is more pronounced in Shigella strains spread through sexual contact. One possibility is that antibiotics used in the treatment of other sexually transmitted infections also affect Shigella bacteria in the gut, paving the way for the selection of resistant strains. However, researchers state that one should be cautious when establishing a direct cause-and-effect relationship for this mechanism.
The CDC and the California Department of Public Health recommend washing hands and the genital area with soap before and after sexual contact, cleaning sex toys, and using condoms and oral barriers to reduce the risk. California officials also advise avoiding sexual contact with individuals who have had diarrhea within the last two weeks. It is recommended that individuals who suspect a Shigella infection get tested and consult a healthcare facility when necessary.
News Source: 12punto
