Shigella - Credit CDC
#17,831
Last February the CDC released a HAN (Health Alert Network) Advisory (see below) on the recent rise in Extensively-Drug-Resistant Shigellosis in the United States. Today, about 1 in 20 Shigella infections in the United States are classified as XDR, while a decade ago, it was virtually unheard of.
Increase in Extensively Drug-Resistant Shigellosis in the United States
Distributed via the CDC Health Alert Network
February 24, 2023, 11:30 AM ET
CDCHAN-00486
The CDC maintains an extensive set of web pages on Shigella – Shigellosis, which describes the bacteria and how it is spread.
Shigella bacteria cause an infection called shigellosis. Shigella cause an estimated 450,000 infections in the United States each year and an estimated $93 million in direct medical costs.
The four species of Shigella are:S. dysenteriae and S. boydii are rare in the United States, though they continue to be important causes of disease in areas with less access to resources. Shigella dysenteriae type 1 can be deadly.
- Shigella sonnei (the most common species in the United States)
- Shigella flexneri
- Shigella boydii
- Shigella dysenteriae
How do Shigella bacteria spread?
Shigella spread easily; it takes just a small number of bacteria to make someone ill. People with a Shigella infection can spread the infection to others for several weeks after their diarrhea ends.
You can get infected by swallowing Shigella. Some ways Shigella can get into your mouth are:
- Getting Shigella on your hands and touching your mouth. Shigella can get on your hands by:
- Touching surfaces, such as toys, bathroom fixtures, changing tables, and diaper pails, contaminated with Shigella bacteria from someone with an infection.
- Changing the diaper of a child with a Shigella infection.
- Taking care of a person with an infection, including cleaning up after the person uses the toilet.
- Eating food prepared by someone with a Shigella infection.
- Swallowing water you swim or play in, such as lake water or improperly treated swimming pool water.
- Swallowing contaminated drinking water, such as water from a well that’s been contaminated with sewage or flood water.
- Exposure to poop during sexual contact with someone with a Shigella infection or who has recently recovered from a Shigella infection.
Yesterday, the UK's Health Security Agency (UKHSA) raised new concerns with the release of an HPR (Health Protection Report) and following press release that describes a worrisome rise in the number of resistant Shigella cases over the past 12 months.
Excerpts from both reports follow, after which I'll have a bit more.
Warning after rise in extremely drug-resistant Shigella
The UK Health Security Agency (UKHSA) reports a concerning rise in Shigella cases, a gut infection that causes diarrhoea, stomach cramps and fever.
From:UK Health Security Agency Published21 December 2023
There has been a concerning rise in cases of extensively antibiotic-resistant Shigella sonnei infections, mainly in gay, bisexual, and other men who have sex with men (GBMSM), UKHSA has announced.
Since the beginning of 2023, the number of extensively-antibiotic resistant Shigella cases has increased by 53%. Much of this increase has been driven by a cluster of extensively-antibiotic resistant Shigella sonnei, of which there have been 97 cases in 2023 (up to and including November), compared to just 4 cases last year.
The strain is difficult to treat because it does not respond to the antibiotics typically used to treat Shigella. Cases have been diagnosed in all regions of England, but cases are concentrated in London (45), the North West (21) and South East (12).
In January 2022, there was a similar rise in cases of extensively antibiotic-resistant Shigella sonnei infections caused by another outbreak strain.
Cases of Shigella have been rising since the easing of COVID-19 restrictions in July 2021, with annual cases now higher than the average before the pandemic. The month with the highest number of reported Shigella diagnoses prior to the COVID-19 pandemic was 392 in September 2019, which increased to 485 in September 2023 – representing a 24% increase.
Shigella is a gut infection that causes diarrhoea (sometimes mixed with blood), stomach cramps and fever. It is caused by bacteria found in faeces.
It can be passed on through the faecal-oral route during sex, either directly or via unwashed hands and only a tiny amount of bacteria can spread the infection. Symptoms are typically seen between 1 and 4 days after exposure and are commonly mistaken for food poisoning.
HPR volume 17 issue 15: news (20 and 21 December 2023)
Updated 21 December 2023
Increase in extensively-drug resistant Shigella sonnei in England predominantly affecting men who have sex with men
There has been an increase in Shigella cases reported in England between January 2022 and November 2023, during which period there has also been an increase in the proportion of extensively-drug resistant (XDR) Shigella spp. The recent increase in XDR Shigella spp. from June 2023 onwards has been driven by one specific cluster of Shigella sonnei.
Shigella spp. are bacterial enteric pathogens transmitted through faecal-oral contact that cause acute bacillary dysentery. In England, while Shigella infection is a common cause of travellers’ diarrhoea and transmission can be foodborne, it is increasingly associated with sexual contact among gay, bisexual, and other men who have sex with men (GBMSM). Antimicrobial resistance among Shigella spp. is a public health concern, with the World Health Organization listing Shigella as an antimicrobial resistant ‘priority pathogen’ (1).
As of 18 December 2023, the number of reported Shigella spp. cases in England has increased between January 2022 and November 2023 reaching a monthly peak of 485 in September 2023. There has also been an increase in the number of XDR Shigella spp., which peaked at 67 cases in June 2023 (Figure 1).
This XDR increase has been driven by a single cluster of closely related Shigella sonnei (outbreak strain t10.1814). The number of cases within this cluster increased substantially in 2023, such that in 2023 (up to and including November) there were 97 cases within this cluster (Figure 2); 90% of cases are adult males with a median age of 35 years, which suggests a predominance of sexual transmission of this strain of Shigella among gay, bisexual, and other men who have sex with men (GBMSM).
(Continue . . . )
While there are a lot of other avenues for the development of antimicrobial resistance (AMR), sexually transmitted diseases are increasingly a cause for concern. Earlier this year in Massachusetts DPH: First Detection Of Gonorrhea Strain With Resistance To 5 Classes of Antibiotics we looked at growing concerns over antibiotic resistant gonorrhea in the United States.
Last summer the UKHSA reported: Gonorrhoea and Syphilis at Record Levels in 2022, and just last week we looked at a report from Denmark SSI: The Number of Gonorrhea Cases in Denmark is Increasing.
Whether it is vaccines, antibiotics, antifungals, or antivirals, we are engaged in an endless `arms race' with countless thousands of constantly evolving pathogens whose very survival depends on evading our medical armamentarium.
While antibiotics still work today for most infections, for tens of thousands of people every year, that `post-antibiotic era' is already here. According to a recent report from the CDC:
In the 2019 report, the last year comprehensive healthcare and community data were available to calculate, CDC estimated that more than 2.8 million antimicrobial-resistant infections occur in the U.S. each year, with more than 35,000 people dying as a result.
While I cover AMR topics occasionally in this blog, I can heartily recommend CIDRAP's Antimicrobial Stewardship Project as the best place to learn about the growing global threat of AMR.
