Researchers from the Institut Pasteur warn of the appearance of strains of “Shigella sonnei” (shigella) highly resistant to antibiotics, in France. These bacteria are responsible for shigellosis, an infection of the intestine responsible for diarrhoea, sometimes bloody.
[Mise à jour le 22 mars 2023 à 15h04] Among bacterial infections, shigellosis. This one is very contagious and touch them intestines. It is characterized by intense symptoms to type of bloody diarrhea. Several strains of shigellas or “shigella” (bacteria responsible for shigellosis) exist. However, researchers from the Institut Pasteur warned in a press release of March 15, 2023 of the appearance of strains of “Shigella sonnei” highly resistant to antibiotics, in France. “These strains, originating in South Asia, are spreading especially among men who have sex with men“. They are also called XDR for “extensively drug-resistant”. Studies by French scientists have shown that these bacteria are resistant to antibiotics such as ciprofloxacin, azithromycin and the cephalosporins. There shigellosis is a disease whose transmission is fecal-oral.
Definition: what is shigellosis?
Shigellosis (also called bacillary dysentery) designates a infectious disease caused by bacteria of the genus Shigella. It mainly affects tropical regions and leads to the death of several hundred thousand people a year in developing countries, in particular the children under 5 years old. “These bacteria are capable of causing a digestive infection, rarely a disseminated infection, which will destroy the intestinal epithelial cells then the tissue constituting the recto-colic mucosa, details the Professor Jean Paul Stahl, specialist in Infectious and Tropical diseases. This process results in intense inflammation with varying degrees of tissue destruction. Shigellosis causes bloody diarrhea. It often progresses to spontaneous healing after a few days. And faster after administration of antibiotics. In 2007, the National Reference Center for Escherichia coli and Shigella (Institut Pasteur) identified more than 850 strains of Shigella.
What is Shigella sonnei?
Among the different types of Shigella, Shigella sonnei is the majority type that circulates in industrialized countries or in the process of industrialization. Infection can lead to short-lived diarrhea (3-4 days). “Antibiotic treatment becomes necessary, however, for moderate to severe cases (bloody diarrhea, risk of complications) or to stop transmission between people in epidemic contexts” explain the scientists of the Institut Pasteur. The acquisition by the bacterium of mechanisms of resistance to antibiotics then limits the therapeutic options.
What causes shigellosis?
Shigellosis is caused by bacteria belonging to the genus Shigella called “shigella”. According to the Institut Pasteur, the most common species in developing countries, and responsible for the most severe symptoms are Shigella flexneri, causing the endemic form of the disease, and Shigella dysenteriae serotype 1 (or Shiga bacillus), responsible for sudden epidemics. another species, Shigella sonnei, is prevalent in emerging and industrialized countries.
Is shigellosis contagious?
The disease is highly infectious and can be transmitted through food or drink. Transmission by human contact is very rare.
Shigella are transmitted by fecal-oral route (by the stools of infected patients or convalescent carriers): 10 to 100 bacilli are enough to cause the disease. Man is the only reservoir and can eliminate these bacteria in his stool for weeks after a dysenteric episode. Direct contagion is via the orofecal route. “It’s a disease linked to a lack of hygiene, continues the specialist. Indirect contagion is through food, water or objects contaminated with excreta containing ShigellaFlies can also transmit the disease.
“Hands should be washed thoroughly before handling food”
What are the symptoms of shigellosis?
The incubation period of Shigella is between 1 and 4 days. “It usually manifests abruptly with abdominal pain, numerous diarrheas (10 to 30 per day), and blood in the stools“, says the Professor. “A high fever at 40°C may be present”. Of the complications can however enamel the evolution of the disease, especially in infants and young children: hypoglycaemia, bacteraemia or sepsis, dehydration due to fever and abundant fluid and electrolyte losses from diarrhea, collapse, acute renal failure, intestinal obstruction, peritonitis. “In children, diarrhea is one of the leading causes of death in poor countries, through dehydration”, recalls Professor Stahl.
How long does shigellosis last?
“If left untreated, the disease can become chronic”insists the doctor. “But with antibiotic treatment, the disease progresses spontaneously to recovery within a few days.”
“The diagnosis is not always obvious in view of significant diarrheathat’s why the doctor asks for a stool bacteriology”, inform the doctor. “In addition, the examination of the mucosa by endoscopy found multiple ulcerations.”
What are the treatments for shigellosis?
The treatment is based on antibiotics, but we note the emergence of multi-resistant strains (S. flexneri and S. dysenteriae).
In adults, we will use:
- A fluoroquinolone (such as ciprofloxacin 500 mg orally every 12 hours for 3 to 5 days)
- Azithromycin 500 mg orally on day 1 and 250 mg orally once a day for 4 days
- Ceftriaxone 2 g/day IV for 5 days
In children:
- Ceftriaxone 50 mg/kg (maximum 1.5 g) IV once a day for 5 days
- Azithromycin 10 to 12 mg/kg orally as a single dose on day 1, followed by 6 mg/kg (maximum 250 mg) once/day for 4 days
“Prevention is based on sanitary measures and in particular learning about hygiene. Hands must be carefully washed before handling food”, concludes our interlocutor.
Thanks to Dr. Jean Paul Stahl, professor of infectious and tropical diseases at Grenoble University Hospital.
Source: Emergence in France of a strain of Shigella Sonnei highly resistant to antibiotics, press release from the Institut Pasteur, March 15, 2023.