What is Shigella Bacteria? Experts explain shigellosis symptoms, causes and treatments as drug-resistant cases raise concern

The cases of Shigella bacteria ‘extremely drug resistant’ are on the rise and pose a “serious threat to public health,” the Centers for Disease Control and Prevention warned last week. In February 2022, the UK reported 84 cases of ultra-drug resistant Shigella, an unusually high number for the region. Hundreds of cases in travelers returning to the United States and other countries in Europe from Cape Verde resorts included some cases of multi-drug resistance.

The CDC said there are signs that the percentage of Shigella bacteria cases resistant to a wide range of antibiotics has started to climb sharply in the United States. Antimicrobial resistance occurs when germs such as bacteria or mushrooms develop mutations and no longer respond to drugs designed to fight them, making it more difficult to treat these infections or illnesses, according to the World Health Organization. antibiotic resistant “superbugs” are a growing concern worldwide.

These strains can also spread their resistance genes to other stomach bugs, so that typical antibiotics that were successful in the past no longer work, leading to more illness and death from diseases that were previously curable. .

“We are seeing an increase in infections that are actually resistant to all first-line antibiotics,” infectious disease physician Dr. Payal Patel told CBS News. “It’s important not only for the public to know this, but for doctors to know and watch out for it in case they see a patient with this infection.”

What is Shigella Bacteria?

Shigella bacteria are gram-negative, rod-shaped bacteria recognized worldwide as the most common cause of dysentery, a gastrointestinal disease resulting in severe diarrhea. According to the American Academy of Pediatricians, there are four species of Shigella bacteria, and one of the four species only causes gastrointestinal infection in humans.

The bacteria causes an infection called shigellosis, which the CDC says infects about 450,000 people a year in the United States. An estimated 242,000 infections involve antimicrobial resistant strains.

Shigella bacteria that have developed resistance to all standard first-line antibiotics – known as “drug resistant” or XDR Shigella – first start to spread in the United States in 2015 by Americans who probably picked it up overseas. The CDC says 5% of all Shigella test samples collected in 2022 were classified as XDR, up from 1% in 2019.

States have reported 148 cases to the CDC of drug-resistant outbreaks, the agency said Feb. 28; 39% of these cases resulted in hospitalization. No deaths have been reported.

How is Shigella Bacteria Spread?

Shigella is found in the intestinal tract of humans and can be easily transmitted through contaminated food or water or by touching objects containing fecal germs and then touching the mouth. The bacteria is highly contagious and it only takes a small trace to infect another person, the CDC explains.

Medical experts say that washing your hands thoroughly and frequently with soap and water, especially after using the bathroom, is the best way to protect yourself from infections. Travelers should also drink bottled or filtered water to reduce the risk of infection.

Asymptomatic carriers can transmit the disease. Additionally, sexual transmission has become an important route for the spread of shigellosis, the World Health Organization has said.

What are the symptoms of a Shigella infection?

Symptoms of a shigella infection include watery or loose stools. The incubation period is 12 to 96 hours after exposure. Symptoms usually begin one to two days after infection and can last up to seven days.

In some cases, symptoms can be more severe and include fever, stomach pain and cramps, and mucus-filled or bloody stools. Other reported symptoms include nausea, vomiting, loss of appetite, headache and malaise.

“If you have bloody diarrhea more than three times a day and you can’t hold anything back, now is a good time to start thinking about going to the ER,” Patel says.

In some cases, bowel habits (the frequency and consistency of stools) do not return to normal for several months, the CDC explains.

Who is at risk for Shigella infection?

Anyone can get sick from Shigella bacteria.

Children are more likely to get shigellosis because they often get infected when they put their hands carrying small amounts of bacteria in their mouths. Day care centers and schools frequently experience outbreaks. Children and teachers should wash their hands frequently to reduce the spread of disease.

The CDC says the data suggests that the strains of Shigella circulating so far in children are almost all susceptible to antibiotics.

Public health agencies say other high-risk groups for shigellosis include men who have sex with men, international travelers who drink contaminated water, and people with weakened immune systems.

Most drug resistance outbreaks have been reported in adults who are international travelers, men who have sex with men (MSM), people living with HIV, or homeless, the CDC said.

“The highest proportion of XDR cases are in adult males (85%). These trends are also consistent with recent increases in outbreaks of antimicrobial resistant shigellosis among MSM,” CDC’s Dr. Naeemah Logan said in a statement. communicated.

Is there a treatment or cure?

Most people recover from a Shigella infection without going to the hospital or taking antibiotics. The most common recommendation is bed rest and fluids, and patients can recover in 5-7 days.

But sometimes the infection can be serious. Shigella bacteria are one of the leading causes of death from diarrheal disease worldwide.

“Only use antibiotics if your doctor has prescribed them, and try to be aware of antimicrobial resistance and what we can do as citizens to ensure we save antibiotics for our children,” says Patel.

Lab tests can determine if a Shigella infection involves “extremely drug resistant” bacteria. XDR Shigella has shown resistance to all generally recommended first-line antibiotic treatments: azithromycin, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole and ampicillin.

For patients with drug-resistant infections who need to be treated with antibiotics, doctors must search for a handful of options that are largely untested or generally unavailable. In a recent webinar, the CDC highlighted the drugs fosfomycin and meropenem as potential options that have been used overseas, but acknowledged that there was far from enough evidence for “official recommendations.” of the agency.

–Reporting provided by Alexander Tin

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