There has been an extensive increase in the drug-resistant Shigella bacteria responsible for watery and possibly bloody diarrhea, according to the latest data.

The U.S. Centers for Disease Control and Prevention (CDC) issued a health advisory Friday warning the public of the potentially serious public health concern.

According to the advisory, the national surveillance systems saw an increase in extensively drug-resistant Shigella infections. Cases due to XDR strains reportedly jumped 5% in 2022 compared to 0% in 2015.

Since the strains are resistant to antibiotics, clinicians treating patients only have limited treatment options. What’s more, is that Shigella bacteria are easily transmissible.

Shigella can be transmitted in multiple ways aside from the fecal-oral route. Direct contact between person-to-person, sexual contact and indirect contact through contaminated food and water are ways by which the bacteria spread.

The characteristic symptom of shigellosis is diarrhea, which often contains mucus or blood. Other signs and symptoms present include stomach pain or cramps, fever and nausea or vomiting. The symptoms usually last for about five to seven days or even longer in some cases, as per the Mayo Clinic.

Aside from being easily transmissible, the new drug-resistant strains can spread antimicrobial resistance genes to other bacteria that infect the intestines, causing a more serious health issue.

“Given these potentially serious public health concerns, CDC asks healthcare professionals to be vigilant about suspecting and reporting cases of XDR Shigella infection to their local or state health department and educating patients and communities at increased risk about prevention and transmission,” the CDC stated in its advisory.

Shigella causes an infection called shigellosis that typically affects young children. However, the rise in antimicrobial-resistant strains has been pronounced in adult populations, especially in men who have sex with men, people living with HIV, those who travel internationally and homeless individuals, CNN reported.

The new strains are resistant to commonly prescribed antibiotics, including azithromycin, ceftriaxone, ciprofloxacin, trimethoprim-sulfamethoxazole and ampicillin. The CDC has yet to release recommendations for optimal antimicrobial treatment.

A 2019 CDC report indicated that the U.S. witnesses more than 2.8 million antimicrobial-resistant infections and around 35,000 deaths each year.

Meanwhile, the World Health Organization (WHO) previously reported an estimated 5 million deaths due to drug-resistant pathogens in 2019. The death toll is expected to jump to 10 million by 2050, if no interventions are made.