The Centers for Disease Control and Prevention (CDC) has raised concerns about a rise in extensively drug-resistant cases of Shigella, a bacterial infection that is a major cause of inflammatory diarrhea. The new form of the infection is being called a “serious public health threat” by the agency and is spreading rapidly, apparently through sexual contact, both in the U.S. and abroad. The CDC held a call with health officials in Colorado and the U.K. to alert doctors about the spread of a form of the bacterium that is resistant to all typically recommended antibiotic treatments.
A parallel ongoing outbreak of nearly 200 recent extensively drug-resistant cases of Shigella in Britain that the U.K. health agency announced last month most likely stemmed from a single initial infection. The CDC said in a health alert on Friday that the proportion of the approximately 450,000 annual U.S. Shigella infections that were resistant to all known antibiotic treatments rose from zero in 2015 to 0.4% in 2019 to 5% last year, indicating a potential for greater spread.
How Shigella Bacteria Spreads, According to the CDC
Shigella is highly infectious and spreads when infected fecal matter enters the mouth or the nose, including through sexual activity, poor hand-washing after diaper changes, unsanitary food handling or swimming in contaminated water. The European Centre for Disease Prevention and Control issued an alert on Friday about 221 confirmed and 37 possible cases among people who traveled to Cabo Verde off West Africa since September and returned home to about a dozen nations, including the U.S.


The CDC Response to the Rise in Shigella Bacteria
The CDC has called on healthcare providers to be vigilant for potential Shigella infections and to report suspected cases to state and local health departments, while educating people most at risk about shigellosis. In addition to being transmitted by sexual activity, antibiotic-resistant Shigella infections have been on the rise among people experiencing homelessness, international travelers, and people living with HIV.
Doctors face a considerable challenge caring for patients with this form of Shigella as there are limited alternative antibiotics available. The CDC has called on people who have shigellosis to stay home if they work in health care, food service, or child care. The agency advises that during the illness and for two weeks after, people should avoid preparing food for others, wash hands often, refrain from swimming and abstain from sexual contact, or at least observe rigorous hygiene before and after sexual activity.
There’s a Deeper Cause, According to the CDC
The emergence of drug-resistant pathogens is largely driven by the misuse and overuse of antibiotics in people and livestock, and the World Health Organization cites this as one of the top 10 global public health threats facing humanity.