A macaque suffering from diarrhea caged at a primate importation and breeding facility in Florida. Photo obtained by PETA.
Yemassee, S.C. - PETA today released a new report showing that Shigella, a highly contagious, often drug-resistant pathogen spread through fecal contamination, for which humans and other primates are the only natural hosts, is widespread and often un- or underreported among monkeys in the U.S. experimentation industry. The findings raise serious public health concerns as infected monkeys are transported among importers, quarantine facilities, breeders, contract laboratories, and universities across the country. There are more than 100,000 monkeys currently in U.S. laboratories, breeding, and holding facilities.
In a letter sent today, PETA urges the Centers for Disease Control and Prevention (CDC) to publicly release pathogen surveillance data tied to primate experimentation, including Shigella prevalence, antimicrobial resistance profiles, and documented worker exposures. The letter argues that the CDC cannot warn the public about rising drug-resistant Shigella infections while withholding information about a known reservoir moving through a federally authorized monkey importation and experimentation pipeline.
PETA’s report comes on the heels of a recent CDC warning about rising cases of extensively drug-resistant Shigella infections in humans. Yet the agency failed to acknowledge that primates, long recognized as a natural reservoir for Shigella, are a documented source of infection, even though the CDC acknowledges that imported monkeys can carry pathogens “that may be a public health concern such as clinical signs consistent with filovirus infection, confirmed Shigella and Campylobacter infection, and malaria.”
Compiling years of scientific publications, veterinary and necropsy records, and institutional documents, PETA’s report shows that Shigella is an entrenched pathogen circulating throughout the U.S. monkey research industry, infecting workers, persisting in colonies, and contributing to the emergence and spread of multidrug-resistant strains. As one attendee at a University of Washington Safety Committee meeting observed, “Virtually everyone who works in the [primate] units gets ill at some point in their first 6 months, due to meeting staph and Shigella for the first time and being around aerosolized fecal matter.” The University of Washington is home to one of the seven federally funded National Primate Research Centers.
Monkeys have been transported with contagious gastrointestinal disease despite that no illness was documented on their records, PETA found. Just days after 68 monkeys were trucked from the University of Washington's breeding facility in Arizona to Seattle in September 2023, 47 tested positive for Shigella. Yet, they were certified for transport with zero signs of infectious disease.
“Drug-resistant Shigella is swirling throughout the U.S. monkey experimentation and importation world, where chronic diarrheal disease in primate colonies fuels ongoing transmission, repeated antibiotic exposure, and risks to both workers and public health,” says PETA Senior Science Advisor on Primate Experimentation Dr. Lisa Jones-Engel. “Shigella infections in humans are reportable nationwide, and the CDC has no defensible reason to allow infections in monkeys in the experimentation pipeline to remain invisible to public health authorities.”
Reps. Greg Steube (R-Fla.-17) and Dina Titus (D-Nev.-01) have introduced a bipartisan bill, the Preventing Risky Importation of Monkeys to Avoid Toxic Exposures (PRIMATE) Act (HR 8471), that would ban the importation of monkeys for use in U.S. laboratories. This would end the introduction and spread of pathogens that accompany monkeys brought to the U.S. In 2025, more than 22,000 primates originating from facilities in Asia and Africa were sent to the U.S.
PETA—whose motto reads, in part, that “animals are not ours to experiment on”—points out that when it comes to the ability to feel pain, hunger, and thirst, a monkey is a dog is a boy. For more information, please visit PETA.org or follow PETA on X, Facebook, or Instagram.