An “aggressive” rhesus monkey reportedly infected with Covid, hepatitis C, and herpes escaped in Mississippi on Tuesday afternoon after a truck transporting lab primates overturned on an interstate. The truck, carrying a shipment of rhesus monkeys from a research facility affiliated with Tulane University, went off the road into a ditch north of Heidelberg, according to the Jasper County Sheriff’s Department.

Panic follows as escaped monkey evades massive search effort

The sheriff’s department said the roughly 40-pound monkeys were carrying Covid, hepatitis C, and herpes, and warned that they were “aggressive to humans.” Officials cautioned against handling the animals without protective equipment, according to a New York Post report. The crash damaged the animals’ cages, allowing several to escape into a nearby valley. While it remains unclear exactly how many monkeys were being transported, all but one of the escapees were quickly captured and euthanized. Authorities urged anyone spotting the remaining monkey to call 911 and keep a safe distance.

Tulane University disputes claims, says monkeys are not infectious

Tulane University pushed back on the sheriff department’s characterization of the animals as infectious. In a statement, the university said the non-human primates at its National Biomedical Research Center are supplied to other research organizations for scientific purposes, clarifying that the monkeys involved in the crash belonged to a different entity and were not infectious. The university added that it was coordinating with local authorities and would send an animal care team to assist as needed.

As of 2 pm Tuesday, the sheriff’s office, along with Mississippi Wildlife and Fisheries and an animal disposal company, was continuing to search the area for the missing monkey.

An adult rhesus monkey typically weighs between 9 and 26 pounds depending on sex. The species’ close genetic resemblance to humans makes it a common subject in scientific research. According to National Geographic, mature female rhesus monkeys generally produce at least one offspring per year, meaning the species’ population isn’t a conservation concern. Rhesus monkeys have played a notable role in scientific history, including Albert II, the first monkey sent into space by the United States in 1948, and their role in helping researchers identify different human blood groups through rhesus antigens.