Bitten by an iguana? You could get a rare bacterial infection, new study says

Iguanas, those pesky green critters that come out in full force during the summer months in South Florida, are more than just a nuisance. They also pose health risks.

While touching an iguana or its feces can cause salmonella, a new Centers of Disease Control & Prevention report links an iguana’s bite to a rare bacterial infection called mycobacterium marinum.

The discovery came after a  3-year-old girl from California and her family had taken a trip to Costa Rica. While eating cake on the beach, an iguana snapped it out of her left hand and bit her. The girl was immediately taken to a local clinic and found to have a superficial bite for which doctors gave her a five-day course of oral amoxicillin. But five months later, a cyst appeared.

After it was removed and biopsied, scientists took a closer look at the growth in the lab and discovered that the child had a rare infection caused by the bite. That type of infection usually infects humans only after a wound has been exposed to the bacteria in water.

Most antibiotics alone don’t typically work on mycobacterium marinum, so doctors put the girl on rifampin, an antimicrobial, and clarithromycin, an antibiotic often used for skin infections. A report shows the infection responded well to the treatment.

Out of control iguanas infesting South Florida

Dr. Jordan Mah, the author of the report that will appear in the June 2023 issue of Emerging Infectious Diseases, CDC’s monthly peer-reviewed public health journal, said it’s not unusual for it to take a few months for a growth to surface. Usually mycobacterium marinum is assoiated with snake bites, he said.

“The course this pathogen takes with this infection happens over a period of time,” said Mah, an expert in medical microbiology who worked at the lab that tested the cyst as a part of the Department of Pathology at Stanford University.

“I think the key thing is not to feed these animals so they don’t get used to associating humans with food,” he said. “I am pretty sure people on the beach fed him and it led to him biting the child to get food.”

Iguanas, particularly the green ones plentiful in South Florida, are herbivores and feed on foliage, flowers and fruit. Some will eat animal material such as insects, lizards, and other small animals, nesting birds and eggs.

Tom Portuallo, owner of Iguana Control, said South Floridians are seeing more iguanas than usual for this type of year because of the unusually warm winter.

Portuallo, in the iguana removal business for 14 years, said he hasn’t heard of anyone getting bitten by an iguana.  “They are not designed to kill prey and are more apt to run away than towards you,” he said.

He has, however, seen dogs get sick from licking iguana feces and children get sick from touching iguana droppings.

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Wherever they bask in the sun, iguanas leave behind their droppings almost as large as dog poop. Since lawns and pool decks are favorite places, it’s easy to accidentally come in to contact with their bacteria-filled droppings.

Portuallo says iguanas cannot be relocated. His company will kill the iguanas and repurpose them into fish chum.

Mah said Floridians shouldn’t worry about getting salmonella or mycobacerium marinum from an iguana who swims in their pool. “It is chlorinated, so that should kill organisms. Even in a fresh water lake or river, you would need a cut for organisms to get in.”

Sun Sentinel health reporter Cindy Goodman can be reached at [email protected].