CNN
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A California girl’s hand lump is mysterious – and growing. It wasn’t until he saw two doctors and underwent a biopsy that his family realized the cause: The boy had bitten into a hungry iguana with a sweet tooth, resulting in what may be the first documented infection of a rare bacterial infection. infection in a person from an iguana bite.
The girl, Lena Mars, was featured in a scientific presentation on the case to be given at the European Congress of Clinical Microbiology and Infectious Diseases in April. He is still recovering at his family home in San Jose, California after the unexpected ordeal, which began on a vacation in March 2022.
Mars and his parents, Julian and Luisa, traveled to Costa Rica. While enjoying one of the country’s many beautiful beaches, the girl’s parents gave her a snack. But it turns out she’s not the only one who’s hungry: A wild iguana appears as the young woman eats her cake by the water.
Iguanas are common in Costa Rica. They are harmless herbivores, known mostly for sunning themselves under trees and eating fruits and leaves, but experts say this animal may have a sweet tooth.
The iguana ran up to the girl and bit her on the back of her left middle finger, causing her to loosen her grip on the cake. The reptile then ran off with the snack, but left something else behind.
Dr. Jordan Mah, an author of the presentation and an expert in medical microbiology, worked on lab testing for the case as part of the Department of Pathology at Stanford University. Mah said the girl’s parents probably didn’t think about the bite when they took her to the doctor because of the lump on her hand.
“I think when they went to get medical attention for the bump initially, the bite kind of slipped their mind because they didn’t see it as a potential exposure, because it just healed. And it was on the side late in the course of treatment, because it got worse, that their memory jogged a bit and they brought it to the doctor’s attention,” he said.
Mah said Mars responded immediately after the iguana encounter. The wound looked superficial, but they took the girl to a local clinic, where staff disinfected the wound with alcohol and gave her five days’ worth of antibiotics.
The wound appears to have cleared up in about two weeks. It wasn’t until five months later, when her parents noticed a dime-size lump on the girl’s hand in the same spot, that they considered taking her to another doctor. The girl told them it didn’t hurt, and there were no other symptoms.
Her pediatrician thought the lump might be a harmless cyst and told her parents to keep an eye on it. But when the tumor continued to grow and began to cause mild pain, her parents took the girl to an orthopedist, who suggested a biopsy.
In November, the doctor removed the 2-centimeter mass. Scientists examined the growth in the lab and discovered that the child had a rare infection Mycobacterium marinum, a non-tuberculous mycobacterium that more commonly causes a tuberculosis-like disease in fish.
It is ubiquitous in fresh and salt water but rarely infects humans. Usually, when people become infected, it is after a wound has been exposed to the bacteria in the water. Most who get these infections develop a rash that may spread in a spherical pattern. It can have a lump with pus or even an ulcer.
Mostly just antibiotics don’t usually work with these types of infections, so doctors started the woman on rifampin, an antimicrobial, and clarithromycin, an antibiotic often used for skin infections. The infection responds well to treatment.
“Typically, with these infections, because they take so long to grow and they’re a little bit faster, you have to treat them for a longer period of time, sometimes months,” Mah said. “That’s why he’s getting better. I won’t say 100%, but he’s better than the first one.
Mah believes this is the first time a person has contracted this type of infection from an iguana bite. He wanted to present the case to warn clinicians of the possibility.
Growing M. marinum in the lab requires lower temperatures than most bacteria. This particular bacteria likes to grow at about 82 to 86 degrees Fahrenheit. Most bacteria culture around 95 to 98.6 degrees, so the diagnostics are slightly different. With lizards and iguanas having lower body temperatures than humans, Mah said, they may be the perfect host for this type of bacteria.
“We know a lot about animal bites and bacteria, infections, following, say, dogs or cats, but really not much for lizards, let alone iguanas,” he said. “I don’t think people should be scared, but doctors should be aware of the possibility.”
Iguanas native to South and Central America and Mexico have become an invasive species in South Florida, Hawaii, Texas and Puerto Rico, so people can have more encounters with them. But experts who work with iguanas say they’re usually pretty harmless, so there’s no reason to fear them.
Anna Meyer, operations manager at Iguanaland, Florida’s largest reptile zoo, said the behavior of one in this case was unusual.
“Usually, they’ll go about their day and don’t want to bother anyone or be bothered by anyone. But like any wildlife, if they start to associate people with food, they’ll risk getting too close,” Meyer said. In this case, other tourists in Costa Rica may have fed the wild iguana until it became habituated to people and developed certain expectations of them.
“That’s an animal that has become accustomed to people feeding it,” Meyer said. Perhaps it realizes that it can get a “higher amount of food” from the baby without too much risk to itself.
The lesson here, he said, is that no one should feed wildlife, because the animal thinks that stealing food from a child is, well, like taking candy from a baby.
“The cake has more calories than the mango or the leaf,” he said.
The Mars family said their son is still recovering from his injury, and they praised him for the spirit with which he handled the entire experience.
“Our daughter, Lena, celebrated her 4th birthday and is still recovering from the operation in November. The wound is still closing, and the whole healing process took more energy than the bite,” the family said in a statement. “Lena is the bravest child we can think of, and she handled the situation well. She definitely remembers the bite and knows the bacteria came from the iguana. She probably won’t forget the experience, but we hope that one day we can all laugh at what happened.”
