A young girl has become the victim of an unusual crime and the subject of the first reported case of a Mycobacterium marinum infection from a cake-snatching iguana.

While vacationing with her family in Costa Rica, the three-year-old was eating cake when the reptile suddenly bit her on the left hand before scampering off with the snack, the treating doctors report.

The single superficial bite over her third metacarpal was disinfected and treated with five days of amoxycillin prophylaxis for potential salmonella poisoning, which is common after reptile bites.

The wound completely resolved, said US doctors, who will present the case at the European Congress of Clinical Microbiology and Infectious Diseases in Copenhagen this month.