Why can a chigoe flea infestation lead to secondary infections?

A chigoe flea infestation, caused by the jigger flea (Tunga penetrans), leads to secondary infections primarily because the female flea burrows directly into the host's skin, typically on the feet.1

As the pregnant flea develops, it lives within a cyst that forms around it, which continues to enlarge as the flea's abdomen swells to the size of a pea. This process causes intense itching, and the resulting open or irritated skin site created by the burrowing and the cyst formation provides an entry point for pathogens, which can lead to serious secondary infections.1