It is caused by the bacterium Rickettsia typhi, and is transmitted by the fleas that infest rats. While rat fleas are the most common vectors, cat fleas and mouse fleas are less common modes of transmission. These fleas are not affected by the infection. Human infection occurs because of flea-fecal contamination of the bites on human skin. Rats, cats, opossums maintain the rickettsia colonization by providing it with a host for its entire life cycle. Rats can develop the infection, and help spread the infection to other fleas that infect them, and help multiply the number of infected fleas that can then infect humans. Less often, endemic typhus is caused by Rickettsia felis and transmitted by fleas carried by cats or opossums. In the United States of America,<unk>  is found most commonly in southern California, Texas and Hawaii. In some studies, up to 13% of children were found to have serological evidence of infection.
Murine typhus
Scrub typhus
Haverhill fever
Epidemic typhus
Flying squirrel typhus
Boutonneuse fever
Tomato fever
Scarlet fever