CASE HISTORY Brad,a Nine-Year-Old from Connecticut,developed a Fever and a Large (8

CASE HISTORY
Brad,a nine-year-old from Connecticut,developed a fever and a large (8 cm) reddish rash with a clear center (erythema migrans) on his arm.He also had some left facial nerve palsy.Brad had returned a week earlier from a Boy Scout camping trip to the local woods,where he did a lot of hiking.When asked by his physician,Brad admitted finding a tick on his stomach while in the woods but thought little of it.The doctor ordered serological tests for Borrelia burgdorferi (the organism that causes Lyme disease) ,Rickettsia rickettsii (which produces Rocky Mountain spotted fever) ,and Anaplasma phagocytophilum (which causes ehrlichiosis) .The ELISA for B.burgdorferi came back positive,confirming a diagnosis of Lyme disease.The boy was given a three-week regimen of doxycycline (a tetracycline derivative) ,which led to resolution of the rash and palsy.
Which is true of B.burgdorferi and Lyme disease?

A) It is commonly transmitted via the bite of the deer tick, but may also be transmitted by rabbits, rodents, and mosquitoes.
B) B. burgdorferi is a spirochete bacterium with an unusual genome.
C) Lyme disease can be contracted only in the United States and is named for the community of Lyme, Connecticut.
D) Most people naturally clear Lyme infection without treatment; fewer than 10% naturally progress to stage 2 infection.