Five species of Bartonella have been found to infect humans, henselae,
quintana, elizabethae, bacilliformis, and vinsonii. The most common o
f these in North America are Bartonella quintana and Bartonella hensel
ae, the agents of trench fever, bacillary angiomatosis, and parenchyma
l peliosis, and in the case of B. henselae cat-scratch disease. B. bac
illiformis is endemic in Peru and Ecuador, where it causes oroya fever
or Carrion's disease. New methods of diagnosing Bartonella infections
have resulted in increased recognition of the many manifestations of
these infections. Early recognition is crucial, as these are potential
ly fatal opportunistic infections that usually respond rapidly to appr
opriate antimicrobial therapy.