Bartonella quintana and Bartonella vinsonii subsp. vinsonii bloodstream co-infection in a girl from North Carolina, USA.

The genus Bartonella consists of globally distributed and highly diverse alpha-proteobacteria that infect a wide-range of mammals. Medically, Bartonella spp. constitute emerging, vector-borne, zoonotic, intravascular organisms that induce long-lasting bacteremia in reservoir-adapted (passive carrier of a microorganism) hosts. At times, these bacteria are accidentally transmitted by animal scratches, bites, needles sticks or vectors to animal or human hosts. We report the first documented human case of blood stream infection with Bartonella vinsonii subsp. vinsonii in a girl from North Carolina, USA, who was co-infected with Bartonella quintana. Limitations of Bartonella spp. serology and the challenges of microbiological culture and molecular diagnostic confirmation of co-infection with more than one Bartonella spp. are discussed. When and where these infections were acquired is unknown; however, exposure to rodents, fleas and cats in the peri-equestrian environment was a suspected source for transmission of both organisms.

[Bartonella quintana endocarditis. Aortic localization and mitral valve abscess]. / Endocardite à Bartonella quintana. Localisation aortique et abcès mitral.

Bartonella Quintana is an exceptionally rare cause of endocarditis. The frequency of this condition is increasing and is probably underestimated because of the difficulty in diagnosing. The clinical context is that of socially deprived classes, the agent of transmission of the germ being body lice. The commonest valve affected is the aortic valve. This infection may also give rise to a mitral annulus abscess, as in this particular case. The diagnosis should be suspected in all cases of endocarditis with negative blood cultures in socially deprived patients as special diagnostic methods are required. Bartonellosis serology and drainage of effusions to perform a Gimenez stain to show intra-cellular bacteria and a polymerase chain reaction to sequence the nucleic acids, will give an accurate diagnosis. Similarly, the operative specimens should be sent to a specialised department for the culture of these bacteria (in France, the Marseille Ricketsioses Institute). The treatment of Bartonella endocarditis is very controversial. The usual recommendations are an association of betalactamines and an aminoside for one month and macrolides or tetracyclines. There is lack of consensus about follow-up. It would seem prudent to perform a clinical examination to search for a relapse of the infection and monthly serologies until they return to normal values.