Bartonella infection

Last reviewed:December 2019

Last updated:March 2018

Summary

Infectious disease caused by various species of the bacterial genus Bartonella; the three most important pathogens responsible for the majority of infections are B henselae, B quintana, and B bacilliformis.

Some species are worldwide in distribution (B henselae), whereas others are geographically localised (B bacilliformis).

Bartonella species are transmitted from an infected natural host to the susceptible human host either by direct contact (cat bite or scratch for B henselae) or via an insect vector (body lice for B quintana, sand fly for B bacilliformis).

Bartonella species infect erythrocytes and cause vascular proliferation, giving rise to prolonged fever, lymphadenopathy, and hepatosplenomegaly.

Laboratory diagnosis is established by culture, serology, or histopathology. Molecular techniques such as polymerase chain reaction (PCR) are useful for blood and tissue specimens, including heart valves, where available.

Treatment depends on the species of Bartonella and the type of clinical presentation, but usually consists of antibiotic therapy. In some cases (e.g., cat-scratch disease), needle aspiration may be necessary.

Definition

Human bartonellosis is caused by Bartonella, a genus of facultative intracellular bacteria. Since 1993, 45 Bartonella species have been identified, some of which have been reported to cause human infections.[1][2][3]

The three most common infections described in humans include: cat-scratch disease (B henselae); Carrion's disease (B bacilliformis), which consists of a bacteraemic phase (Oroya fever) and an eruptive phase (verruga peruana or Peruvian wart); and trench fever (B quintana).[4][5]

Bartonella species are responsible for a broad spectrum of clinical syndromes, including prolonged fever of unknown origin, haematological manifestation, encephalitis and encephalopathy, generalised lymphadenopathy, hepatosplenic disease, retinopathy, culture-negative endocarditis, osteomyelitis, arthritis, mediastinal mass, and pleurisy.[4][5]

B henselae and B quintana are also known to cause bacillary angiomatosis in immunocompromised hosts.[4][5]

Human infections caused by other species of Bartonella (e.g., B vinsonii, B elizabethae, B clarridgeae, B grahamii, B alsatica, B rochalimae, B washoensis, and B koehlerae) do occur but are rare.[5][6][7][8][9][10][11]

Although predominantly an animal species, B vinsonii subsp. berkhoffii has been noted to cause human disease.[12] Infections caused by B vinsonii subsp. arupensis in humans have been reported in France, Russia, and Nepal causing febrile illnesses, suggesting they are geographically widespread.[13]