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Bartonella quintana infection

Background

Overview

Definition
Bartonella quintana infection, also known as trench fever, is a bacterial infection caused by the intracellular Gram-negative bacterium Bartonella quintana.
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Pathophysiology
Bartonella quintana, an intracellular, Gram-negative bacterium, is primarily transmitted by the body louse (Pediculus humanus humanus) through louse feces on altered skin. The bacterium invades endothelial cells and is released every 4-5 days, leading to relapsing fever. Bartonella quintana can also invade RBCs and persist for months, evading the host immune response and reducing the efficacy of antimicrobial therapy.
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Risk factors
Risk factors for Bartonella quintana infection include immunocompromised states, such as HIV infection and organ transplantation, as well as homelessness and poor sanitation increasing the risk of exposure to body lice, the primary vector of Bartonella quintana.
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Disease course
Trench fever typically presents with recurrent febrile episodes, often following a 5-day fever pattern, followed by a week of resolution. It is usually accompanied by other symptoms such as headache, myalgia, bone pain, maculopapular rash, anorexia, and sweating. Severe complications of Bartonella quintana infection, such as endocarditis, bacillary angiomatosis, and neurological manifestations, can occur in immunocompromised patients.
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Prognosis and risk of recurrence
Bartonella endocarditis is associated with a 9-12% mortality rate. Bacillary angiomatosis may be life-threatening if left untreated.
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Guidelines

Key sources

The following summarized guidelines for the evaluation and management of Bartonella quintana infection are prepared by our editorial team based on guidelines from the U.S. Department of Health and Human Services (DHHS 2025) and the Infectious Diseases Society of America (IDSA 2008).
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Diagnostic investigations

Serologic testing: as per DHHS 2025 guidelines, measure anti-Bartonella indirect fluorescent antibody immunglobulin G antibody titers at the time of diagnosis and, if positive, followed with sequential endpoint titers every 6-8 weeks during treatment, preferably until at least a fourfold decrease is documented.
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Medical management

Preferred therapy: as per DHHS 2025 guidelines, administer doxycycline (100 mg PO or IV every 12 hours) or erythromycin (500 mg PO or IV every 6 hours) for the management of bacillary angiomatosis, bacteremia, or osteomyelitis caused by Bartonella quintana in patients with HIV infection.
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  • Alternative therapy

  • Suppressive therapy

  • Antiretroviral therapy

Specific circumstances

Pregnant patients
As per DHHS 2025 guidelines:
Adminisyer erythromycin or an alternative macrolide rather than tetracyclines (such as doxycycline) as first-line therapy during pregnancy due to toxicity profile.
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Consider administering third-generation cephalosporins as second-line therapy during pregnancy. Do not use first- and second-generation cephalosporins because of their lack of efficacy against Bartonella.
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  • Patients with Bartonella bacilliformis infection

Preventative measures

Eradication of body lice: as per DHHS 2025 guidelines, counsel patients with HIV experiencing homelessness or in marginal housing about the risks of serious illness associated with body louse infestation and provide appropriate measures to eradicate body lice, if present.
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  • Primary prophylaxis

Follow-up and surveillance

Management of treatment failure
As per DHHS 2025 guidelines:
Consider switching to a different preferred regimen (for example, from doxycycline to erythromycin) in patients failing to respond to initial treatment, again with treatment duration of ≥ 3 months. Add a rifamycin class antibiotic for severe infections.
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Continue treatment until at least a fourfold decrease in the antibody titers is documented in patients with positive or increasing antibody titers, but with clinical improvement.
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