Bartonella Antibody Panel, IgG and IgM, Serum (LAB785); Bartonella, Molecular Detection, PCR, Varies (BARRP)

Serology is the mainstay of diagnostic testing for detection of Bartonella with rare indications for supplemental molecular testing.

Clinical Background
  • Cat scratch disease (CSD) is caused by Bartonella henselae, which is carried bythe cat flea (Ctenocephalides felis).Humans are typically infected via scratches, bites, or licks from infected cats or kittens.
  • Symptoms of typical CSD may begin with an erythematous papule at the site of injury, and progress to fever, lymphadenopathy, and fatigue. Fever and fatigue usually resolve within two weeks, while lymphadenopathy may persist for several months. Immunodeficient patients are at increased risk for extranodal CSD with additional complications.
  • The primary diagnostic test for B. henselae infection is the Bartonella antibody panel (LAB785), which is performed at Mayo Clinic, results within 1-3 days, and provides results for B. henselae IgG and IgM, as well as B. quintana IgG and IgM. An IgG titer value of ≥1:256 is usually indicative of recent infection. A real-time PCR performed on tissue for Bartonella is also available (BARRP) as a send-out to Mayo Clinic.
Common Pitfalls
  • CSD is typically acquired via scratches from an infected cat. Typical symptoms include lymphadenopathy, fever, and fatigue.
  • Laboratory diagnosis of CSD is made via serum serology, which is rapid and quantitative. Tissue PCR could aid in diagnosis in certain contexts. Blood PCR is not indicated for diagnosis.
Key Takeaways
  • Serology
    • Approximately 25% of patients will remain IgG positive for over a year after infection
    • Some patients may serorevert to negative despite progression to chronic disease
    • There is significant cross-reactivity between B. henselae and B. quintana
    • Coxiella burnetti, Chlamydia species, Brucella species, and Enterococcus faecalis may cause false positive results
  • PCR
    • Testing on blood is not indicated for typical CSD diagnosis due to low sensitivity
    • PCR methods demonstrate variable sensitivity depending on timing and progression of disease
References
  1. Portia Mira, Elitza S. Theel. Update on common Bartonella infections. Clinical Microbiology Newsletter, Volume 47, 2024, Pages 1-8, ISSN 0196-4399, https://doi.org/10.1016/j.clinmicnews.2024.05.002.
  2. Nelson CA, Saha S, Mead PS. Cat-Scratch Disease in the United States, 2005–2013. Emerging Infectious Diseases. 2016;22(10):1741-1746. doi:10.3201/eid2210.160115.

Written By: Justin Burk, DO

Reviewed By: Rebekah Dumm, PhD

Last Edited: 2025-01-10

Last Reviewed: 2025-01-10