Andrea Cox, M.D., Ph.D., Christopher J. Hoffmann M.D., M.P.H.
Bartonella spp. described in ticks, canines and felines in many African locales, so clearly endemic.
- Little literature in either HIV+ or non-HIV+ patients in Africa. Most described disease from North Africa/Mediterranean regions, and these are of endocarditis, not bacillary angiomatosis or peliosis hepatis.
- One study in S. Africa suggested 10% of their HIV clinic had Bartonella bacteremia (see Frean J, et al. reference). Unclear if this is representative.
Zambia Information Author: Paul Auwaerter, M.D.
- Definition: blood filled cavities (lakes) in liver that develop through Bartonella-induced neo-angiogenesis. Often accompanied by peliosis in the spleen.
- Causes: in HIV+ pts usually caused be infection by Bartonella spp. In HIV-negative (and some HIV+) pts, caused by anabolic steroids, Castleman's disease, Hodgkin's lymphoma, leukemia, other malignancies including hepatic tumors
- Pathogens: Bartonella henselae and B. quintana (formerly known as Rochalimea henselae and R. quintana)
B. henselae: linked to cat and flea exposure
B. quintana: linked to homelessness, low-income, and lice exposure
- Small, fastidious, gram-negative aerobic bacilli
- Occurs at low CD4 counts; usually <100
- May be associated with immune reconstitution inflammatory syndrome (IRIS) and higher CD4 count during reconstitution
- Characterized by multiple, small, dilated blood-filled cavities in hepatic & splenic parenchyma.
- Sx: indolent course of fevers, nausea, abdominal pain, & malaise.
- PE: hepatosplenomegaly, 10-30% may also have bacillary angiomatosis
- Lab: alk phos 5-10 x ULN, ALT & AST may be 2x ULN; thrombocytopenia & pancytopenia have been reported
- Rarely may cause hypovolemic shock in HIV+ pts due to hepatic hemorrhage.
- Blood Cxs rarely positive for Bartonella, Cx sensitivity increases with use of isolator tubes or tubes containing EDTA; specific lab conditions required to enhance yield, so notify lab of suspicion for Bartonella infection.
- Definitive Dx by isolating organism from Cx of blood or tissue. Warthin-Starry silver staining shows masses of small, dark staining bacteria. staining, PCR, and serology findings.
- Abdominal CT: hepatomegaly +/- splenomegaly with hypodense lesions scattered throughout liver parenchyma. Other conditions producing similar radiographic findings: lymphoma, disseminated MAC, hepatic KS, and extrapulmonary pneumocystosis.
- Serologic methods (based on studies of cat scratch disease [CSD]): IFA and EIA. IFA IgG titer <1:64 suggests no infection;1:64 - 1:256 suggests possible infection;>1:256 suggests active or recent infection. Repeat testing in 10-14 days for titers suggesting possible infection. HIV and low CD4 associated with decreased probability of seropositivity. Anti-B. henselae IgM recently shown to be useful in Dx of CSD.
- Given presence of Ab titers to B. henselae of >1:256 in 4.8% of healthy controls (Sander Aet al. ref.) and lower likelihood of detectable Abs with low CD4 (Mohle-Boetani JC et al. ref.), PCR may be more useful in pts with AIDS. Can distinguish between Bartonella spp.