A. Spectrum of Bartonella (Rochalimaea) Infections

1. Cat Scratch Disease
2. Bacillary Angiomatosis
   1. Rare in normal persons
   2. Usually occurs in HIV, transplantation [4], malignancy
3. Febrile Bacteremia
4. Endocarditis
5. Bacillary Splenitis
6. Bacillary Peliosis Hepatis (mainly in HIV infected patients)
7. Granulomatous hepatitis
8. Other: Aseptic meningitis, Trench Fever, Oroya Fever
9. Increased incidence in immunocompromised persons, mainly HIV and transplant [10]

B. Bartonella Species and Diagnosis

1. Small Gram Negative Rods, fastidious, previously thought to be rickettsia
2. Closely related to Brucella and Agrobacterium
3. Five species infect humans:
   1. B. quintana - associated with cat and/or flea exposure [3]; Trench Fever in World War I
   2. B. henselae - associated with with low income, homelessness, exposure to lice [3]
   3. B. elizabethae
   4. B. vinsonii
   5. B. bacilliformis - causes Oroya fever (endemic in Peru)
   6. Novel B. species (related to B. bacilliformis) - case report of fever, splenomegaly [7]
4. In North America, B. quintana, and B. henselae are most common
   1. B. henselae and B. quintana both cause cutaneous bacillary angiomatosis
   2. Only B. henselae is associated with hepatosplenic disease [3]
5. Diagnostic Testing
   1. EIA or ELISA are available for serological testing (serum, plasma or cerebrospinal fluid)
   2. Acute and convalescent titers must be obtained
   3. Indirect immunofluorescent antibody (IFA) specific for Bartonella
   4. Culture from blood (using rabbit blood)

C. Cat Scratch Disease [2,4,5]

1. Bartonella (Rochalemia) henselae is the etiologic agent
   1. Primarily carried by domestic cats
   2. Cats are usually bacteremic at time of transmission
   3. Agent found in cat saliva also
   4. Most often affects immunocompromised hosts [4]
   5. Can occur in normal hosts
2. Clinical Syndrome
   1. Exposure by cat scratch or bite or simply handling cat
   2. Primary papule appears about 1 week after exposure to B. henselae
   3. Regional lymphadenopathy occurs about 2 weeks after exposure
   4. Adenitis may be local, usually with resolution of symptoms in 2-6 months
   5. Liver and spleen may become involved
   6. Severe fevers, systemic illness in minority of cases, including normal immune system [2]
   7. Severe disease with local ulceration and/or bacteremia in immunosuppressed persons
3. Most cases occur in fall or winter; usually young persons
4. Symptoms
   1. Lymphadenopathy in 100%
   2. Fever ~50%
   3. Malaise ~50%
   4. Skin Lesion - pustule, may be necrotic ~25%
   5. Other: anorexia, conjunctivitis, osteomyelitis, retinitis, encephalopathy [6]
   6. Rigors, weight loss, progressive anemia in severe disease [2]

D. Bacillary Angiomatosis [3,4]

1. Caused by either B. henselae or B. quintana
2. Occurs primarily in AIDS patients (CD4<200/µL)
3. Also reported in in organ transplant and other immunocompetent patients
4. Rare in healthy persons
5. Cat scratch, bite often associated with disease
6. Cutaneous or subcutaneous lesions, usually multiple
7. Constitutional symptoms not uncommon

E. Bacillary Peliosis Hepatis

1. May be associated with cutaneous bacillary angiomatosis or bactermia
2. Gastrointestinal symptoms: nausea, vomiting, diarrhea, abdominal distention
3. Fever, chills, hepatosplenomegaly common
4. Histopathology
   1. Positive staining for organism within stroma of liver
   2. Dilated capillaries and blood-filled cavernous spaces
5. Caused only by B. henselae
6. Frequently associated with exposure to cats and/or fleas
7. Most common in HIV+ persons, but also in pregnancy [8]

F. Treatment [1,4]

1. Duration varies with immune status of host
   1. HIV-Positive - may require life-long suppression
   2. Immunosuppressed - at least 4 weeks or until immunosuppression resolves
   3. Immunocompetent - 2-4 weeks or longer assessed by response
   4. Endocarditis may require prolonged therapy [9]
2. Agents
   1. Erythromycin 0.5-1gm q6 hours IV or po depending on condition and immune status
   2. Clarithromycin or azithromycin may be substituted and better tolerated than erythromycin
   3. Doxycycline 100mg bid probably as effective as erythromycin and better tolerated
   4. Trimethoprim / Sulfamethoxazole (TMP/SMX) IV or high dose oral
   5. Rifampin 600mg po qd - often as adjunctive therapy with one of the agents above
   6. Aminoglycosides are the only bactericidal agents for cat-scratch disease [5]
   7. Sparfloxacin also has in vitro activity
3. Jarisch-Herxheimer reaction may occur [4]
   1. Rapid lysis of infectious organisms
   2. Fever, neutrophil predominance, within 24 hours of effective antibiotic

References

1. Schwartzman W. 1996. Annu Rev Med. 47:355
2. Pelton SI, Kim JY, Kradin RL. 2006. NEJM. 355(9):941 (Case Record)
3. Koehler JE, Sanchez MA, Garrido CS, et al. 1997. NEJM. 327(26):1877
4. Koehler JE and Duncan LM. 2005. NEJM. 353(13):1387 (Case Record)
5. Tan JS. 1997. Arch Intern Med. 157(17):1933
6. Riviello JJ and Ruoff. 1998. NEJM. 338(2):112 (Case Report)
7. Eremeeva ME, Gerns HL, Lydy SL, et al. 2007. NEJM. 356(23):2381
8. McCormack G, Fenelon LE, Sheehan K, McCormick PA. 1998. Lancet. 351(9117):1700
9. Jacoby GA Jr and Hay CM. 1997. NEJM. 336(3):205 (Case Report)
10. Patel UD, Hollander H, Saint S. 2004. NEJM. 350(19):1990 (Case Discussion)