Bartonellosis Flashcards
What infections are caused by Bartonella species?
Cat scratch disease, retinitis, trench fever, relapsing bacteremia, culture-negative endocarditis, bacillary angiomatosis (BA), bacillary peliosis hepatis.
Fourteen Bartonella species have been implicated in human infections.
In which population does bacillary angiomatosis (BA) most often occur?
Individuals who are immunocompromised, particularly those with HIV and CD4 counts <50 cells/mm3.
BA can last months to over a year in people with HIV.
What is the vector for B. quintana?
Body louse.
B. quintana is associated with body louse infestation and homelessness.
What is the primary vector for B. henselae in humans?
Cat fleas.
Cats are the most common vector responsible for transmitting B. henselae to humans.
What are common clinical manifestations of bacillary angiomatosis (BA)?
Cutaneous lesions, subcutaneous nodules, osteomyelitis, systemic symptoms (fever, night sweats, weight loss).
BA lesions can resemble Kaposi sarcoma and pyogenic granuloma.
How is the diagnosis of BA confirmed?
Histopathologic examination of biopsied tissue.
BA lesions show vascular proliferation and numerous bacilli with modified silver stains.
What is the role of serologic testing in diagnosing Bartonella infections?
It helps in diagnosis and monitoring treatment response.
Anti-Bartonella antibodies may not be detectable for 6 weeks after acute infection.
What is the recommended treatment for Cat Scratch Disease?
Doxycycline 100 mg PO or IV every 12 hours, or Erythromycin 500 mg PO or IV every 6 hours.
Both are considered first-line treatments.
What is the duration of therapy for all manifestations of Bartonella infection in patients with HIV?
At least 3 months.
Long-term suppressive therapy may be needed if relapse occurs.
What is the indication for long-term suppressive therapy for Bartonella?
Relapse after a ≥3-month course of primary treatment with CD4 count <200 cells/mm3.
Some specialists suggest a 4-fold decrease in Bartonella titers as a criterion.
Which antibiotics should not be used for treating bartonellosis?
Penicillins and first-generation cephalosporins.
These have no in vivo activity against Bartonella.
What are the potential adverse effects associated with macrolides?
Nausea, vomiting, abdominal pain, elevations of liver transaminases, potential QT interval prolongation.
Serious side effects can occur with rifamycin class antibiotics.
True or False: Primary chemoprophylaxis for Bartonella-associated disease is recommended.
False.
A macrolide was found protective against developing Bartonella infection in a case-control study.
What should patients treated with oral doxycycline be cautioned about?
Pill-associated esophagitis and photosensitivity.
Monitoring of antibody titers is recommended during treatment.
What is the importance of monitoring anti-Bartonella antibody levels?
To assess treatment response and detect potential relapse of infection.
Sequential endpoint titers should be checked every 6 to 8 weeks.
Fill in the blank: The cat flea is the vector for _______ in cats.
B. henselae.
This is a key transmission route to humans.
What are the major risk factors for acquiring B. henselae?
Contact with cats infested with fleas, receiving cat scratches.
Immunocompromised individuals should consider risks of cat ownership.
What should be done if a person with HIV has a cat-associated wound?
Wash it promptly with soap and water.
This is critical to prevent potential infection.
What is the recommended monitoring frequency for sequential endpoint titers during treatment?
Every 6 to 8 weeks during treatment
Preferably until at least a fourfold decrease is documented.
What side effects should patients treated with oral doxycycline be cautioned about?
Pill-associated esophagitis and photosensitivity
Adverse effects should be communicated to patients.
List some adverse effects associated with macrolides.
- Nausea
- Vomiting
- Abdominal pain
- Elevations of liver transaminase levels
- Potential QT interval prolongation
These effects should be monitored during treatment.
What serious side effects can occur with rifamycin class antibiotics?
- Hypersensitivity reactions
- Thrombocytopenia
- Interstitial nephritis
- Hemolytic anemia
- Hepatitis
These side effects necessitate careful monitoring.
How do rifamycin class antibiotics affect the cytochrome P450 enzyme system?
They strongly induce the cytochrome P450 enzyme system
This is important when other medications are taken simultaneously.
What is a recommended action for patients who fail to respond to initial treatment for Bartonella infections?
Switch to a different preferred regimen
For example, from doxycycline to erythromycin, with treatment duration of ≥3 months.
What should be done for severe Bartonella infections?
Addition of a rifamycin class antibiotic is indicated
This is a recommendation for severe cases.
When should treatment for Bartonella infections continue after clinical improvement is observed?
Until at least a fourfold decrease in antibody titers is documented
This is crucial for ensuring effective management.
What is recommended after a primary course of treatment for Bartonella infections?
Close monitoring for evidence of relapse
This includes monitoring symptoms and antibody titers.
What is the recommendation if a relapse of Bartonella infection occurs?
An additional course of treatment is recommended
Followed by long-term suppression of infection.
How long can long-term suppression therapy be discontinued after effective treatment?
After at least 3 to 4 months of therapy
Provided the CD4 count remains >200 cells/mm3 on effective ART for ≥6 months.
What complications are associated with B. bacilliformis infection during pregnancy?
Increased complications and risk of death
Data on B. quintana or B. henselae during pregnancy is not available.
What should be used as first-line therapy for Bartonella infections during pregnancy?
Erythromycin or an alternative macrolide
Tetracyclines like doxycycline are avoided due to risks.
What is the recommendation for cephalosporins in treating Bartonella infections in pregnant people?
Third-generation cephalosporins may have efficacy
Considered second-line therapy after a macrolide.
Which cephalosporins are not recommended for Bartonella infections?
First- and second-generation cephalosporins
Due to their lack of efficacy against Bartonella.
