Bartonellosis in Children

Introduction to Bartonellosis in Children

Bartonellosis refers to a group of infectious diseases caused by bacteria of the genus Bartonella. These gram-negative bacilli are responsible for several clinical syndromes in children, with cat scratch disease (CSD) being the most common. Other important manifestations include bacillary angiomatosis, Carrión's disease, and trench fever.

In pediatric populations, Bartonellosis presents unique challenges due to its varied clinical presentations and the potential for both acute and chronic manifestations. The disease is particularly important for pediatricians to understand because:

  • It's a common cause of regional lymphadenopathy in children
  • It can mimic other infectious and non-infectious conditions
  • Immunocompromised children are at risk for more severe manifestations
  • Diagnosis often requires a high index of suspicion

Understanding the spectrum of Bartonella infections in children is crucial for timely diagnosis, appropriate management, and prevention of complications.

Etiology of Bartonellosis

Bartonellosis is caused by various species of Bartonella, gram-negative bacteria that can infect erythrocytes and endothelial cells. In children, the most clinically relevant species include:

  1. Bartonella henselae:
    • The primary cause of cat scratch disease
    • Transmitted mainly through cat scratches or bites
  2. Bartonella quintana:
    • Causes trench fever and bacillary angiomatosis
    • Transmitted by the human body louse
  3. Bartonella bacilliformis:
    • Responsible for Carrión's disease (Oroya fever and verruga peruana)
    • Transmitted by sandflies

Key factors in the etiology of Bartonellosis in children include:

  • Vector-borne transmission: Fleas, lice, and sandflies play crucial roles in transmission
  • Reservoir hosts: Cats are the primary reservoir for B. henselae, while humans are the reservoir for B. quintana
  • Bacterial virulence factors: Bartonella species possess various virulence factors that allow them to evade the immune system and persist in the host
  • Host factors: The child's immune status significantly influences the course and severity of the infection

Understanding these etiological factors is essential for comprehending the diverse clinical presentations and implementing effective prevention strategies in pediatric populations.

Epidemiology of Bartonellosis in Children

Bartonellosis, particularly cat scratch disease (CSD), is a worldwide zoonosis with significant impact on pediatric populations. Key epidemiological features include:

  1. Age Distribution:
    • CSD is most common in children and adolescents under 18 years
    • Peak incidence occurs in children aged 5-9 years
  2. Geographic Distribution:
    • Worldwide occurrence, but prevalence varies by region
    • Higher incidence in warm, humid climates where flea populations thrive
  3. Seasonal Variation:
    • Cases of CSD typically peak in fall and winter months in temperate regions
    • This seasonality may be related to increased indoor contact with cats
  4. Risk Factors:
    • Owning or frequent contact with cats, especially kittens
    • Living in households with flea-infested cats
    • Immunocompromised status (for more severe manifestations)
  5. Prevalence:
    • Estimated annual incidence of CSD in the US: 4.5-9.3 per 100,000 population
    • Higher rates observed in children and adolescents
  6. Transmission Patterns:
    • B. henselae: Primarily through cat scratches or bites; cat fleas play a role in cat-to-cat transmission
    • B. quintana: Transmitted by the human body louse, associated with poor hygiene and crowded living conditions
    • B. bacilliformis: Endemic in certain areas of the Andes, transmitted by sandflies

Understanding these epidemiological patterns is crucial for:

  • Identifying at-risk populations
  • Implementing targeted prevention strategies
  • Guiding diagnostic suspicion in pediatric patients presenting with compatible symptoms

Clinical Presentation of Bartonellosis in Children

The clinical manifestations of Bartonellosis in children vary widely, depending on the causative species and the child's immune status. The most common presentations include:

  1. Cat Scratch Disease (CSD):
    • Primary lesion: Papule or pustule at the site of inoculation (often overlooked)
    • Regional lymphadenopathy: Most common in axillary, epitrochlear, or cervical regions
    • Systemic symptoms: Low-grade fever, malaise, headache
    • Complications: Ocular manifestations (Parinaud's oculoglandular syndrome), hepatosplenic involvement, encephalopathy (rare)
  2. Bacillary Angiomatosis:
    • More common in immunocompromised children
    • Cutaneous lesions: Red, friable vascular papules or nodules
    • Systemic involvement: Can affect liver, spleen, bone, and other organs
  3. Carrión's Disease:
    • Acute phase (Oroya fever): Severe hemolytic anemia, fever, hepatomegaly
    • Chronic phase (Verruga peruana): Cutaneous eruptions of reddish-purple nodules
  4. Trench Fever:
    • Relapsing febrile illness
    • Headache, shin pain, splenomegaly
  5. Atypical Manifestations:
    • Endocarditis: Rare but serious, often culture-negative
    • Neuroretinitis: Visual loss, often associated with CSD
    • Hepatosplenic abscesses: Can occur in immunocompetent children

Key points for clinicians:

  • The classic triad of CSD (inoculation site, regional lymphadenopathy, and fever) may not always be present
  • Lymphadenopathy may persist for months in some cases
  • Immunocompromised children are at risk for more severe, disseminated disease
  • Consider Bartonellosis in the differential diagnosis of prolonged fever of unknown origin in children

Diagnosis of Bartonellosis in Children

Diagnosing Bartonellosis in children can be challenging due to its varied presentations and the limitations of some diagnostic tests. A combination of clinical suspicion, epidemiological factors, and laboratory tests is often required.

  1. Clinical Diagnosis:
    • Based on history of cat exposure (for CSD)
    • Characteristic lymphadenopathy or other typical manifestations
    • Exclusion of other causes of lymphadenopathy
  2. Serological Tests:
    • Indirect Fluorescence Assay (IFA):
      • Most commonly used test
      • IgM titers ≥1:16 or IgG titers ≥1:256 suggest recent infection
      • Sensitivity: 88-100%; Specificity: 92-98%
    • Enzyme-Linked Immunosorbent Assay (ELISA):
      • Alternative to IFA
      • Comparable sensitivity and specificity
  3. Molecular Diagnostics:
    • Polymerase Chain Reaction (PCR):
      • Can be performed on lymph node tissue, aspirates, or blood
      • High specificity, but sensitivity varies (43-76%)
  4. Culture:
    • Definitive but rarely used due to slow growth of Bartonella species
    • Requires specialized media and prolonged incubation
  5. Histopathology:
    • Lymph node biopsy: Granulomatous inflammation with microabscesses
    • Warthin-Starry silver stain may reveal pleomorphic bacilli
  6. Imaging Studies:
    • Ultrasound: Can help characterize lymphadenopathy
    • CT or MRI: For evaluation of disseminated disease or complications

Diagnostic Pearls:

  • A negative serology does not rule out early CSD; consider repeat testing in 2-3 weeks
  • PCR on lymph node aspirates or tissue has higher yield than blood PCR
  • In immunocompromised patients, blood culture with prolonged incubation may be necessary
  • Consider other causes of regional lymphadenopathy in the differential diagnosis (e.g., tuberculosis, toxoplasmosis, lymphoma)

Treatment of Bartonellosis in Children

The approach to treating Bartonellosis in children depends on the clinical presentation, severity of symptoms, and the child's immune status. Here are the key considerations and treatment strategies:

  1. Typical Cat Scratch Disease (CSD) in Immunocompetent Children:
    • Often self-limiting; may not require antibiotic treatment
    • Supportive care: Analgesics, antipyretics, warm compresses for lymph nodes
    • Antibiotics may be considered for severe or systemic symptoms:
      • Azithromycin: 10 mg/kg on day 1, followed by 5 mg/kg daily for 4 days
      • Alternative: Rifampin, trimethoprim-sulfamethoxazole, or ciprofloxacin
  2. Complicated CSD or Disseminated Disease:
    • Requires antibiotic therapy, often with combination regimens
    • Options include:
      • Doxycycline (for children >8 years) plus rifampin
      • Gentamicin plus doxycycline
      • Azithromycin plus rifampin
    • Duration: Usually 14-21 days, or longer for severe cases
  3. Bartonellosis in Immunocompromised Children:
    • Requires prompt and aggressive treatment
    • Combination therapy often recommended:
      • Erythromycin or doxycycline plus rifampin
      • Consider adding gentamicin for severe cases
    • Duration: Typically 4-6 weeks, or until clinical improvement
  4. Bacillary Angiomatosis:
    • Erythromycin or doxycycline for at least 3 months
    • Close monitoring for recurrence
  5. Carrión's Disease:
    • Acute phase (Oroya fever): Chloramphenicol plus beta-lactam antibiotic
    • Chronic phase (Verruga peruana): Rifampin or streptomycin
  6. Management of Lymphadenopathy:
    • Needle aspiration may be considered for large, fluctuant nodes
    • Incision and drainage generally not recommended due to risk of chronic draining sinus

Treatment Pearls:

  • Antibiotic treatment may not significantly alter the course of uncomplicated CSD but can be beneficial in shortening the duration of symptoms
  • Close follow-up is essential, especially for immunocompromised patients or those with systemic disease
  • Corticosteroids are generally not recommended, except in cases of severe neurologic complications
  • Treatment response can be slow; patience is often required, and clinical improvement may take several weeks
  • Relapses can occur, particularly in immunocompromised patients, necessitating prolonged or repeated courses of antibiotics
  • In cases of Bartonella endocarditis, prolonged antibiotic therapy (6 weeks to 6 months) is typically required, often in conjunction with valve replacement surgery
  • Consultation with infectious disease specialists is recommended for complicated cases or in immunocompromised children

It's important to note that while antibiotics can be beneficial in many cases, the decision to treat should be individualized based on the patient's presentation, immune status, and the specific manifestations of the disease. Regular reassessment and adjustment of the treatment plan may be necessary.

Prevention of Bartonellosis in Children

Preventing Bartonellosis in children primarily involves minimizing exposure to the bacteria and their vectors. Here are key preventive strategies:

  1. Pet-Related Precautions:
    • Avoid rough play with cats, especially kittens
    • Promptly clean any scratches or bites from cats with soap and water
    • Keep cats' nails trimmed
    • Wash hands after handling cats, especially before eating
  2. Flea Control:
    • Implement regular flea control measures for pets
    • Use flea collars, topical treatments, or oral medications as recommended by veterinarians
    • Regularly clean areas where pets sleep
  3. Environmental Measures:
    • Keep cats indoors to reduce their exposure to infected fleas
    • Avoid letting cats lick open wounds or scratches
    • Control rodent populations around the home, as they can be reservoirs for Bartonella
  4. Hygiene Practices:
    • Encourage regular handwashing, especially after outdoor activities or contact with animals
    • Teach children not to touch or play with stray or unfamiliar animals
  5. Special Considerations for Immunocompromised Children:
    • Consider avoiding cat ownership or close contact with cats
    • If cat ownership is maintained, ensure strict flea control and hygiene measures
    • Prompt medical evaluation for any potential exposure or symptoms
  6. Vector Control for Other Bartonella Species:
    • Use insect repellents in areas where sandflies are prevalent (for B. bacilliformis)
    • Maintain good personal hygiene to prevent louse infestations (for B. quintana)
  7. Education:
    • Educate children and families about the risks associated with animal scratches and bites
    • Provide information on proper pet care and the importance of regular veterinary check-ups
  8. Healthcare Provider Awareness:
    • Maintain a high index of suspicion for Bartonellosis in children presenting with compatible symptoms
    • Provide anticipatory guidance to families with cats, especially those with young children or immunocompromised family members

Prevention Pearls:

  • There is currently no vaccine available for Bartonellosis in humans
  • The risk of transmission from cats can be significantly reduced with proper flea control
  • While declawing cats is sometimes suggested, it's controversial and not routinely recommended by veterinarians
  • Regular veterinary care for pets, including screening for Bartonella infection, can help reduce the risk of transmission to humans

By implementing these preventive measures, the risk of Bartonellosis in children can be significantly reduced. However, it's important to balance these precautions with the potential benefits of pet ownership, which can have positive impacts on child development and well-being.



Objective QnA: Bartonellosis in Children
  1. What are the main species of Bartonella that cause disease in children?
    Bartonella henselae, Bartonella quintana, and Bartonella bacilliformis
  2. Which Bartonella species is responsible for cat-scratch disease?
    Bartonella henselae
  3. What is the vector for Bartonella quintana?
    Human body lice
  4. What is Carrion's disease, and which Bartonella species causes it?
    Carrion's disease is caused by Bartonella bacilliformis and has acute (Oroya fever) and chronic (verruga peruana) phases
  5. What is the geographical distribution of Bartonella bacilliformis?
    It is endemic to the Andes regions of Peru, Ecuador, and Colombia
  6. What is trench fever, and which Bartonella species causes it?
    Trench fever is caused by Bartonella quintana and is characterized by relapsing fevers
  7. Can Bartonella species cause endocarditis in children?
    Yes, particularly in children with pre-existing heart valve abnormalities
  8. What is bacillary angiomatosis, and in which population is it most common?
    Bacillary angiomatosis is a vascular proliferative disease caused by B. henselae or B. quintana, most common in immunocompromised individuals
  9. What is the most common clinical presentation of bartonellosis in immunocompetent children?
    Cat-scratch disease with regional lymphadenopathy
  10. Can Bartonella infections cause neurological symptoms in children?
    Yes, including encephalopathy, seizures, and focal neurological deficits
  11. What is the recommended diagnostic test for Bartonella infections?
    PCR on tissue samples or blood, combined with serological testing
  12. What is the first-line antibiotic treatment for uncomplicated cat-scratch disease in children?
    Azithromycin
  13. What is the recommended treatment for Bartonella endocarditis?
    A combination of doxycycline and gentamicin for 6 weeks
  14. Can Bartonella species cause chronic bacteremia in children?
    Yes, especially in immunocompromised children
  15. What is peliosis hepatis, and which Bartonella species can cause it?
    Peliosis hepatis is a vascular proliferation in the liver, primarily caused by B. henselae
  16. How does poverty affect the risk of Bartonella quintana infections?
    Poor hygiene and crowded living conditions increase exposure to body lice, the vector for B. quintana
  17. Can Bartonella infections cause ocular manifestations in children?
    Yes, including neuroretinitis and Parinaud oculoglandular syndrome
  18. What is the role of domestic cats in the transmission of Bartonella henselae?
    Cats are the primary reservoir for B. henselae, which is transmitted to humans through scratches or bites
  19. Can Bartonella infections cause prolonged fever of unknown origin in children?
    Yes, Bartonella should be considered in the differential diagnosis of fever of unknown origin
  20. What is the significance of Bartonella infections in pediatric organ transplant recipients?
    Transplant recipients are at risk for severe, disseminated Bartonella infections
  21. How does Bartonella evade the host immune system?
    By invading erythrocytes and endothelial cells, and modulating the host immune response
  22. Can Bartonella infections cause musculoskeletal symptoms in children?
    Yes, including myalgia, arthralgia, and rarely osteomyelitis
  23. What is the role of lymph node biopsy in diagnosing Bartonella infections?
    Biopsy can provide definitive diagnosis through histopathology and PCR, but is not routinely required
  24. Can Bartonella infections cause hepatosplenic disease in children?
    Yes, hepatosplenic abscesses can occur, especially in immunocompromised children
  25. What is the significance of Bartonella as a cause of culture-negative endocarditis?
    Bartonella species are a leading cause of culture-negative endocarditis, requiring specialized diagnostic techniques
  26. How does climate change potentially affect the distribution of Bartonella infections?
    Changes in vector distribution and human-animal interactions may alter the epidemiology of Bartonella infections
  27. Can Bartonella infections cause skin manifestations other than cat-scratch disease papules?
    Yes, including bacillary angiomatosis lesions and verruga peruana in B. bacilliformis infections
  28. What is the role of co-infections in Bartonella disease severity?
    Co-infections with other vector-borne pathogens may lead to more severe or atypical presentations
  29. How does Bartonella affect the vascular endothelium?
    It can induce vascular proliferation and inflammation, leading to various clinical manifestations
  30. What is the significance of Bartonella infections in children with congenital heart disease?
    These children are at increased risk for Bartonella endocarditis and should be monitored closely


Further Reading
Tags:

Powered by Blogger.