bartonellosis
DESCRIPTION
BARTONELLOSIS. By Nonso Emegoakor. Outline. Introduction Bartonellosis (CARRION’S DISEASE) Other human bartonella infections. Introduction. Bartonella species are fastidious, facultative intracellular, slow-growing, gram-negative bacteria that cause a broad spectrum of diseases man . - PowerPoint PPT PresentationTRANSCRIPT
BARTONELLOSIS
ByNonso Emegoakor
Outline
• Introduction
• Bartonellosis (CARRION’S DISEASE)
• Other human bartonella infections
Introduction
• Bartonella species are fastidious, facultative intracellular, slow-growing, gram-negative bacteria that cause a broad spectrum of diseases man .
• About 22 Bartonella species or subspecies have been identified
• B. bacilliformis, B. quintana, B.henselae cause majority of bartonella associated human infections
• Prolonged intraerythrocytic infection in animals creates a reservoir for human infections
Bartonellosis
• B.bacilliformis is the aetiologic agent• The dx is endemic to certain areas of the
Andean regions of Peru, Columbia, and Ecuador, referred to as the "verruga zone.
• Transmitted by Lutzomyia verrucarum, a sand fly of the genus Phlebotomus.
• Geographic limitation seems to be related to the environmental requirements of the vector.
Bartonellosis(carrion’s dx)
• Oroya fever is the initial,acute, bacteremic, systemic form of the disease
• verruga peruana is its late-onset, eruptive manifestation i.e the chronic cutaneous phase
• Oroya fever majorly affects tourists and transient workers who are immunologically-naive to B. bacilliformis,
• whereas most cases of verruga peruana involve native populations in the Andes.
Clinical features(oroya fever)• The acute or hematic phase usually begins about three weeks
after inoculation, typically with an insidious onset of mild fever, headache, anorexia, and malaise, lasting from several days to several weeks.
• Anemia,jaundice,painless hepatomegaly and lymphadenopathy.
• The inoculum size of the organism, specific organism virulence factors, nutritional status of the host, and the host's immune response to B. bacilliformis play a role in determining severity
• Oroya fever is associated with a greater than 40 percent mortality if untreated. In those who recover, symptoms dissipate and anemia subsides after two to three weeks
• Infectious complications are primarily superinfection with Salmonella spp, Shigella, Staphylococcus aureus, or Enterobacter spp.
• The most common noninfectious problems
include anasarca, neurologic manifestations, and pericardial effusion.
Verruga peruana
• Red, hemangioma-like, cutaneous vascular lesions of various sizes appear either weeks to months after systemic illness.
• verruga lesions have been classified into three types: miliary, nodular (subdermic), and mular
• miliary lesions appear as small, round, soft, pinpoint papules that cluster in crops and are confined to the papillary dermis.
• Untreated, miliary lesions progress to the nodular phase with nontender, wart-like lesions that may become pedunculated.
• Some lesions may be subcutaneous but become apparent on the skin surface as they push upward, making the overlying skin thin and purplish in color.
• As they evolve into larger and superficial lesions, they are classified as the mular form; these lesions are highly vascular, bulbous, tend to bleed easily, and can ulcerate
Veruga peruana(miliary lesions)
Nodular(subdermic) lesions
Mular lesion
Investigation
• FBC shows anemia with reticulocytosis.• Giemsa-stained blood films show typical
intraerythrocytic bacilli,• blood and bone marrow cultures• Serology — Antibody tests for B. bacilliformis
include an immunoblot test and indirect fluorescence antibody (IFA) test.
• Biopsy may be required to confirm the diagnosis of verruga peruana
Treatment
• Oroya fever• Chloramphenicol (500 mg PO/IV qid for 14 days) plus
another antibiotic (-lactam preferred) or ciproflox 500mg b.d x10days
• Verruga peruana• Rifampin (10 mg/kg PO qd, to a maximum of 600 mg,
for 14 days) or Streptomycin (15–20 mg/kg IM qd for 10 days)
• large lesions or those interfering with function may require excision
Cat scratch disease• Caused by B.henselae
• Usually a self limiting illness
• Two general clinical presentations,namely Typical CSD and
• atypical CSD
Epidemiology
• Occurs worldwide, favoring warm and humid climates. in the tropics, disease occurs year-round.
• healthy cats constitute the major reservoir of B. henselae, and cat fleas (Ctenocephalides felis) are responsible for cat-to-cat transmission.
• Acquired through contact with cat(especially kittens).
• Estmated incidence in U.S. is about 10 cases/100000
Pathogenesis
• Inoculation of B. henselae, usually results from a cat scratch or bite
• With lymphatic drainage to one or more regional lymph nodes in immunocompetent hosts, a TH1 response can result in necrotizing granulomatous lymphadenitis.
• Dendritic cells, along with their associated chemokines, play a role in the host inflammatory response and granuloma formation
Clinical features
• The primary lesion, a small (0.3- to 1-cm) painless erythematous papule or pustule, develops at the inoculation site (usually the site of a scratch or a bite) within days to 2 weeks.
• Lymphadenopathy develops 1–3 weeks after cat contact.
• Affected lymph node(s) are enlarged and usually painful, sometimes have overlying erythema, and suppurate in 10–15% of cases
Clinical features ctd
• Some patients patients have low grade fever, malaise, and anorexia.
• A smaller proportion experience weight loss and night sweats mimicking the presentation of lymphoma.
• Resolution is slow, requiring weeks (for fever, pain) and months (for nodal shrinkage)
Primary lesion
Primary innoculation lesion
Cervical lymph node
Atypical catscratch dx
• Extranodal or complicated disease,with or without lymphadenopathy.
• Extra nodal manifestations include; neurologic involvement (encephalopathy, seizures, myelitis, radiculitis, cerebellitis, facial and other cranial or peripheral nerve palsies
• PUO, myalgia, arthritis or arthralgia, osteomyelitis, tendinitis, neuralgia,
• Parinaud's oculoglandular syndrome
• Granulomatous hepatitis/splenitis,
• In immunocompetent individuals, CSD—whether typical or atypical—usually resolves without treatment and without sequelae
• Lifelong immunity is the rule.
Pre-auricular lymphadenopathy
Diagnosis
• Histopathology initially shows lymphoid hyperplasia and later demonstrates stellate granulomata with necrosis, coalescing microabscesses, and occasional multinucleated giant cells
• PCR of lymph node tissue, pus, or the primary
inoculation lesion is highly sensitive and specific
Treatment
• Typical CSD; For extensive lymphadenopathy,; Azithromycin 500mgx 1/7, then 50mg qds x4/7
• CSD Retinitis and other atypical CSD;Doxycycline 100mg x/7 and rifampin 300mg b.d x4-6 weeks
Bacillary angiomatosis
• Is a vascular,proliferative form of bartonella infection
• Occurs primarily in immunocompromised patients,
• Caused by B. henselae or B. quintana,
• Characterized by neovascular proliferative lesions involving the skin and other organs.
RISK FACTORS
• HIV infection, CLL, Chemotherapy, organ transplant
• Cat ownership, cat bites and scratches
• Homelessness, low socioeconomic status, exposure to body lice
Lesion sites/types
• Cutaneous lesions; result equally from both• Subcut lesions; mainly from B.quintana• Osseous lesions; mainly from B.quintana• Visceral involvement(peliosis); almost
exclusively from B.henselae• Neurological involvement; more of B.quintana
Clinical features• Cutaneous lesions may be solitary or multiple, red, flesh coloured
papules, plaques.
• Plaques may ulcerate,discharge and become crusted.
• verrucous growths, large,pendunculated or polypoid exophytic masses are also seen
• Subcutaneous masses or nodules
• Painful osseous lesions, most often involving long bones, may underlie cutaneous lesions and occasionally develop in their absence.
Diagnosis• biopsy of lesion; shows lobular vascular proliferations composed of
rounded vessels lined by variably protuberant plump endothelial cells
• In addition, clusters of neutrophils, neutrophilic debris, and lymphocytes are scattered throughout the lesions, especially around eosinophilic granular aggregates.
• Warthin-Starry silver staining of these aggregates reveals masses of small, dark-staining bacteria
• Blood cultures may be positive, PCR of tissue specimen
Nodular lesion on BA
Nodular lesions
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TREATMENT
• Bacillary angiomatosis;1. Erythromycind (500 mg PO qid for 3
months)or2. Doxycycline (100 mg PO bid for 3 months)
• Cryotherapy, curettage and surgical excision• Excellent prognosis,antibiotics are curative
COMPLICATIONS
• Disfigurement• Jaundice, biliary obstruction• G I bleeding• Laryngeal obstruction• encephalopathy
Endocarditis• Bartonella sp are implicated stongly in culture negative
endocarditis.• B.quintana and b.henselae are most commonly involved• Risk factors associated with B. quintana endocarditis include
homelessness, alcoholism, and body louse infestation• B. henselae endocarditis is associated with exposure to cats.
Most cases involve native rather than prosthetic valves; • Patients with B. henselae endocarditis usually have
preexisting valvulopathy, whereas B. quintana often infects normal valves
Clinical features
• prolonged, minimally febrile or even afebrile indolent illness, with mild nonspecific symptoms lasting weeks or months before the diagnosis is made.
• Initial echocardiography may not show vegetations.
• Acute, aggressive disease is rare.
diagnosis
• Blood cultures, even with use of special techniques (lysis centrifugation or EDTA-containing tubes), are positive in only 25% of cases—mostly those caused by B. quintana and only rarely those caused by B. henselae.
• Prolonged incubation of cultures (up to 6 weeks) is required.
• Serologic tests—either immunofluorescence or enzyme immunoassay—usually demonstrate high-titer IgG antibodies
treatment
• For Suspected Bartonella endocarditis;
Gentamicinb (1 mg/kg IV q8h for 14 days) plus doxycycline (100 mg PO/IV bid for 6 weeksc) plus ceftriaxone (2 g IV qd for 6 weeks
others
• B. quintana causes bacteremia in homeless people
• Spectrum of infection ranges from asymptomatic infection to a febrile illness with headache, severe leg pain, and thrombocytopenia.
• Also historically associated with trench fever,which was an epidermic in the trenches of WW1
• The human body louse (Pediculus humanuscorporis) has been identified as the vector and humans as the only known reservoir.
• Chronic bacteremia is managed with Gentamicin (3 mg/kg IV qd for 14 days) plus doxycycline (200 mg PO qd or 100 mg PO bid for 6 weeks)
conclusion
• Bartonella species cause a variety of human infections
• Adequate clinical evaluation however results in proper management most of the times
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