Recommendations for treatment of human infections caused by Bartonella species

[Bartonella henselae, an ubiquitous agent of proteiform zoonotic disease]

Bartonella henselae is the causative agent of cat scratch disease, a human infection usually characterized by persistent regional lymphadenopathy. It is transmitted to humans by cat scratches or bites. Cats are the major reservoir for this bacterium thus B. henselae has a worldwide distribution. The bacterial pathogenicity may bay emphasized by the immune status of the infected host. Angiomatosis or hepatic peliosis are the most frequent clinical manifestations in immunocompromised patients. B. henselae is also responsible for endocarditis in patients with valvular diseases, and may induce various clinical presentations such as: bacteriemia, retinitis, musculoskeletal disorders, hepatic or splenic diseases, encephalitis, or myocarditis. Several diagnostic tools are available; they may be combined and adapted to every clinical setting. B. henselae is a fastidious bacterium; its diagnosis is mainly made by PCR and blood tests. No treatment is required for the benign form of cat scratch disease. For more severe clinical presentations, the treatment must be adapted to every clinical presentation.

Comparative activity of pradofloxacin, enrofloxacin, and azithromycin against Bartonella henselae isolates collected from cats and a human

Using Bartonella henselae isolates from cats and a human, the activity of pradofloxacin was compared with those of enrofloxacin and azithromycin. By Etest and disc diffusion assay, pradofloxacin showed greater antimicrobial activity than did other antibiotics. We conclude that pradofloxacin may prove useful for the treatment of B. henselae infections.

Guidelines for the Prevention and Treatment of Opportunistic Infections among HIV-exposed and HIV-infected children: recommendations from CDC, the National Institutes of Health, the HIV Medicine Association of the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the American Academy of Pediatrics

This report updates and combines into one document earlier versions of guidelines for preventing and treating opportunistic infections (OIs) among HIV-exposed and HIV-infected children, last published in 2002 and 2004, respectively. These guidelines are intended for use by clinicians and other health-care workers providing medical care for HIV-exposed and HIV-infected children in the United States. The guidelines discuss opportunistic pathogens that occur in the United States and one that might be acquired during international travel (i.e., malaria). Topic areas covered for each OI include a brief description of the epidemiology, clinical presentation, and diagnosis of the OI in children; prevention of exposure; prevention of disease by chemoprophylaxis and/or vaccination; discontinuation of primary prophylaxis after immune reconstitution; treatment of disease; monitoring for adverse effects during treatment; management of treatment failure; prevention of disease recurrence; and discontinuation of secondary prophylaxis after immune reconstitution. A separate document about preventing and treating of OIs among HIV-infected adults and postpubertal adolescents (Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents) was prepared by a working group of adult HIV and infectious disease specialists. The guidelines were developed by a panel of specialists in pediatric HIV infection and infectious diseases (the Pediatric Opportunistic Infections Working Group) from the U.S. government and academic institutions. For each OI, a pediatric specialist with content-matter expertise reviewed the literature for new information since the last guidelines were published; they then proposed revised recommendations at a meeting at the National Institutes of Health (NIH) in June 2007. After these presentations and discussions, the guidelines underwent further revision, with review and approval by the Working Group, and final endorsement by NIH, CDC, the HIV Medicine Association (HIVMA) of the Infectious Diseases Society of America (IDSA), the Pediatric Infectious Disease Society (PIDS), and the American Academy of Pediatrics (AAP). The recommendations are rated by a letter that indicates the strength of the recommendation and a Roman numeral that indicates the quality of the evidence supporting the recommendation so readers can ascertain how best to apply the recommendations in their practice environments. An important mode of acquisition of OIs, as well as HIV infection among children, is from their infected mother; HIV-infected women coinfected with opportunistic pathogens might be more likely than women without HIV infection to transmit these infections to their infants. In addition, HIV-infected women or HIV-infected family members coinfected with certain opportunistic pathogens might be more likely to transmit these infections horizontally to their children, resulting in increased likelihood of primary acquisition of such infections in the young child. Therefore, infections with opportunistic pathogens might affect not just HIV-infected infants but also HIV-exposed but uninfected infants who become infected by the pathogen because of transmission from HIV-infected mothers or family members with coinfections. These guidelines for treating OIs in children therefore consider treatment of infections among all children, both HIV-infected and uninfected, born to HIV-infected women. Additionally, HIV infection is increasingly seen among adolescents with perinatal infection now surviving into their teens and among youth with behaviorally acquired HIV infection. Although guidelines for postpubertal adolescents can be found in the adult OI guidelines, drug pharmacokinetics and response to treatment may differ for younger prepubertal or pubertal adolescents. Therefore, these guidelines also apply to treatment of HIV-infected youth who have not yet completed pubertal development. Major changes in the guidelines include 1) greater emphasis on the importance of antiretroviral therapy for preventing and treating OIs, especially those OIs for which no specific therapy exists; 2) information about the diagnosis and management of immune reconstitution inflammatory syndromes; 3) information about managing antiretroviral therapy in children with OIs, including potential drug--drug interactions; 4) new guidance on diagnosing of HIV infection and presumptively excluding HIV infection in infants that affect the need for initiation of prophylaxis to prevent Pneumocystis jirovecii pneumonia (PCP) in neonates; 5) updated immunization recommendations for HIV-exposed and HIV-infected children, including hepatitis A, human papillomavirus, meningococcal, and rotavirus vaccines; 6) addition of sections on aspergillosis; bartonella; human herpes virus-6, -7, and -8; malaria; and progressive multifocal leukodystrophy (PML); and 7) new recommendations on discontinuation of OI prophylaxis after immune reconstitution in children. The report includes six tables pertinent to preventing and treating OIs in children and two figures describing immunization recommendations for children aged 0--6 years and 7--18 years. Because treatment of OIs is an evolving science, and availability of new agents or clinical data on existing agents might change therapeutic options and preferences, these recommendations will be periodically updated and will be available at http://AIDSInfo.nih.gov.

The pathophysiology of the acute phase of human bartonellosis resembles AIDS

Human bartonellosis is a South American anthroponosis caused by Bartonella bacilliformis. The disease has an acute phase characterized by invasion of red blood cells by parasites, and consequent severe anemia; and a chronic phase presenting with benign vascular tumors. During the acute phase, affected individuals are prone to developing opportunistic infections with a variety of organisms similar to the ones seen in AIDS. After antibiotic treatment is instituted, a subgroup of patients may develop atypical symptoms which potentially represent clinical manifestations of the restoration of macrophage function. We speculate that the pathophysiology of the acute phase of human bartonellosis resembles AIDS, with a period of immunosuppression following the infection and later, clinical manifestations of immune reconstitution subsequent to treatment.

Fatal myocarditis-associated Bartonella quintana endocarditis: a case report

Introduction

Bartonella spp. infection is not rare and must be considered with great care in patients with suspected infective endocarditis, particularly if regular blood cultures remain sterile. Management of these infections requires knowledge of the identification and treatment of these bacteria.

Case presentation

A 50-year-old Senegalese man was admitted to our Department of Cardiac Surgery with a culture-negative endocarditis. Despite valvular surgery and adequate antibiotic treatment, recurrence of the endocarditis was observed on the prosthetic mitral valve. Heart failure required circulatory support. Weaning off the circulatory support could not be attempted owing to the absence of heart recovery. Bacteriological diagnosis of Bartonella quintana endocarditis was performed by molecular methods retrospectively after the death of the patient.

Conclusions

This case report underlines the severity and difficulty of the diagnosis of Bartonella quintana endocarditis. The clinical picture suggested possible Bartonella quintana associated myocarditis, a feature that should be considered in new cases.

Bartonella quintana associated neuroretinitis

We report an observational case of Bartonella quintana-associated neuroretinitis. The patient had a positive IgM IFA titer for Bartonella quintana early in the disease. After treatment, the neuroretinitis and IgM resolved. Given the patient's history, symptoms, response to treatment, and IgM course, we believe his neuroretinitis was secondary to Bartonella quintana.

Zoonoses of dermatologic interest

Zoonoses are infectious diseases that can be transmitted from animals to humans. Transmission occurs directly or through vectors such as ticks, mosquitoes, or flies. The causative agents include bacteria, parasites, viruses, and fungi. Domestic pets and livestock, as well as wild animals, can be the source of disease. In this summary, we will focus on a number of dermatologically relevant examples.

Safety and Efficacy Review of Doxycycline

Doxycycline is a member of the tetracycline class of antibiotics and has been used clinically for more than 40 years. It is a well-tolerated drug that is bacteriostatic and acts via the inhibition of bacterial ribosomes. It is generally given at a dose of 100-mg daily or twice daily. It is well absorbed and has generally good tissue penetration. The serum half-life is 18-22 hours and dosage does not need to be adjusted in the presence of renal or hepatic impairment. Major side effects are gastro-intestinal and dermatological and it is generally contra-indicated in pregnancy or childhood because of concerns about discolouration of developing teeth and potential effects on growing bones. Drug interactions are not common although can occur with the concomitant use of methotrexate and the oral contraceptive pill, and its absorption can be reduced by the co-administration with some antacids and iron preparations. It has activity against many organisms, including Gram-positives, Gram-negatives and atypical bacteria. In addition, it appears to have some potentially clinically useful anti-inflammatory properties.

North American zoonoses

A variety of infectious agents can be transmitted from animals to humans, either directly or indirectly. Unfortunately, the diagnosis of a zoonosis may not be considered at presentation, which can lead to a delay in initiating appropriate therapy, or is never made because the symptoms are non-specific and no exposure history is obtained. The keys to making a diagnosis are to recognize the clinical manifestations of the diseases (eg, fever of unknown origin, arthritis, rash, or lymphadenopathy), to obtain an exposure history, and to understand the local epidemiology. When a child presents with an unexplained febrile illness or infectious disease, clinicians should ask about potential exposures to animals, including pets, ingestion of unusual foods, such as raw or unpasteurized milk, and a travel history.

Laboratory maintenance of Bartonella quintana

Trench fever is the common name for the acute febrile syndrome associated with a Bartonella quintana bacterial infection. The focus of this unit is to describe reliable methods for cultivation and cryopreservation of B. quintana and can be applied to cultivation and preservation of all Bartonella. Detailed recipes for preparation of three types of semisolid media are also included.

P26-based serodiagnosis for Bartonella spp. infection in cats

Bartonella henselae P26 has been identified as an immunodominant antigen expressed during feline infection. We used antisera from cats experimentally infected with B. henselae (n = 6), B. clarridgeiae (n = 4), or B. koehlerae (n = 2) and from a sample of naturally infected cats (B. henselae, n = 34; B. clarridgeiae, n = 1) to evaluate recombinant P26 (rP26) as a serodiagnostic antigen. Immunoblots using antisera from cats infected with B. henselae and B. clarridgeiae reacted strongly with rP26, whereas B. koehlerae antisera did not. A capture ELISA was designed to evaluate the kinetics of rP26 IgG in sera from experimentally infected cats. For B. henselae and B. clarridgeiae antisera, the kinetic profiles of reactivity were similar for rP26 capture ELISA and Bartonella spp. indirect fluorescence assay. However, for B. koehlerae antisera, reactivity in rP26 capture ELISA was consistently low. The serodiagnostic potential of rP26 capture ELISA was evaluated using sera from cats with known Bartonella sp. exposure histories. All 24 (100%) uninfected cats were seronegative, and 33 of 35 (94.3%) cats bacteremic for Bartonella spp. were seropositive. We propose that rP26-based serology can serve as a useful adjunct tool for the diagnosis of feline infection with B. henselae and B. clarridgeiae, but it may not be useful for feline infection with B. koehlerae.

Beyond cat scratch disease: widening spectrum of Bartonella henselae infection

Bartonella henselae was discovered a quarter of a century ago as the causative agent of cat scratch disease, a clinical entity described in the literature for more than half a century. As diagnostic techniques improve, our knowledge of the spectrum of clinical disease resulting from infection with Bartonella is expanding. This review summarizes current knowledge regarding the microbiology, clinical manifestations, diagnostic techniques, and treatment of B. henselae infection.

Abscess-forming lymphadenopathy and osteomyelitis in children with Bartonella henselae infection

Bartonella henselae is the agent of cat-scratch disease (CSD), a chronic lymphadenopathy among children and adolescents. A systemic infection is very rare and most of these cases are found in patients with immunodeficiency. Here, cases involving four children of 6–12 years of age are reported. Three of the children had an abscess-forming lymphadenopathy and surrounding myositis in the clavicular region of the upper arm. The diagnosis was made serologically and, in one case, using eubacterial universal PCR. One child was treated with erythromycin for 10 days, the second received cefotaxime and flucloxacillin for 14 days and the third child was not treated with antibiotics. The fourth child had a different course: a significantly elevated signal intensity affecting the complete humerus was found in magnetic resonance imaging, consistent with osteomyelitis. A lymph node abscess was also found in the axilla. Diagnosis was established by indirect fluorescence assay and lymph node biopsy. Antibiotic therapy using clarithromycin, clindamycin and rifampicin was gradually successful. Immunodeficiency was excluded. All described lesions healed without residues. In immunocompetent patients, infection affects skin and draining lymph nodes; however, prolonged fever of unknown origin as in the fourth patient indicated a systemic complication of CSD.

Molecular method for Bartonella species identification in clinical and environmental samples

A new, efficient molecular method for detection of Bartonella, based on the 16S-23S rRNA intergenic spacer and 16S rRNA amplification by multiplex PCR combined with reverse line blotting, was designed. This assay could simultaneously detect 20 different known species and other Bartonella species not described previously.

Encephalopathy with retinitis due to cat-scratch disease

Cat-scratch disease is one of several diseases known to be caused by Bartonella species. Some infections due to Bartonella resolve spontaneously without treatment with antibiotics, but in other cases the disease can be fatal without treatment. This case study reports a 7-year-old male who presented with an unexplained encephalopathy and unusual retinal findings associated with evidence supporting infection by B. henselae. The 7-year-old male presented with a 2-week history of general malaise and cervical lymphadenopathy progressing onto fever, headache, vomiting, and confusion associated with meningism. Lumbar puncture revealed a raised cerebrospinal fluid protein, low glucose, and raised white cell count. Abnormal retinal findings and raised antibodies titres to B. quintana indicated a diagnosis of cat-scratch disease. He was treated with azithromycin orally for 3 weeks and made a complete recovery.

Encephalopathy complicated by Guillain-Barre syndrome and hydrocephalus and associated with acute Bartonella quintana infection

We describe a 16-month-old girl who suffered from encephalopathy leading to intensive care unit hospitalization, complicated by Guillain-Barre syndrome and hydrocephalus, and who had serologic and molecular evidence of central nervous system infection by B. quintana. The possible association of B. quintana with Guillain-Barre syndrome and hydrocephalus has not been previously described and demonstrates the growing spectrum of neurologic complications of Bartonella spp. infections.

Transverse Myelitis in 2 Patients With Bartonella henselae Infection (Cat Scratch Disease)

Cat scratch disease is usually a benign, self-limiting condition. Neurological manifestations are uncommon and may consist of encephalopathy, seizures, and coma. This report describes 2 cases of transverse myelitis: 1 case in a 46-year-old man who had lymph node biopsy and serological testing results that were positive for Bartonella henselae and 1 case in a 13-year-old adolescent boy who had serological testing results that were positive for B. henselae. These are 2 of the only 3 cases of transverse myelitis associated with cat scratch disease that have been reported since the causative organism was first reported.

Utility of MR imaging in cat-scratch neuroretinitis

About 80% of cat-scratch disease (CSD) infections occur in children, and CSD neuroretinitis (optic neuropathy with retinal exudates in a "macular star" pattern) mostly occurs in children and young adults. A recent study suggested that CSD optic neuropathy has specific features on MR imaging. However, MR imaging findings in CSD neuroretinitis are not well described in the pediatric literature. We present a patient with CSD neuroretinitis in whom these specific MR imaging features preceded the macular star, a funduscopic finding strongly suggestive of neuroretinitis. This case demonstrates how knowledge of these features is important in the appropriate diagnostic work-up of optic neuropathy. MR imaging also incidentally revealed neuritis of another cranial nerve in the auditory canal-a rare manifestation of CSD.

Experimental infection of domestic cats with passaged genotype I Bartonella henselae

The influence of in vitro passage on Bartonella henselae pathogenesis in cats has not been thoroughly evaluated. Our objective was to examine the bacterial kinetics and humoral immune responses in cats experimentally infected with three different in vitro passages of B. henselae F1, a genotype I strain of feline origin. The F1 strain was in vitro passaged 20 and 40 times, and each was inoculated into a group of 5 cats. The kinetics of bacteremia and the feline humoral immune response to bacterial antigens were compared to a previous study involving a group of six cats inoculated with the original F1 strain. Among the three groups of cats, the kinetics of bacteremia profiles and the humoral immune responses to B. henselae lysates were similar. The influence of passage on bacterial membrane proteins was examined. In vitro passage altered the expression of 4/17 (23.5%) bacterial membrane proteins and 6/15 (40%) bacterial membrane antigens. An association between poor seroreactivity to three lysate antigens (15-, 18- and 45kDa), prolonged bacteremia and decreased serum bactericidal activity was noted. Our data show that in vitro passage of B. henselae did not alter the kinetics of bacteremia, including the occurrence of relapsing bacteremia, in experimentally infected cats. This suggests that highly passaged strains may not be suitable for future vaccination studies. Furthermore, in vitro passage results in phenotypic and antigenic changes in the bacterial membrane protein profile, which warrants caution in the interpretation of studies involving passaged B. henselae strains.

Bone infection in cat-scratch disease: A review of the literature

OBJECTIVE

To describe the main features of bone infection associated with Cat-scratch disease (CSD).

METHODS

We searched for articles indexed in the international literature databases by using the following key words: "Bartonella", "bone", "cat-scratch", "osteomyelitis" and "osteolytic".

RESULTS

Cases of 47 patients were reviewed. The median age was 9 years, with an equal sex distribution. Bone pain and fever were the main symptoms. The presence of fever and increased age were more common in patients with bone infection than classically reported in uncomplicated (i.e. nodal) CSD. The vertebral column and pelvic girdle were the most common sites of infection. Radiological examination typically confirmed bone osteolysis. All patients recovered without complications or chronic infection, although they received a various combination antibiotic regimen and duration therapy. The mechanism by which infection might spread to the bone is via the haematogenous route, accounting for most of the disseminated cases and via the lymphatic route, for those with regional limited extension.

CONCLUSIONS

Bone infection is rare but should be considered when bone pain and fever are present in a patient with nodal CSD. The prognosis is good, whatever treatment is given. Thus bone biopsy should be recommended only in a difficult diagnostic setting, when other bacteria or malignant disease are suspected.

Molecular mechanisms of resistance to antibiotics in Bartonella bacilliformis

OBJECTIVES

Bartonella bacilliformis is the aetiological agent of Carrion's disease. Although ciprofloxacin, rifampicin and erythromycin have been successfully used in the treatment of the disease, failures and relapses have been reported. The objective of our study was to select in vitro mutants resistant to antibiotics in order to determine the frequency of mutations and to characterize the mechanism of resistance at the molecular level.

METHODS

Antibiotic-resistant mutants were selected by serial passages of bacteria on blood agar plates containing antibiotics. Candidate genes involved in resistance were amplified and sequenced and compared in order to look at mutations associated with antibiotic resistance.

RESULTS

Ciprofloxacin-, rifampicin- and erythromycin-resistant mutants were obtained after five, three and four passages, respectively. Conversely, no mutant was obtained with either gentamicin or doxycycline even after 16 passages. The ciprofloxacin mutant contained an amino acid change at position 87 (Asp --> Asn) in its quinolone resistance-determining region of the DNA gyrase protein, whereas the rifampicin-resistant strain had an amino acid change at position 531 (Ser --> Phe) in the rifampicin resistance-determining region of the rpoB gene. Similarly, the erythromycin-resistant mutant showed an A2058G mutation in the 23S rRNA gene.

CONCLUSIONS

According with the current knowledge on the treatment of human bartonellosis, we believe that doxycycline in association with gentamicin may be the preferred regimen for the treatment of the acute and eruptive stages of Carrion's disease, but clinical trials are warranted to support our findings.

From cat scratch disease to endocarditis, the possible natural history of Bartonella henselae infection

Background

Most patients with infectious endocarditis (IE) due to Bartonella henselae have a history of exposure to cats and pre-existing heart valve lesions. To date, none of the reported patients have had a history of typical cat scratch disease (CSD) which is also a manifestation of infection with B. henselae.

Case presentation

Here we report the case of a patient who had CSD and six months later developed IE of the mitral valve caused by B. henselae.

Conclusion

Based on this unique case, we speculate that CSD represents the primary-infection of B. henselae and that IE follows in patients with heart valve lesions.

Cat-scratch disease relapse in a kidney transplant recipient

Cat-scratch disease, an infectious illness infrequently reported in kidney transplant patients, is caused by the organism Bartonella henselae and is transmitted through contact with cats or kittens. It is a self-limited disorder in the general pediatric population. Here we present a case of unsuspected cat-scratch disease in a pediatric kidney transplant patient who presented with fever and lymphadenopathy. Eight months after treatment with a short course of azithromycin, the patient developed a recurrence of cat-scratch disease. We emphasize that the evaluation of a young immunocompromised kidney transplant patient presenting with fever and lymphadenopathy should include unusual infections such as cat-scratch disease. We review the diagnosis and treatment of this uncommon infection in the organ transplant population.