Cat-scratch disease in patient with AIDS: atypical skin manifestation

Bartonella spp. as emerging human pathogens

Members of the genus Bartonella (formerly Rochalimaea) were virtually unknown to modern-day clinicians and microbiologists until they were associated with opportunistic infections in AIDS patients about 6 years ago. Since that time, Bartonella species have been associated with cat scratch disease, bacillary angiomatosis, and a variety of other disease syndromes. Clinical presentation of infection with Bartonella ranges from a relatively mild lymphadenopathy with few other symptoms, seen in cat scratch disease, to life-threatening systemic disease in the immunocompromised patient. In some individuals, infection manifests as lesions that exhibit proliferation of endothelial cells and neovascularization, a pathogenic process unique to this genus of bacteria. As the spectrum of disease attributed to Bartonella is further defined, the need for reliable laboratory methods to diagnose infections caused by these unique organisms also increases. A brief summary of the clinical presentations associated with Bartonella infections is presented, and the current status of laboratory diagnosis and identification of these organisms is reviewed.

Bacterial infections

Non-opportunistic bacterial infections are an important cause of morbidity and mortality for HIV-infected adults and children. Factors associated with increased risk of these include altered B- and T-cell function; altered phagocytic cell function; skin and mucous membrane defects; and use of indwelling vascular catheters, antibiotics, or cytotoxic agents. The pathogens encountered most frequently are S. aureus, S. pneumoniae, H. influenzae, Salmonella sp., and Pseudomonas aeruginosa. Less commonly encountered organisms include Rhodococcus equi, Listeria monocytogenes, Shigella sp., and Nocardia asteroides, Strategies for prevention as well as diagnosis and treatment of these are discussed.

Bacillary angiomatosis in an HIV seronegative patient on systemic steroid therapy

Bacillary angiomatosis is an unusual systemic vascular proliferation seen predominantly in patients with the acquired immunodeficiency syndrome. These vascular lesions are due to infection with a Bartonella species, most commonly B. henselae, but sometimes B. quintana. It is treatable and often curable, but without therapy may be life-threatening. Clinically, the disorder often resembles several different vascular disorders, particularly pyogenic granuloma and Kaposi's sarcoma. We now report a clinically typical patient with bacillary angiomatosis who was HIV seronegative, but who had idiopathic thrombocytopenic purpura, was status-post splenectomy and to whom long-term systemic prednisone had been administered.

Bartonella (Rochalimaea) quintana infections

Bartonella (formerly Rochalimaea) quintana is the etiological agent of trench fever, a disease extensively reported during the World Wars. Recent molecular biology approaches have allowed dramatic extension of the spectrum of Bartonella infections. B. quintana is now also recognized as an etiological agent of fever and bacteremia, endocarditis, bacillary angiomatosis, and chronic lymphadenopathy. Human immunodeficiency virus-infected patients and/or homeless people are the most vulnerable to infection. Poverty and louse infestation were the main epidemiological factors associated with B. quintana infections during wartime. Although poverty and chronic alcoholism have been associated with modern cases of trench fever and bacteremia due to B. quintana in Europe and the United States, vectors for B. quintana have not been clearly identified and B. quintana has not been isolated from modern-day lice. Microscopic bacillary angiomatosis lesions are characterized by tumor-like capillary lobules, with proliferating endothelial cells. In vitro experiments have shown that B. quintana survives within endothelial cells and stimulates cell proliferation. These observations, together with the finding that lesions may regress when antibiotic therapy is administered, strongly suggest that B. quintana itself stimulates angiogenesis. Bartonella infections are characterized by a high frequency of relapses after brief courses of antibiotic therapy. It is to be noted that in vitro, although Bartonella species are highly susceptible to antibiotics, only the aminoglycosides have proved to be bactericidal. However, the most effective antibiotic regimen for Bartonella infections remains to be established.

Characterization of a 17-kilodalton antigen of Bartonella henselae reactive with sera from patients with cat scratch disease

A library of Bartonella (Rochalimaea) henselae DNA was constructed in the cloning vector lambda ZAPII and screened for expression of antigenic proteins by using a pool of sera from patients who had been diagnosed with cat scratch disease (CSD) and had antibodies to Bartonella spp., as determined by indirect fluorescent-antibody (IFA) assay. Ten immunoreactive phages were subcloned as recombinant plasmids by in vivo excision. All 10 recombinants expressed a protein of approximately 17 kDa when they were examined by immunoblot with the pool of human sera. Restriction endonuclease digestion of each recombinant plasmid indicated seven profiles, suggesting that cloning bias was not the reason for repeated isolation of clones expressing the 17-kDa antigen. The gene coding for the 17-kDa antigen was sequenced and shown to code for an open reading frame of 148 amino acids with a predicted molecular mass of 16,893 Da. The amino terminus of the deduced amino acid sequence was hydrophobic in nature and similar in size and composition to signal peptides found in gram-negative bacteria. The remainder of the deduced amino acid sequence was more hydrophilic and may represent surface-exposed epitopes. Further subcloning of the 17-kDa antigen as a biotinylated fusion protein in the expression vector PinPoint Xa-2 resulted in a 30-kDa protein that was highly reactive on immunoblots with individual serum samples from patients with CSD. The agreement between reactivity with the 30-kDa fusion protein on immunoblot analysis and the results obtained by IFA assay was 92% for IFA-positive sera and 88% for IFA-negative sera. The recombinant-expressed 17-kDa protein should be of value as an antigen for serologic diagnosis of CSD and Bartonella infections and warrants further study in attempts to develop a subunit vaccine to prevent long-term Bartonella infection in cats and the potential for further spread of these organisms to humans.

Bacillary epithelioid angiomatosis in acquired immunodeficiency syndrome (AIDS)--clinicopathological and ultrastructural study of a case with a review of the literature

Bacillary epithelioid angiomatosis (BEA) is a rare cutaneous disorder usually affecting patients with human immunodeficiency virus (HIV) infection often misdiagnosed as a vascular tumour. We describe a 51-year-old, HIV-positive, Caucasian, homosexual male who developed scattered papulo-nodular lesions with clinicopathological and ultrastructural features of BEA. He had a dramatic therapeutic response to systemic antibiotics. There has been a lack of such reports in the European literature. The differential diagnosis is discussed and a brief review of the English literature to date is included.

AIDS: Part I

Acquired immunodeficiency syndrome (AIDS) is caused by infection with a pathogenic human retrovirus known as human immunodeficiency virus (HIV). Approximately 1 million people are currently infected with HIV in the United States, with 8 to 10 million infected individuals worldwide. The virus is transmitted predominantly through genital sexual contact, although orogenital spread has been rarely reported. Heterosexual transmission has been most common in the Third World, whereas male homosexual transmission has predominated in the United States and western Europe. Transmission through homosexual contact has been steadily declining over the past 5 years as transmission through illicit intravenous drug use and promiscuous unprotected heterosexual activity has increased. Sexually transmitted diseases that cause inflammatory or ulcerative lesions of the genital tract act as important cofactors in increasing the risk of transmission through sexual contact. Perinatal transmission of HIV occurs in approximately 30% of infants born to infected mothers. Transmission to infants through breast-feeding has also been documented. Health care workers have been infected with HIV through accidental high-risk percutaneous or mucous membrane exposures, albeit at a low transmission rate of 0.3%. Infection of patients by infected health care professionals is a rare event, having been reported only once in 10 years of the epidemic. Infection with HIV results in a chronic lifelong infection. The major targets for HIV are CD4+ T-helper lymphocytes and cells of monocyte/macrophage lineage. Infection of the T-helper lymphocyte ultimately results in the death of the cell. Over time (measured in years), a progressive destruction of the T-helper lymphocyte population occurs, which results in profound immune suppression. Infection of monocytes/macrophages is not cidal, but these cells do have functional alterations as a result of the infection, which may contribute to the immune deficiency. In addition, chronically infected tissue macrophages may act as an important reservoir for HIV, particularly in the central nervous system. Infection of the T-helper lymphocytes and monocytes/macrophages is mediated through attachment of HIV through a specific binding interaction between CD4 expressed in the plasma membrane of these cells and a surface glycoprotein on the virus, gp120. Once the virus nucleocapsid (core particle) enters the cytoplasm of the target cell, the viral RNA genome is reverse transcribed by a reverse transcriptase enzyme into proviral DNA. This proviral DNA migrates into the nucleus where it integrates into the host cellular genome, which results in a chronically infected cell.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical, histologic, microbiologic, and biochemical characterization of the causative agent of bacillary (epithelioid) angiomatosis: a rickettsial illness with features of bartonellosis

It has been suggested that bacillary (epithelioid) angiomatosis (BEA) is a manifestation of cat scratch disease (CSD). Because of clinical similarity between this condition and the verruga peruana phase of bartonellosis, we sought to further characterize this disease as well as its causative agent and to compare it to bartonellosis. We isolated a small flagellated pleomorphic bacillus from skin lesions of two patients with BEA. Organisms were stained successfully with Warthin-Starry silver stains, but immunohistochemistry failed to demonstrate binding with a polyclonal antibody directed against the cat scratch bacillus. Whole cell fatty-acid gas chromatography performed on both BEA organisms and Bartonella bacilliformis demonstrated marked similarity between the two. Electron microscopy of BEA organisms in tissue and in suspension revealed features characteristic of a gram negative bacillus. Based on these findings, we propose that this unusual rickettsial infectious disease with vascular proliferation may represent an unusual variant of infection with a bartonella-like organism rather than a manifestation of cat scratch disease.

Recent advances in pediatric infectious diseases and their impact on dermatology

The past five years have seen numerous advances in the field of pediatric infectious diseases, and many of these have a substantial impact on the practice of dermatology. We review some of these advances and discuss their implications on etiology, diagnosis, therapy and complications of some relatively common conditions. The etiologic agent of exanthum subitum (roseola infantum) has been clearly implicated as a herpesvirus-6. Although in the classically described situation high fever in a young child is followed by defervescence and rash, two new scenarios have been described associated with this virus. The first is fever without rash and the second is rash without fever. The etiologic agent of erythema infectiosum ("slapped cheek") has been shown to be a human parvovirus B19. The virus has also been associated with aplastic crises (in hemoglobinopathies), hydrops fetalis, and a syndrome of subacute arthralgias in women. The etiologic agent in cat-scratch disease has recently been shown to be a small pleomorphic bacillus that also can produce pyogenic granuloma-like lesions in patients with acquired immunodeficiency syndrome. The number of cases of congenital syphilis, particularly in large cities, is increasing tremendously. Many of these infants have received no prenatal care because of drug abuse problems in their parents. Finally, we describe the changing etiology of impetigo that is predominantly associated with Staphylococcus aureus. We further describe the growing resistance to erythromycin and several new erythromycin drug-drug interactions.

The current status of cat-scratch disease: an update

Cat-scratch disease (CSD) is a benign inoculative lymphoreticulosis, first described in independent reports by Pierre Mollaret [1] and Robert Debre in 1950 [2]. The disease usually self-limited, with spontaneous resolution occurring after several weeks, appears to be related to the presence of an identified gram-negative bacteria.

Clinical and pathological features of bacillary peliosis hepatis in association with human immunodeficiency virus infection

BACKGROUND

Peliosis hepatis is characterized by cystic, blood-filled spaces in the liver and is seen in patients with chronic infections or advanced cancer and as a consequence of therapy with anabolic steroids. Cutaneous bacillary angiomatosis is a bacterial infection that occurs in patients with human immunodeficiency virus (HIV) infection; its histologic appearance is that of a pseudoneoplastic vascular proliferation.

METHODS

We studied liver tissue from eight HIV-infected patients with peliosis hepatis, two of whom also had cutaneous bacillary angiomatosis. For comparison we examined tissue from four patients who had peliosis hepatis without HIV infection. Tissues were examined histologically on routine sections and with special stains and electron microscopy.

RESULTS

The histologic features seen in peliosis hepatis associated with HIV infection, but not in the four cases unrelated to HIV infection, were myxoid stroma and clumps of a granular purple material that on Warthin-Starry staining and electron microscopy proved to be bacilli. The bacilli, which could not be cultured, were morphologically identical to those found in the skin lesions of cutaneous bacillary angiomatosis. The clinical courses of two of the patients with this "bacillary peliosis hepatis" indicate that it responds to antibiotic treatment.

CONCLUSIONS

HIV-associated bacillary peliosis hepatis is an unusual, treatable opportunistic infection, probably caused by the same organism that causes cutaneous bacillary angiomatosis. Our failure to find bacilli in non-HIV-associated cases implies that other pathogenetic mechanisms may also be responsible for peliosis hepatis.

Bacillary angiomatosis: a newly characterized, pseudoneoplastic, infectious, cutaneous vascular disorder

Bacillary angiomatosis (also called epithelioid angiomatosis) is a newly recognized disease most often characterized by a cutaneous infection with reddish papules of vascular origin. It is caused by a weakly reactive gram-negative bacillus, which can be easily demonstrated in tissue sections with the Warthin-Starry stain. Bacillary angiomatosis usually responds readily to treatment with oral erythromycin, 250 to 500 mg, taken four times a day for 2 weeks to 1 month. Because the skin is the most common site of involvement, it is important that the dermatologist recognize this unusual condition. It is essential that treatment be started as soon as possible because deaths may result from visceral and mucosal involvement. The clinical, histologic, and microbiologic aspects of bacillary angiomatosis are discussed and depicted in detail and speculations regarding the pathogenesis are rendered.

Cat-scratch disease: a review of the literature

Cat-scratch disease (CSD) is a common cause of chronic lymphadenopathy (especially regional) that primarily affects children and adolescents. The clinical diagnosis of CSD is based on the presence of three of four criteria, which may include a positive CSD skin test. Usually a benign, self-limiting disease, CSD may sometimes have atypical manifestations and serious complications, particularly in immunocompromised hosts. Cat-scratch disease is now known to be caused by a small, gram-negative, pleomorphic bacterium. Antibiotics are dramatically effective against CSD in immunocompromised patients, but are not [corrected] of proven benefit in typical cases. Most patients recover with only symptomatic treatment. This article reviews the history of CSD research, clinical features of typical and atypical CSD, and current topics of interest in CSD research, especially in the areas of diagnosis and treatment.