Bartonella henselae infections in solid organ transplant recipients: report of 5 cases and review of the literature

Donor-derived bartonellosis in solid organ transplant recipients from unhoused donors in Alberta

Bartonella quintana infection is rarely described to be transmitted through solid organ transplant (SOT). We report a cluster of using donor-derived B quintana infection and the attack rate from Bartonella seropositive donors. In this retrospective study of SOT recipients that received an organ from an unhoused deceased donor (UDD) in Alberta in 2022-2023, serology testing for Bartonella was performed indirect immunofluorescent assay on UDDs and recipients of UDDs with positive serology. Titers ≥1:64 were considered positive. During the study period, 31/32 UDDs were tested for immunoglobulin G to Bartonella (20 negative, 11 positive for B quintana and/or B henselae). Thirty-two organs were transplanted from the 11 seropositive donors. Six SOT recipients developed bartonellosis secondary to B quintana (4 SOT recipients received organs from 3 seropositive donors, and 2 SOT recipients from 1 UDD with no stored sample for testing). The attack rate for clinical disease from positive donors was 12.5% (4/32). The main presentation was skin nodules/papules (median 5.5 months) with bacillary angiomatosis in 4/6. Bartonella serology was positive in 5/6 SOT recipients (initially negative in 2) and blood B quintana quantitative polymerase chain reaction in 1. None had visceral involvement. All donors had history of substance use. This outbreak of bartonellosis reinforces the potential for unexpected donor-transmitted infections. Clinicians should be aware of high transmission of B quintana through transplant from infected UDDs.

Bartonella quintana Infection in Kidney Transplant Recipients from Donor Experiencing Homelessness, United States, 2022

Bartonella quintana infection can cause severe disease that includes clinical manifestations such as endocarditis, chronic bacteremia, and vasoproliferative lesions of the skin and viscera. B. quintana bacteria is transmitted by the human body louse (Pediculus humanus corporis) and is associated with homelessness and limited access to hygienic services. We report B. quintana infection in 2 kidney transplant recipients in the United States from an organ donor who was experiencing homelessness. One infection manifested atypically, and the other was minimally symptomatic; with rapid detection, both recipients received timely treatment and recovered. B. quintana was identified retrospectively in an archived donor hematoma specimen, confirming the transmission link. Information about the organ donor's housing status was critical to this investigation. Evaluation for B. quintana infection should be considered for solid organ transplant recipients who receive organs from donors with a history of homelessness or of body lice infestation.

Clinicopathological differences between Bartonella and other bacterial endocarditis-related glomerulonephritis - our experience and a pooled analysis

Background

Although Staphylococcus aureus is the leading cause of acute infective endocarditis (IE) in adults, Bartonella spp. has concomitantly emerged as the leading cause of "blood culture-negative IE" (BCNE). Pre-disposing factors, clinical presentation and kidney biopsy findings in Bartonella IE-associated glomerulonephritis (GN) show subtle differences and some unique features relative to other bacterial infection-related GNs. We highlight these features along with key diagnostic clues and management approach in Bartonella IE-associated GN.

Methods

We conducted a pooled analysis of 89 cases of Bartonella IE-associated GN (54 published case reports and case series; 18 published conference abstracts identified using an English literature search of several commonly used literature search modalities); and four unpublished cases from our institution.

Results

Bartonella henselae and Bartonella quintana are the most commonly implicated species causing IE in humans. Subacute presentation, affecting damaged native and/or prosthetic heart valves, high titer anti-neutrophil cytoplasmic antibodies (ANCA), mainly proteinase-3 (PR-3) specificity, fastidious nature and lack of positive blood cultures of these Gram-negative bacilli, a higher frequency of focal glomerular crescents compared to other bacterial infection-related GNs are some of the salient features of Bartonella IE-associated GN. C3-dominant, but frequent C1q and IgM immunofluorescence staining is seen on biopsy. A "full-house" immunofluorescence staining pattern is also described but can be seen in IE -associated GN due to other bacteria as well. Non-specific generalized symptoms, cytopenia, heart failure and other organ damage due to embolic phenomena are the highlights on clinical presentation needing a multi-disciplinary approach for management. Awareness of the updated modified Duke criteria for IE, a high index of suspicion for underlying infection despite negative microbiologic cultures, history of exposure to animals, particularly infected cats, and use of send-out serologic tests for Bartonella spp. early in the course of management can help in early diagnosis and initiation of appropriate treatment.

Conclusion

Diagnosis of IE-associated GN can be challenging particularly with BCNE. The number of Bartonella IE-associated GN cases in a single institution tends to be less than IE due to gram positive cocci, however Bartonella is currently the leading cause of BCNE. We provide a much-needed discussion on this topic.

Bartonella henselae as a putative trigger for chronic type 2 leprosy reactions

Leprosy reactions are an acute inflammatory phenomenon that can arise before diagnosis, during treatment, or after cure of leprosy. These reactions are considered one of the main diseases that cause physical disabilities. Immunosuppressive treatment for these immune responses makes these patients susceptible to coinfections, which can trigger new leprosy reactions. The main objective of this study was to evaluate the occurrence of infection by Bartonella sp. in blood samples from 47 patients who had untreatable episodes of type 2 leprosy reactions for more than six months, comparing them with a control group. Cultures and molecular methods (PCR) were used. Amplicons from species-specific reactions and sequencing showed a higher prevalence of Bartonella henselae infection in patients, 19/47 (40.4 %), compared to control, 9/50 (18.0 %), p = 0.0149. Five patients accepted treatment for coinfection, and all showed improvement in leprosy reactions with treatment for B. henselae infection. We conclude that these bacteria can trigger chronic reactions of type 2 leprosy and should be investigated in these patients. SUMMARY LINE: Patients who have chronic type 2 leprosy reactions are more susceptible to Bartonella henselae infection than controls: 19/47 (40.4 %) compared 9/50 (18.0 %), p = 0.0149.

Comparison of molecular methods for Bartonella henselae detection in blood donors

The Bartonella genus consists of neglected pathogens associated with potentially transfusional-transmitted and fatal human diseases. We aimed to evaluate Bartonella sp. prevalence in 500 blood donors and compare the results with the data already published about these samples. We used molecular diagnostic methods to detect Bartonella sp.-DNA from blood and liquid culture samples: (A) conventional PCR for two gene regions, the ITS targeting the genus Bartonella and the specific gltA Bartonella henselae; (B) nested PCR for the ftsZ gene and (C) qualitative real-time PCR for the gltA gene, both B. henselae specific. We obtained 30/500 (6%) DNA detections from the blood samples; 77/500 (15.4%) DNA detections from liquid culture samples and five (1%) samples had DNA detection from both. In total, we detected B. henselae DNA from 102/500 (20.4%) donors. The samples used in this study had already been submitted for Bartonella sp.-DNA detection using only a conventional PCR in liquid culture. Sixteen samples (3.2%) were positive previously, and from these 16 samples, 13 were negative in the new investigation. We concluded that the use of liquid culture combined with different molecular tests increases the possibility of detecting Bartonella sp.-DNA, but the tests do not avoid false-negative results. More than a fifth of blood donors had at least one PCR that detected Bartonella sp.-DNA among the eight molecular reactions performed now (four reactions in whole blood and four in liquid culture). Seven percent had B. henselae-DNA detection for two or more distinct regions. Considering the results obtained previously, the DNA of Bartonella spp. was detected or the agent isolated in 23% of analyzed blood donors. The results establish that the low bacteremia and the fastidious characteristics of the bacterium are challenges to laboratory diagnosis and can make it difficult to confirm the infection in patients with bartonelloses.

Culture-Negative Endocarditis in an Immunocompromised Patient: A Case of Suspected Bartonella and Coxiella Co-Infection

We present the case of a 23-year-old man with a previous deceased-donor renal transplant maintained on tacrolimus and prednisone who developed culture-negative endocarditis (CNE) of the mitral and aortic valves. He was suspected of being co-infected with Bartonella henselae and Coxiella burnetii, confirmed with serology testing. He was successfully managed with appropriate antibiotics and dual valve replacement.

Haemophagocytic lymphohistiocytosis associated with bartonella peliosis hepatis following kidney transplantation in a patient with HIV

Bacillary peliosis hepatis is a well recognised manifestation of disseminated Bartonella henselae infection that can occur in immunocompromised individuals. Haemophagocytic lymphohistiocytosis is an immune-mediated condition with features that can overlap with a severe primary infection such as disseminated Bartonella spp infection. We report a case of bacillary peliosis hepatis and secondary haemophagocytic lymphohistiocytosis due to disseminated Bartonella spp infection in a kidney-transplant recipient with well controlled HIV. The patient reported 2 weeks of fever and abdominal pain and was found to have hepatomegaly. He recalled exposure to a sick dog but reported no cat exposures. Laboratory evaluation was notable for pancytopenia and cholestatic injury. The patient met more than five of eight clinical criteria for haemophagocytic lymphohistiocytosis. Pathology review of a bone marrow core biopsy identified haemophagocytosis. A transjugular liver biopsy was done, and histopathology review identified peliosis hepatis. Warthin-Starry staining of the bone marrow showed pleiomorphic coccobacillary organisms. The B henselae IgG titre was 1:512, and Bartonella-specific DNA targets were detected by peripheral blood PCR. Treatment with doxycycline, increased prednisone, and pausing the mycophenolate component of his transplant immunosuppression regimen resulted in an excellent clinical response. Secondary haemophagocytic lymphohistiocytosis can be difficult to distinguish from severe systemic infection. A high index of suspicion can support the diagnosis of systemic Bartonella spp infection in those who present with haemophagocytic lymphohistiocytosis, especially in patients with hepatomegaly, immunosuppression, and germane animal exposures.

Cryptogenic hepatitis patients have a higher Bartonella sp.-DNA detection in blood and skin samples than patients with non-viral hepatitis of known cause

Background

This study aimed to assess the prevalence of Bartonella sp.-DNA detection in blood and skin samples from patients with non-viral end-stage liver disease awaiting liver transplantation.

Methodology/Principal findings

Blood samples and healthy skin fragments from 50 patients were tested using microbiological and molecular methods. Fifteen patients had cryptogenic hepatitis (CH) and 35 had alcoholic, drug-induced or autoimmune liver disease. DNA was extracted from whole blood and liquid culture samples, isolates, and skin fragments. Thirteen of the 50 patients (26%) had Bartonella henselae DNA detection in their blood (9/50) and/or skin (5/50) samples. Colonies were isolated in 3/50 (6%) and infection was detected in 7/50 (14%) of the 50 patients. B. henselae-DNA detection was more prevalent in patients with CH than in other patients (p = 0.040). Of 39 patients followed-up for at least two years, a higher mortality rate was observed among patients with CH infected with B. henselae (p = 0.039).

Conclusions/Significance

Further studies assessing the role of B. henselae infection in the pathogenesis of hepatitis patients must be urgently conducted.

One in four patients with end-stage liver disease awaiting liver transplantation for hepatitis of non-viral origin had documented B. henselae-DNA detection and cryptogenic hepatitis patients have a higher bacterium molecular detection than patients with non-viral hepatitis of known cause.

Severe Bartonella henselae bone infection in a kidney transplanted young man

We present a case of a young kidney transplanted man. He was admitted with lymphadenopathy, fluctuating fever and night sweats 2 months after a cat bite. After admission, he developed severe pain around his right hip. An 18F-fluorodeoxyglucose (FDG)-positron emission tomography/CT revealed intense FDG-uptake in lymph nodes, spleen and bone, suggestive of lymphoma. An extracted lymph node showed confluent granulomas, microabscesses with neutrophils and scattered multinucleated giant cells histologically. The patient had history of latent tuberculosis and proteinase 3 -anti-neutrophil cytoplasmic antibodies associated (PR3-ANCA) vasculitis, making differential diagnostic considerations complicated. Bartonella henselae antibodies was detected in blood and B. henselae DNA in a lymph node. He was started on doxycycline and rifampicin. Due to severe drug interactions with both tacrolimus and increasing morphine doses, rifampicin was changed to azithromycin. He received 12 days of relevant antibiotic treatment and responded well. He was discharged after 16 days with close follow-up and was still in habitual condition 12 months later.

Serious and atypical presentations of Bartonella henselae infection in kidney transplant recipients

This article describes 5 cases of bartonellosis with fever and atypical clinical presentations in kidney transplant recipients: thrombotic microangiopathies, recurrent hemophagocytosis, and immune reconstitution syndrome after treatment. The diagnosis, the pathological lesions, and treatments are described. Bartonellosis must be researched in solid organ transplant recipients with fever of undetermined origin.

Bartonella henselae infection in the pediatric solid organ transplant recipient

Bartonella henselae infection can cause a wide spectrum of diseases in both the immunocompetent and immunocompromised host with BA a severe form relegated to immunocompromised hosts, including solid organ transplant population. There are established criteria for diagnosis of Bartonella infection based on clinical presentation, serologic testing, imaging studies and, when indicated, tissue sampling for histopathological evaluation, particularly for BA. However, treatment recommendations for BA are inconclusive. Furthermore, there are no studies in the pediatric solid organ transplant population for antimicrobial therapy during BA secondary to Bartonella henselae infection. A case of BA following heart transplant is presented along with a literature review of clinical presentation; diagnosis and therapy for BA in the pediatric solid organ transplant population.

Early post-transplant cutaneous bacillary angiomatosis in a kidney recipient: Case report and review of the literature

Bacillary angiomatosis (BA) is an uncommon systemic disease caused by Bartonella henselae (BH) or Bartonella quintana (BQ) that occurs primarily in immunocompromised hosts. Few cases of BA recipients have been reported in adult solid transplant recipients over the years, with most cases presenting years after transplant. We describe a case of a kidney transplant recipient who developed cutaneous BA very early in the post-transplant period despite not having any exposures. Retrospective testing of donor and recipient's serum was performed and raised the concern for possible donor-derived infection. A literature review encompassing 1990 to present was also performed in order to better understand the clinical presentation, diagnostics and therapeutic approach of this unusual disease. Combined serology, histopathology and molecular testing (polymerase chain reaction [PCR]) were useful in diagnosing BA in our patient as serology alone might be unreliable. Macrolides or doxycycline for at least 3 months is the recommended therapeutic strategy; however, the optimal duration of treatment is not well established in transplant recipients. In our patient, we decided to use doxycycline for 1 year due to gradual resolution of lesions and ongoing immunosuppression. Patient responded successfully without any documented relapse.

Bartonellosis in transplant recipients: A retrospective single center experience

BACKGROUND

Bartonellosis is a rare but challenging condition to diagnose with a spectrum of clinical presentations in the immunocompromised host.

AIM

To further characterize the presentation of Bartonella henselae (B. henselae) infections in solid organ and hematopoietic stem cell transplant recipients.

METHODS

We conducted a single-center retrospective study of all B. henselae testing for 5012 transplant recipients receiving care at a single institution between 2011 and 2018.

RESULTS

We identified 38 patients who underwent testing for B. henselae, and three of 38 were found to have bartonellosis. Two of the patients were renal transplant recipients who presented with visceral bartonellosis and symptoms concerning for post-transplant lymphoproliferative disorder. One autologous stem cell transplant recipient presented with cat scratch disease. We detail the clinical courses of these three cases and review the literature concerning the clinical presentations, differential diagnosis, and limitations of diagnostic tests for B. henselae infections in transplant recipients.

CONCLUSION

Although the incidence of B. henselae infection in transplant recipients is unknown, it merits inclusion in the differential diagnosis for fever of unknown origin in this population.

Disseminated bartonellosis in a child with steroid-dependent nephrotic syndrome receiving mycophenolate mofetil monotherapy

Cat scratch disease, usually a benign infectious disease, may develop as multisystem disease with multiorgan involvement, particularly in immunocompromised patients. We report on a patient who developed disseminated bartonellosis while receiving mycophenolate mofetil monotherapy treating steroid-dependent nephrotic syndrome, highlighting that severe infection can be observed in those patients. Therefore, this category of patients should be cautious when having contact with kittens and receives proper prevention advice.

Endocarditis in kidney transplant recipients: a systematic review

Infective Endocarditis (IE) carries significant mortality. Bacteremia, which is a predisposing factor for IE, occurs more frequently in immunocompromised individuals. Interestingly, IE in kidney transplant recipients has not been adequately described. The aim of this study was to systematically review all published cases of IE in kidney transplant recipients and describe their epidemiology, microbiology, clinical characteristics, treatment and outcomes. A systematic review of PubMed (through 13^th December 2019) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE in kidney transplant recipients was performed. A total of 60 studies, containing data of 117 patients, were included in the analysis. The most common causative pathogens were gram-positive microorganisms in 57.4%, gram-negative microorganisms in 14.8%, fungi in 20%, while in 18.9% of cases, IE was culture-negative. Aortic valve was the most commonly infected valve followed by mitral, tricuspid and the pulmonary valve. Diagnosis was set with a transthoracic ultrasound in half the cases, followed by transesophageal ultrasound and autopsy. Fever was present in most cases, while embolic phenomena were noted in two out of five cases. Aminoglycosides, cephalosporins and aminopenicillins were the most commonly used antimicrobials, and surgical management was performed in one out of three cases. Clinical cure was noted in 60.9%, while overall mortality was 45.3%. To conclude, this systematic review thoroughly describes IE in kidney transplant recipients and provides information on epidemiology, clinical presentation, treatment and outcomes. Moreover, it identifies the emerging role of Enterococci, gram-negatives and fungi in IE in this population.

Clinicopathologic Features of Tissue Granulomas in Transplant Recipients: A Single Center Study in a Nontuberculosis Endemic Region

CONTEXT.—

There is a paucity of literature about tissue granulomas in transplant patients.

OBJECTIVE.—

To characterize the clinicopathologic features of granulomas in this population and develop a clinically judicious approach to their evaluation.

DESIGN.—

We performed chart reviews of solid organ and allogeneic hematopoietic stem cell transplant recipients at Yale New Haven Hospital to identify patients with granulomas on biopsy obtained pathologic specimens. Pretransplant and posttransplant specimens were included. Data points included demographics, clinical presentation, epidemiologic risk factors, biopsy indication, location and timing, immunosuppression, histopathology, microbiology, and associated clinical diagnosis. Granuloma-related readmissions and mortality were recorded at 1, 3, and 12 months.

RESULTS.—

Biopsy proven granulomas were identified in 56 of 2139 (2.6%) patients. Of 56, 16 (29%) were infectious. Common infectious etiologies were bartonellosis (n = 3) and cytomegalovirus hepatitis (n = 3). Tuberculosis was not identified. Clinical symptoms prompted tissue biopsy in 27 of 56 (48.2%) cases while biopsies were obtained for evaluation of incidental findings or routine disease surveillance in 29 of 56 (51.8%). Presence of symptoms was significantly associated with infectious etiologies; 11 of 27 (40.7%) symptomatic patients compared with 5 of 29 (17.2%) asymptomatic patients had infectious causes. One death from granulomatous cryptogenic organizing pneumonia occurred. In pretransplant asymptomatic patients, no episodes of symptomatic disease occurred posttransplantation.

CONCLUSIONS.—

Granulomas were uncommon in a large transplant population; most were noninfectious but presence of symptoms was associated with infectious etiologies. Granulomas discovered pretransplant without clear infectious etiology likely do not require prolonged surveillance after transplantation. Symptomatology and epidemiologic risks factors should guide extent of microbiologic evaluation.

Imaging analysis of Bartonella species in the skin using single-photon and multi-photon (second harmonic generation) laser scanning microscopy

We demonstrate Bartonella spp are abundant in skin lesions resembling striae distensae. These striae distensae-like lesions, coincidental with sudden onset of neuropsychiatric symptoms, indicate testing for suspected Bartonella spp. infection.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

Peliosis Hepatis Simulating Metastatic Liver Disease on FDG PET/CT

A 20-year-old man with gastrointestinal symptoms and weight loss underwent FDG PET/CT, which revealed multiple hypermetabolic hepatic lesions concerning for metastatic liver disease. The outcome of liver biopsy was consistent with the diagnosis of peliosis hepatis which is a rare benign disease characterized by multiple blood-filled cystic spaces in the hepatic parenchyma. The findings of peliosis on FDG PET/CT are not well reported in the literature. These interesting images emphasize the importance of including peliosis hepatis in the differential diagnosis of multiple hypermetabolic hepatic lesions on FDG PET/CT, which could simulate malignancy.

Lymphadenitis associated with cat-scratch disease simulating a neoplasm: Imaging findings with histopathological associations

The lymphadenitis associated with cat-scratch disease (CSD) is often confused with neoplasms by a number of radiologists and clinicians, and consequently, unnecessary invasive procedures or surgeries are performed. In the present study, the contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) findings of 10 patients (6 men and 4 women) with clinically and pathologically confirmed lymphadenitis associated with CSD were retrospectively analyzed (CT in 3 patients, MRI in 6 patients, and CT and MRI in 1 patient) at The Second Affiliated Hospital of Zhejiang University School of Medicine (Hangzhou, China) between January 2007 and November 2014. As a result, 17 enlarged lymph nodes were identified in 10 cases. The 5 nodes identified by CT scan exhibited relatively inhomogeneous isodensity to muscle, with patchy low density in the center. All 14 nodes identified by MRI scan exhibited homogeneous or heterogeneous isointensity to muscle or slightly increased intensity compared with that of muscle on T1-weighted images (T1WI), and homogeneous or heterogeneous hyperintensity on fat-suppressed T2WI. Following enhancement, all 17 enlarged lymph nodes associated with CSD demonstrated the following 3 different enhancement patterns: Moderate homogeneous enhancement (n=8), which was associated with histologically identified early disease stage; marked heterogeneous enhancement with no enhancement of the necrotic areas (n=4), and heterogeneous enhancement with progressively ‘spoke-wheel-like’ (defined as radiating enhancement from the center) enhancement of the patchy low-density area (n=1), which was associated with histologically identified intermediate disease stage; and astral low-density/hypointensity with marked enhancement (n=2) or a ‘rose flower’ sign (n=2), which was associated with histologically identified late disease stage. We hypothesized that the CT and MRI results of lymphadenitis in CSD may be associated with the pathological features. It may be suggested that the diagnosis of CSD may be formed when considering the characteristic CT and MRI features of astral low-density/hypointensity with marked enhancement or a ‘rose flower’ sign (defined as marginal petaloid enhancement) in the late disease stage, or the MRI results of homogeneous, moderate enhancement in the early disease stage, or the CT/MRI data of heterogeneous enhancement with non-enhancing area in the center in the intermediate disease stage, in solitary or multiple enlarged lymph nodes associated with general subcutaneous edema in the vicinity of the nodes on CT/MRI and with a history of cat exposure.

[Cutaneous infections: Pathologist's role in unusual or atypical situations]

In infectious pathology, the gold standard consists of the detection of the pathogen within the sample. Identification of the pathogen is often difficult despite the presence of few and inexpensive tools, such, as special stain, immunohistochemistry, or in situ hybridization specific of the pathogen. In infectious pathology, there are morphological signs, which can guide us towards an etiology. We present some clinicopathological examples illustrating rare or unusual situations in cutaneous infectious pathology.

Bartonellosis in Chronic Kidney Disease: An Unrecognized and Unsuspected Diagnosis

Systemic cat scratch disease or bartonellosis is a clinical entity caused by Bartonella henselae, which manifests with necrotizing granulomas in visceral organs. The cat flea, Ctenocephalides felis, is the vector responsible for horizontal transmission of the disease from cat to cat, and its bite can also infect humans. In immunocompromised patients including chronic kidney disease and renal transplant recipients, it can cause persistent and disseminated cat scratch disease. The aim of this paper is to perform a systematic review of the studies that have addressed the diagnostic methods of cat scratch disease in chronic kidney disease and renal transplant recipients. This review was searched via electronic PubMed and Google scholar databases. Few qualitative full-text original articles in chronic kidney disease and kidney transplant were extracted. At this paper, 19 articles identified including six articles in chronic kidney disease and 13 articles in renal transplant recipients. Of these six identified case reports in chronic kidney disease, serology via immunofluorescence antibody test was led to diagnosis of cat scratch disease in five patients and a one patient showed nonreactive serologic test. Polymerase chain reaction usage to detect deoxyribonucleic acid in tissue biopsy and bone marrow biopsy was led to diagnosis. Cat scratch disease diagnosis in 13 renal transplant recipients was attained more by combining serology and polymerase chain reaction to detect deoxyribonucleic acid in tissue specimens. These selected studies demonstrate that serology and polymerase chain reaction via deoxyribonucleic acid extraction of tissue specimens yield the best outcome in diagnostic field of bartonellosis.

An unusual case of bacillary angiomatosis in the oral cavity of an AIDS patient who had no concomitant tegumentary lesions - case report and review

Bacillary angiomatosis (BA) is an angioproliferative disease of immunocompromised patients that usually presents as vascular tumors in the skin and subcutaneous tissues. It is caused by chronic infections with either Bartonella henselae or B. quintana. Oral cavity BA is exceedingly rare and even rarer without simultaneous cutaneous disease. We report herein the case of a 51-year-old HIV-infected man who presented severe odynophagia and an eroded lesion on the hard palate that progressed to an oronasal fistula. No cutaneous lesions were recorded. Doxycycline led to complete resolution. To the best of our knowledge, only six previous cases of oral BA without tegumentary disease have been previously reported and none of them progressed to fistula.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

Disseminated cat-scratch disease presenting as nausea, diarrhea, and weight loss without fever in a heart transplant recipient

We report the case of an afebrile 59-year-old heart transplant recipient presenting with nausea, vomiting, diarrhea, weight loss, and diffuse lymphadenopathy. Lymph node biopsies revealed non-caseating granulomatous inflammation. Cat-scratch disease was confirmed by serologic studies, Warthin-Starry staining, and polymerase chain reaction testing of lymph node tissue. The patient's symptoms resolved with 3 months of doxycycline. We review clinical presentations of Bartonella henselae infection and review diagnostic approaches for B. henselae in this patient population.

Seroprevalence of Bartonella henselae in patients awaiting heart transplant in Southern Italy

BACKGROUND

Bartonella henselae is the etiologic agent of cat-scratch disease. B. henselae infections are responsible for a widening spectrum of human diseases, although often symptomless, ranging from self-limited to life-threatening and show different courses and organ involvement due to the balance between host and pathogen. The role of the host immune response to B. henselae is critical in preventing progression to systemic disease. Indeed in immunocompromised patients, such as solid organ transplant patients, B. henselae results in severe disseminated disease and pathologic vasoproliferation. The purpose of this study was to determine the seroprevalence of B. henselae in patients awaiting heart transplant compared to healthy individuals enrolled in the Regional Reference Laboratory of Transplant Immunology of Second University of Naples.

METHODS

Serum samples of 38 patients awaiting heart transplant in comparison to 50 healthy donors were examined using immunfluorescence assay.

RESULTS

We found a B. henselae significant antibody positivity rate of 21% in patients awaiting heart transplant (p = 0.002). There was a positive rate of 8% (p > 0.05) for immunoglobulin (Ig)M and a significant value of 13% (p = 0.02) for IgG, whereas controls were negative both for IgM and IgG antibodies against B. henselae. The differences in comorbidity between cases and controls were statistically different (1.41 ± 0.96 vs 0.42 ± 0.32; p = 0.001).

CONCLUSIONS

Although this study was conducted in a small number of patients, we suggest that the identification of these bacteria should be included as a routine screening analysis in pretransplant patients.

Seroprevalence of Bartonella Species in Patients with Ocular Inflammation

Bartonella species, vector-borne etiologic agents of many systemic or self-limited infections, are responsible for a widening spectrum of diseases in humans, including inflammatory conditions of the eye. The aim of this study was to determine whether there is any relationship between uveitis and the evidence of Bartonella spp. infection in the serum, ocular fluid, and cataract mass in patients with intraocular inflammation. Polymerase chain reaction (PCR)-based tests and DNA sequencing were performed on surgery-extracted specimens of intraocular fluid and lens mass of 33 patients. Sera from 51 patients and 101 control subjects were tested for the presence of specific antibodies against Bartonella spp. Neither IgM-class antibodies against Bartonella spp. nor Bartonella spp. DNA were detected. A specific IgG-class antibody was found in 33.3% of the patients with uveitis. The rate of positive Bartonella serology was higher among the uveitis patients than that in control subjects. This high rate may in part result from unrecognized indirect mechanisms rather than the immediate presence and multiplication of Bartonella spp. in the eyeball. Nonetheless we believe that screening for Bartonella spp. should become part of the diagnostic workup in uveitis.

Molecular Testing in Emerging Infectious Diseases

It was widely believed in the late 1960s that infectious diseases had been conquered by vaccines and antibiotics and humans were no longer under threat by microbial pathogens. Yet, since that time more than 60 pathogens have been discovered that can cause serious emerging infectious diseases. Molecular methods have played critical roles in the discovery, monitoring, and clinical diagnostics of emerging pathogens. In this chapter, we present well-recognized emerging pathogens. We provide examples of the utility of molecular assays in research and clinical care of emerging infectious diseases. We also discuss some theoretical and practical limitations of molecular tests and the future prospects of expanding molecular diagnostics for emerging pathogens based on new advances of knowledge and technologies.

Seronegative disseminated Bartonella spp. infection in an immunocompromised patient

An 11 year old, hispanic girl with a history of B-cell acute lymphoblastic leukemia was admitted to the hospital for symptoms compatible with Bartonella henselae infection. The first molecularly diagnosed case of disseminated Bartonella henselae infection was reported in an immunocompromised patient in Lima, Peru. The analysis was confirmed by Polymerase Chain Reaction and automated sequencing of a liver biopsy sample, even though the serologic tests were negative. In conclusion, Bartonella spp. infection should have a particular diagnostic consideration in immunocompromised patients with fever of unknown origin and further investigation regarding the patient's past exposures with cats should also be elicited.

Selected Topics in Aerobic Bacteriology

Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of the normal microbiota of the human host and animals, in soil and water, on plants, on fomites in the hospital, and on hospital equipment. This review provides information from relevant studies about what are the most common aerobic bacteria associated with patients who have cancer and/or are being treated for it, or who have other diseases which lead to immunodeficiencies, such as HIV, multiple myeloma, aplastic anemia, chronic diseases, and aging. A discussion of the appropriate laboratory tests needed for diagnosis of aerobic infections and information about antibiotics and susceptibility testing are also included.

Ultrasound imaging as the basis of a clinical diagnosis of systemic bartonellosis in a patient after bone marrow transplantation. A case report

Infections in immunocompromised patients after hematopoietic stem cell transplantation can have a severe and atypical course. Some opportunistic pathogens are difficult to detect in microbiological tests, and that is why treatment success depends on an accurate clinical diagnosis. This article presents a case of a 7-year-old girl with severe aplastic anemia treated with bone marrow transplantation with post-transplantation period complicated by persistent, hectic fever, with peak episodes of 39–40°C, lasting several weeks. Repeated microbiological tests failed to reveal the etiological agent, and empirical anti-infective treatment was ineffective. In the fourth week of fever, imaging showed multiple foci resembling abscesses in the patient's internal organs and, subsequently, in soft tissues. The characteristics of these changes and data concerning environmental exposure led to the clinical diagnosis of cat scratch disease (bartonellosis) with multi-organ involvement and enabled the targeted treatment to be implemented. Fever subsided and organ lesions regressed. In this case, repeated ultrasound imaging was the basic diagnostic tool that helped arrive at a correct diagnosis and implement effective treatment of this life-threatening complication after hematopoietic stem cell transplantation.

Bartonella henselae transmission by blood transfusion in mice

BACKGROUND

Bartonella spp. are neglected fastidious Gram-negative bacilli. We isolated Bartonella henselae from 1.2% of 500 studied blood donors and demonstrated that the bacteria remain viable in red blood cell units after 35 days of experimental infection. Now, we aim to evaluate the possibility of B. henselae transmission by blood transfusion in a mouse model.

STUDY DESIGN AND METHODS

Eight BALB/c mice were intraperitoneal inoculated with a 30 µL of suspension with 10(4) CFU/mL of B. henselae and a second group of eight mice were inoculated with saline solution and used as control. After 96 hours of inoculation, the animals were euthanized. We collected blood and tissue samples from skin, liver, and spleen. Thirty microliters of blood from four Bartonella-inoculated animals were transfused into a new group (n = 4). Another group received blood from the control animals. B. henselae infection was investigated by conventional and nested polymerase chain reaction (PCR).

RESULTS

Blood samples from all 24 mice were negative by molecular tests though half of the tissue samples were positive by nested PCR in the intraperitoneal Bartonella-investigated animals. Tissues from two of the four mice that received blood transfusions from Bartonella-inoculated animals were also nested PCR positives.

CONCLUSIONS

Transmission of B. henselae by transfusion is possible in mice even when donor animals have undetectable bloodstream infection. The impact of human Bartonella sp. transmission through blood transfusion recipients must be evaluated.

Cat scratch disease in an immunosuppressed patient with systemic lupus erythematosus

Cat scratch disease is an infectious disorder transmitted by cats that typically affects children and young adults. Immunosuppression is a well-known risk factor for the development of severe and atypical forms of the disease; hence it is under-diagnosed in patients with compromised immunity. We are reporting the first case of cat scratch disease, which presented as fever and fatigue, in a patient with systemic lupus erythematosus while receiving immunosuppressant therapy after a kidney transplant.

Ocular bartonellosis in transplant recipients: two case reports and review of the literature

Cat scratch disease is caused by Bartonella henselae and usually manifests as localized lymphadenopathy and fever in immunocompetent patients. Immunocompromised patients are at risk for developing disseminated disease affecting the liver, spleen, eyes, central nervous system, and other organs. Bartonellosis is infrequently reported in solid organ transplant recipients, and published case reports usually discuss disseminated infection. Localized ocular disease with B. henselae, while well documented in immunocompetent hosts, is uncommon in immunocompromised patients. Herein, we present 2 cases of ocular bartonellosis in renal transplant patients, 1 with disseminated infection, and 1 without.

Persistent cat scratch disease requiring surgical excision in a patient with MPGN

We present the case of a 13-year-old immunosuppressed patient with unrelenting cat scratch disease despite 9 months of antibiotic therapy. The patient was being treated with mycophenolate and prednisone for membranoproliferative glomerulonephritis (type 1) diagnosed 13 months before the onset of cat scratch disease. Cat scratch disease was suspected due to epitrochlear lymphadenitis and an inoculation papule on the ipsilateral thumb, and the diagnosis was confirmed by the use of acute and convalescent titers positive for Bartonella henselae. The patient experienced prolonged lymphadenitis despite azithromycin and rifampin therapy, and she developed a draining sinus tract ∼4 months after initial inoculation while receiving antibiotics. Acute exacerbation of the primary supratrochlear node prompted incision and drainage of the area, with no improvement in the disease course. Ultimately, excision of all affected nodes and the sinus tract 9 months after the initial diagnosis was required to achieve resolution. Bartonella was detected at a high level according to a polymerase chain reaction assay in the excised nodes. Persistent treatment with oral antibiotics may have prevented disseminated infection in this immunosuppressed patient. Surgical excision of affected nodes should be considered in patients with cat scratch disease that persists beyond 16 weeks.

Peliosis Hepatis Shows Isometabolism on (18)F-FDG PET/CT: Two Case Reports

Peliosis hepatis (PH) is a rare benign disease that is characterized by multiple blood-filled cystic spaces in the hepatic parenchyma. It is also characterized by a range of radiologic findings that might mimic various diseases, including metastatic liver disease and hepatocellular carcinoma. The findings of PH on (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) are not well reported. We here report two cases of biopsy-proven PH. Both patients had been treated for cancer (advanced gastric carcinoma and rectal adenocarcinoma), and follow-up CT of both cases revealed hepatic lesions with the possibility of metastasis. Examination of (18)F-FDG PET/CT images suggested that the lesions were isometabolic, having metabolism similar to that of adjacent hepatic parenchyma. The outcomes of hepatic core-needle biopsies were consistent with peliosis hepatis.

Initial diagnosis of HIV/AIDS in a 56-year-old man with non-healing forearm lesion

A 56-year-old Hispanic man with no significant medical problems presented with a 2-month history of a non-healing right forearm lesion that progressed despite several courses of empiric antibiotics. The patient underwent incision and drainage. Warthin-Starry stain with immunohistochemistry testing diagnosed bacillary angiomatosis secondary to Bartonella quintana. Subsequently, the patient was diagnosed with HIV, with a CD4 count of 68 cells/mm(3), and a HIV viral load of 47, 914 copies/mL. The patient was treated with doxycycline and started on antiretroviral therapy. The lesion has resolved and he has had no recurrence after 16 months of treatment.

Koch's postulates and the pathogenesis of comparative infectious disease causation associated with Bartonella species

In his homage to Lucretius (‘Georgica’), Vergil is credited with stating: ‘Felix qui potuit rerum cognoscere causas’ (‘Fortunate is he who knows the causes of things’). Based on numerous commentaries and publications it is obvious that clinicians, diagnosticians and biomedical research scientists continue to struggle with disease causation, particularly in the assessment of the pathogenic role of ‘stealth pathogens’ that produce persistent infections in the host. Bartonella species, because of their evolutionary ability to induce persistent intravascular infections, present substantial challenges for researchers attempting to clarify the ability of these stealth bacteria to cause disease. By studying the comparative biological and pathological behaviour of microbes across mammalian genera, researchers might be able more rapidly to advance medical science and, subsequently, patient care by undertaking focused research efforts involving a single mammalian species or by attempting to recapitulate a complex disease in an rodent model. Therefore, in an effort to further assist in the establishment of disease causation by stealth pathogens, we use recent research observations involving the genus Bartonella to propose an additional postulate of comparative infectious disease causation to Koch's postulates.

Detection of microorganisms in granulomas that have been formalin-fixed: review of the literature regarding use of molecular methods

Granuloma is an organized aggregate of immune cells that under the microscope appear as epithelioid macrophages. A granuloma can only be diagnosed when a pathologist observes this type of inflammation under the microscope. If a foreign body or a parasite is not observed inside the granuloma, stains for acid-fast bacilli and fungi are ordered since mycobacteria and fungi are frequently the cause of this type of inflammation. It is calculated that 12 to 36% of granulomas do not have a specific etiology and many have wondered if with new molecular methods we could reduce this number. This paper will summarize the frequently known causes of granulomas and will present the recent literature regarding the use of molecular techniques on tissue specimens and how these have helped in defining causative agents. We will also briefly describe new research regarding formation and function of granulomas and how this impacts our ability to find an etiologic agent.