Bartonella infections diagnosed in the French reference center, 2014-2019, and focus on infections in the immunocompromised.

We studied retrospectively 651 PCR-confirmed Bartonella infections diagnosed at the French reference center for bartonellosis from 2014 to 2019. The most common form was cat-scratch disease (89%) followed by endocarditis (9%). Disseminated forms (2%) mainly presented as bacillary angiomatosis or peliosis hepatis in solid organ transplant recipients.

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.

Infectious and Autoimmune Causes of Encephalitis in Children.

BACKGROUND AND OBJECTIVES: Encephalitis can result in neurologic morbidity and mortality in children. Newly recognized infectious and noninfectious causes of encephalitis have become increasingly important over the past decade. METHODS: We retrospectively reviewed medical records from pediatric patients in Houston diagnosed with encephalitis in both an urban and rural catchment area between 2010 and 2017. We conducted an investigation to understand the etiology, clinical characteristics, and diagnostic testing practices in this population. RESULTS: We evaluated 231 patients who met the case definition of encephalitis, among which 42% had no recognized etiology. Among those with an identified etiology, the most common were infectious (73; 31%), including viral (n = 51; 22%), with the most frequent being West Nile virus (WNV; n = 12), and bacterial (n = 19; 8%), with the most frequent being Bartonella henselae (n = 7). Among cases of autoimmune encephalitis (n = 60; 26%), the most frequent cause was anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis (n = 31). Autoimmune causes were seen more commonly in female (P < .01) patients. Testing for herpes simplex virus and enterovirus was nearly universal; testing for anti-NMDAR encephalitis, WNV, and Bartonella was less common. CONCLUSIONS: WNV was the most common infectious cause of encephalitis in our pediatric population despite lower testing frequency for WNV than herpes simplex virus or enterovirus. Increasing testing for anti-NMDAR encephalitis resulted in frequent identification of cases. Increased awareness and testing for WNV and Bartonella would likely result in more identified causes of pediatric encephalitis. Earlier etiologic diagnosis of encephalitides may lead to improve clinical outcomes.

Ahnak-knockout mice show susceptibility to Bartonella henselae infection because of CD4+ T cell inactivation and decreased cytokine secretion.

The present study evaluated the role of AHNAK in Bartonella henselae infection. Mice were intraperitoneally inoculated with 2 × 108 colony-forming units of B. henselae Houston-1 on day 0 and subsequently on day 10. Blood and tissue samples of the mice were collected 8 days after the final B. henselae injection. B. henselae infection in the liver of Ahnak-knockout and wild-type mice was confirmed by performing polymerase chain reaction, with Bartonella adhesion A as a marker. The proportion of B. henselaeinfected cells increased in the liver of the Ahnak-knockout mice. Granulomatous lesions, inflammatory cytokine levels, and liver enzyme levels were also higher in the liver of the Ahnak-knockout mice than in the liver of the wild-type mice, indicating that Ahnak deletion accelerated B. henselae infection. The proportion of CD4＋interferon-γ (IFN-γ)＋ and CD4＋interleukin (IL)-4＋ cells was significantly lower in the B. henselae-infected Ahnak-knockout mice than in the B. henselae-infected wild-type mice. In vitro stimulation with B. henselae significantly increased IFN-γ and IL-4 secretion in the splenocytes obtained from the B. henselae-infected wild-type mice, but did not increase IFN-γ and IL-4 secretion in the splenocytes obtained from the B. henselae-infected Ahnak-KO mice. In contrast, IL-1α, IL-1ß, IL-6, IL-10, RANTES, and tumor necrosis factor-α secretion was significantly elevated in the splenocytes obtained from both B. henselae-infected wild-type and Ahnak-knockout mice. These results indicate that Ahnak deletion promotes B. henselae infection. Impaired IFN-γ and IL-4 secretion in the Ahnak-knockout mice suggests the impairment of Th1 and Th2 immunity in these mice. [BMB Reports 2019; 52(4): 289-294].

Typical and Atypical 18FDG PET/CT Findings in Two Cases of Cat Scratch Disease.

Cat scratch disease (CSD) is a rare zoonotic infection disease, and the imaging performance for evaluation varies. We present FDG PET/CT images of two cases of CSD. In one case, images showed typical findings of regional lymph node enlargement. In another case, images showed atypical findings of extensive superficial and deep lymph node enlargement.

Serological and molecular evidence of Bartonella henselae in cats from Luanda city, Angola.

A total of 100 domestic cats from Luanda (Angola) were tested for the presence of antibodies against Bartonella henselae and spotted fever group of Rickettsia (SFGR) using indirect immunofluorescence assay (IFA). Molecular screening targeting the riboflavin synthase (ribC) gene for Bartonella and outer membrane protein B (ompB) gene for Rickettsia, using conventional PCR and sequencing was also performed in cat´s blood samples. Sixty-six percent of the cats from Luanda had IgG antibodies against Bartonella species but none of them had antibodies against SFGR. Of the total seroreactive cats for Bartonella henselae, 4.5% had an IgG titre of 64 (cut-off), 60.6% a titre of 128, 28.8% a titre of 256 and 6.1% a titre of 512. A statistically significant association was observed between seropositivity for Bartonella henselae and the lack of access to prophylaxis against ectoparasites (p = 0.018). Molecular detection and further sequence analysis of the positive amplicons allowed identification of Bartonella henselae in a 2-year old male cat. To the best of our knowledge this study confirms for the first time, the presence of Bartonela henselae circulating in domestic cats from Luanda. This fact call the attention for the possible cases of cat-scratch disease in humans.

Serological and molecular detection of Bartonella henselae in specimens from patients with suspected cat scratch disease in Italy: A comparative study.

Cat scratch disease (CSD) is an infectious disease caused by Bartonella henselae, usually characterized by self-limiting regional lymphadenopathy and fever. Given the low clinical diagnostic sensitivity and specificity of conventional anti-B. henselae indirect immunofluorescence assays (IFAs), real-time polymerase chain reaction (PCR)-based detection of B. henselae is now being proposed as a more sensitive tool to diagnose CSD. Thus, here we have assessed the efficacy of real-time PCR in detecting B. henselae in different specimens from patients with suspected CSD and compared it to that of IFA. From March 2011 to May 2016, at the Microbiology and Virology Unit, Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, Turin, Italy, 115 clinical specimens (56 aspirated pus, 39 fresh lymph node biopsies, and 20 whole blood samples) and 99 sera from 115 patients with suspected CSD (62 females and 53 males between the ages of 3 months and 68 years) were analyzed by both real-time PCR, used in a qualitative way, and IFA (IgM and IgG) for the presence of B. henselae. For 16 patients, serological results were not available due to a clinical decision not to request the test. B. henselae DNA positivity was detected by real-time PCR in 37.39% of patients, while 62.61% of them were negative. Thus, patients were divided into two groups: real-time PCR+ (n = 43) and real-time PCR- (n = 72). Real-time PCR screening of whole blood, biopsies, and aspirated pus revealed B. henselae positivity in 40%, 38.46%, and 35.71% of patients, respectively. When we analyzed samples by IFA, we found the presence of B. henselae in 28 out of 99 (28.28%) patients, of which 11 (11.11%) belonged to the real-time PCR+ group and 17 (17.17%) to the real-time PCR- group. Among the 71 seronegative subjects, 16 (16.16%) were found positive for B. henselae by real-time PCR. Thus, by combining the results of both assays, we were able to increase the percentage of B. henselae positive specimens from 27.27% (real-time PCR) or 28.28% (IFA) to 44.44% (real-time PCR+IFA). Altogether, these findings indicate that the early detection of B. henselae in patients with suspicious CSD through combined real-time PCR and serological analyses can lead to a more accurate diagnosis of CSD, thereby allowing prompt and appropriate disease management.

Cat Scratch Disease: Not a Benign Condition.

PURPOSE: Describe a case series of ocular Cat-scratch-disease (CSD) with vision-threatening findings and poor outcomes, indicating severity of disease. METHODS: Retrospective case series from the Uveitis Department of São Paulo Federal University from 2011 to 2015. RESULTS: In this period, six eyes of four patients had confirmed diagnosis of CSD. Two were male and two female. Mean age was 24.8 years old [7-45]. Two had bilateral disease. Visual acuity at presentation ranged from no light perception to 20/25. Three patients were treated with doxycycline and one with clarithromycin and prednisone. Visual outcome after treatment ranged from counting fingers to 20/20: 5/6 eyes had final visual acuity of less than 20/40 and 3/6 had final visual acuity equal or less than 20/400. CONCLUSION: Although usually described as a benign disease with spontaneous resolution, CSD can present with atypical manifestations such as vascular angiomatous lesions, serous retinal detachment, and vascular occlusion syndromes, carrying a severe course and guarded prognosis.

Utility of Bartonella henselae IgM Western Blot Bands for Serodiagnosis of Cat Scratch Disease.

We evaluated the utility of Western blot (WB) bands of Bartonella henselae in detecting anti-B. henselae immunoglobulin M (IgM) for serodiagnosis of cat scratch disease (CSD). IgM band patterns were examined using sera from 92 patients clinically suspected of having CSD and from 130 healthy individuals. Positive WB bands were observed in 49 (53.5%) of the 92 patient sera. Three bands at 8 to 10, 31 to 35, and 70 kDa were regarded as relevant for B. henselae because all of the positive sera yielded at least one of the three bands, and none of the healthy control sera showed reactivity to any of them. In contrast, the positive rate of the patient sera by conventional indirect fluorescence antibody assay (IFA) for B. henselae IgM was 28.3% (26/92) among the patients. These finding suggest that the IgM-WB assay, although cumbersome to perform, can be used for confirmatory diagnosis of CSD with no false positivity in the control sera. Purification of proteins in the specific bands may contribute to the development of an IgM enzyme-linked immunosorbent assay (IgM-ELISA) with improved specificity and sensitivity.

Cat scratch disease during etanercept therapy in a rheumatoid arthritis patient. / Enfermedad por arañazo de gato en paciente con artritis reumatoidea tratado con etanercept.

Cat scratch disease (CSD) is an infectious disorder caused by Bartonella henselae and characterized by fever and granulomatous lymphadenopathy. Immunosuppression is a risk factor for the development of atypical forms of the disease. We report the case of a 52-year-old woman who presented with fever and bilateral inguinal lymph node enlargement. She did not have apparent contact with animals. The patient was receiving etanercept therapy for rheumatoid arthritis. Lymph node biopsy demonstrated granulomatous lymphadenitis. She was successfully managed by discontinuing etanercept and by treatment with minocycline. She developed clinical remission and typical seroconversion. Infection with Bartonella should be considered in the differential diagnosis in rheumatoid arthritis patients with lymphadenopathy of unknown origin.

[A negleted bacteria with a case: Bartonella henselae]. / Bir olgu ile ihmal edilen bir etken: Bartonella henselae.

Bartonella henselae the causative agent of cat scratch disease (CSD), is a gram-negative, coccobacillus, facultative intracellular bacterium CSD usually presents as a clinical form of benign local lymphadenopathy (LAP) but sometimes it may progress to severe life threatening complications. Despite the fact that CSD is known to be a common disease, which is one of the important causes of local LAPs in the world, there are few publications in our country. For the diagnosis, the clinician should suspect for CSD and has to ask to the patient whether there is a story of cat scratch or not. In our country the diagnosis of CSD is usually done by invasive pathological examination instead of simple serological tests. In this report, a 14 years old case with CSD with antibody titers of 1/384 IgM, 1/2048 IgG B.henselae antibody determined by indirect fluorescent antibody (IFA) method in serum and B.henselae positivity by polymerase chain reaction (PCR) from LAP sample of the patient with axillary LAP was presented. Even though molecular techniques have been used for the diagnosis of the previous reported cases, it is the first B.henselae positive case in our country detected with PCR. In the history of the case it was learned that the patient was scratched by a street cat few months ago and the axillary LAP developed 4-5 weeks later. Axillary ultrasonography shawed abscesses with the largest 22 x 44 mm compatible with LAP. No growth was detected in the LAP biopsy specimen culture. Leucocyte count was normal but sedimentation rate (68 mm/h), and C-reactive protein (41.7 mg/L) were higher.Therapy was started with azitromycin 500 mg/day but two weeks later as there was no regression of LAP, considering the development of resistance, the treatment was changed to doxycycline 2 x 100 mg/day and rifampicin 1 x 300 mg/day. As the LAP was in abscess formation and the titers found in IFA was higher than the predictive value of B.henselae antibody titer for endocarditis, the treatment has been extended to four weeks and the patient has been cured. Especially children and adolescents are at very high risk for zoonotic infections transmitted from pets in our country due to the intense immigration to the city from the rural areas and the unconscious and uncontrolled livelihood of friendship with street animals. We should accept that this is not a rare condition, as the cat scratch disease can change from harmless to very serious forms the diagnosis and treatment should be quickly and carefully performed. Currently, serological examinations for Bartonella are rarely done in some certain reference laboratories in our country. The number of these laboratories should be increased or the usage of the tests in these reference laboratories should be at least expanded.

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.

Hemophagocytic Lymphohistiocytosis Associated With Bartonella henselae Infection in an HIV-Infected Patient.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome that often occurs in immunocompromised patients. We report the first case of HLH due to Bartonella henselae infection in a patient with human immunodeficiency virus infection. Early recognition of HLH and B. henselae through liver biopsy and serological tests led to the patient's recovery.

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.

[Cat scratch disease: still current zoonosis]. / Felinóza- stále aktuální zoonóza

OBJECTIVES: A retrospective evaluation of a group of patients which is focused on clinical picture, serological diagnosis, therapy and familial occurrence of the disease. MATERIAL AND METHODS: Cat scratch disease (CSD) was considered within the scope of a differential diagnosis of lymphadenopathy. Serological diagnosis was based on detection of antibodies against Bartonella henselae by indirect immunofluorescence, where the level of IgG antibodies of at least 1 : 256 or any positive level of IgM antibodies were considered positive for CSD. If a histological examination was conducted, the suspicion of CSD was supported by finding granulomatous inflammation. Macrolides were used for treatment in both children and adults. In addition to macrolides, doxycycline was used in adults. RESULTS: From 2004 to 2013, a total of 27 patients aged 7-73 years were diagnosed with CSD at the Clinic of Infectious Medicine, University Hospital in Ostrava. None of them suffered from immunodeficiency detected earlier. Diagnostic extirpation of a lymph node was performed in 5 patients diagnosed with granulomatous inflammation. Lymph node syndrome was observed in all patients, with cervical, inguinal and axillary nodes being most frequently affected. However, two patients had supraclavicular nodes affected and a 52-year-old woman had unusual swelling of lymphatic tissue in the scapular region with skin lesions. Lymph node syndrome accompanied by encephalopathy was observed in one 50-year-old patient. Positive IgM antibodies were detected in only 8 patients. There were two cases of familial occurrence affecting 2 and 3 family members. Antibiotic therapy with full resolution of clinical findings was successful in 24 patients, including the patient with encephalopathy. In spite of the antibiotic treatment, three patients developed lymph node colliquation requiring surgical intervention. CONCLUSIONS: Atypical lymph node localization in 3 patients, encephalopathy in 1 patient, positive levels of IgM antibodies in 8 only patients, delayed antibodies production in 4 patients and antibiotic therapy coupled with extirpation of colliquated lymph nodes in 3 patients were found in the group of 27 patients.

A case report of seronegative cat scratch disease, emphasizing the histopathologic point of view.

Cat scratch disease, necrotizing granulomatous lymphadenitis caused by Bartonella henselae, usually benign and self-limited. However, various clinical manifestations and no pathognomonic histopathologic features can lead to misinterpretations and diagnostic disputes. We report a case of cat scratch disease in a 39-yr-old male patient with fever and left axillary lymphadenitis. He had a history of cat bite on the left hand dorsum. On excision, the lymph node showed follicular hyperplasia, stellate microabscesses with a rim of granulomatous inflammation. Warthin-Starry silver staining showed many clumps of silver-stained bacilli within the necrotic foci. Serological tests were negative. Diagnosis was established by PCR analysis. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1877499238123059.

[Accuracy and diagnostic utility of IgM in Bartonella henselae infections]. / Exactitud y utilidad diagnóstica de la IgM en infecciones por Bartonella henselae.

INTRODUCTION: Laboratory diagnosis of cat scratch disease (CSD) is based on the determination of specific antibodies anti-Bartonella henselae by different techniques. The CDC recommends IgG by immunofluorescent assay (IFA) as the gold standard. OBJECTIVE: To determine the accuracy and diagnostic utility of anti-B.henselae IgM by IFA for CSD. MATERIAL AND METHODS: Anti-B. henselae IgG was determined in serum of 108 patients with CSD suspicion; in addition, specific IgM was determined separately and blindly by two thoroughly trained laboratory professionals. We calculated sensitivity (S), specificity (Sp), predictive values both positive (PPV) and negative (NPV), and likelihood ratio (LR) for IgM positive (LR +) and negative (LR-). RESULTS: In 37 patients with positive anti-B.henselae IgG, IgM was positive in 16 and negative in 21; in 71 patients with negative IgG, IgM was negative in 69 and positive in 2. Therefore, IgM showed S 43%, E 97%, PPV 88%, NPV 77%, LR (+) 15 and LR (-) 0.58. CONCLUSIONS: The results show that a positive IgM supports, but a negative one does not rule out a B. henselae infection. Therefore, IgG should be still considered as the gold standard for the diagnosis of CSD.

Exactitud y utilidad diagnóstica de la IgM en infecciones por Bartonella henselae / Accuracy and diagnostic utility of IgM in Bartonella henselae infections

Introduction: Laboratory diagnosis of cat scratch disease (CSD) is based on the determination of specific antibodies anti-Bartonella henselae by different techniques. The CDC recommends IgG by immunofluorescent assay (IFA) as the gold standard. Objective: To determine the accuracy and diagnostic utility of anti-B.henselae IgM by IFA for CSD. Material and Methods: Anti-B. henselae IgG was determined in serum of 108 patients with CSD suspicion; in addition, specific IgM was determined separately and blindly by two thoroughly trained laboratory professionals. We calculated sensitivity (S), specificity (Sp), predictive values both positive (PPV) and negative (NPV), and likelihood ratio (LR) for IgM positive (LR +) and negative (LR-). Results: In 37 patients with positive anti-B.henselae IgG, IgM was positive in 16 and negative in 21; in 71 patients with negative IgG, IgM was negative in 69 and positive in 2. Therefore, IgM showed S 43%, E 97%, PPV 88%, NPV 77%, LR (+) 15 and LR (-) 0.58. Conclusions: The results show that a positive IgM supports, but a negative one does not rule out a B. henselae infection. Therefore, IgG should be still considered as the gold standard for the diagnosis of CSD.

Introducción: El diagnóstico de laboratorio de la enfermedad por arañazo de gato (EAG) se basa en la determinación de anticuerpos específicos anti-Bartonella henselae por distintas técnicas. El CDC de E.U.A. recomienda como estándar de oro la IgG mediante inmunofluorescencia (IF). Objetivo: Determinar la exactitud y utilidad diagnóstica de la IgM anti-B. henselae por IF para EAG. Material y Método: En suero de 108 pacientes a quienes se realizó IgG anti-B. henselae por sospecha de EAG, se determinó la presencia de IgM específica, en forma separada y ciega por dos profesionales de laboratorio ampliamente entrenados. Se calculó sensibilidad (S), especificidad (E), valores predictores positivo (VPP) y negativo (VPN) y likelihood ratio (LR) para una IgM positiva (LR+) y negativa (LR-). Resultados: En 37 pacientes con IgG anti-B. henselae positiva, la IgM fue positiva en 16 y negativa en 11; en 71 pacientes con IgG negativa, la IgM fue negativa en 69 y positiva en 2. Por consiguiente, la IgM presentó S 43%, E 97%, VPP 88%, VPN 77%, LR(+) 15 y LR(-) 0,58. Conclusiones: Los resultados sugieren que una IgM positiva apoya el diagnóstico de EAG, pero una negativa no permite descartarlo. Por tanto, la IgG debe seguir considerándose como el estándar de oro para el diagnóstico de infecciones por B. henselae.

Bartonella henselae infection associated with autoimmune thyroiditis in a child.

BACKGROUND: Bartonella henselae was discovered a quarter of a century ago as the causative agent of cat-scratch disease. More recently, Bartonella has been found to be responsible for a broad range of clinical syndromes (prolonged fever, hepatosplenic disease, encephalopathies, ocular disease) and associated with autoimmune conditions. CASE: This is the first report of autoimmune thyroiditis related to B. henselae infection. We describe an 11-year-old boy who presented with goiter and weight loss. At the time of admission a 2 × 1 cm mildly tender right supraclavicular lymph node was noted in association with an erythematous papule at the same side of the neck. We describe an association of autoimmune hyperthyroidism (Hashitoxicosis) with B. henselae infection (cat-scratch disease) in a pediatric patient. CONCLUSION: Different types of infections are implicated in the pathogenesis of autoimmune thyroid disease through molecular mimicry or other mechanisms, despite their role is disputed. We speculated that autoimmune thyroiditis should be added to the spectrum of clinical syndromes that can be triggered by B. henselae.