Cat scratch disease in Connecticut. Epidemiology, risk factors, and evaluation of a new diagnostic test

Vector-Borne Zoonotic Lymphadenitis-The Causative Agents, Epidemiology, Diagnostic Approach, and Therapeutic Possibilities-An Overview

In addition to common skin pathogens, acute focal lymphadenitis in humans can, in rare cases, be caused by a zoonotic pathogen. Furthermore, it can develop in the absence of any direct or indirect contact with infected animals, in cases when the microorganism is transmitted by a vector. These clinical entities are rare, and therefore often not easily recognized, yet many zoonotic illnesses are currently considered emerging or re-emerging in many regions. Focal zoonotic vector-borne lymphadenitis and its numerous causative agents, with their variegated clinical manifestations, have been described in some case reports and small case series. Therefore, we summarized those data in this narrative overview, with the aim of raising clinical awareness, which could improve clinical outcomes. This overview briefly covers reported pathogens, their vectors and geographic distribution, and their main clinical manifestations, diagnostic possibilities, and recommended therapy. Vector-borne tularemia, plague, bartonellosis, rickettsioses, borreliosis, and Malayan filariasis are mentioned. According to the existing data, when acute focal bacterial vector-borne zoonotic lymphadenitis is suspected, in severe or complicated cases it seems prudent to apply combined aminoglycoside (or quinolone) plus doxycycline as an empirical therapy, pending definite diagnostic results. In this field, the "one health approach" and further epidemiological and clinical studies are needed.

Prevalence of Tick Infection with Bartonella in China: A Review and Meta-analysis

OBJECTIVE

Bartonellosis is a global vector-borne zoonosis caused by Bartonella, a genus of intracellular Gram-negative bacteria. It is one of 14 emerging infectious diseases that have recently been identified in China, and the prevalence varies by region. A more in-depth understanding is needed regarding the role and influencing factors of ticks in the transmission of Bartonella, including the infection rate of ticks with Bartonella in different regions. This study explored the prevalence of Bartonella in ticks and the factors that influence it.

METHODS

Databases (PubMed, Embase, Elsevier ScienceDirect, Cochrane Library, Web of Science, CNKI, VIP, CBM, and WanFang) were searched to review the preliminary research on Bartonella-carrying ticks in China.

RESULTS

We identified and included 22 articles. Bartonella infection rates in ticks varied from 0 to 22.79% examined by the included studies. Our meta-analysis revealed that the prevalence of Bartonella in ticks was 3.15% (95% CI: 1.22 - 5.82%); the prevalence was higher in parasitic ticks (4.90%; 95% CI: 1.39 -10.14%) than ticks seeking hosts (1.42%; 95% CI: 0.62 - 2.50%) (P = 0.047).

CONCLUSION

The prevalence of Bartonella in the southern region of China (6.45%) was higher than that in the northern region (1.28%) (P = 0.030). Knowledge of ticks' vectors and reservoir competence is crucial to reduce the disease burden.

Cat-scratch disease: a rare cause of osteomyelitis

Cat-scratch disease is a zoonosis caused by Bartonella henselae, characterised by regional lymphadenopathy. Rarer presentations, such as osteomyelitis, can occur.We present an adolescent girl with severe right lumbar pain and fever, without animal contacts or recent travels. On examination, pain on flexion of torso, movement limitation and marked lordosis were noted, but there were no inflammatory signs, palpable masses or lymph nodes. Serological investigations revealed elevated inflammatory markers. Imaging revealed a paravertebral abscess with bone erosion. Several microbiological agents were ruled out. After a second CT-guided biopsy, PCR for Bartonella spp was positive. At this point, the family recalled having a young cat some time before. Cat-scratch disease was diagnosed, and complete recovery achieved after treatment with doxycycline and rifampicin.Cat-scratch disease is a challenging diagnosis in the absence of typical features. However, B. henselae must be investigated if common pathogens are ruled out and response to therapy is poor.

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.

CAT-SCRATCH DISEASE: 9 YEARS OF EXPERIENCE AT A PEDIATRIC CENTER

Background

A more complete understanding of the epidemiology, risk factors, and clinical features of cat scratch disease (CSD) in children could help guide patient care.

Methods

We conducted a retrospective analysis of children presenting to a tertiary pediatric hospital system in Atlanta, Georgia between January 1, 2010, and December 31, 2018 who had serology, PCR and/or cytopathological results consistent with a Bartonella henselae infection. We also retrospectively reviewed veterinary diagnostic results performed at the University of Georgia (UGA) from 2018-2020 to ascertain the burden of bartonellosis in companion animals within the state.

Results

We identified 304 children with CSD over 9 years with the largest proportion of diagnoses made during August (41/304, 13.5%) and September (47/304, 15.5%). The median age of child cases was 8.1 years (interquartile range (IQR) 5.4-12.1]; 156 (51.3%) were female; 242/262 (92.4%) reported feline exposure, while 55/250 (22%) reported canine exposure of those with exposure histories documented in the medical record. Although lymphadenopathy was present on physical examination in the majority of cases (78.8%), atypical presentations lacking lymphadenopathy were also common (63/304, 20.7%). Among children with radiographic imaging, 20/55 (36.4%) had splenomegaly and 21/55 (38.1%) had splenic and/or hepatic microabscesses. Among veterinary data, Bartonella seroprevalence was 12/146 (8.2%), all among canines, with a geographic distribution that spanned the state of Georgia.

Conclusion

Distinguishing clinical features of CSD included subacute regional lymphadenopathy in school-aged children in the late summer, almost all of whom had cat exposure. Atypical clinical manifestations of CSD were also commonly identified.

Prevalence and Risk Factors for Bartonella spp. and Haemoplasma Infections in Cats from Greece

Simple Summary

Bartonellosis and haemoplasmosis are diseases with global impact on the health of domestic cats and of zoonotic importance. This is the first study investigating the risk factors for Bartonella spp. and haemoplasma species infections in cats from Greece. In addition, this study determined the serologic and molecular prevalence of Bartonella spp. and haemoplasma species infections in different populations of cats living in different regions of Greece. A total of 452 cats were enrolled into the study. Blood was collected from each cat for the serological detection of Bartonella henselae antibodies and the molecular detection of Bartonella spp. and haemoplasma species infections. Overall, the seroprevalence of B. henselae was 35.4%, while the molecular prevalence of Bartonella spp. and haemoplasma species was 2.9% and 19%, respectively. The results of this study indicate that cats with partial or exclusive outdoor access and cats with flea infestation are at the greatest risk for B. henselae seropositivity. Furthermore, cats living in warmer regions such as Attica and Crete are at the greatest risk. Lack of ectoparasiticide use was identified as a risk factor for haemoplasma species infection. This suggests that the use of ectoparasiticides in cats may be an effective means of preventing haemoplasma species infection in cats.

Abstract

Bartonellosis and haemoplasmosis are vector-borne diseases with global impact on the health of domestic cats and of zoonotic importance. The aim of this study was to describe the epidemiological aspects of various populations of cats infected with Bartonella spp. or haemoplasma species. The populations evaluated included client-owned cats, stray cats and cats that live in breeding catteries in Greece. A total of 452 cats were prospectively enrolled into the study. A commercially available indirect immunofluorescence antibody testkit was used for the detection of Bartonella henselae IgG antibodies in serum. PCRs for the detection of Bartonella spp. and haemoplasma species DNA in the blood were also performed in a subgroup of 242 of the 452 cats. Risk factors for B. henselae seropositivity and infection with the haemoplasma species were determined using multivariable analysis. Overall, 160 (35.4%) of the 452 cats were seropositive for B. henselae. Seven (2.9%) and 46 (19%) of the 242 cats were PCR-positive for Bartonella spp. and haemoplasma species, respectively. The factors associated with B. henselae seropositivity, based on multivariate analysis, included older age, outdoor access, living region and flea infestation. Non-administration of ectoparasiticides was associated with haemoplasma species infection. This study shows a high prevalence of seropositivity for B. henselae and a relatively high prevalence of infection with haemoplasma species. Therefore, it is necessary to establish optimal strategies for the prevention of Bartonella spp. and haemoplasma species infections, considering the high-risk groups of cats identified in this study.

Detection of Bartonella spp. and Rickettsia spp. in cat fleas (Ctenocephalides felis) collected from free-roaming domestic cats in southeastern Georgia, USA

The cat flea (Ctenocephalides felis) is a competent vector of numerous bacterial pathogens in the genera Bartonella and Rickettsia. In the United States, free-roaming domestic cats (Felis catus) increase the risk of exposure to C. felis for humans and their companion animals. In collaboration with a trap-neuter-return program, we collected fleas from 283 feral/stray cats in southeastern Georgia between May and July of 2020. A total of 3,643 flea specimens were collected, and C. felis was the only flea species recovered from all cats sampled. The mean number of fleas per cat host was highest in the month of June when compared to May and July, and higher in juvenile cats (< 1 year) than the adults (≥ 1 year). Real-time PCR assays were used to test a subset of the collected fleas (n = 468) for the presence of Bartonella spp. and Rickettsia spp. DNA. Among those flea pools tested, 35.2% were positive for genus-specific citrate synthase gene of Bartonella, 16.5% were positive for the genus-specific 17-kDa protein antigen gene of Rickettsia, and none were positive for the species-specific outer membrane protein B gene of Rickettsia typhi. The identification of potential flea-borne pathogens was more frequent from the subset of C. felis collected in May, and female cats had more Bartonella-positive fleas and less Rickettsia-positive fleas than male cats. Overall, the present study provides valuable insights into the frequency of C. felis from outdoor community cats in southeastern Georgia, and highlights the possible risk for human exposure to potential flea-borne pathogens.

Occurrence and bacterial loads of Bartonella and haemotropic Mycoplasma species in privately owned cats and dogs and their fleas from East and Southeast Asia

Bartonella spp. and haemoplasmas are pathogens of veterinary and medical interest with ectoparasites mainly involved in their transmission. This study aimed at molecular detection of Bartonella spp. and haemoplasmas in cats (n = 93) and dogs (n = 96), and their related fleas (n = 189) from countries in East and Southeast Asia. Ctenocephalides felis was the dominant flea species infesting both cats (97.85%) and dogs (75%) followed by Ctenocephalides orientis in dogs (18.75%) and rarely in cats (5.2%). Bartonella spp. DNA was only detected in blood samples of flea‐infested cats (21.51%) (p < .0001, OR = 27.70) with Bartonella henselae more frequently detected than Bartonella clarridgeiae in cat hosts (15.05%, 6.45%) and their associated fleas (17.24%, 13.79%). Out of three Bartonella‐positive fleas from dogs, two Ct. orientis fleas carried Bartonella vinsonii subsp. berkhoffii and Bartonella clarridgeiae, while the 3rd flea (Ct. felis) carried Candidatus Bartonella merieuxii. Felines represented a risk factor for Bartonella spp. infections, where fleas collected from cats (32.25%) presented an increased likelihood for Bartonella spp. occurrence (p < .0001, OR = 14.76) than those from dogs (3.13%). Moreover, when analysing infectious status, higher Bartonella spp. DNA loads were detected in fleas from bacteraemic cats compared to those from non‐bacteraemic ones (p < .05). The haemoplasma occurrence was 16.13% (15/93) and 4.17% (4/96) in cat and dog blood samples from different countries (i.e. Indonesia, Malaysia, the Philippines, Taiwan and Thailand), with cats more at risk of infection (p < .01, OR = 5.96) than dogs. Unlike Bartonella spp., there was no evidence for flea involvement in the hemoplasmas' transmission cycle, thus supporting the hypothesis of non‐vectorial transmission for these pathogens. In conclusion, client‐owned cats and dogs living in East and Southeast Asia countries are exposed to vector‐borne pathogens with fleas from cats playing a key role in Bartonella spp. transmission, thus posing a high risk of infection for humans sharing the same environment.

Molecular Diagnosis of Cat Scratch Disease: a 25-Year Retrospective Comparative Analysis of Various Clinical Specimens and Different PCR Assays

Cat-scratch disease (CSD), caused primarily by Bartonella henselae, is a common etiology of infectious regional lymphadenopathy. Lymphadenopathy is preceded by a primary inoculation lesion and may progress to suppuration. Laboratory diagnosis of CSD is hampered by the limitations of available confirmatory tests. PCR, in general, is highly sensitive and specific; however, clinical sensitivity in CSD varies greatly between studies. We aimed to identify clinical specimens and PCR assays best suited for CSD diagnosis using a national CSD registry and a uniform case definition. Different clinical specimens and PCR assays, including conventional and real-time PCR, were evaluated. PCR was positive in 335/390 (86%) CSD patients and 425/482 (88%) PCR tests. The highest PCR sensitivity was achieved in lymph node pus aspirates (96%; n = 278 tests) followed by primary lesions (88%; n = 50), lymph node fine needle aspirations (85%; n = 46), lymph node biopsy specimens (73%; n = 91) and paraffin-embedded lymph nodes (59%; n = 17), (P < 0.001). Sensitivity was similar in all types of PCR assays studied. PCR negative predictive value of pus aspirate and lymph node biopsy specimen patient groups was 82% and 72%, respectively. Specificity was 100% based on 125 non-CSD patients with negative PCR. In conclusion, the specimen type rather than the PCR assay type has a major impact on CSD molecular diagnosis. We assume that the inadequate sensitivity of the biopsy specimens was due to sampling errors or the presence of inhibitory factors. Primary lesions should be sampled more frequently for CSD diagnosis. Physicians should be aware of the low PCR negative predictive value of lymph node biopsy specimens. IMPORTANCE Polymerase chain reaction (PCR) for the detection of Bartonella henselae is an important tool for the diagnosis of cat scratch disease (CSD); however, clinical sensitivity varies greatly between studies. The current study shows that the specimen type, with pus aspiration, fine needle aspiration, and primary inoculation lesion having significantly higher sensitivity than fresh or formalin-fixed paraffin-embedded lymph node biopsy specimen, rather than the type of the PCR assay, whether a conventional or a real-time assay, has a major impact on the performance of diagnostic PCR for CSD. The new data provide new tools for the clinical microbiologist when interpreting the results of the PCR assays. Primary inoculation lesions, although easily accessible, are often neglected and should be sampled more frequently for molecular diagnosis of CSD. Physicians should be aware that negative PCR, particularly if performed on fresh or paraffin-embedded lymph node biopsy specimens, does not exclude CSD.

Serological and Molecular Detection of Bartonella henselae in Cats and Humans From Egypt: Current Status and Zoonotic Implications

Bartonellosis is a vector-borne zoonotic disease caused by the intracellular bacterium of genus Bartonella. The disease has a worldwide distribution and cats represent the major reservoir of this disease. Despite its global distribution, very limited previous studies have investigated the occurrence of bartonellosis in cats and their owners in Egypt. In an endeavor to explore this topic, we investigated the occurrence of Bartonella henselae (B. henselae) infection in 225 samples (blood, saliva, and claw) obtained from 75 healthy cats in Upper Egypt. These samples were routinely obtained during veterinary clinic visits. This study also involved an examination of 100 humans, including cat owners and people with a history of contact with cats. Attempted isolation and identification of B. henselae in cats were also performed. Furthermore, PCR was performed for molecular identification of B. henselae in blood samples from cats. Meanwhile, an immunofluorescent assay was performed to study the seroprevalence of B. henselae infection in humans. In this study, B. henselae could not be isolated from any of the examined blood, saliva, or claw samples from cats. Interestingly, B. henselae was identified molecularly in 8% (6/75) of blood samples from cats. The seroprevalence of B. henselae in humans was 46% and its occurrence was higher in females (46.6%) than in males (41.7%) (P = 0.748). B. henselae infection was higher among cat owners [51.4% (19/37)] than among people with a history of contact with cats [42.9% (27/63)] (P = 0.410). Infection was higher in rural regions [79.5% (31/39)] than in urban regions [24.6% (15/61)] (P < 0.001). Collectively, this data provide interesting baseline information about the occurrence of B. henselae in cats and humans in Upper Egypt, which reflects the potential zoonotic transmission of this bacterium. Future study is mandatory to explore the occurrence of B. henselae in major reservoirs in Egypt.

Emerging rodent-associated Bartonella: a threat for human health?

Background

Species of the genus Bartonella are facultative intracellular alphaproteobacteria with zoonotic potential. Bartonella infections in humans range from mild with unspecific symptoms to life threatening, and can be transmitted via arthropod vectors or through direct contact with infected hosts, although the latter mode of transmission is rare. Among the small mammals that harbour Bartonella spp., rodents are the most speciose group and harbour the highest diversity of these parasites. Human–rodent interactions are not unlikely as many rodent species live in proximity to humans. However, a surprisingly low number of clinical cases of bartonellosis related to rodent-associated Bartonella spp. have thus far been recorded in humans.

Methods

The main purpose of this review is to determine explanatory factors for this unexpected finding, by taking a closer look at published clinical cases of bartonellosis connected with rodent-associated Bartonella species, some of which have been newly described in recent years. Thus, another focus of this review are these recently proposed species.

Conclusions

Worldwide, only 24 cases of bartonellosis caused by rodent-associated bartonellae have been reported in humans. Possible reasons for this low number of cases in comparison to the high prevalences of Bartonella in small mammal species are (i) a lack of awareness amongst physicians of Bartonella infections in humans in general, and especially those caused by rodent-associated bartonellae; and (ii) a frequent lack of the sophisticated equipment required for the confirmation of Bartonella infections in laboratories that undertake routine diagnostic testing. As regards recently described Bartonella spp., there are presently 14 rodent-associated Candidatus taxa. In contrast to species which have been taxonomically classified, there is no official process for the review of proposed Candidatus species and their names before they are published. This had led to the use of malformed names that are not based on the International Code of Nomenclature of Prokaryotes. Researchers are thus encouraged to propose Candidatus names to the International Committee on Systematics of Prokaryotes for approval before publishing them, and only to propose new species of Bartonella when the relevant datasets allow them to be clearly differentiated from known species and subspecies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05162-5.

The Clinical Profile of Cat-Scratch Disease’s Neuro-Ophthalmological Effects

Cat-scratch disease is an illness caused by Bartonella henselae that occurs as a result of contact with an infected kitten or dog, such as a bite or scratch. It is more prevalent in children and young adults, as well as immunocompromised individuals. There are limited publications examining the features of CSD in patients. As such, the purpose of this research was to assess the clinical neuro-ophthalmological consequences of CSD reported in the literature. Among the ophthalmologic disorders caused by cat-scratch disease in humans, Parinaud oculoglandular syndrome, uveitis, vitritis, retinitis, retinochoroiditis and optic neuritis are the most prevalent. The neurological disorders caused by cat-scratch disease in humans include encephalopathy, transverse myelitis, radiculitis, and cerebellar ataxia. The current review addresses the neuro-ophthalmological clinical manifestations of cat-scratch disease, as described in papers published over the last four decades (1980–2022). All the data gathered were obtained from PubMed, Medline and Google Scholar. The current descriptive review summarizes the most-often-encountered clinical symptomatology in instances of cat-scratch disease with neurological and ocular invasion. Thus, the purpose of this review is to increase knowledge of cat-scratch disease’s neuro-ophthalmological manifestations.

Atlantoaxial instability secondary to Bartonella henselae osteomyelitis managed surgically by atlantoaxial instrumentation: A case report and systematic review

Cat scratch disease (CSD), caused by Bartonella henselae, may atypically present with vertebral osteomyelitis. Antibiotic regimens are tailored to presentation, which is markedly variable and not well defined for any atypical disease. In cases of spinal instability, the use of antibiotics alone may not be sufficient. Atlantoaxial instability caused by osteomyelitis is a rare complication of CSD. In this report, we describe the rare case of vertebral osteomyelitis complicated by atlantoaxial instability, requiring both antibiotics and atlantoaxial fusion. We discuss our case, surgical technique, rationale, and outcome. In addition, we conducted a systematic review of the literature of vertebral osteomyelitis in pediatric secondary to B. henselae. A 2-year-old child presented with a 2-month history of irritability, fever, and rigid neck pain along with a recent history of feline exposure. Physical examination revealed cervical tenderness and decreased range of motion. Computed tomography (CT) showed osteolysis of the right C1 lateral mass and pars articularis; T1-weighted magnetic resonance imaging with contrast showed enhancement around the right C1 lateral mass. The titer for B. henselae was high. A diagnosis of cat scratch osteomyelitis with cervical instability was made, for which the patient underwent surgery with atlantoaxial fusion. Postoperative imaging demonstrated resolution of the contrast-enhanced lesion. At 6-year follow-up, the patient showed no signs of residual complications from surgical intervention with a solid fusion. Our review revealed 44 cases of pediatric CSD vertebral osteomyelitis. Conservative management with antibiotic employed in 86% while antibiotics with surgical intervention in 14% of the cases. Surgical intervention was most often in the form of incision for drainage and decompression without fusion. Average follow-up 10 months with 86% achieved complete resolution. Cervical instability caused by osteolysis is a rare complication of CSD. This can subsequently lead to vertebral instability, requiring definitive surgical intervention.

Management of Infectious Lymphadenitis in Children

Lymphadenopathy is an irregularity in the size and texture of the lymph nodes, which is quite common in childhood. When the enlargement of lymph nodes is caused by inflammatory and infectious processes, it is called lymphadenitis. The main objective of this manuscript is to summarize the common infectious etiologies and presentations of lymphadenitis in children providing a management guide for clinical practice. PubMed was used to search for all of the studies published up to April 2021 using keywords such as "lymphadenitis" and "children". Literature analysis showed that the differential diagnosis for lymphadenitis in pediatrics is broad. Although lymph node enlargement in children is usually benign and self-limited, it is important to exclude malignant etiology. In most cases, history and physical examination allow to identify the correct diagnosis and start a proper treatment with a prompt resolution of the lymphadenopathy. However, particularly in the case of persistent lymphadenitis, determining the cause of lymph node enlargement may be difficult, and the exact etiology may not be identified despite extensive investigations. Further studies should develop and validate an algorithm to assist pediatricians in the diagnosis and timely treatment of lymphadenitis, suggesting situations in which a watchful waiting may be considered a safe approach, those in which empiric antibiotic therapy should be administered, and those requiring a timely diagnostic work-up.

Schizophrenia and Bartonella spp. Infection: A Pilot Case-Control Study

Recently, infections with emerging zoonotic bacteria of the genus Bartonella have been reported in association with a range of central nervous system (CNS) symptoms. Currently, it remains unknown if Bartonella spp. infection is associated with symptoms of schizophrenia/schizoaffective disorder (SCZ/SAD). The objective of this study was to determine if there is an association between Bartonella species infection and SCZ/SAD. A secondary objective was to determine if SCZ/SAD symptoms were more severe among participants with documented Bartonella spp. infection. Using a case-control study design, 17 cases and 13 controls were evaluated with a series of clinical and cognitive assessments. Blood samples were collected and tested for Bartonella spp. infection using serological, microbiological, and molecular techniques. People with SCZ/SAD were more likely than healthy volunteers to have Bartonella spp. DNA in their bloodstream, with 11 of 17 cases (65%) positive by Bartonella spp. droplet digital PCR (ddPCR). In comparison, only one healthy volunteer was Bartonella spp. ddPCR positive (8%, p = 0.0024). Based on serology, Bartonella spp. exposure was common among people with SCZ/SAD (12 of 17) as well as among healthy volunteers (12 of 13), with no significant difference between the groups (p = 0.196). Within the case group of people with SCZ/SAD, there was no significant difference in SCZ/SAD severity scores between people with and without ddPCR evidence of Bartonella spp. infection. This pilot study provides preliminary evidence in support of future investigations that should examine a potential contribution of Bartonella spp. infection to SCZ/SAD.

Cat Scratch Disease and Bartonellaceae: The Known, the Unknown and the Curious

Since the early 1900s, Bartonella species were known only to cause human disease resulting from very restricted geographic (bartonellosis) or environmental influences ("trench fever"). In the 1990s, and in parallel, cat scratch disease and bacillary angiomatosis were definitively linked to Bartonella species. Subsequently, widespread use of modern diagnostic methods revealed the broad ecologic niche of this organism and greatly expanded our knowledge of the epidemiology and clinical presentations associated with this genus. A large number of reservoirs and vectors involved with Bartonella propagation and transmission to humans have been identified; cats and various arthropods remain the most well-studied to date. Though not completely understood, it appears that specific immune-modulated interactions between the infecting species and host-related factors play a major role in the observed breadth of human clinical syndromes associated with Bartonellae, the large differences in immunopathologic features of tissue samples among different syndromes and potentially the varied responses to antimicrobial therapy. Further, the clinical management for cat scratch disease in particular is quite variable among clinicians, reflecting a poor evidence base. No preventive measures have been developed beyond suggestions to avoid at-risk behavior with known vectors.

Bartonella henselae IgM seropositivity in both adult and pediatric patients with diverse clinical conditions in Turkey

Bartonella henselae is the causative agent of cat scratch disease (CSD). In this study, we aimed to investigate the clinical data of patients with suspicion of CSD and delineate current epidemiological features.A total of 785 patients with suspected CSD were included in the study. B. henselae IgM antibody was determined by indirect fluorescent antibody (IFA) test using a commercial kit (Euroimmun, Germany). Sex, age, clinical pre-diagnosis and animal contact information of the patients were obtained from hospital electronic database records.Seventy-eight (9.9%) of 785 samples were seropositive. Out of 78 patients, 46 with animal contact data were further analyzed. Of these patients, 56% were male, and 41% were under 18 years of age. Seropositivity was more commonly observed in fall and winter. The most common finding was lymphadenitis (63%). Thirty-five patients (76%) had a previous history of animal contact (cat/dog). Of the 46 seropositive patients, 78.3, 15.2, 4.4, and 2.1% had titers of 1:80, 1:160, 1:320, and 1:640, respectively.Our study confirms that CSD is not rare in Turkey. Thus, it should always be considered in the differential diagnosis of patients presenting with lymphadenopathy in all age groups, particularly children. Questioning of cat exposure should never be neglected, especially in areas with intense population of stray cats, such as Istanbul.

Small Indian Mongooses (Herpestes auropunctatus) Serve As Reservoirs of Bartonella henselae and Rickettsia felis Vectored by Ctenocephalides felis

Small Indian mongooses (SIMs, Herpestes auropunctatus) have invasively inhabited over 60 islands worldwide. They have been confirmed as a reservoir of rabies, leptospirosis, and salmonellosis; however, their role in the epidemiology of other zoonoses is little known. On St. Kitts, as well as other islands, SIMs harbor Ctenocephalides felis, which can vector several zoonotic diseases. In this study, SIMs were examined for fleas, and the collected fleas analyzed by PCR and DNA sequencing for Bartonella henselae, Rickettsia felis, Yersinia pestis, and Dipylidium caninum. Of the 87 SIMs, 75 (86.2%) harbored C. felis. C. felis recovered from nine (10.3%), one (1.1%), and one (1.1%) of the SIMs was positive for B. henselae, R. felis, and D. caninum, respectively. These data indicate that SIMs serve as an additional reservoir of B. henselae and R. felis, which should be taken into consideration in control and prevention of these rapidly emerging zoonoses.

Hepatosplenic Bartonellosis in an Immunocompetent Teenager: An Atypical Presentation of Cat-Scratch Disease

Infection with Bartonella henselae,a gram-negative coccobacillus, most frequently presents as cat-scratch disease (CSD) and often accompanies a recent history of cat bite or scratch. As compared to adults, teenagers and children or immunocompromised patients are predominantly affected by CSD. In immunocompetent individuals, CSD is typically a self-limiting clinical syndrome with complete resolution of febrile illness in two to four weeks with or without antimicrobial therapy. While most cases present with fever of unknown origin (FUO), previous reports have also documented atypical clinical presentation or systemic symptoms in few cases, including reports of hepatosplenic involvement. We present a case of visceral bartonellosis in an immunocompetent 15-year-old female, who presented with a six-week history of fever and abdominal pain with hepatosplenomegaly. She recovered completely after prolonged antibiotic treatment for six weeks with doxycycline and amikacin. We emphasize that in the workup of FUO, it may be pertinent to include bartonellosis as a differential especially in cases exhibiting hepatosplenomegaly on examination along with hepatosplenic lesions on imaging.

Clinical Manifestations Associated with Bartonella henselae Infection in a Tropical Region

Bartonella henselae is a zoonotic Gram-negative Bacillus associated with self-limited regional lymphadenopathy. In recent decades, an expanding spectrum of clinical manifestations has been described, in part, due to improved diagnostics. However, updated epidemiological data are sparse. We retrospectively reviewed the clinical features of 31 patients with B. henselae infection over 15 years from 2005 to 2019, in the tropical Top End of Australia. Our annual disease incidence of 1.3 cases per 100,000 population is lower than that in the national database surveillances in the United States, but the hospitalization incidence of 0.9 per 100,000 population in our region is higher than those reported in the literature, with an average length of stay of 9 days. Patients were more commonly male, aboriginal, and aged less than 14 years (median age: 7 years), living in a rural setting with presentation during our monsoon season. The disease spectrum included lymph node disease (74%), organ peliosis, endocarditis, cutaneous lesions, parapharyngeal abscess, parotitis, and neurologic and ocular syndromes. Lymph node disease was far commoner in children than the more serious systemic B. henselae infections associated with adults (P = 0.074). Although no deaths were reported, significant morbidities were observed. Two endocarditis cases presented with glomerulonephritis, and hematological and neurological features mimicking vasculitis, and consequently received immunosuppressants. One case was only diagnosed after representation with serial embolic strokes. Given the heterogeneity of disease manifestations with nonspecific symptoms and significant consequences, a timely and accurate diagnosis is needed to avoid unnecessary treatments or interventions.

Not cat-scratch disease: Bartonella henselae neuroretinitis associated with non-feline pet mammals

To describe the ocurrence of Bartonella-associated neuroretinitis secondary to non-feline pet exposure, we retrospectively reviewed medical records and imaging from patients with a clinical and serologic diagnosis of Bartonella henselae (BH). Retinal imaging included color fundus photography, optical coherence tomography (OCT) and fluorescein angiography (FA). Four eyes of two patients with cat-scratch disease were included in this study, with a mean age of 35 years. The mean follow-up was 13 months, after presentation of infectious neuroretinitis. Both patients suffered from bilateral neuroretinitis after direct contact with family pets (ferret and guinea pig). All patients were treated with a long-term systemic antimicrobial therapy. Visual acuity in all improved to 20/30 or better at six months. In conclusion, humans may develop cat-scratch disease when they are exposed to Bartonella henselae (BH) in the saliva of infected cats or BH-containing flea feces reaching the systemic circulation through scratches or mucous membranes. As the cat flea (Ctenocephalides felis) may reside on non-feline mammals, Bartonella-associated neuroretinitis may result from contact with other furred family pets.

Transmission of Bartonella henselae within Rhipicephalus sanguineus: Data on the Potential Vector Role of the Tick

Bartonella henselae is a fastidious intraerythrocytic, gram-negative bacteria that causes cat scratch disease in humans. Ixodes ricinus has been confirmed to be a competent vector of B. henselae, and some indirect evidences from clinical cases and epidemiological studies also suggested that some other tick species, including Rhipicephalus sanguineus, may transmit the bacteria. B. henselae has been detected in R. sanguineus but no experimental investigations have been performed to evaluate the vector competency of this tick species regarding B. henselae transmission. To this end, this work aimed to assess the transstadial transmission of B. henselae between larvae and nymphs of R. sanguineus as well as transmission by nymphs infected at the larval stage. Four hundred B. henselae negative larvae were fed with B. henselae-infected blood by using an artificial membrane feeding system. After five days of feeding, B. henselae was detected by PCR in 57.1% (8/14) of engorged larval pools, 66.7% (4/6) of semi-engorged larval pools, and 66.7% (2/3) of larval feces pools. After molting, B. henselae DNA was also detected in 10% (1/10) of nymph pools, but not in tick feces. After a pre-fed step of nymphs infected at the larval stage on non-infected blood meal, B. henselae was detected by PCR in blood sample from the feeder, but no Bartonella colonies could be obtained from culture. These findings showed that B. henselae could be transstadial transmitted from R. sanguineus larvae to nymphs, and also suggest that these nymphs may retransmitted the bacteria through the saliva during their blood meal. This is the first study that validated the artificial membrane feeding system for maintaining R. sanguineus tick colony. It shows the possibility of transstadial transmission of B. henselae from R. sanguineus larvae to nymphs.

B. henselae is gram-negative bacteria that infects red blood cells of humans and companion animals and causes cat scratch disease in humans. Ticks were considered to be potential vectors of B. henselae for a long time until it was finally experimentally demonstrated for Ixodes ricinus. Since then, no evidence on B. henselae transmission by other tick species was reported. This study was performed 1) to validate the use of artificial membrane system to feed and infect R. sanguineus ticks and 2) to determine the possibility of B. henselae transmission by R. sanguineus, a world-widely distributed ticks. Our results show that the artificial membrane feeding system can be used to maintain R. sanguineus colony in the laboratory, and that B. henselae can be acquired by R. sanguineus during a blood meal on artificial membrane feeding system and can be transmitted from larvae to nymphs that were able to inject bacterial DNA to blood during a new blood meal. However, further investigations are still needed to confirm the viability of bacteria transmitted to blood by nymphs infected at the larval stage in order to validate B. henselae transmission by R. sanguineus.

Scratching Past Lymphadenopathy: A Case of Bartonella henselae Encephalitis

A previously healthy 6-year-old boy presented with new onset seizure activity and altered mental status. His prehospital course included prolonged fever, vague abdominal complaints, and unusual behavior. Neurological testing was unrevealing, and his symptoms slowly improved without intervention. His primary pediatrician had ordered serum antibody titers to Bartonella henselae for testing of prolonged fever in the setting of exposure to a kitten; these were found to be positive for both immunoglobulin G and immunoglobulin M. Further examination for organ involvement revealed splenic and liver micro-abscesses. After completion of his antibiotic course, the patient returned to his cognitive and neurologic baseline with resolution of his abdominal abscesses. This case emphasizes the importance of obtaining a thorough exposure history when evaluating for infectious causes of encephalitis. [Pediatr Ann. 2020;49(8):e359-e362.].

Isolation of Candidatus Bartonella rousetti and Other Bat-associated Bartonellae from Bats and Their Flies in Zambia

Bat-associated bartonellae, including Bartonella mayotimonensis and Candidatus Bartonella rousetti, were recently identified as emerging and potential zoonotic agents, respectively. However, there is no report of bat-associated bartonellae in Zambia. Thus, we aimed to isolate and characterize Bartonella spp. from bats and bat flies captured in Zambia by culturing and PCR. Overall, Bartonella spp. were isolated from six out of 36 bats (16.7%), while Bartonella DNA was detected in nine out of 19 bat flies (47.3%). Subsequent characterization using a sequence of five different genes revealed that three isolates obtained from Egyptian fruit bats (Rousettus aegyptiacus) were Ca. B. rousetti. The isolates obtained from insectivorous bats (Macronycteris vittatus) were divided into two previously unclassified bat-associated bartonellae. A phylogenetic analysis of the six genotypes of Bartonella gltA sequences from nine pathogen-positive bat flies revealed that three genotypes belonged to the same clades as bat-associated bartonellae, including Ca. B. rousetti. The other three genotypes represented arthropod-associated bartonellae, which have previously been isolated only from ectoparasites. We demonstrated that Ca. B. rousetti is maintained between bats (R. aegyptiacus) and bat flies in Zambia. Continuous surveillance of Bartonella spp. in bats and serological surveys in humans in Africa are warranted to evaluate the public health importance of bat-associated bartonellae.

A non-coding RNA controls transcription of a gene encoding a DNA binding protein that modulates biofilm development in Bartonella henselae

Bartonella henselae (Bh) is a Gram-negative zoonotic bacterium that can grow as large aggregates and form biofilms in vitro dependent upon the adhesin BadA. Previously, we reported that the Houston-1 strain of Bh has a family of nine small, highly-expressed intergenic transcripts called Bartonellaregulatory transcripts, Brt1-9. Each of the Brts bears a stem and loop structure on the 3' end followed by a gene encoding a DNA binding protein called the Transcriptional regulatory proteins, Trp1-9. RNA-seq analysis of laboratory-grown bacteria revealed the trps were poorly transcribed suggesting that the 3' stem and loop on the Brts results in transcript termination upstream of the trp genes under these conditions. Here we demonstrate that transcription of brt1 continues into trp1 when Bh is grown in a biofilm. Deletion of brt1, or just the 3' terminus of brt1 (containing the stem and loop structure), resulted in increased transcription of both trp1 and badA and increased biofilm formation. Trp1 was shown to directly bind the putative badA promoter region as demonstrated by an electrophoretic mobility shift assay (EMSA). Our data suggest that the 3' end of brt1 responds to a stimulus generated by growth of Bh in an in vitro biofilm to allow increased trp1 transcription. We further show that transcription of trp1 increases under conditions consistent with the mammalian host but is not highly expressed in the cat flea vector until the bacterium is excreted into the flea feces. Based on these data, we hypothesize that the 3' end of Brt1 functions to control trp1 transcription and Trp1 in turn results in increased badA expression and enhanced biofilm formation.

Epizootic Situation of Feline Bartonella Infection in Eastern Poland

Introduction

The aim of the study was to establish the prevalence of Bartonella spp. in cats in eastern Poland, and to determine the factors associated with the infection.

Material and Methods

PCRs were performed to detect Bartonella DNA in the whole blood of 672 cats from four regions in eastern Poland (the Lublin, Podlasie, Masovian, and Subcarpathian provinces). The association between the previously selected variables and the dependent variable (presence of Bartonella DNA) was investigated using a logistic regression model.

Results

The overall prevalence of infection was 40.48%. All PCR positive cats were infected with B. henselae. The living conditions of the animals (free outdoor roaming), mixed breed cats, Subcarpathian region, and absence of tick control were significant risk factors associated with Bartonella infection at a 95% confidence level.

Conclusion

Cats in eastern Poland appear to be at risk of a bartonellosis epizootic. Factors which seem to impact the likelihood of infection in cats and factors which seem not to impact it have been suggested. We advocate additional research into the ways bartonellosis spreads, its geographical scope, and the factors that favour its development.

Ocular complications of cat scratch disease

Cat scratch disease (CSD) in humans is caused by infection with Bartonella henselae or other Bartonella spp. The name of the disease reflects the fact that patients frequently have a history of contact (often involving bites or scratches) with infected cats. Patients with CSD typically develop lesions at the site where the skin is broken together with regional lymphadenopathy but may go on to exhibit systemic symptoms and with deep-seated infections at a range of sites including the eye. Patients with CSD may present with a range of inflammatory eye conditions, including Parinaud's oculoglandular syndrome, neuroretinitis, multifocal retinitis, uveitis and retinal artery occlusion. Bartonella spp. are fastidious bacteria that are difficult to culture from clinical specimens so microbiological diagnosis is frequently made on the basis of positive serology for anti-Bartonella antibodies or detection of bacterial DNA by PCR. Due to the lack of clinical trials, the evidence base for optimal management of patients with CSD-associated eye infections (including the role of antibiotics) is weak, being derived from single reports or small, uncontrolled case series.

Bacillary angiomatosis triggered by severe trauma in a healthy Caucasian patient: A case report

Bacillary angiomatosis represents a cutaneous and systemic infection caused by Bartonella species, typically described in the past in HIV-positive patients or associated with immunodeficiencies. More recent case reports had brought into attention the probability that this entity may manifest in otherwise healthy individuals, triggered by trauma and skin burns. The physiopathology of this neoproliferative process is based on the production of angiogenetic molecules, such as vascular endothelial growth factor (VEGF) and IL-8. In case of an inadequate treatment, the evolution can be fatal, with a systemic dissemination of the abscesses within the gastro-intestinal tract, respiratory tract, brain and bones. The appropriate therapy is with oral erythromycin and doxycycline, but several treatments such as cephalosporins, penicillins, macrolides, aminoglycosides, rifampin, dapsone, ciprofloxacin, have been tried with favorable results. Herein we present the case of a Caucasian patient, seronegative for HIV, who developed multiple vascular papules and nodules on the face, after a severe trauma and which healed after an adequate antibiotic therapy with oral clarithromycin.

Emerging tick-borne pathogens in the Nordic countries: A clinical and laboratory follow-up study of high-risk tick-bitten individuals

Despite the presence of several microorganisms, other than Borrelia burgdorferi sensu lato (Bbsl) and TBE virus, in Ixodes ricinus ticks from the Nordic countries, data is lacking on their pathogenic potential in humans. In this study, we wanted to investigate the aetiology and clinical manifestations of tick-transmitted infections in individuals seeking medical care following a tick-bite. The sampling frame was participants of a large-scale, prospective, multi-centre, follow-up study of tick-bitten volunteers recruited in Sweden, Finland and Norway in the years 2007-2015. Participants who sought medical care during the three-month follow-up period and from whom blood samples were collected during this healthcare visit (n = 92) were tested, using PCR, for exposure to spotted fever group (SFG) Rickettsia spp., Anaplasma phagocytophilum and Babesia spp. Moreover, 86 of these individuals had two serum samples, collected three months apart, tested serologically for six tick-borne microorganisms. The selected organisms - Bbsl, SFG rickettsiae, Anaplasma phagocytophilum, TBE virus, Babesia microti and Bartonella henselae - have all been detected in field-collected ticks from the Nordic countries. Medical records were reviewed and questionnaires were completed to determine clinical manifestations. We found Lyme borreliosis to be the most common tick-transmitted infection as seen in 46 (54%) of the 86 participants with available medical records. Among the 86 participants with paired sera, serological or molecular evidence of recent exposure to other microorganisms than Bbsl could be demonstrated in eight (9%). Five participants (6%) exhibited serological evidence of recent concomitant exposure to more than one tick-borne microorganism. Clinical presentations were mild with one exception (TBE). In conclusion, our data suggest a low risk of infection with tick-borne microorganisms, other than Bbsl, in immunocompetent tick-bitten persons from the examined regions, a low occurrence of co-infection and mostly mild or no overt clinical signs of infection in immunocompetent persons exposed to the studied agents.

Ecological and Socioeconomic Factors Associated with Bartonella henselae Exposure in Dogs Tested for Vector-Borne Diseases in North Carolina

Bartonella henselae is a zoonotic vector-borne pathogen affecting both humans and dogs. Little is known about the epidemiology of B. henselae in dogs, including risk factors associated with exposure. The objectives of this study were to map the current distribution of B. henselae in dogs in North Carolina (NC) and to identify ecological and socioeconomic factors influencing B. henselae seroreactivity. Results from 4446 B. henselae serology samples from dogs in NC submitted by veterinarians for clinical diagnostic testing to the North Carolina State University College of Veterinary Medicine Vector Borne Disease Diagnostic Laboratory between January 1, 2004 and December 31, 2015 were retrospectively reviewed. These results were used to generate a map of B. henselae seroreactivity. To account for sparsely sampled areas, statistical smoothing using head banging and areal interpolation kriging was performed. Using previously described risk factors for exposure to canine tick-borne diseases, eight multivariable logistic regression models based on biologically plausible hypotheses were tested, and a final model was selected using an Akaike's Information Criterion weighted-average approach. Seroreactivity among dogs tested for vector-borne disease was variable across the state: higher along the southern/eastern coastal plains and eastern Piedmont, and lower in the western mountains. Of 25 explanatory factors considered, the model combining demographic, socioeconomic, climatic, and land use variables fits best. Based on this model, female intact sex and increasing percentage of the county with low-intensity development and evergreen forest were associated with higher seroreactivity. Conversely, moderate development, increasing median household income, and higher temperature range and relative humidity were associated with lower seroreactivity. This model could be improved, however, by including local and host-scale factors that may play a significant role in dogs' exposure.

Bartonella henselae- and quintana-associated uveitis: a case series and approach of a potentially severe disease with a broad spectrum of ocular manifestations

PURPOSE

To evaluate the clinical manifestations of intraocular inflammation associated with Bartonella infection and describe the assessment and management of patients with cat-scratch disease (CSD).

METHODS

This is a retrospective review of the clinical records of patients diagnosed with Bartonella henselae and Bartonella quintana intraocular inflammation from 2011 to 2018 in the Department of Ocular Inflammations and Infections of the University Eye Clinic of Ioannina (Greece). An analysis of the current literature concerning Bartonella-related intraocular infections was also carried out.

RESULTS

This is a retrospective study of 13 patients (7 males and 6 females) with a mean age of 39.2 years that were diagnosed with unilateral intraocular inflammation, except one case with bilateral affection, attributed to Bartonella (either henselae or quintana). Twelve (12) patients (92.3%) had a positive history of traumatic cat contact. The main ocular clinical findings with regard to the type of uveitis included neuroretinitis in 5 eyes (38.5%), vasculitis in 3 eyes (23.1%), iridocyclitis in 2 eyes (15.4%), intermediate uveitis in 2 eyes (15.4%), posterior uveitis in 1 eye (7.7%), panuveitis in 2 eyes (15.4%), retinochoroiditis in 2 eyes (15.4%), vitritis in 1 eye (7.7%), peripheral choroidal granuloma in 1 eye (7.7%). Immunoglobulin (Ig) G was positive in all cases. All patients were treated with antibiotics (mainly rifampicin, doxycycline and azithromycin). The visual acuity was noted to be improved in all patients after treatment, but some of them experienced disturbing complications.

CONCLUSION

CSD may manifest with various ocular pathological findings. Taking into consideration the increasing frequency of infections by B. henselae and B. quintana, clinicians should always incorporate CSD in the differential diagnosis of such presentations of uveitis. Educating vulnerable groups (children, immunosuppressed, etc.) and also general population, the appropriate preventing measures can contribute in limiting the risk of infection.

Effectiveness of a 10% imidacloprid/4.5% flumethrin polymer matrix collar in reducing the risk of Bartonella spp. infection in privately owned cats

BACKGROUND

Bartonella henselae, Bartonella clarridgeiae and the rare Bartonella koehlerae are zoonotic pathogens, with cats being regarded as the main reservoir hosts. The spread of the infection among cats occurs mainly via fleas and specific preventive measures need to be implemented. The effectiveness of a 10% imidacloprid/4.5% flumethrin polymer matrix collar (Seresto®, Bayer Animal Health), registered to prevent flea and tick infestations, in reducing the risk of Bartonella spp. infection in privately owned cats, was assessed in a prospective longitudinal study.

METHODS

In March-May 2015 [Day 0 (D0)], 204 privately-owned cats from the Aeolian Islands (Sicily) were collared (G1, n = 104) or left as controls (G2, n = 100). The bacteraemia of Bartonella spp. was assessed at enrolment (D0) and study closure (D360) by PCR and DNA sequencing both prior to and after an enrichment step, using Bartonella alpha proteobacteria growth medium (BAPGM).

RESULTS

A total of 152 cats completed the study with 3 in G1 and 10 in G2 being positive for Bartonella spp. Bartonella henselae genotype I ZF1 (1.35%) and genotype II Fizz/Cal-1 (6.76%) as well as B. clarridgeiae (5.41%) were detected in cats of G2. Bartonella clarridgeiae was the only species detected in G1. Based on the yearly crude incidence of Bartonella spp. infection (i.e. 3.85% in G1 and 13.51% in G2; P = 0.03) the Seresto® collar achieved a preventative efficacy of 71.54%. The incidence of Bartonella spp. infection was more frequent in flea-infested cats (6/33, 18.18%) than in uninfested ones (7/112, 5.88%) (P = 0.036).

CONCLUSIONS

Cats living in the Aeolian Islands are exposed to B. henselae and B. clarridgeiae. The Seresto® collar provided significant risk reduction against Bartonella spp. infection in outdoor cats under field conditions. Such a preventative tool could be a key contribution for decreasing the risk of Bartonella spp. infection in cats and thus ultimately to humans.

Development of a Specific and Sensitive Enzyme-Linked Immunosorbent Assay as an In Vitro Diagnostic Tool for Detection of Bartonella henselae Antibodies in Human Serum

Bartonella henselae causes cat scratch disease and several other clinical entities. Infections with B. henselae are frequently occurring; however, the infection is only rarely diagnosed, mainly due to a lack of knowledge in the medical community. Microscopic immunofluorescence assays (IFA) are widely used for the serodiagnosis of B. henselae infections but are laborious and time-consuming, and interpretation is subjective. An easy and reliable method for the serological diagnosis of B. henselae infections is needed to overcome the shortcomings of the current IFA. Here, we report the development of an ELISA detecting human anti-B. henselae antibodies from serum samples. By separating the water-insoluble fraction of B. henselae Houston-1 via ion-exchange chromatography, 16 subfractions were generated and tested for immunoreactivity via line blotting. One particular fraction (fraction 24) was selected and spotted on ELISA plates using an industrial production platform. By use of well-characterized human sera from the strictly quality-controlled serum library of the German National Consiliary Laboratory for Bartonella infections, the sensitivity of this ELISA was 100% for PCR-proven infections and 76% for clinically suspected infections at a specificity of 93%. This ELISA is therefore a reliable high-throughput method allowing the serodiagnosis of B. henselae infections.

Ocular manifestations of bartonellosis

PURPOSE OF REVIEW

To review the systemic and ocular complications of Bartonella spp. infections specifically cat scratch disease, encompassing epidemiology, laboratory diagnostics, ophthalmic imagining, and treatment.

RECENT FINDINGS

Recent studies have shown that ocular manifestations occur in approximately 4.4% of cat scratch disease patients. The annual prevalence is lower than previously reported to be approximately 12 500 cases annually. Mainstay treatment continues to be oral antibiotics with and without corticosteroids and is dependent on associated systemic manifestations, age, and patient immune status. More recently anti-VEGF agents have been used for complications such as cystoid macular edema and choroidal neovascularization.

SUMMARY

Bartonella spp. infections continue to be a common cause uveitis with ophthalmic manifestations ranging from neuroretinits, vascular occlusions, to choroidal granulomas. Review of associated risk factors including contact with feline reservoirs will aid in recognition and diagnosis of this disease entity. Laboratory diagnostics continue to improve to help with the diagnosis of this entity.

Cat-Scratch Disease in an AIDS Patient Presenting with Generalized Lymphadenopathy: An Unusual Presentation with Delayed Diagnosis

Patient: Female, 44

Final Diagnosis: Cat-scratch disease

Symptoms: Lymfadenopathy

Medication: —

Clinical Procedure: Lymph node biopsy

Specialty: Infectious Diseases

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.

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.

Molecular survey of Bartonella henselae and Bartonella clarridgeiae in pet cats across Japan by species-specific nested-PCR

Cats are known to be the main reservoir for Bartonella henselae and Bartonella clarridgeiae, which are the agents of 'cat-scratch disease' in humans. In the present study, we investigated the prevalence of the two Bartonella species on 1754 cat bloods collected from all prefectures in Japan during 2007-2008 by a nested-polymerase chain reaction (PCR) targeting the 16S-23S rRNA internal transcribed spacer region. Overall, Bartonella DNA was detected in 4·6% (80/1754) of the cats examined. The nested-PCR showed that 48·8% (39/80) of the positive cats were infected with B. henselae mono-infection, 33·8% (27/80) with B. clarridgeiae mono-infection and 17·5% (14/80) were infected with both species. The prevalence (5·9%; 65/1103) of Bartonella infection in the western part of Japan was significantly higher than that (2·3%; 15/651) of eastern Japan (P < 0·001). Statistical analysis of the cats examined suggested a significant association between Bartonella infection and FeLV infection (OR = 1·9; 95% CI = 1·1-3·4), but not with FIV infection (OR = 1·6; 95% CI = 1·0-2·6).

Carcinoma of Maxillary Gingiva with Non-specific Cervical Lymph Node Swelling

Swelling of the cervical lymph nodes may indicate lymphadenitis, malignant lymphoma, or metastasis. Lymph nodes larger than 10 mm on computed tomography (CT) are strongly indicative of postoperative metastasis from carcinoma. Here, we report a case of large, inflamed lymph nodes mimicking metastasis. The patient was a 76-year-old woman who experienced discomfort in the left-side maxillary gingiva commencing in August 2011. By September, the area had become painful, causing her to visit the Tokyo Dental College Chiba Hospital, at which time a 75×50-mm swollen ulcer was observed in the maxillary gingiva on the left side. A CT image revealed a neoplastic lesion between the alveolar bone on the left side of the maxilla and the base of the maxillary sinus, together with evidence of osteoclastic activity. The bilateral cervical lymph nodes were Level II and had a uniform interior of approximately 5 mm. The lesion was subsequently excised under general anesthesia. At 34 days postoperatively, CT imaging revealed bilateral 40-mm internal heterogeneous lymphadenopathy at Level II. No inflammation of the maxillary gingiva was observed, however, and blood tests revealed no inflammatory findings. Bilateral cervical lymph node metastasis was diagnosed based on CT and oral cavity observation. Radical neck dissection of left cervical region was performed under general anesthesia. Histopathological examination of the lymph nodes revealed no metastasis at Levels I-V, however. The reason for this increase in lymph node size is discussed.

Diverse Clinical Signs of Ocular Involvement in Cat Scratch Disease

Objectives:

To describe ocular manifestations, diagnosis, and treatment of cat scratch disease.

Materials and Methods:

Clinical records of patients with ocular cat scratch disease were reviewed.

Results:

Thirteen eyes of 10 patients (7 female, 3 male) with a mean age of 26.9±18.5 years were included. Nine patients had a history of cat contact and had systemic symptoms associated with cat scratch disease 2-90 days prior to the ocular symptoms. Ocular signs were: neuroretinitis in 4 eyes (associated with serous retinal detachment in the inferior quadrant in 1 eye), optic neuropathy in 2 eyes (1 papillitis and optic disc infiltration, 1 optic neuritis), retinal infiltrates in 6 eyes, retinochoroiditis in 1 eye, branch retinal arteriolar occlusion in 3 eyes, and endophthalmitis in 1 eye. Visual acuities at presentation were 1.0 in 7 eyes, 0.3 in 1 eye, ≤0.1 in 4 eyes, and light perception in 1 eye. Bartonella henselae immunoglobulin (Ig) M and/or IgG were positive in all patients. Systemic antibiotic therapy was administered in all patients. Systemic corticosteroid treatment (15-40 mg/day) was added to the therapy in 4 patients, following 5 days of intravenous pulse methylprednisolone in 2 patients. Treatment was ongoing for 1 patient and the mean treatment duration of the other 9 patients was 47±14.5 days. Visual acuities at final visit were 1.0 in 9 eyes, 0.8 in 1 eye, 0.4 in 1 eye, and no light perception in 1 eye.

Conclusion:

Cat scratch disease may present with different ocular signs and should be considered in the differential diagnosis in patients with such presentations.

Bartonella Osteomyelitis of the Acetabulum: Case Report and Review of the Literature

INTRODUCTION

Bartonella henselae commonly involves the mononuclear phagocyte system (MPS), and its most common presentation is lymphadenitis. Rarely, it can cause isolated osteomyelitis. We present a case of a 3 year old with constitutional symptoms and new onset of limp. Previously reported cases of osteomyelitis due to B. henselae are also reviewed here, keeping the index case in mind.

METHODS

We conducted a Medline search using MeSH subject headings Bartonella and osteomyelitis, limited to humans.

RESULTS

The index case is a 3-year-old female who had a subacute presentation with new-onset leg pain and fever. Subsequent imaging demonstrated osteomyelitis of the acetabulum. Multiple diagnostic attempts were unsuccessful, and the patient did not respond to empiric therapy. Despite indeterminate serology, the diagnosis of Bartonella osteomyelitis was eventually confirmed by PCR on bone biopsy of the lesion. The literature search revealed 48 publications, which were reduced to 28 when limiting articles to the English language and the pediatric population. After a report of 36 pediatric cases in 2007, there have been an additional 12 pediatric cases since 1998. Generally, these patients had a subacute presentation with relatively mild constitutional symptoms. Most commonly, bone involvement occurred as osteolytic lesions of the axial skeleton. Of the total 48 cases reported, only four reported involvement of the axial skeleton.

CONCLUSION

We present the first case, to our knowledge, of pediatric osteomyelitis of the pelvis due to B. henselae with indeterminate serologic and positive PCR results. Bartonella osteomyelitis should be included in the differential diagnosis when typical pathogens are not identified or if the patient is slow to respond to standard therapies. The sensitivity of tissue PCR for Bartonella osteomyelitis is now better than the current gold standard of serology, and new management guidelines may need to reflect this.