Is Bartonella sp. infection relevant in hematological malignancies in HIV-negative patients? A literature review

Bartonelloses are diseases caused by Bartonella sp., transmitted to humans by blood sucking arthropod vectors. Clinical presentations include bacillary angiomatosis, cat scratch disease and atypical forms. We performed a review of cases of bartonelloses and hematological malignancies published in HIV-negative patients. Terms used were Bartonella or Bacillary Angiomatosis and Leukemia, Lymphoma, Multiple Myeloma, or Cancer. Fifteen cases met our criteria. Clinical presentations included bacillary angiomatosis, chronic fever, chronic lymphadenopathy, osteomyelitis, neuroretinitis, chronic anemia and hepatosplenic peliosis. Fourteen patients were asymptomatic after antibiotic therapy, and one died before antibiotic treatment. Clinicians should be suspicious of Bartonella sp. infections in immunocompromised patients.

Viability and Desiccation Resistance of Bartonella henselae in Biological and Non-Biological Fluids: Evidence for Pathogen Environmental Stability

Pathogen environmental stability is an often-neglected research priority for pathogens that are known to be vector-transmitted. Bartonella henselae, the etiologic agent of Cat Scratch Disease, has become a "pathogen of interest" in several serious human illnesses, which include neoplastic, cardiovascular, neurocognitive, and rheumatologic conditions. Survival in the flea gut and feces as well as the association with a biofilm in culture-negative endocarditis provides insight into this organism's ability to adjust to environmental extremes. The detection of B. henselae DNA in blood and tissues from marine mammals also raises questions about environmental stability and modes of pathogen transmission. We investigated the ability of B. henselae to survive in fluid matrices chosen to mimic potential environmental sources of infective materials. Feline whole blood, serum and urine, bovine milk, and physiologic saline inoculated with a laboratory strain of B. henselae San Antonio 2 were subsequently evaluated by culture and qPCR at specified time intervals. Bacterial viability was also assessed following desiccation and reconstitution of each inoculated fluid matrix. Bartonella henselae SA2 was cultured from feline urine up to 24 h after inoculation, and from blood, serum, cow's milk, and physiologic saline for up to 7 days after inoculation. Of potential medical importance, bacteria were cultured following air-desiccation of all fluid inoculates. The viability and stability of Bartonella within biological and non-biological fluids in the environment may represent a previously unrecognized source of infection for animals and human beings.

Comparison of molecular methods for Bartonella henselae detection in blood donors

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

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

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

Validation of a Novel Commercial ELISA Test for the Detection of Antibodies against Coxiella burnetii

Q fever is a zoonosis caused by Coxiella burnetii, a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against C. burnetii Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics.

Prevalence of Bartonella spp. Infection in Patients with Sickle Cell Disease

Background: The inherent characteristics of the sickle cell disease (SCD), the most common genetic hematological disorder, increase the propensity of infections. Bartonella spp. are emerging and neglected bacteria. A large spectrum of clinical manifestations has been linked to bartonella bloodstream infection in the last two decades that can cause fatal outcomes, especially in immunodeficient patients. The goal of this study was to evaluate the prevalence of bartonella infection in SCD patients. Materials and Methods: We evaluated Bartonella spp. prevalence in 107 SCD patients. Blood samples and enrichment blood cultures were analyzed by molecular detection of Bartonella spp. DNA. Bartonella DNA was amplified using conventional genus-specific Bartonella PCR which amplifies the Intergenic Transcribed Spacer region and Bartonella henselae-specific nested PCR which amplifies the FtsZ gene. Positive patient DNAs were tested with ssrA conventional PCR. All amplicons were sequenced. Findings: Ten of 107 patients tested positive for B. henselae infection in at least one molecular test. All obtained amplicons were sequenced and similar to B. henselae sequences deposited in GenBank (accession number BX897699). Based on statistical results, bloodstream infection with B. henselae was not associated with animal contact or blood transfusions. Conclusion: We detected B. henselae DNA in 10 (9.3%) SCD studied patients. These patients were notified and treatment was offered to them.

Bartonella henselae bacteremia diagnosed post-mortem in a myelodysplastic syndrome patient

This study involves a 49-year-old male, who for three years suffered with a myelodysplastic syndrome and who needed frequent blood transfusions. One day following a transfusion, he presented fever and abdominal pain. The fever became persistent and only improved temporarily with two cycles of intravenous ciprofloxacin. Nearly 120 days after beginning the second cycle of treatment, he had experienced a weight loss of 16 kg and recurring fever. Screening for fever of unknown origin was conducted, including Bartonella infection. No etiology could be found. The patient improved with an antimicrobial regimen composed of oral doxycycline and intravenous ciprofloxacin. After 15 days afebrile, the patient was discharged with a four-month oral prescription of doxycycline and ciprofloxacin. Eight months following the antibiotic treatment, the patient received an allogeneic bone marrow transplant. Five days following the transplant, the patient initiated a febrile neutropenia and died. From a blood sample collected and stored at the time of hospitalization, a microbiological and molecular study was performed again. Blood- and liquid culture-PCRs from the same blood sample were all negative, but an isolate from solid subculture was found. The molecular reactions from this isolate were all positive and the sequence was 100% homologous to Bartonella henselae . The present report points to the limitations of laboratory techniques currently available for investigation of possible cases of bartonellosis in clinical practice, and the potential risk of Bartonella spp. transmission through blood transfusions.

Cutaneous manifestations of bartonellosis

Bartonellosis are diseases caused by any kind of Bartonella species. The infection manifests as asymptomatic bacteremia to potentially fatal disorders. Many species are pathogenic to humans, but three are responsible for most clinical symptoms: Bartonella bacilliformis, Bartonella quintana, and Bartonella henselae. Peruvian wart, caused by B. bacilliformis, may be indistinguishable from bacillary angiomatosis caused by the other two species. Other cutaneous manifestations include maculo-papular rash in trench fever, papules or nodules in cat scratch disease, and vasculitis (often associated with endocarditis). In addition, febrile morbilliform rash, purpura, urticaria, erythema nodosum, erythema multiforme, erythema marginatus, granuloma annularis, leukocytoclastic vasculitis, granulomatous reactions, and angioproliferative reactions may occur. Considering the broad spectrum of infection and the potential complications associated with Bartonella spp., the infection should be considered by physicians more frequently among the differential diagnoses of idiopathic conditions. Health professionals and researchers often neglected this diseases.

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

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

Seroprevalence of six pathogens transmitted by the Ixodes ricinus ticks in asymptomatic individuals with HIV infection and in blood donors

The objective of our study was to estimate the seroprevalence of six pathogens transmitted by ticks in HIV-infected persons and blood donors in Poland (B. burgdorferi s.l., A. phagocytophilum, Ehrlichia spp., Babesia spp., Rickettsia spp. Bartonella henselae) to assess the frequency of exposure to such microorganisms in immunocompetent and immunocompromised individuals in endemic regions for I. ricinus ticks. Serum samples were collected from 227 HIV-infected patients and 199 blood donors. All samples were analyzed for antibodies against six tick-borne pathogens and seroprevalence rates were statistically compared between two tested group as well as age, sex and lymphocyte T CD4+ level in HIV infected patients. The seroprevalence of tick-borne infections in HIV-infected patients is higher than that of the healthy population in Poland, although no association between serological status of patients and lymphocyte CD4+ T cell level has been observed. The frequency of tick-borne coinfections and doubtful results of serological tests were significantly higher in HIV-positive individuals. In Poland, the possibility of tick-borne diseases transmission with blood is rather negligible.

Bartonella henselae Infection in Sickle Cell Disease Mice Is Associated with Hyperalgesia

BACKGROUND

Sickle cell disease (SCD) is the most prevalent hematologic genetic disorder. Acute vaso-occlusive painful crisis is the hallmark of the disease and may be related to subclinical infections. Bartonellosis, a rare and neglected infection, is caused by Bartonella spp., which can be found in donated blood. These bacteria cause intraerythrocytic and endothelial infection and pain, all of which occur in SCD. It is likely that this infection is transmitted to SCD patients during transfusion from donated blood, leading to pain. We, therefore, evaluated whether Bartonella henselae infection would cause hyperalgesia in mice with SCD.

MATERIALS AND METHODS

SCD mice were generated by transplantation of nucleated bone marrow cells harvested from transgenic Berkeley sickle mice into 2-month-old irradiated C57BL/6 mice. We infected four SCD mice by intraperitoneal inoculation with B. henselae, and inoculated four other mice with the same volume of saline. Mechanical hyperalgesia was determined using von Frey monofilaments by two blinded observers. Thereafter, the animals were anesthetized and euthanized to collect blood, liver, and spleen samples to seek B. henselae infection by PCR.

FINDINGS

We confirmed the experimental infection in all animals by PCR. Tremors and mechanical hypersensitivity were demonstrated by SCD mice infected with B. henselae infection but not in those receiving saline.

CONCLUSION

B. henselae infection may be related to pain and other symptoms in SCD.

Carrion's Disease: the Sound of Silence

Carrion's disease (CD) is a neglected biphasic vector-borne illness related to Bartonella bacilliformis. It is found in the Andean valleys and is transmitted mainly by members of the Lutzomyia genus but also by blood transfusions and from mother to child. The acute phase, Oroya fever, presents severe anemia and fever. The lethality is high in the absence of adequate treatment, despite the organism being susceptible to most antibiotics. Partial immunity is developed after infection by B. bacilliformis, resulting in high numbers of asymptomatic carriers. Following infection there is the chronic phase, Peruvian warts, involving abnormal proliferation of the endothelial cells. Despite potentially being eradicable, CD has been expanded due to human migration and geographical expansion of the vector. Moreover, in vitro studies have demonstrated the risk of the development of antimicrobial resistance. These findings, together with the description of new Bartonella species producing CD-like infections, the presence of undescribed potential vectors in new areas, the lack of adequate diagnostic tools and knowledge of the immunology and bacterial pathogenesis of CD, and poor international visibility, have led to the risk of increasing the potential expansion of resistant strains which will challenge current treatment schemes as well as the possible appearance of CD in areas where it is not endemic.

Chronic lymphadenopathy caused by a Brazilian strain of Bartonella henselae

Bartonella henselae is a relevant causative agent of bartonelloses in humans. We described an immunocompetent patient with clinical manifestation of chronic cervical lymphadenopathy after a cat-scratch in her forearm. This case shows B. henselae infection persistence even after prolonged antibiotic treatment.

Bartonella henselae transmission by blood transfusion in mice

BACKGROUND

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

STUDY DESIGN AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Bartonella spp. bacteremia in blood donors from Campinas, Brazil

Bartonella species are blood-borne, re-emerging organisms, capable of causing prolonged infection with diverse disease manifestations, from asymptomatic bacteremia to chronic debilitating disease and death. This pathogen can survive for over a month in stored blood. However, its prevalence among blood donors is unknown, and screening of blood supplies for this pathogen is not routinely performed. We investigated Bartonella spp. prevalence in 500 blood donors from Campinas, Brazil, based on a cross-sectional design. Blood samples were inoculated into an enrichment liquid growth medium and sub-inoculated onto blood agar. Liquid culture samples and Gram-negative isolates were tested using a genus specific ITS PCR with amplicons sequenced for species identification. Bartonella henselae and Bartonella quintana antibodies were assayed by indirect immunofluorescence. B. henselae was isolated from six donors (1.2%). Sixteen donors (3.2%) were Bartonella-PCR positive after culture in liquid or on solid media, with 15 donors infected with B. henselae and one donor infected with Bartonella clarridgeiae. Antibodies against B. henselae or B. quintana were found in 16% and 32% of 500 blood donors, respectively. Serology was not associated with infection, with only three of 16 Bartonella-infected subjects seropositive for B. henselae or B. quintana. Bartonella DNA was present in the bloodstream of approximately one out of 30 donors from a major blood bank in South America. Negative serology does not rule out Bartonella spp. infection in healthy subjects. Using a combination of liquid and solid cultures, PCR, and DNA sequencing, this study documents for the first time that Bartonella spp. bacteremia occurs in asymptomatic blood donors. Our findings support further evaluation of Bartonella spp. transmission which can occur through blood transfusions.

Bartonella is a genus of small bacteria with worldwide distribution, transmitted by blood-sucking insects, and is capable of causing disease in humans and animals. Some of the clinical presentations of Bartonella spp., such as cat scratch disease, trench fever, and bacillary angiomatosis are well documented; however, novel presentations have been described in the last two decades, ranging from cyclic flu-like syndrome to neurologic disease and life-threatening endocarditis. Asymptomatic human infection is possible and accidental blood transmission has been reported. Bacterium isolation is very difficult because they grow slowly and require special culture media and procedures. Serology testing poorly predicts active Bartonella infection, except in infection of cardiac valves. Therefore, diagnosis is generally challenging. However, when molecular detection techniques are coupled with special culture protocols, enhanced sensitivity and specificity can be achieved. We investigated Bartonella spp. infection prevalence in a large blood donor population and confirmed bacteremia in 1.2% of the subjects. Bloodstream infection was detected with at least three different molecular methods in 3.2% of donors. These results indicate that Bartonella is a genus of importance for transfusion medicine.

Bartonella clarridgeiae bacteremia detected in an asymptomatic blood donor

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.

Exposure and risk factors to coxiella burnetii, spotted fever group and typhus group Rickettsiae, and Bartonella henselae among volunteer blood donors in Namibia

BACKGROUND

The role of pathogen-mediated febrile illness in sub-Saharan Africa is receiving more attention, especially in Southern Africa where four countries (including Namibia) are actively working to eliminate malaria. With a high concentration of livestock and high rates of companion animal ownership, the influence of zoonotic bacterial diseases as causes of febrile illness in Namibia remains unknown.

METHODOLOGY/PRINCIPAL FINDINGS

The aim of the study was to evaluate exposure to Coxiella burnetii, spotted fever and typhus group rickettsiae, and Bartonella henselae using IFA and ELISA (IgG) in serum collected from 319 volunteer blood donors identified by the Blood Transfusion Service of Namibia (NAMBTS). Serum samples were linked to a basic questionnaire to identify possible risk factors. The majority of the participants (64.8%) had extensive exposure to rural areas or farms. Results indicated a C. burnetii prevalence of 26.1% (screening titre 1∶16), and prevalence rates of 11.9% and 14.9% (screening titre 1∶100) for spotted fever group and typhus group rickettsiae, respectively. There was a significant spatial association between C. burnetii exposure and place of residence in southern Namibia (P<0.021). Donors with occupations involving animals (P>0.012), especially cattle (P>0.006), were also significantly associated with C. burnetii exposure. Males were significantly more likely than females to have been exposed to spotted fever (P<0.013) and typhus (P<0.011) group rickettsiae. Three (2.9%) samples were positive for B. henselae possibly indicating low levels of exposure to a pathogen never reported in Namibia.

CONCLUSIONS/SIGNIFICANCE

These results indicate that Namibians are exposed to pathogenic fever-causing bacteria, most of which have flea or tick vectors/reservoirs. The epidemiology of febrile illnesses in Namibia needs further evaluation in order to develop comprehensive local diagnostic and treatment algorithms.

Feline bartonellosis

Bartonella infection is common among domestic cats, but the role of Bartonella species as feline pathogens requires further study. Most Bartonella species that infect cats are zoonotic. Cats are the mammalian reservoir and vector for Bartonella henselae, an important zoonotic agent. Cat fleas transmit Bartonella among cats, and cats with fleas are an important source of human B henselae infections. New information about Bartonella as feline pathogens has recently been published, and this article summarizes much of that information. Issues surrounding diagnosis and treatment of feline Bartonella infections are described, and prevention of zoonotic transmission of Bartonella is discussed.

Bartonella spp. infection in HIV positive individuals, their pets and ectoparasites in Rio de Janeiro, Brazil: serological and molecular study

BACKGROUND

Bartonella is the agent of cat-scratch disease, but is also responsible for more severe conditions such as retinitis, meningoencephalitis, endocarditis and bacillary angiomatosis. Its seroprevalence is unknown in Brazil.

METHODS

Patients in an AIDS clinic, asymptomatic at the time of the study, were enrolled prospectively. They answered a structured questionnaire and had blood taken for serological and molecular assays. Cat breeder's pets were tested serologically and collected ectoparasites were tested by molecular biology techniques. Blood donors, paired by age and sex, were tested for Bartonella IgG antibodies.

RESULTS

125 HIV positive patients with a median age of 34 were studied; 61 were male and 75% were on HAART. Mean most recent CD4 count was 351-500 cells/mm(3). A high rate of contact with ticks, fleas and lice was observed. Bartonella IgG seroreactivity rate was 38.4% in HIV positive individuals and breeding cats was closely associated with infection (OR 3.6, CI 1.1-11.9, p<0.05). No difference was found between the sexes. Titers were 1:32 in 39 patients, 1:64 in seven, 1:128 in one and 1:256 in one. In the control group, IgG seroreactivity to Bartonella spp. was 34%, and female sex was correlated to seropositivity. Fourteen of 61 (23%) males vs 29/64 (45.3%) females were seroreactive to Bartonella (OR 2.8, CI 1.2-6.5, p<0.01). Titers were 1:32 in 29 patients, 1:64 in ten and 1:128 in four.

CONCLUSIONS

Bartonella spp. seroprevalence is high in HIV positive and in blood donors in Rio de Janeiro. This may be of public health relevance.

Molecular evidence of perinatal transmission of Bartonella vinsonii subsp. berkhoffii and Bartonella henselae to a child

Bartonella vinsonii subsp. berkhoffii, Bartonella henselae, or DNA of both organisms was amplified and sequenced from blood, enrichment blood cultures, or autopsy tissues from four family members. Historical and microbiological results support perinatal transmission of Bartonella species in this family. It is of clinical relevance that Bartonella spp. may adversely influence human reproductive performance.

Blood cell findings resembling Bartonella spp

Some Bartonella species are able to invade red blood cells (RBC) and may cause persistent infection in the susceptible host. Use of transmission electron microscopy (TEM) demonstrates, inside erythrocytes, the typical triple-walled agents. However, when examining ultrathin sections of blood cells, the authors have, on several occasions, detected intraerythrocytic abnormalities that mimic but are not typical of Bartonella spp. Small endovesicles, pseudoinclusions, cavities, and irregular hemoglobin granules distribution, resulting in regions of increased or decreased electron density, may be observed in the erythrocytes and platelets, which may be confused with bartonellas. So far, detailed ultrastructural findings of Bartonella spp. in blood cells have not yet been described. Aiming to improve TEM interpretation of blood cells changes, in routine examination of blood sections of patients with suspected bartonellosis, the authors studied the morphological findings they have observed, and present their putative nature, according to information in the literature.