Analytical and clinical evaluation of new automated chemiluminescent immunoassays for the detection of IgG and IgM anti-Bartonella henselae antibodies

Presumed Bartonella-Associated Spondylodiscitis in a 3-Year-Old Child: A Case Report and Review of the Literature

With an incidence of 0.3 per 100,000, spondylodiscitis is a rare condition in children. It is typically bacterial in origin and most commonly caused by Staphylococcus aureus. Bone involvement in cat-scratch disease (CSD) due to Bartonella henselae is exceedingly rare, occurring in only 0.17-0.27% of cases. We present the case of a 3-year-old boy with a two-week history of intermittent back pain and a recent onset fever. Initial laboratory findings were unremarkable, and MRI revealed spondylodiscitis at L3/4 without abscess formation. Empirical antibiotic treatment with ampicillin/sulbactam showed no clinical response. Serologic testing revealed a positive Bartonella henselae IgM (IgG negative), leading to a change in antibiotic treatment to azithromycin and rifampicin for three weeks, resulting in rapid clinical improvement. Follow-up at nine weeks showed marked clinical and radiologic improvement. Although IgM subsequently turned negative without IgG seroconversion-a pattern previously described in Bartonella infections-this does not exclude the diagnosis. Biopsy or tissue PCR was not performed due to the mild clinical course. A review of the literature identified 28 pediatric cases of Bartonella henselae spondylodiscitis, with significant variation in diagnostic and treatment approaches. This case underscores the importance of considering Bartonella in the differential diagnosis of pediatric vertebral osteomyelitis.

Bartonella quintana Endocarditis Complicated by Cerebral Stroke: A Case Report

Bartonella quintana is rarely associated with neurological manifestations. This report describes a rare case of endocarditis complicated by a cerebral stroke caused by B. quintana. We also briefly reviewed the neurological clinical spectrum of B. quintana disease described in the literature. Serology tests were performed using the VIRCLIA®-system (chemiluminescence assay, Vircell, Spain) and immunofluorescence assay (IFA; Focus Diagnostics, USA). Cerebrospinal fluid (CSF) was tested using the BioFire-CSF-FilmArray-Meningitis/Encephalitis Panel (bioMérieux, France). CSF, plasma, and biopsy samples were tested using Bartonella-qPCR combined with Sanger-sequencing. A 23-year-old male Afghan refugee residing in Belgium presented with persistent fatigue and cough. A calcified aortic bicuspid with severe insufficiency and moderately associated stenosis was diagnosed. A transesophageal echocardiogram revealed a shrinking valve and a mobile mass attached to the calcification of the free edge at the aorta. He developed fever, a moderate inflammatory syndrome with normocytic anemia, and renal failure with hematuria and proteinuria, indicating probable glomerulonephritis. He met the Duke criteria for infective endocarditis, though blood cultures were initially negative. Bartonella serology later returned positive. He developed a fever and intense headache. CSF showed moderate pleiocytosis, but a negative-FilmArray. Neurovascular MR-angiography revealed a multifocal ischemic stroke. His aortic valve was replaced (Ross procedure). The biopsy showed nodular and degenerative fibro-calcified rearrangements. B.  quintana presence was confirmed in CSF, blood, and mitral valve samples. Our report underlines that B. quintana is a rare but a possible cause of endocarditis and neurological damage, and emphasizes the need for effective healthcare access, which is often limited in the countries of origin of migrants and even for migrants residing in high-resource countries.

An autochthonous case of cutaneous bacillary angiomatosis not related to major immunosuppression: An emerging or overlooked disease?

Cutaneous bacillary angiomatosis (cBA) is a vascular proliferative disorder due to Bartonella henselae or Bartonella quintana that has been mostly described in people living with HIV. Since cBA is considered to be rare in hosts not affected by major immunosuppression, it could be underdiagnosed in this population. Moreover, antimicrobial treatment of cBA has been poorly validated, thus reporting experiences on this clinical entity is important. We reported a challenging and well-characterized case of an Italian 67-year-old gentleman without a history of major immunocompromizing conditions, although he was affected by conditions that can be associated with impaired immune function. The patient reported herein was diagnosed after a long time since the initiation of symptoms and was successfully treated with combined antibiotic therapy including macrolides and quinolones under the guidance of molecular test results. Physicians should consider cBA as a possible manifestation of Bartonella spp. Infection in patients not suffering from major immunocompromizing conditions. Until evidence-based guidelines are available, molecular tests together with severity and extension of the disease can be useful to personalize the type of treatment and its duration.

Seroprevalence of vector-borne pathogens in outdoor workers from southern Italy and associated occupational risk factors

Background

Vector-borne diseases (VBDs) represent an emerging global threat to public health due to the geographical expansion of arthropod vectors. The study aims to assess the seroprevalence of selected vector-borne pathogens (VBPs) in different groups of outdoor workers and the occupational risk factors for exposure to arthropod bites.

Methods

A cross-sectional study was conducted on 170 workers recruited in two different regions of southern Italy, including farmers, forestry workers, veterinarians, geologists/agronomists and administrative employees, and tested for IgG antibodies against Bartonella henselae, Borrelia spp. Coxiella burnetii and Rickettsia conorii, using a chemiluminescent immunoassay (CLIA). The relationship among job characteristics, tick exposure and the prevalence of seropositive subjects for each pathogen was investigated by applying categorical principal component analysis (CATPCA).

Results

A high seroprevalence for C. burnetii (30.0%) and R. conorii (15.3%) was reported, mainly in farmers (67.7% and 54.8%, respectively) and forestry workers (29.0% and 16.1%, respectively), while a low prevalence was observed for B. henselae and Borrelia spp. (8.8% and 4.1%, respectively). The regression equation by CATPCA was significant for C. burnetii and R. conorii (P < 0.001), showing a positive association with job, tick bite exposure, working area and contact with animals.

Conclusions

These findings highlight the need of activating an appropriate occupational health response for minimizing the risk of arthropod vector exposure in workplaces, considering specific preventive measures in particular in high-risk job categories.

Graphical Abstract

Detection of antibodies against three zoonotic Bartonella spp. and cross-reactivity among species and Coxiella burnetii in dogs and cats from Central Thailand

Dogs and cats are important reservoir hosts of bacterial zoonotic pathogens, especially the Proteobacteria, Bartonella spp., and Coxiella burnetii. Bartonella spp. and C. burnetii are Gram-negative intracellular bacteria causing cat-scratch disease and query fever, respectively. Despite these two pathogens being dangerous, studies of their seroprevalence and cross-reactivity are limited in Thailand. The objectives of this study were to detect the seroprevalence of three zoonotic species of Bartonella and to evaluate cross-reactivity among Bartonella spp. and with C. burnetii. In total, 570 dog and cat serum samples were detected for antibodies against Bartonella spp. and C. burnetii using an indirect immunofluorescence antibody (IFA) test. At titer ≥ 1:64, tested serum that had a fluorescent intensity score ≥ 2 was interpreted as positive. Additionally, possible factors related to the seroprevalence were analyzed consisting of sex, breed, age, residing area, and ectoparasite control. Overall, the seroprevalence levels of Bartonella spp. and C. burnetii were 13.16% and 1.23%, respectively. All antigens of Bartonella were reacted to sera (1.23-7.72%), furthermore, both phases of C. burnetii were revealed in sera (0.35-1.05%). Interestingly, there was a poor agreement of cross-reactivity among Bartonella spp. at 5.56-8.70%, while cross-reactivity between Bartonella spp. and C. burnetii also showed poor agreement (2.80%). It is suggested that dogs and cats are important reservoirs of Bartonella spp., even in animals with ectoparasite control. The Bartonella seroprevalence was high in pure-breed animals with ectoparasite control, reflecting that Bartonella spp. infections can occur in owned, well-cared-for, and asymptomatic dogs and cats.

Novel approaches for rapid detection of COVID-19 during the pandemic: A review

The rapid spread of the SARS-CoV-2 virus that caused the COVID-19 disease, has highlighted our urgent need for sensitive, fast and accurate diagnostic technologies. In fact, one of the main challenges for flatting COVID-19 spread charts is the ability to accurately and rapidly identify asymptomatic cases that result in spreading the virus to close contacts. SARS-CoV-2 virus mutation is also relatively rapid, which makes the detection of COVID-19 diseases still crucial even after the vaccination. Conventional techniques, which are commercially available have focused on clinical manifestation, along with molecular and serological detection tools that can identify the SARS-CoV-2 virus however, owing to various disadvantages including low specificity and sensitivity, a quick, low cost and easy approach is needed for diagnosis of COVID-19. Scientists are now showing extensive interest in an effective portable and simple detection method to diagnose COVID-19. There are several novel methods and approaches that are considered viable advanced systems that can meet the demands. This study reviews the new approaches and sensing technologies that work on COVID-19 diagnosis for easy and successful detection of SARS-CoV-2 virus.