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.

Bacteria from the genus Bartonella are emerging blood-borne bacteria, capable of causing long-lasting infection in marine and terrestrial mammals, including humans. Bartonella are generally well adapted to their main host, causing persistent infection without clinical manifestation. However, these organisms may cause severe disease in natural or accidental hosts. In humans, Bartonella species have been detected from sick patients presented with diverse disease manifestations, including cat scratch disease, trench fever, bacillary angiomatosis, endocarditis, polyarthritis, or granulomatous inflammatory disease. However, with the advances in diagnostic methods, subclinical bloodstream infection in humans has been reported, with the potential for transmission through blood transfusion been recently investigated by our group. The objective of this study was to determine the risk factors associated with Bartonella species infection in asymptomatic blood donors presented at a major blood bank in Southeastern Brazil. Five hundred blood donors were randomly enrolled and tested for Bartonella species infection by specialized blood cultured coupled with high-sensitive PCR assays. Epidemiological questionnaires were designed to cover major potential risk factors, such as age, gender, ethnicity, contact with companion animals, livestock, or wild animals, bites from insects or animal, economical status, among other factors. Based on multivariate logistic regression, bloodstream infection with B. henselae or B. clarridgeiae was associated with cat contact (adjusted OR: 3.4, 95% CI: 1.1–9.6) or history of tick bite (adjusted OR: 3.7, 95% CI: 1.3–13.4). These risk factors should be considered during donor screening, as bacteremia by these Bartonella species may not be detected by traditional laboratory screening methods, and it may be transmitted by blood transfusion.

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.

f 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. CASE REPORT

spp. are bacteria of worldwide distribution that cause asymptomatic to fatal infections in animals and humans. The most common zoonotic species is , for which cats are the major natural reservoir host. To better understand sp. diagnostic limitations, we determined the frequency of bloodstream infection in 112 cats by comparing and combining the results of multiple conventional and nested PCRs from blood and liquid culture samples. Using liquid culture conventional PCR, sp. DNA was amplified from 27.7% of samples (31/112) compared to 90.2% of samples (101/112) by combining nested PCR from blood and liquid culture, indicating that PCR testing of more than one type of sample provides better sensitivity than a standalone PCR and that bloodstream infection is very frequent among cats in southeastern Brazil. This study reinforces the need for multistep testing for sp. infection to prevent false-negative diagnostic results, even in reservoir hosts such as cats that typically maintain higher bacteremia levels.

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 30μLof suspension with 104 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.

We report a fatal case of Bartonella henselae bacteremic patient. He had negative serology and PCRs from whole blood and liquid culture; only ftsZ nested PCR was positive from the blood liquid culture. The isolate had positive PCRs. When considered, bartonellosis diagnosis can be still challenging because of technical limitations.

We evaluated culture-negative, community-acquired endocarditis by using indirect immunofluorescent assays and molecular analyses for Bartonella spp. and Coxiella burnetii and found a prevalence of 19.6% and 7.8%, respectively. Our findings reinforce the need to study these organisms in patients with culture-negative, community-acquired endocarditis, especially B. henselae in cat owners.