RESUMO
BACKGROUND: Human Borna disease virus (BDV) infections have recently been reported in China. BDV causes cognitive and behavioural disturbances in animals. The impact on human mental disorders is subject to debate, but previous studies worldwide have found neuropsychiatric patients more frequently infected than healthy controls. A few isolates were recovered from severely depressed patients, but contagiousness of BDV strain remains unknown. METHOD: We addressed the risk of infection in health care settings at the first affiliated hospital of Chongqing Medical University (CQMU), located in downtown Chongqing, a megacity in Southwest China. Between February 2012 and March 2013, we enrolled 1529 participants, of whom 534 were outpatients with major depressive disorder (MDD), 615 were hospital personnel, and 380 were healthy controls who underwent a health check. Infection was determined through BDV-specific circulating immune complexes (CIC), RNA, and selective antibodies (blood). RESULTS: One-fifth of the hospital staff (21.8%) were found to be infected (CIC positive), with the highest prevalence among psychiatry and oncology personnel, which is twice as many as were detected in the healthy control group (11.1%), and exceeds the prevalence detected in MDD patients (18.2%). CONCLUSION: BDV circulates unnoticed in hospital settings in China, putting medical staff at risk and warranting clarification of infection modes and introduction of prevention measures.
Assuntos
Doença de Borna/virologia , Vírus da Doença de Borna/isolamento & purificação , Transtorno Depressivo Maior/virologia , Pessoal de Saúde/estatística & dados numéricos , Doenças Profissionais/virologia , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Doença de Borna/sangue , Doença de Borna/diagnóstico , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Estudos de Casos e Controles , China/epidemiologia , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/epidemiologia , Feminino , Hospitais/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/sangue , Doenças Profissionais/diagnóstico , Doenças Profissionais/epidemiologia , Exposição Ocupacional/estatística & dados numéricos , Adulto JovemRESUMO
Borna disease virus (BDV) is a non-cytolytic, neurotropic RNA virus that can infect many vertebrate species, including humans. To date, BDV infection has been reported in a range of animal species across a broad global geographic distribution. However, a systematic epidemiological survey of BDV infection in domesticated animals in China has yet to be performed. In current study, BDV RNA and antibodies in 2353 blood samples from apparently healthy animals of eight species (horse, donkey, dog, pig, rabbit, cattle, goat, sheep) from three areas in western China (Xinjiang province, Chongqing municipality, and Ningxia province) were assayed using reverse transcription qPCR (RT-qPCR) and ELISA assay. Brain tissue samples from a portion of the BDV RNA- and/or antibody-positive animals were subjected to RT-qPCR and western blotting. As a result, varying prevalence of BDV antibodies and/or RNA was demonstrated in various animal species from three areas, ranging from 4.4 % to 20.0 %. Detection of BDV RNA and/or antibodies in Chongqing pigs (9.2 %) provided the first known evidence of BDV infection in this species. Not all brain tissue samples from animals whose blood was BDV RNA and/or antibody positive contained BDV RNA and protein. This study provides evidence that BDV infection among healthy domestic animal species is more widespread in western China than previously believed.
Assuntos
Animais Domésticos/virologia , Doença de Borna/virologia , Vírus da Doença de Borna/fisiologia , Animais , Anticorpos Antivirais/sangue , Doença de Borna/sangue , Doença de Borna/diagnóstico , Doença de Borna/epidemiologia , Vírus da Doença de Borna/genética , Vírus da Doença de Borna/imunologia , Vírus da Doença de Borna/isolamento & purificação , Bovinos , China/epidemiologia , Cães , Equidae , Cabras , Cavalos , Coelhos , Ovinos , SuínosRESUMO
Borna disease virus (BDV) is a non-cytolytic, neurotropic RNA virus that can infect a wide variety of vertebrate species from birds and primates to humans. Several studies have been carried out to investigate whether BDV is associated with neuropsychiatric diseases. However, this association is still inconclusive. Two panels of subjects consisting of 1,679 various neuropsychiatric patients and healthy people from three western China provinces were enrolled in this study. BDV p24 or p40 RNA in peripheral blood mononuclear cells (PBMCs) were detected in the first panel of 1,481 subjects using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and cerebrospinal fluid (CSF) samples from the BDV RNA-positive individuals were subjected to BDV p24 antibodies testing by enzyme-linked immunosorbent assay (ELISA). BDV p24 or p40 RNA in PBMCs and p24 antibodies in plasma were detected in the second panel of 198 subjects by RT-qPCR and Western blot. A higher prevalence for BDV RNA was demonstrated in patients with viral encephalitis (6.70%), Guillain-Barré syndrome (6.70%), schizophrenia (9.90%) and chronic fatigue syndrome (CFS) (12.70%) compared to healthy controls in the first panel. CSF p24 antibodies were demonstrated in three viral encephalitis patients, two schizophrenia patients and two major depressive disorder (MDD) patients. The prevalences of p24 antibodies in plasma from patients with viral encephalitis (13.24%), multiple sclerosis (25.00%) and Parkinson's disease (22.73%) were significantly higher than healthy controls. This study demonstrates that BDV infection also exists in humans from three western China provinces, and suggests the involvement of the contribution of BDV in the aetiology of Chinese patients with some neuropsychiatric disorders, including viral encephalitis, schizophrenia, CFS, multiple sclerosis and Parkinson's disease.
Assuntos
Doença de Borna/virologia , Vírus da Doença de Borna/isolamento & purificação , Doenças do Sistema Nervoso/virologia , Esquizofrenia/virologia , Adulto , Anticorpos Antivirais/sangue , Anticorpos Antivirais/líquido cefalorraquidiano , Doença de Borna/sangue , Doença de Borna/líquido cefalorraquidiano , Doença de Borna/epidemiologia , China , Ensaio de Imunoadsorção Enzimática , Síndrome de Fadiga Crônica/sangue , Síndrome de Fadiga Crônica/líquido cefalorraquidiano , Síndrome de Fadiga Crônica/epidemiologia , Síndrome de Fadiga Crônica/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/sangue , Doenças do Sistema Nervoso/líquido cefalorraquidiano , Doenças do Sistema Nervoso/epidemiologia , RNA Viral/sangue , Esquizofrenia/sangue , Esquizofrenia/líquido cefalorraquidiano , Esquizofrenia/epidemiologiaRESUMO
Distribution of Borna disease virus (BDV) infection outside endemic areas has been studied in several countries. We examined serum samples for anti-BDV antibodies in purebred racing horses and other domestic animals in Turkey. In total serum samples of 437 animals including 282 horses, 50 sheep, 25 goats, 50 cattle, and 30 cats were tested by indirect immunofluorescence assay (IFA). Anti-BDV antibodies were detected in 4.9% of horses, 12% of sheep, 4% of goats, 14% of cattle and 6.6% of cats. No statistical difference was observed between seroprevalence in Arabic and English purebred horses from four different racing centers (p > 0.05). Antibody titers ranged between 1:10 and 1:320. The highest antibody titers were found in sheep and horses and the lowest titer in cattle. Clinical symptoms of Borna disease were not observed in any animal of any species examined. This study confirms the presence of anti-BDV antibodies in racing horses as well as cat population in Turkey. Moreover anti-BDV antibodies are demonstrated for the first time in sheep, goats and cattle in Turkey.
Assuntos
Anticorpos Antivirais/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/isolamento & purificação , Animais , Doença de Borna/sangue , Doença de Borna/imunologia , Vírus da Doença de Borna/imunologia , Gatos , Bovinos , Cabras , Cavalos , Estudos Soroepidemiológicos , Ovinos , Turquia/epidemiologiaRESUMO
Avian Borna virus (ABV) has recently been shown to be the causal agent of proventricular dilatation disease (PDD) a lethal neurologic disease of captive psittacines and other birds. An immunoblot assay was used to detect the presence of antibodies against avian Borna virus in the serum of affected birds. A lysate from ABV-infected duck embryo fibroblasts served as a source of antigen. The assay was used to test for the presence of antibodies to ABV in 117 birds. Thirty of these birds had biopsy or necropsy-confirmed proventricular dilatation disease (PDD), while the remaining 87 birds were apparently healthy or were suffering from diseases other than PDD. Sera from 27 of the 30 PDD cases (90%) contained antibodies to ABV. Seventy-three (84%) of the apparently "healthy" birds were seronegative. Additionally, sera from seven macaws and one parrot trapped in the Peruvian Amazon were seronegative. Positive sera recognized the bornaviral nucleoprotein (N-protein). While the presence of antibodies to ABV largely corresponded with the development of clinical PDD, 14 apparently healthy normal birds possessed detectable antibodies to ABV. The existence of a carrier state was confirmed when 13 of 15 apparently healthy cockatiels were shown by PCR to have detectable ABV RNA in their feces. Western blot assays may be of significant assistance in diagnosing proventricular dilatation disease. Many apparently healthy birds may however be seronegative while, at the same time, shedding ABV in their feces.
Assuntos
Anticorpos Antivirais/sangue , Western Blotting/veterinária , Doença de Borna/diagnóstico , Vírus da Doença de Borna/imunologia , Psittaciformes , Animais , Doenças das Aves/sangue , Doenças das Aves/imunologia , Doenças das Aves/virologia , Doença de Borna/sangue , Sensibilidade e Especificidade , Testes Sorológicos/veterináriaAssuntos
Doença de Borna/virologia , Vírus da Doença de Borna/patogenicidade , Transtornos Mentais/virologia , Animais , Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Doença de Borna/diagnóstico , Vírus da Doença de Borna/química , Vírus da Doença de Borna/isolamento & purificação , Vírus da Doença de Borna/fisiologia , Encéfalo/virologia , Genes Virais/genética , Saúde Global , Humanos , Técnicas Imunoenzimáticas/métodos , Transtornos Mentais/prevenção & controle , Modelos Moleculares , Proteínas do Nucleocapsídeo/genética , Fosfoproteínas/genética , Filogenia , Prevalência , Vírus de RNA/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Proteínas Estruturais Virais/genéticaRESUMO
Borna Disease Virus (BDV) is a unique RNA virus, whose organs of manifestation are the brain and blood of animals as well as humans. The infection disrupts certain cell functions, but does not damage the cell structure. The infection with BDV can exist without associated clinical symptoms. Furthermore the majority of natural BDV-infections occur unnoticed without causing symptoms particularly those in connection with only a slight BDV-infection. BDV-infected horses can be detected by an extremely practicable ELISA based on blood samples and developed by the Berlin Working Group under guidance of Ludwig and Bode. All three serological Borna-Disease (BD) parameters antigen-, immune complex- and antibody-titer can be measured with this ELISA. However a single testing can not lead to a final evaluation of the infection so that progressive investigations are unavoidable. Blood tests in intervals of 4-6 weeks show the course of infection and help to adjust the specific treatment. After an infection an examination of the antigen- and immune complex-titer will show whether this occurrence is acute and activated or not. Therefore we examined 3481 blood samples of different horses by ELISA. 1841 (50%) were BDV-infected. Approximately 40% of the infected horses were clinically healthy and approximately 43% were clinically ill. The relatively high infection rate could be justified by the fact that these subjects had more or less direct contact with clinically ill horses. Furthermore, it is possible that the highly Borna positive, but not clinically ill horses were tested shortly before the symptoms of disease would appear. Moreover there were also horses that have had a high BDV-titer without showing any sign of the BDV-disease. These animals were thus able to live with the infection. Our investigations focused on highly seropositive BDV-infected horses (1) (Fig. 1). The results can not be linked to BD typical endemic regions due to the fact of today's far more sophisticated testing methods. Horses are more than ever used for leisure activity and become subjects to a worldwide marketing and movement. Any stress situation, especially in competitions as shown in long-term monitoring of sick horses, leads to worsening of symptoms. In this context it should be noted that a test for activated BDV-infection is still not common. EU-wide regulations should therefore be considered.
Assuntos
Amantadina/uso terapêutico , Antivirais/uso terapêutico , Doença de Borna/diagnóstico , Doença de Borna/tratamento farmacológico , Vírus da Doença de Borna/imunologia , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/tratamento farmacológico , Animais , Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Portador Sadio , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática , Alemanha , Doenças dos Cavalos/sangue , CavalosAssuntos
Amantadina/uso terapêutico , Doença de Borna/diagnóstico , Doença de Borna/tratamento farmacológico , Bornaviridae/imunologia , Amantadina/administração & dosagem , Animais , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Diagnóstico Diferencial , Esquema de Medicação , Cavalos , Comprimidos/administração & dosagem , Comprimidos/uso terapêuticoRESUMO
In Europe, Borna disease virus (BDV) infection has been linked with staggering disease. The aim of this study was serological investigation for BDV infection in Australian cats. De-identified sera were obtained from domestic cats presented at various veterinary clinics. BDV antigen levels were measured by a monoclonal antibody-based ELISA. Antibody to BDV measured semiquantitatively by ELISA was detected in 0.8% of cats from South Australia and 3.2% of animals from NSW Confirmatory assays for ELISA positive samples included Western blot and immunofluorescence assay (IFA) with BDV-specific staining. Seven BDV-antigen positive sera (2.4%) were identified in sera from cats from New South Wales (NSW). In blinded testing, amongst a large number of negative results, repeat submissions over a seven-month period from a cat co-infected with Feline Immunodeficiency Virus (FIV) were BDV-antigen positive. Anti-BDV antibody detected in this cat by ELISA was confirmed by Western blot (p24/ p40/p56) and IFA. For 4 other anti-BDV ELISA-positive samples, specific reactions with BDV proteins were observed by Western blot. Ten other anti-BDV ELISA-positive samples were IFA positive. These data provide consistent serological evidence that, while horses in Australia are free of BDV infection, there may be a low rate of BDV infection in cats.
Assuntos
Anticorpos Antivirais/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Doenças do Gato/epidemiologia , Animais , Antígenos Virais/sangue , Austrália/epidemiologia , Western Blotting , Doença de Borna/sangue , Doenças do Gato/sangue , Gatos , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Estudos SoroepidemiológicosAssuntos
Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Adolescente , Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiopatologia , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Recém-Nascido , Itália/epidemiologia , Masculino , Fatores de Risco , Estudos SoroepidemiológicosAssuntos
Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , População UrbanaAssuntos
Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Doenças do Gato/sangue , Doenças do Gato/epidemiologia , Doenças dos Cavalos/sangue , Doenças dos Cavalos/epidemiologia , Adolescente , Animais , Gatos , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Cavalos , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Soroepidemiológicos , Sicília/epidemiologiaAssuntos
Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Transtornos Mentais , Criança , Feminino , Humanos , Masculino , Transtornos Mentais/virologia , Cidade de Roma/epidemiologia , Estudos SoroepidemiológicosAssuntos
Anticorpos Antivirais/sangue , Complexo Antígeno-Anticorpo/sangue , Antígenos Virais/sangue , Doença de Borna/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Borna/transmissão , Criança , Pré-Escolar , Alemanha/epidemiologia , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Pessoa de Meia-Idade , Estudos SoroepidemiológicosRESUMO
Borna disease virus (BDV) causes neurological disease in horses, however, there is no consensus as to the extent or significance of human infection. BDV antigen levels in plasma (BDVpAg) and anti-BDV were measured by ELISAs. Confirmation was by Western blot (WB), immunofluorescence assay (IFA) or BDV-peptide-epitope ELISA. For 42 volunteers psychiatrically-defined as non-depressed (82 samples) neither BDVpAg nor anti-BDV was detected. For 104 patients with diagnosed depression (290 samples) 1 was BDVpAg positive and 5 anti-BDV positive, one epitope-e8 positive and 4 IFA positive, with 96% concordance for repeat samples. No BDVpAg was detected in 214 pregnant women, 2 were anti-BDV positive, one WB-confirmed (p24/p40). For 219 donors 2 were BDVpAg positive with anti-BDV detected in 5 (2.3%) one IFA 1:10, another IFA 1:40/epitope-e8 positive. In multitransfused patients, 3/168 were BDV pAg positive, with 14/168 anti-BDV positive, 1 epitope-e8 positive, 2 WB positive and 1 IFA 1:10. In BDVpAg positive multi-transfused patients there was an elevated risk of transaminitis. In one case, a patient BDV-negative prior to transfusion was BDVpAg positive for several months posttransfusion (associated with transaminitis). These data provide serological evidence, supported by confirmatory assays and repeat-sample concordance, of BDV infection in Australia, particularly in multi-transfused patients.
Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/sangue , Transfusão de Sangue , Doença de Borna/sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/imunologia , Depressão/sangue , Depressão/imunologia , Austrália/epidemiologia , Western Blotting , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Peptídeos/imunologia , Gravidez , Fatores de RiscoAssuntos
Doença de Borna , Vírus da Doença de Borna/fisiologia , Vírus da Doença de Borna/patogenicidade , Animais , Doença de Borna/sangue , Doença de Borna/tratamento farmacológico , Doença de Borna/fisiopatologia , Encéfalo/fisiopatologia , Humanos , Inflamação/patologia , Transtornos Mentais/sangue , Transtornos Mentais/fisiopatologia , Neurônios/metabolismo , Virulência , Cultura de VírusAssuntos
Patógenos Transmitidos pelo Sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/isolamento & purificação , RNA Viral/sangue , Reação Transfusional , Viremia/epidemiologia , Doadores de Sangue , Doença de Borna/sangue , Doença de Borna/transmissão , Doença de Borna/virologia , Vírus da Doença de Borna/genética , Transmissão de Doença Infecciosa , Feminino , Doenças Hematológicas/complicações , Doenças Hematológicas/terapia , Humanos , Imunocompetência , Hospedeiro Imunocomprometido , Masculino , Paris/epidemiologia , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/sangue , Complicações Infecciosas na Gravidez/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Risco , Fatores de Risco , Viremia/transmissão , Viremia/virologiaRESUMO
BACKGROUND AND OBJECTIVES: Borna disease virus (BDV) can infect a wide range of vertebrate species causing neurological disease. In order to ensure the safety of blood supplies, it is essential to monitor blood for emerging pathogens. MATERIALS AND METHODS: One-hundred individual white cell pellets and pools representing 25 000 plasma donations from human blood were screened for BDV by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: BDV RNA was not detected in any of the samples. CONCLUSIONS: The results indicate that BDV is not widely spread in the UK human population and does not represent a risk as a transfusion-transmitted agent.
Assuntos
Doadores de Sangue , Doença de Borna/epidemiologia , Vírus da Doença de Borna/isolamento & purificação , RNA Viral/sangue , Viremia/epidemiologia , Doença de Borna/sangue , Doença de Borna/virologia , Doenças Transmissíveis Emergentes/epidemiologia , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Risco , Escócia/epidemiologia , Reação Transfusional , Viremia/virologiaRESUMO
Borna disease virus (BDV) is a neurotropic RNA virus with a wide host range. Human infections, although controversial, have been described in Europe, Asia, and the United States. The present study investigated the existence of BDV infections in immunocompromised human beings, namely, 82 human immunodeficiency virus (HIV)-infected and 80 therapeutically immunosuppressed patients. BDV p40 RNAs were detected in peripheral white blood cells with reverse transcription-nested PCR and hybridization in, respectively, 11 (13.41%) and 1 (1.25%) of the two groups of patients. BDV p24 RNAs were identified in only one of those. BDV RNA was detected in the absence of any neuropsychiatrical illness, suggesting that BDV infections may occur in asymptomatic carriers. The severity and particularity of cellular immunosuppression could explain the significantly increased detection of BDV RNA in HIV-infected patients.
Assuntos
Doença de Borna/diagnóstico , Vírus da Doença de Borna/genética , Hospedeiro Imunocomprometido , Sequência de Bases , Doença de Borna/sangue , Doença de Borna/etiologia , Vírus da Doença de Borna/isolamento & purificação , Primers do DNA , França , Geografia , Infecções por HIV/virologia , Humanos , Dados de Sequência Molecular , Plasmídeos/genética , Reação em Cadeia da Polimerase/métodos , RNA Viral/genética , RNA Viral/isolamento & purificação , Alinhamento de Sequência , Homologia de Sequência do Ácido NucleicoRESUMO
BACKGROUND: The recent observation that Borna disease virus (BDV)-reactive antibodies from psychiatric patients exhibit only low avidity for BDV antigen called into question their diagnostic value and raised the possibility that antigenically related microorganisms or self antigens caused the production of these antibodies. We further characterized the specificity of these antibodies. METHODS: We established a peptide array-based screening test that allows the identification of antibodies directed against linear epitopes of the two major BDV proteins, the nucleoprotein (N) and the phosphoprotein (P). RESULTS: Initial tests employing sera of BDV-infected mice and rats or horses with Borna disease revealed a high specificity and sensitivity of this test. All sera recognized epitopes of N, P, or both. Sera of noninfected rats, mice, and horses showed no signals on either peptide array. Several human sera that recognized BDV antigen by indirect immunofluorescence contained antibodies that recognized various linear epitopes of one or even both BDV proteins. Remarkably, antibodies purified from such human serum by matrix-immobilized peptides showed high-avidity binding to BDV antigens when assayed by IFA or Western blotting. CONCLUSIONS: These data suggest that reactive antibodies found in psychiatric patients indeed indicate infection with BDV or a BDV-like agent. However, the poor affinity maturation of BDV-specific human antibodies remains unexplained.