Blood is commonly known as the ‘living liquid’ or ‘life-giving liquid’. Blood transfusion is usually provided to patients with life threatening blood loss, with severe anaemia and during major surgeries. Despite their critical usage in medicine, blood transfusions have become risky because of transmission of viruses like human immunodeficiency virus (HIV), hepatitis B and herpes simplex through blood. In clinical practice, the blood samples are screened for viruses using biochemical or molecular biological methods. In addition to already known infectious viral agents, recent researches have identified another virus called Borna disease virus (BDV) that threatens humans with neuropsychiatric illnesses.
BDV is a neurotrophic virus, originally described as an infectious agent causing fatal meningo-encephalitis (immune-mediated behavioural syndrome) in horses. It is said to be the only non-segmented, negative-sense RNA virus replicated in the nucleus and classified as a new family Bornaviridae under Mononegavirales Reference Briese, Schneemann and Lewis(1). The BDV genome is reported to be transcribed and expressed in psychiatric patients Reference Bode, Zimmermann, Ferszt, Steinbach and Ludwig(2). Still it is questionable whether BDV causes neuropsychiatric illness in human beings. When tested in animal models, this virus induces neuropsychiatric illness. BDV or viral particles have been detected in some patients with schizophrenia, bipolar mood disorder, obsessive-compulsive disorder and major depressive disorder Reference Bode and Ludwig(3). It is more striking that the first BDV was isolated from a patient with depression Reference Bode, Durrwald, Rantam, Ferszt and Ludwig(4). Till date six BDV isolates have been isolated, in-fact all were isolated from patients with neuropsychiatric illness Reference Bode and Ludwig(3).
Bode and colleagues Reference Bode and Ludwig(3) reported that 20–30% of the healthy blood donors seem to be positive for BDV infection. It can be hypothesized that the healthy donors positive for BDV infection are carriers, either because the donors have not developed any psychiatric illness or they were not examined for neuropsychiatric illness, at the time of blood donation. If the healthy blood donors have BDV infection or as BDV carriers, there might be a possibility of transferring the virus or viral particles into recipients who are transfused with this blood.
BDV have been shown to induce neuropsychiatric illness in animal models or infected animals. In human beings, we are not able to state yet that BDV is involved in neuropsychiatric illness. In the Department of Psychiatry and Psychotherapy, Hannover Medical School, Germany, patients with psychiatric illness with BDV infection were reported to have got relief with Amantadine. The viral antigen seems to be reduced during treatment with Amantadine in neuropsychiatric illness. This has also been reported in research reports Reference Bode, Dietrich, Stoyloff, Emrich and Ludwig(5,Reference Dietrich, Bode and Spannhuth6). Treatment with Amantadine in obsessive-compulsive patients shows that there were variations in brain potential amplitudes with respect to BDV specific immune complexes Reference Dietrich, Zhang and Bode(7). Thus the possibility of BDV-inducing neuropsychiatric illness cannot be rejected.
Given the possibility that BDV can cause neuropsychiatric illness, it can involve a potential risk in transfusion medicine. Therefore, it should be considered necessary to test for BDV infection during blood transfusion. Former World Health Organization (WHO) Director-General Dr GH Brundtland said that in next 20 years depression will be the second cause of global disease burden. If BDV infection is also a causative agent in neuropsychiatric illness, then this will be realized within a shorter time span. So in order to prevent potential risk of BDV infection through transfusion medicine, precautionary measures should be taken to diagnose and prevent BDV infection during blood transfusion.
