London: Scientists led by Oxford researchers have identified a mysterious new virus in patients with severe brain infections in Vietnam.
Further research is needed to determine whether the virus is responsible for the symptoms of disease, researchers said.
The virus was found in 28 out of 644 patients with severe brain infections in the study, but not in any of the 122 patients with non-infectious brain disorders that were tested.
Scientists identified the virus, tentatively named CyCV-VN, in the fluid around the brain of two patients with brain infections of unknown cause.
The virus was subsequently detected in an additional 26 out of 642 patients with brain infections of known and unknown causes.
Using next-generation DNA sequencing techniques, the team sequenced the entire genetic material of the virus, confirming that it represents a new species that has not been isolated before.
They found that it belongs to a family of viruses called the Circoviridae, which have previously only been associated with disease in animals, including birds and pigs.
"We don`t yet know whether this virus is responsible for causing the serious brain infections we see in these patients, but finding an infectious agent like this in a normally sterile environment like the fluid around the brain is extremely important," Dr Rogier van Doorn, Head of Emerging Infections at the Wellcome Trust Vietnam Research Programme and Oxford University Clinical Research Unit Hospital for Tropical Diseases in Vietnam, said.
"We need to understand the potential threat of this virus to human and animal health," van Doorn said.
The researchers were not able to detect CyCV-VN in blood samples from the patients but it was present in eight out of 188 faecal samples from healthy children.
The virus was also detected in more than half of fecal samples from chickens and pigs taken from the local area of one of the patients from whom the virus was initially isolated, which may suggest an animal source of infection.
"The evidence so far seems to suggest that CyCV-VN may have crossed into humans from animals, another example of a potential zoonotic infection," Dr Le Van Tan of the Oxford University Clinical Research Unit in Vietnam said.