Circovirus: “It was completely unexpected”

A research team discovers a previously unknown virus while investigating the cause of a patient’s hepatitis. Many questions remain open.

PARIS – A research group at France’s Pasteur Institute has discovered a new virus that apparently can make people sick. The previously unknown circovirus, provisionally named human circovirus 1 (HCirV-1), was found in a patient with liver disease. “The patient had unexplained chronic hepatitis with few symptoms,” explains Mark Elliott, co-author of the study. in the journal Emerging infectious diseases published had become.

The 61-year-old patient had a heart-lung transplant 17 years ago and has been observed regularly since then. “We had access to a large number of samples from different years, and thus were able to identify this new virus,” Eloit reported in one. communication. “It was completely unexpected.”

The research team discovered a previously unknown virus – that infects liver cells

The research team analyzed tissue samples from 61 years old for microbial sequences and compared them to sequences of known microbes. Eloit explains.

Thousands of RNA sequences were analyzed in parallel using algorithms until the research team identified a previously unknown circovirus. No other viral or bacterial sequences were found.

The research team found that the newly discovered virus infects human liver cells, multiplies inside them and thus damages them – and this is the reason for the patient’s symptoms of hepatitis.

Finding the causes of hepatitis is not always easy

Finding the cause of hepatitis of unknown origin remains a challenge even today, as evidenced by cases of hepatitis in children in the UK and other countries around the world over the past year. “We need to know what is causing the hepatitis and, more importantly, whether or not it is viral in order to provide appropriate treatment,” explains Anne Gamet, a co-author of the study.

Circoviruses are no stranger – they were first discovered in various animal species in 1974. In animals, highly flexible DNA viruses can cause respiratory, kidney, skin and reproductive problems. According to the research group, the patient’s symptoms remained mild, and the virus could only be identified because she was closely monitored after a two-organ transplant.

It is still not clear if the newly discovered virus is circulating between humans or comes from animals, and the source of infection is also unknown. The research group has developed a PCR test that can be used to check for cases of hepatitis with an unknown trigger. (unpaid bill)