NEW LIVER CIRCOVIRUS. Scientists have found a human circovirus in a 61-year-old French woman, a virus that normally only affects pigs and birds. Named HCirV-1, this new virus would be responsible for liver damage and hepatitis.
[Mis à jour le 3 février 2023 à 10h38] It is a discovery in the scientific field. One new virustemporarily named Human Circovirus 1 or HCirV-1been identified by doctors and scientists of the’Pastor Instituteaccording to a statement posted on their site on January 25, 2023. This unknown species of circovirus (which normally only attacks animals (pigs and birds)) would be able to cause significant liver damage in humans. A study published in the scientific journal Emerging Infectious Diseaseson January 3, 2023, reports that he would have been responsible for hepatitis in a 61-year-old French patient, doubly transplanted and under immunosuppressive treatment. What do we know about this new virus? Should we fear it in France? How does it attack the liver? Is there a vaccine to protect against it? Knowledge to date.
Presentation: what is the Human Circovirus 1 virus?
Temporarily baptized Human Circovirus 1 ou HCirV-1 by the scientists who discovered it (researchers from the Institut Pasteur, with scientists from the Necker Hospital, Inserm within the Imagine Institute, Paris Cité University and the National Veterinary School of ‘Alfort), this new virus is part of the family of circoviruses, a set of “very resistant small DNA viruses, initially identified in 1974 in different animal species, can we read in the press release from the Institut Pasteur.
► In animals (pigs and birds), circoviruses may be responsible for respiratory, renal, dermatological and reproductive problems.
► In manthis new type of circovirus could cause significant liver damage and it This would be the first circovirus linked to hepatitis in humans.
The effects of this new virus on the liver have been demonstrated through the analysis of pathological tissue samples froma 61-year-old patient with unexplained chronic hepatitis, who had received a heart and lung transplant 17 years earlier. These samples were subjected tosequencing of thousands of RNAs (ribonucleic acids, molecules responsible for transmitting the information encoded in our genome), which have been analyzed and compared to those of already known microbes. After ruling out common common etiologies, the analysis identified this unknown species of circovirus and its involvement in the patient’s hepatitis (2-3% of his liver cells were infected), causing hepatic cytolysis, in other words, the destruction of liver cells. “Effectively, once this virus has used the resources of the liver cell to multiply, it destroys it“, report scientists from the Institut Pasteur. During the analyses, no other viral or bacterial sequences were found. This clearly shows that HCirV-1 is the cause of the patient’s chronic hepatitis. The origin of the virus, as well as the source of the infection itself (contact, food…) remain however to identify.
What symptoms does HCirV-1 cause?
As previously described, Human Circovirus 1 could cause hepatitis in humans, responsible for liver damage and of liver cell death. Hepatitis is an often asymptomatic disease or giving mild and non-specific symptoms such as:
- Tiredness
- Loss of appetite (and therefore weight loss)
- Sometimes a slight fever
- A feeling of unease
- Rarely, fluid in the abdomen (ascites)
- When it is at a very advanced stage: liver failure, jaundice…
For information, the 61-year-old patient was asymptomatic with the exception of weight loss but without severity.
How is a Human Circovirus infection diagnosed?
The diagnosis of unexplained hepatitis remains a major challenge, insist the scientists of the Institut Pasteur. “To adapt the treatment and follow-up of patients, it is essential for us to know the cause of hepatitis, and in particular to know if it is viral“, emphasizes Anne Jamet, from the clinical microbiology department of the Necker-Enfants Malades Hospital AP-HP, affiliated with Inserm, and co-author of the study. Thus, thanks to this discovery, the scientists were able to put on point a specific PCR test now available for the etiological diagnosis of hepatitis of unknown origin. This test, available from the medical community, is now readily available for other cases of unexplained hepatitis (remember the cases of acute hepatitis reported in children in the UK and Ireland in April 2022 and reported by WHO). A serological test is also in development.
Is there a treatment for Human Circovirus?
L’administration d’antiviral treatment is possible to stop hepatic cytolysis (destruction of liver cells), reports the Institut Pasteur.
Is there a vaccine against Human Circovirus?
Certain circoviruses, pathogenic for animals, can be vaccinated, especially in pigs. On the other hand, HCirV-1 being the first pathogenic circovirus for humans, there is no vaccine yet to protect against it.
Should we be worried in France?
So far, human circovirus 1 has only been found in a single patient in France. It is therefore, to date, an isolated case. The authorities therefore do not seem to be ringing the alarm bell, which could nevertheless be the case, if other cases of hepatitis linked to this virus are observed.
Sources :
– Discovery of a circovirus involved in human hepatitis, Institut Pasteur, press release of January 25, 2023
– Circovirus Hepatitis Infection in Heart-Lung Transplant Patient, France, EID Journal, Volume 29, Number 2—February 2023
