The first circovirus with the potential to infect humans was discovered in a woman.

In March 2022, a 61-year-old woman who had received a heart-lung transplant 17 years earlier sought treatment in France. chronic hepatitis He was suffering from it and which was mainly characterized by a significant increase in liver enzymes.

After ruling out common etiologies such as hepatitis viruses, including hepatitis E virus, a large group of health workers and researchers from different French institutions used mNGS (metagenomic next generation sequencing) high-throughput sequencing technologies to analyze liver biopsy samples from patient Used. ,

The results are published in the first days of February 2023 and announce that, An unknown species of circovirus, tentatively named human circovirus 1, has been identified in a liver sample (HCIRV-1).

circoviruses are small viruses The family Circoviridae whose circular single-stranded DNA genomes are among the smallest known. this group of viruses associated with a broad spectrum of diseases ranging from asymptomatic to fatal Among various birds, pigs, moose, cows, dogs, pandas, bears, bobcats, pumas, foxes, minks, civets, sea lions, many rodents, as well as reptiles and fish. Circoviruses have also been described in several species of bats. Even then, This is the first time that a circovirus with the potential to infect humans has been detected., In general, circoviruses appear to be species-specific. For example, within birds there are different circoviruses that infect ostriches, finches, canaries, turtle doves or ducks.

Most infections in both wild and domestic species are subclinical and cause few or no symptoms. However, there are exceptions because Circoviruses are important pathogens of pigs, In fact, porcine cercovirosis is a disease that is widespread worldwide affecting infected and/or fattened pigs. Porcine circovirus type 2 is the main causative agent of porcine circovirus disease, a complex multisystem syndrome of domestic pigs that causes a variety of gastrointestinal, neurological, dermatological and respiratory symptoms in animals, most pronounced in young pigs. This disease spoils the animals from weaning to adulthood. The mortality rate in pigs reaches 10%, the morbidity rate reaches 30% and the mortality rate can exceed 40% in severely affected pig farms.

Unfortunately, porcine circovirus type 2 is highly resistant and has a near-ubiquitous distribution, and antibodies to the pathogen have been found in pigs in all countries where it has been tested. InterestingAn association of porcine circovirus type 2 with cases of jaundice in pigs and hepatitis in horses has been demonstrated. Jaundice is often a sign of liver problems.,

In the case of human circovirus 1 (HCirV-1), Its involvement in the development of hepatitis has been demonstrated in a French patient and it has also been shown that the virus is able to multiply in liver cells and destroy them, which supports a role for HCirV-1 in causing liver damage in humans.

Based on phylogenetic analyses, the researchers speculate that HCirV-1 may have a possible animal origin, and that The patient could have contracted it through ingestion of contaminated food or waterHow is the hepatitis E virus transmitted? Whether the virus can transmit from person to person remains to be investigated.

Taking into account the data obtained, it seems reasonable Testing for the presence of human circovirus 1 (HCIRV-1) in cases of hepatitis of unknown origin, Unfortunately, the diagnosis of hepatitis of unknown origin remains a global challenge. It is clear that the identification of a new pathogenic virus in humans and the development of a screening test for it increase the likelihood of diagnosis in patients suffering from hepatitis of unknown etiology.