Lyon IARC polyomavirus (LIPyV) is a circular double‑stranded DNA virus first reported in 2017 in skin swabs from human volunteers. Its genome of about 5.3 kilobases shares roughly 65 % nucleotide identity with raccoon polyomavirus and encodes the conserved polyomavirus proteins. Detection in humans has been rare and the virus is more frequently found in diarrheic cats.
Explanation
LIPyV was identified during a survey of polyomaviruses in human skin samples and was named for the International Agency for Research on Cancer in Lyon, where part of the analysis was performed. Genetic analysis revealed that the circular genome measures approximately 5 263 nucleotides and consists of an early region encoding the small and large T antigens and a late region encoding the structural proteins VP1, VP2 and VP3. Comparative studies show that the VP1, VP2 and VP3 proteins of LIPyV isolates share over 95 % sequence identity, indicating low variation among strains. The virus is phylogenetically related to raccoon polyomavirus, with about 65 % nucleotide similarity. Screening studies in Europe and North America found LIPyV DNA in only a handful of samples: a single benign skin tumour from a liver transplant recipient, nine of 445 skin swabs (2.0 %), one eyebrow hair sample (0.2 %) and three of 140 gargle samples. It was not detected in 689 tonsil samples or 156 healthy adults, and serologic surveys have failed to demonstrate widespread exposure. In contrast, LIPyV DNA has been recovered from the feces of diarrheic cats. A study in China found two LIPyV‑positive cat fecal samples and sequenced a genome designated LIPyV‑GXNN01, which displayed the expected gene organisation and high similarity to other LIPyV strains. These findings suggest that LIPyV infection may be uncommon in humans and possibly reflect cross‑species transmission from feline hosts.
Key points and observations
– LIPyV was discovered in 2017 in human skin swabs and exhibits about 65 % nucleotide identity to raccoon polyomavirus. – Its ~5.3 kb genome encodes the small and large T antigens and the VP1, VP2 and VP3 structural proteins, with high identity across strains. – Screening studies detected LIPyV DNA in a small number of human samples but not in large tonsil or serologic surveys. – LIPyV has been identified in the feces of diarrheic cats, raising the possibility that it primarily infects feline hosts. LIPyV is a recently discovered polyomavirus with a typical genome organisation but extremely low detection in humans. Its presence in feline samples and the scarcity of human cases suggest that it may be an incidental zoonotic exposure rather than a human‑tropic virus. Further research is needed to determine its natural host range and any potential clinical relevance. Related Terms: New Jersey Polyomavirus (NJPyV), Raccoon Polyomavirus, STL Polyomavirus (STLPyV), Malawi Polyomavirus (MWPyV), Human Polyomavirus 12 (HPyV12)