Foamy Viruses Affecting Animals and Humans and their Public Health Concerns: A Review

摘要

Foamy viruses (FVs) are complex retroviruses under the genus Spumavirus of family Retroviridae. They cause induction of multinucleated giant cell formation which presents numerous vacuoles, giving the monolayer culture a foamy appearance. FVs can infect animals as well as humans. In case of the Human foamy virus (HFV), a defective variant (named ΔHFV or HFVΔTas) negatively interferes with replication of parental counterpart. Some species, such as rhesus macaques, African green monkeys, chimpanzees and cats harbor closely related yet serologically distinct FV subtypes. Unanticipated FV pathogenicity may warrant appropriate attention to biosafety practices to prevent occupational infections and the importance of additional studies to better define clinical outcome of these zoonotic infections. During cross-species infection and subsequent passages a rapid and fatal disease can occur, with changes from nonpathogenic to pathogenic potentials. In persons occupationally exposed to non-human primates, Simian foamy virus (SFV) infection occurs persistently showing that simian retroviruses cross into humans more frequently. Simian Immunodeficiency Viruses (SIV), mostly are nonpathogenic in their natural hosts but during cross-species infection a rapid and fatal disease can occur. Enzyme Immuno Assay (EIA), Western blot analysis and Polymerase Chain Reaction (PCR) amplification are the important diagnostic tests for FVs. FVs are also being exploited as potential vectors that can be used for gene therapy which is gaining much attention of the researchers worldwide. Strengthening sero-epidemiological as well as molecular investigations and public health surveillance programme along with extra precautions while transferring xenograft are some of the approaches to prevent these viral infections.