Torovirus is a genus of enveloped, positive-strand RNA viruses in the order Nidovirales and family Tobaniviridae.

Equine torovirus (EToV) was accidentally found in the rectal sample from a horse who was experiencing severe diarrhea.

[5] Toroviruses (ToV) are single-stranded RNA viruses that have a peplomer-bearing envelope that is often correlated with the enteric infections in cattle and possibly humans.

These viruses appear to occur globally, occurrence of ToVs have been reported from countries in various continents like Europe, Americas, New Zealand and South Africa.

[6] Torovirus particles typically possess a helical and symmetrical nucleocapsid that is coiled into a hollow cylindrical shape.

[6] Torovirus share some common characteristics with members of the related family Coronaviridae as they are round, pleomorphic, enveloped viruses about 120 to 140 nm in diameter.

The total length is approximately 25-30kb and they possess a complex replication mechanisms that includes the use of subgenomic mRNA, ribosomal frameshifting, and polymerase stuttering.

[13] Cattle, pig, and horse serve as the natural host of Toroviruses and infection is thought to be via the faecal-oral route.

Many diagnostic techniques for torovirus infection in clinical specimens are now available such as hemagglutination (HA), enzyme-linked immunosorbent assay (ELISA), immune electron microscopy, hemagglutination-inhibition tests (HA/HI), and nucleic acid hybridization.

[citation needed] Diagnosis of the viral infection involves electron microscopy, ELISA or haemagglutination inhibition.

Besides other causes like diarrhea, pneumonia and respiratory problems, central nervous system related symptoms have also been reported in some incidental cases.

Many researchers also suggest that the disinfection and heat sterilization could easily destroy the virus but no scientific data or reports of such results are available so far.

Torovirus like particles (ToVL) was reported in scientific studies from USA, France, The Netherlands, Canada, Great Britain, India and Brazil.

Both the serotypes of the bovine Torovirus possess a hemagglutinin that reacts with red blood cells in the rodents usually.

Although, many recent studies revealed the presence of the torovirus in humans associated with many other enteric infections, diarrhea and conditions like gastroenteritis.

It is also said that the watery diarrhea could be due to lesions in the colon that lead to reduction of water absorption by the cells in the large intestine.

The pathogenicity of the torovirus presence has been widely studied and explored in the bovine species, especially calves in the initial stage of life around 4 to 6 months of age.

[27] Once the BoTV has been inoculated by an animal orally or nasally, it infects the epithelial cells of the villi and then extends to the components of the digestive system like the large intestine in the crypts of jejunum, ileum and colon.

However, there are researchers that also suggest that the viral replication could start in the immature epithelial cells of the crypts and can further spread to the villi.

In 1992, the International Committee on Taxonomy of Viruses ICTV got enough data to consider torovirus in the coronavirus family due to the similarities in structure, replication behavior and the genetic sequencing.

[citation needed] Toroviruses, Coronaviruses and arteriviruses are in the order Nidovirales, a group of non segmented, positive sense single stranded animal viruses.