Rotavirus is a major cause of acute gastroenteritis (diarrhea) in human infants (6 months to 2 years). Adults may also be infected. Transmission occurs by the fecal-oral route, survives an acidic environment in the stomach and initiates infection in mucosal cells of the small intestine

Family Reoviridae contains 9 genera- 4 of which cause human infections- Orthoreovirus- reovirus, Orbivirus, Rotavirus, and Colitivirus. It has icosahedral symmetry; non-enveloped, the double-shelled capsid surrounds a core.

Rhabdovirus contains 6 generas among which Lyssaviruses and Vesiculoviruses are medically recognized. Lyssaviruses Rabies virus (RABV), Australian bat virus (ABV), Duvenhage virus (DUV), European bat virus type 1 (EBV-1), EBV-2, Lagos bat virus (LBV).

Orbiviruses are primarily animal pathogens that cause disease mainly in animals and are transmitted by ticks, mosquitoes, and sand flies. manifestation includes fever, nausea, abdominal pain, headache, myalgia.

Astroviruses are a common cause of diarrhoeal disease transmitted worldwide by fecal-oral route and fomites. In very young and elderly are most at risk and may require rehydration while prolonged excretion occurs in an immunocompromised host

Calicivirus is a common cause of diarrhoeal disease that occurs worldwide and is transmitted by the fecal-oral route and fomites.

Coltivirus is transmitted via tick bite. It causes diseases such as Colorado tick fever, Salman river virus, Beijing virus, Gansu virus, Eyach virus. It belongs to the family Reoviridae.

Filovirus belongs to Family Filoviridae and has two members- Marbury virus (MARV), Ebola virus (EBOV). It causes causes severe hemorrhagic fever in human and non-human primates with case fatality of about 90%.

The family Arenaviridae contains 23 viral species, some of which cause human disease. They are categorized into two complexes- based on Antigenic properties and genetic analysis.

Hepatitis viruses commonly infect the liver but differ in their morphology, replication pattern, and course of infection.