Reovirus's genome is a fragmented double-stranded RNA which is coated with multiple layers of capsids, but the uniqueness of these viruses is that they lack lipid envelopes, and scientists have thus been able to obtain the three-dimensional structure of such viruses. The huge family of Reoviridae contains 30 genera which could be further divided into 87 species. They have a wide range of hosts, including vertebrates, invertebrates, protozoa, plants, and even fungi. Reovirus is able to infect the respiratory tract and gastrointestinal system.