The Bunyaviridae are a very large family of single-strand, enveloped RNA viruses that consist of more than 300 viruses that are commonly found and transmitted through rodents (rodent-borne viruses also called roboviruses) and arthropods such as mosquitoes, fleas, ticks, and sandflies (arthropod-borne viruses also called arboviruses). There are five general types of these viruses which include orthobunyavirus, phlebovirus, nairovirus, hantavirus, tospovirus. These viruses can infect humans causing mild to severe diseases. They can also infect plants and animals. Initially, the gut of the arthropod is infected and after a few days or weeks, the virus appears in the saliva. When these arthropods bite a human or other vertebrae host, this infective saliva enters the small capillaries or lymphatics. When the viruses infect humans and other vertebrates, they replicate in the cytoplasm by transcribing their RNA genome into the messenger RNA (mRNA) which is a single-stranded RNA that is complementary to one of the DNA strands of the genes and corresponds to the genetic sequence of that gene and is read by the ribosome in the process of producing proteins.
The distribution of the disease is determined through the host distribution wherein except for the hantavirus, the biologic transmission is possible through arthropods that are infected for life and in which transovarial transmission is common. To maintain the life cycle of the virus, vertebrates are needed with humans usually considered dead-end hosts except for phleboviruses. For the hantavirus, it can be transmitted through infected rodent urine and human infection is incidental.
