ARBOVIRUSES AND THEIR INFECTIONS

• Arthropod-Borne Viruses, the term indicates route of transmission >500 different viruses classified in different families. Approximately 150 of them produce disease in humans.

• The word “Arbovirus” indicates the transmission route of these viruses, but their structures (morphologies, nucleic acid types, antigenic structures and biochemical characteristics) are different and they are classified in different taxonomic groups.

• Cause essentially zoonotic infections of wild animals and are spread by insects

• All are RNA viruses, most are enveloped and contain hemagglutinin antigens.

• They are generally named after the clinical disease (Yellow fever=severe jaundice with high fever) or the place where they first discovered (Rift Valley, West Nile, California encephalitis, ..)

• The human stage of the virus may be essential (Yellow fever, Dengue), or accidental (equine encephalitis)

• They multiply in a vector (i.e. mosquitoes, ticks, sandflies) and these insects transmit the virus during blood sucking.

• Their vertebrate hosts (reservoirs) may be horses, wild birds, rodents, wild animals or human.

Category: Microbiology Notes