Most flaviviruses are arthropod-borne viruses which cause mild
rash and fever or life-threatening hemorrhagic fever and encephalitis in
infected individuals. These arboviruses, including dengue, yellow fever,
Japanese encephalitis, and tick-borne encephalitis, constitute a major
threat to the developing world where ticks and mosquitoes are endemic.
Arthropod control and vaccination are essential components of newly
developed eradication campaigns.
Another member of the flavivirus family
is Hepatitis C virus (HCV). Hepatitis C is a non-arthropod-borne virus
placed in this family due to its physical structure, properties and
replication strategy. Hepatitis C was discovered in 1989 after a number of
posttransfusion non-A, non-B hepatitis cases were investigated. Hepatitis
C is as common in developed nations as Hepatitis A or B. Although 75% of
infections are subclinical, chronic disease progresses to cirhosis in 20%
of cases. HCV infection may induce the development of
hepatocellular carcinoma in rare cases. Most infected individuals contract
the disease from unscreened
blood transfusions, IV drug use or sexual promiscuity.
Hepatitis G virus is also a transfusion associated flavivirus. It was
first reported in 1996 and currently very little is known about the virus.