Unit 4: Virology
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Lecture 19 – Arbovirus
Arbovirus = arthropode borne virus
Transmitted by arthropode (mosquitoes and ticks
It is named either according to the disease cause or due to
place where discovered
Robovirus = rodent born virus e.g : sin nombre virus
(hantavirus) and white water arroyo virus ( an arenavirus).
Togavirus: icosahedral, enveloped, ss, positive polarity
RNA genome
Flavivirus same as above
Bunyavirus: helical nc with an envelope, and segmented
genome (three segment), and negative polarity RNA.
During the life cycle, the virus should be in high level of
viremia in man to be transmitted to the arthropode.
The man is considerd as an dead end host.
The clinical picture usually fits one of the three
caegories:
1- encephalitis
2- haemorrhagic fever.
3- Fever with arthralgia, myalgia and nonhaemorrhagic
rash.
St.louis encephalitis virus
California encephalitis virus
Colorado tick fever virus
West nile virus
Yellow fever
Dengue fever