Yellow Fever

2 Pages 462 Words

Family : Faviviridae
Genus: Flavivirus
Size: 40-50nm in diameter
Shape: Spherical, nucleocapsid has icosahedral symmetry


* single stranded RNA
* nucleocapsid contains the RNA and a single core protein
* has an envelope (made of lipid bilayer)
* 66% protein, 12% carbohydrate, 17% lipid
* morphogenesis occurs at intracellular membranes, after replication the virions are
transported to the cell surface and are released via exocytosis
* viral infectivity is inactivated by heat (56 degrees for 30 minutes). Also by
ultraviolet radiation and lipid detergents
* small surface projections of envelope that make the envelope appear rough
* it is an arbovirus, which is an RNA containing virus that is transmitted from animals
to humans by insects
* hosts = humans, monkeys
* the virus replicates in a variety of cell cultures which include primary chick and duck
embryos; human cells; hamster, rabbit and monkey kidney cell lines
* the virus is studied by capturing mosquitoes; it is detected through
immunofluorescence

Vectors : Urban areas - Aedes aegypti (mosquitoes)
South America forests - Haemogogus (sylvan mosquitoes)
East Africa - Aedes africanus (monkeys)
- Aedes bromeliae (Ae. simpsoni) (monkey to human)
West Africa - Ae. furcifer-taylori, Ae. luteocephalus (monkey to human)

(from http://www.hc-sc.gc.ca/pphb-dgspsp/msds-ftss/msds167e.html)

The yellow fever virus has symptoms which consist of fever, aches, nausea,
vomiting (of blood), albuminuria (protein in the urine), anuria, prostration and
leukopenia (reduction in white blood cells). It is prevalent in areas of Africa and South
America. The incubation period lasts 3-6 days after a mosquito bite, after which the
individual will have headache, nausea, and aches. A brief remission may then occur...