Retroviruses Flashcards
Retroviruses contains which two viruses?
Oncoviruses and Lentiviruses
What are the characteristics of Retroviruses?
Enveloped, +ssRNA genome
Reverse transriptase to synthesize DNA from RNA
DNA integrates into host cell DNA
What are the two forms of Oncoviruses?
HTLV-1 and HLTV-II
What does HTLV stand for?
Human T-Lymphotropic virus
How is HTLV-I transmitted?
By sexual contact, contaminated blood, mother to child
What happens to someone infected with HTLV-I?
About 1 in 25 infected persons develop cancer as a result of infection
What are the 2 Lentiviruses?
1- SIV(Simian Immunodeficiency Virus)
2- HIV (Human Immune Deficiency Virus)
How many forms of SIV are there?
18 SIVs causing infection in 20 species
What did SIV give rise to?
HIV-1 and HIV-2
What are the 2 forms of SIV we need to know?
SIV cpz and SIV sm
Who has SIV cpz and is most closely related to what?
Chimpanzee strain of SIV and most closely related to HIV-1
How did HIV-1 arise?
Arose are SIV cpz was transmitted from chimps to humans
What is SIV sm from and what is it related to?
SIV from Sooty Mangabey and most closely related to HIV-2
How many types of HIV are there?
2
What are the general ways that HIV-1 and HIV-2 are distinguished?
genetically and antigenically
Which form of HIV is the cause of the current pandemic and which one is found in west Africa but rarely elsewhere?
HIV-1 is the cause of the current pandemic and HIV-2 is in West Africa
What are the 3 groups of HIV-1?
M, N, and O
How many subgroups are there is HIV-1 M?
11 subgroups in M group - A to K
The Major subtype in North America, Latin America and the Caribbean, Europe, Japan and Australia is?
Type B
HIV-1 M subtype B is transmitted most effectively how?
By homosexual intercourse and via blood
How is HIV-1 types C and E transmitted?
found in Africa and transmitted via a heterosexual route
Where do HIV-1 types C and E replicate better?
Cervix, vagina and penis
Where does HIV-1 type B replicate better?
in the rectal mucosa
When was HIV-2 discovered?
1986
What are the similarities and differences between HIV-1 and HIV-2?
HIV-2 is transmitted in the same way as HIV-1, causes AIDS much more slowly than HIV-1 but otherwise clinically the diseases are very similar
What was the origin of HIV/AIDS?
Evidence suggests that HIV-1 originated in West Africa as SIV cpz was transmitted from chimps to humans in food preparation
What type of monkey is HIV-1 from?
Pan troglodytes troglodytes
When was the earliest documented case of HIV?
It was identified in the republic of Congo in a sample of serum that was stored in 1959
What are the 3 alternative ideas for the beginning of aids?
1-Drs Peter Dueserg and Kary Mullis
2-Koch’s postulates
3-The River by Edward Hooper
What was the theory proposed by Drs Peter Duesberg and Kary Mullis?
That HIV is an unjustly maligned by-stander that is found in many immunocompromised states but is not the cause of disease
What are Koch’s postulates? 4
1) Virtually all AIDS patients are HIV-infected
2) HIV can be isolated from virtually all AIDS patients, as well as in almost all seropositive individuals with both early and late stage disease
3) Health care and laboratory workers accidentally infected with concentrates purified HIV have developed AIDS
4) HIV had been isolated from many of these individuals
What is the River by Edward Hooper?
HIV made the jump from simians to humans via the administration of oral polio vaccine in Africa in the 1950’s
