HIV & AIDS part 1 Flashcards
The human immunodeficiency virus (HIV) was first
isolated in 1983 and was retrospectively identified as
the cause of
acquired immunodeficiency syndrome
HIV is a
non-transforming retrovirus (Retroviridae
family) of the lentivirus subfamily.
Two main subtypes, HIV-1 and HIV-2, based on
genetic and antigenic differences, and many strains of
each
HIV-1 being more common (overall) particularly in
—, while HIV-2 is more prevalent in — and associated with — disease course.
sub-Saharan Africa
Western Africa
slower
Since the onset of the worldwide pandemic, more than — people have
been infected with HIV, of whom approximately — have died because of
AIDS
70,000,000
35,000,000
An estimated — million people across the globe are newly infected with HIV
annually
2.7
By the end of 2019, approximately — million people were estimated to be living
with HIV
38
By the end of 2019, approximately 38 million people were estimated to be living
with HIV.
* Eastern and southern Africa ~—%
* Asia and the Pacific ~—%
* Western and central Africa ~—%
* Western and Central Europe and
North America ~–%
54
15
13
6
The vast majority of people infected with
HIV are in
low- and middle-income
countries.
Approximately — million people in the U.S. are living with HIV today
1.2
The Centers for Disease Control and Prevention (CDC) data indicate that the progress has stalled
in recent years, at about — new HIV infections each year between 2014 and 2018. HIV
incidence remained stable in 2018 at a rate of 13.3 (per 100,000 people)
38,000
By sex at birth, in 2018, the rate for males (22.1) was — times the rate for females (4.8)
5
By age group, in 2018, the number of new HIV diagnoses was highest among people aged —
25-44.
Initially in the United States, AIDS primarily affected
non-Hispanic whites and male
homosexuals.
- Today, — remains the
largest single risk factor with greater proportion
of cases arising in blacks/African Americans,
Hispanics/Latinos, females, and heterosexuals.
male-to-male sexual contact
- Although blacks/African Americans represented
only about 14% of the United States population,
they accounted for —% of new HIV infections.
(4) are the main fluids that have
been shown to be associated with transmission of the virus. HIV can also be
found in tears, saliva, cerebrospinal fluid, amniotic fluid, and urine
44
Blood, semen, breast milk, and vaginal secretions
- Region of residence:
South
Transmission of HIV is by exchange of infected bodily fluids predominantly
through
intimate sexual contact and by parenteral means. (Sharing needles and
blood transfusions, organ transplants etc.
HIV infection can occur through oropharyngeal, cervical, vaginal, and
gastrointestinal mucosal surfaces, even in the absence of
mucosal disruption
Infection is particularly aided by the presence of other sexually transmitted
diseases that can produce
mucosal ulceration and inflammation
The most common method of sexual transmission in the United States is anal
intercourse in men who have sex with men (MSM), in whom the risk of HIV
infection is — times higher than in other men and in women
40
Heterosexual transmission (male to female or female to male) is the second most
common form of transmission in the United States but accounts for —% of the
world’s HIV infections
80
Transmission from — is the third largest group affected in the
United States
sharing needles
The risk of transmission from a blood transfusion is estimated to be — because of current screening measures.
less than 1 in
1 million
Children (< 13 yr) usually through — exposure (mother to infant). Casual
contact has not been demonstrated as a means of transmission.
perinatal
Transmission by — fluids is somewhat controversial and rarely documented.
oral
- — contains a number of HIV inhibitory factors, which appear to reduce the
ability of the virus to infect its target cells.
Saliva
- The presence of (3) may predispose an individual to oral transmission.
erosions, ulcerations, and hemorrhagic inflammatory pathoses
(e.g., gingivitis, periodontitis)
Gag
processed to matrix and other core proteins that determine retroviral core
Pol
reverse transcriptase, RNase H and integrase functions
Env
envelope protein, resides in lipid layer; determine viral tropism
Other antigens:
two regulatory proteins:
and four accessory proteins:
(Tat and Rev) that are essential for viral replication
(Nef, Vif, Vpu, Vpr).
Pathophysiology – Cell Cycle
(3)
Entry Replication Release
HIV primarily infects cells with — at the site of HIV entry
CD4 cell-surface
receptor molecules (CD4+ T helper lymphocytes
mainly)
Infection is aided by — cells in mucosal
epithelial surfaces which can become infected
delivering HIV to underlying T cells, ultimately
resulting in dissemination to lymphoid organs.
Langerhans
The virus uses CD4+ cells to
gain entry by fusion
with a susceptible cell membrane or by
endocytosis (with the help of co-receptors
CXCR4 and CCR5)