HIV Flashcards by Iseoluwa Ojo

Prevalence rate of HIV in adults aged 15-49?

1.3[ 0.9-1.7]

How well did you know this?

Not at all

Perfectly

Virology

Genus: _______

Genome:

_____-stranded RNA
(linear or circular?)
_______ -sense, 9–10 kb, ___ploid; genome

four genes required for a replicating retrovirus— _____,_____,____ and _____

Lentivirus

Single; linear
Positive ; di

gag, pro, pol, and env

How well did you know this?

Not at all

Perfectly

Virology

Proteins: ________________ undergoes antigenic variation; reverse transcriptase enzyme contained inside virions; ______ required for production of infectious virus

Envelope:(present or absent?)

Envelope glycoprotein

protease

Present

How well did you know this?

Not at all

Perfectly

Virology

Replication:_________ makes DNA copy from genomic RNA; _______ is template for viral RNA.

Genetic variability is (common or rare?) .

Reverse transcriptase

provirus DNA

Common

How well did you know this?

Not at all

Perfectly

Virology

Maturation: Particles _______ from ______

bud

plasma membrane

How well did you know this?

Not at all

Perfectly

Virology

Outstanding features:

Infect cells of the _____ system

______ remain permanently associated with cells

_______________ is restricted in some cells in vivo

It Cause (slowly or rapidly ?) progressive, (acute or chronic ?) diseases

Replication is usually _____-specific

immune

Proviruses

Viral expression

Slowly ; chronic

species

How well did you know this?

Not at all

Perfectly

Lentivirus

Viruses are transmitted by _______

Virus persists _______ in infected hosts, although it may be present at very ____ levels.

exchange of body fluids.

indefinitely; low

How well did you know this?

Not at all

Perfectly

Lentivirus

Viruses have (low or high?) mutation rates, and __________ will be selected under different conditions (host factors, immune responses, tissue types).

Infected hosts contain “ ______ ” of ______ related viral genomes, known as _______.

High

different mutants

swarms; closely

quasispecies

How well did you know this?

Not at all

Perfectly

Lentivirus

Cells in the macrophage lineage play ______ roles

It may take ______ for disease to develop.

Infected hosts and usually make _____, but they do not ___________

central; years

antibodies

clear the infection, so virus persists lifelong.

How well did you know this?

Not at all

Perfectly

Modes of HIV Transmission

Mention 4

Sexual Contact

Parenteral
Blood transfusion
Perinatal

How well did you know this?

Not at all

Perfectly

Modes of HIV Transmission

Sexual Contact: _________ with infected partner(s)

Parenteral: Contact with HIV-infected _________

Unprotected sexual contact

blood products

How well did you know this?

Not at all

Perfectly

Modes of HIV Transmission

•Blood transfusion; __________ through needle sharing; needle-stick accidents; unsterilized sharp objects

Perinatal:_________ transmission
In utero; during ______ and ____; through ________

Mother-to-child

labour and delivery

breastfeeding

How well did you know this?

Not at all

Perfectly

Transmission through Sexual Contact

• ___________ and ———— transmission of HIV most common
• (Receptive or insertive?) sexual partner at higher risk than ( Receptive or insertive?) partner

Heterosexual and male-to-male

Receptive

insertive

How well did you know this?

Not at all

Perfectly

HIV CAN be transmitted by casual contact, surface contact, or insect bites

T/F

HIV CANNOT be transmitted by casual contact, surface contact, or insect bites

How well did you know this?

Not at all

Perfectly

Molecular Epidemiology of HIV

HIV virus has two types: _____ and ______

Type 1 (HIV-1) and Type 2 (HIV-2)

How well did you know this?

Not at all

Perfectly

Molecular Epidemiology of HIV
•

HIV-1 has a _______ distribution

HIV-2 is ____________

global

limited to West Africa

How well did you know this?

Not at all

Perfectly

Molecular Epidemiology of HIV

HIV-___ is still the predominant type in West Africa

HIV-____ has been further divided into groups and subtypes

How well did you know this?

Not at all

Perfectly

Primary subtypes of HIV-1

in Nigeria are _____________

A, G, and A/G

How well did you know this?

Not at all

Perfectly

Virus receptors

Primary receptor is the _____ molecule, which is expressed on ________ and _____

A ________ in addition to ____ is necessary for HIV-1 to gain entry to cells.

CD4

macrophages and T lymphocytes.

second coreceptor

CD4

How well did you know this?

Not at all

Perfectly

Virus receptors

The virus first binds to _____ and then to the ______.

_______ receptors serve as HIV-1 second receptors.

CD4

coreceptor

Chemokine

Chemokines are (soluble or insoluble ?) factors with ___________________ properties.

Soluble

chemoattractant and cytokine

Virus receptors

_____ is the predominant coreceptor for macrophage-tropic strains ofHIV-1

_____ ,the coreceptor for lymphocyte-tropic strains of HIV-1.

CCR5

CXCR4

Virus receptors

Individuals who possess _____zygous _____ in CCR5 and produce mutant forms of the protein may be protected from infection by HIV-1

Mutations in the CCR5 _______ appear to _____________ .

homo; deletions

gene promoter

delay disease progression

Major Steps in HIV Lifecycle

•HIV attaches to ____ cell
•Releases ___ and enzymes
•Enzyme _______ makes a ____ copy of viral ____

And this is integrated into CD4 cell ____ using enzyme ____

New viral components produced, using cell’s “machinery” . These are assembled together using enzyme ______ and are released as new viruses

CD4; RNA

Reverse Transcriptase ; DNA

RNA; nucleus; integrase

protease

Overview of HIV The duration between primary infection and progression to clinical disease averages about ____ years. In untreated cases, death usually occurs within ___ years after the onset of clinical symptoms.

10 2

Overview of HIV Stages include the ______________, dissemination of virus to ______ clinical _______ _______ HIV expression clinical _________ _______

Primary infection lymphoid organs latency; elevated disease Death

Overview of HIV Following primary infection, there is a ________ period between _____ and ________ the viremia is detectable for about _______. Virus is widely disseminated throughout the body during this time, and the ________ become seeded. ____________ syndrome develops in many patients (50–75%) ____ weeks after primary infection. There is a significant (drop or rise?) in numbers of circulating _____ cells at this early time. An immune response to HIV occurs ____-_____ after infection, plasma viremia (drops or rises?) , and levels of CD4 cells rebound. However, the immune response is _____________________________________________________

4- to 11-day mucosal infection and initial viremia 8–12 weeks.; lymphoid organs An acute mononucleosis- like 3–6 ; drop; CD4 T 1 week to 3 months ; drops unable to clear the infection completely, and HIV-infected cells persist in the lymph nodes.

Natural History of HIV Infection in Adults HIV-1 infection has the following phases: Viral _______ _________ infection ____________ Clinical __________ (Early or late?) symptomatic HIV infection _____ and severe HIV infection

transmission Primary HIV; Sero-conversion latent period; early AIDS

AIDS and severe HIV infection Characterized by Clinical Stage ____ or a CD4 cell count below ____/mm3

4 200

Primary Infection During this phase, a person may experience (specific or non-specific?) ‘___-like’ symptoms. These symptoms do not lead directly to the diagnosis of HIV infection and may not be present in all patients, but commonly include: Fever Fatigue __________ _________ ___________

flu Non-specific Pharyngitis Lymphadenopathy Rash

Primary Infection (2) • Pathogenesis of Primary Infection: Initial infection of _________ and _______ with receptors at site of exposure Dissemination of infection to _______ Burst of viral replication results in __________ Development of ______ immunity (HIV-specific ______) Response by ______ immunity (HIV-specific ___________ cells)

CD4 T-lymphocytes and macrophages lymph nodes; intense viraemia humoral; antibodies cellular CD4 and CD8

Symptomatic Phase (1) Presentation depends on CD4 count At CD4 cell counts over _____ cells/μl, PLHIV may develop complications found in the general population: _________ Bacterial _______ ___________ Minor __________

500 Malaria pneumonia Tuberculosis skin conditions

Symptomatic Phase (1) Presentation depends on CD4 count At CD4 counts between _____ and ______ cells/μl, other conditions, or opportunistic infections, begin to appear: • Pulmonary ________________ • ____________ candidiasis •____________

200 and 500 Tuberculosis (current) Oral or vaginal

Symptomatic Phase (1) Presentation depends on CD4 count The late symptomatic phase is characterized by patients having a CD4 cell count less than ______ cells/μl and conditions such as: ______ syndrome ________ candidiasis ____________-pulmonary TB ___________ pneumonia Recurrent, invasive herpes simplex virus infections

200 Wasting Esophageal Atypical and extra Pneumocystis

Severe HIV Infection and AIDS This phase is characterized by patients having a CD4 cell count less than __ cells/μl and conditions such as: ________ meningitis _________________ _____________ of the brain HIV _________ (PML/dementia) CMV retinitis

50 Cryptococcal Cryptosporidiosis Toxoplasmosis encephalopathy

CD4 Count is an indicator of _________ status (distance to the cliff) Viral Load is an indicator of the ___________ (speed of the train)

immune system amount of virus in the blood

HIV associated Cancers List 2

Kaposi carcinoma Cervical cancer

Key Points (1) The HIV lifecycle involves the following steps: Virus _______ and ______ Transcription of ________ into _______ _________ into human genome New viral components ______ using ______ enzyme. ________ and _________ of virus particles

entry into cell and fusion viral RNA into DNA Integration; assembled; protease Assembly and budding off

Viral replication persists throughout infection T/F

HIV manifests the same way in adults and children T/F

F HIV manifests differently in adults and children

HIV disease progression is determined by ________ and _______

CD4 count and viral load

ARV = _________ ART =________ HAART = _______________

Antiretroviral Antiretroviral Therapy Highly Active Antiretroviral Therapy

Antiretroviral Drugs Antiretroviral drugs act on different points in the life cycle of the virus to prevent _________

viral replication

Goals of ART Virological: ____________ to ___________ (<_______ HIV RNA copies/mL for as long as possible). Immunologic: Quantitative and qualitative _______ with improved immune function Clinical: Prolongation and improved quality of life by reducing ___________ and ____________

Reduction in viral load to undetectable levels; 400 immune reconstitution HIV- associated morbidity and mortality

Goals of ART Therapeutic: Appropriate choice of _________ to achieve the goals of therapy while preserving __________, minimising ______________ and promoting excellent ___________ Epidemiologic: ______________________

ARV regimen future therapeutic options ARV toxicities; adherence Reduce transmission of HIV

Classes of Antiretroviral Drugs _________________________________ (NRTI) _____________________________(NNRTI). ____________________ (PIs) ________________ _______ inhibitors (or ______ inhibitors) _________ inhibitors

Nucleoside and nucleotide reverse transcriptase inhibitors Non-nucleoside reverse transcriptase inhibitors Protease inhibitors Integrase inhibitors Entry ; fusion Maturation

Antiretroviral drugs are broadly classified by the ___________________________________

phase of retrovirus lifecycle that the drug inhibits

Laboratory Testing for HIV Diagnosis Antibody Assays: _________ _________ Confirmatory Assays ————— _____________ Nucleic Acid-based Test (Virologic tests) Assays to detect HIV DNA or RNA (PCR) Other tests: 1. Antigen detection test (_____ antigen) 2. Viral _______

Rapid tests ELISA p24; isolation

Antibody Tests suitable for use in infants under 18 months T/F

F Not suitable for use in infants under 18 months (use PCR instead)