HIV Flashcards
Which type of HIV virus is responsible for the vast majority of HIV infections?
HIV-1
Which virus, found in chimpanzees and gorillas in west Africa, is closely related to HIV1?
Simian immunodeficiency virus
When are HIV viruses through to have crosses species from primaries to humans in Africa?
late 19th / early 20th century
What is the bush meat theory of how HIV transmitted to humans?
The theory that a hunter was bitten or cut while butchering an animal resulting in transmission of HIV to humans
What factors may have triggered or contributed to an epidemic of transmission of HIV when it first emerged in Africa?
Social changes and urbanisation
Unsterile injections
Genital ulcer diseases
Sexual promiscuity
How can HIV be transmitted?
Sexually transmitted IV drug use (sharing needles) Mother to child vertical transmission Contaminated blood products Occupation e.g. needle stick injuries
How does HIV enter the body?
Open cuts Sores Breaks in the skin Mucous membranes (aus/vagina) Direct injection
HIV contains three of its own enzymes which can each be used as drug targets. What are these enzymes?
Integrase
Reverse transcriptase
Protease
Which immune cells does HIV infect?
T helper cells
Macrophages
Dendritic cells
What receptor allows the entry of HIV into immune cells?
CD4+
How does HIV infection cause depletion of CD4+ T cells?
Direct viral killing of cells
Apoptosis of unaffected bystander cells
CD8+ cytotoxic T cell killing of infected CD4+ T cells
How can HIV infection result in inappropriate/excess immunoglobulin production?
By inducing abnormal B cell activation by infected CD4+ T cells
What is the critical level of CD4+ cells at which a person becomes at risk of opportunistic infections and some cancers?
<200
What are the six types of antiretroviral drug used to treat HIV?
Fusion inhibitor
R5 inhibitor
Nucleoside reverse transcriptase inhibitor
Non-nucleoside reverse transcriptase inhibitor
Integrase inhibitor
Protease inhibitors
What type of genetic material does HIV have?
Single stranded RNA
HIV is a non-enveloped virus. T/F?
False - it is an enveloped virus and some of the surface proteins in this envelope have been considered as potential drug treatments
What is viral latency?
A state of reversibly non-productive infection of individual cells
What does the term ‘latency’ refer to in HIV?
The long asymptomatic period between initial infection and advanced HIV
At what point in infection is there no way of curing HIV?
Once the HIV virus genetic material is incorporated into the host DNA as there is no way of removing this
What can help to reduce the risk of drug resistance in HIV?
Taking HIV medications very day, exactly as prescribed
How can drug resistant HIV develop?
As HIV multiplies in the body, the virus sometimes mutates and produces variations of itself. Variation of HIV that develop while a person is taking HIV medicines can lead to drug resistance
What is the main theoretical safety concern against the development of a live attenuated HIV vaccine?
The possibility of reversion to a live virus through mutation
HIV, is diagnosed early and treated appropriately, has a near normal. life expectancy. T/F?
True
When is HIV universally tested for?
Antenatal screening
GUM clinics
IV drug users
Populations in which the prevalence fo HIV is >2/1000
What populations are at higher risk of HIV?
Patients from sub-saharan Africa MSMs Children of people with HIV IV drug users People who have transactional sex
What does the HIV blood test look for?
The presence fo the p24 antigen and His antibody
What is the window period for HIV testing?
4 weeks
If a positive HIV test is done, a confirmatory test is conducted. T/F?
True
What is the other name for primary HIV infection?
HIV seroconversion
What are the differential diagnoses of HIV seroconversion?
Infectious mononucleosis
Secondary syphilis
Drug rash
Other viral infections
What are the main symptoms of acute HIV infection?
Fever Weight loss Malaise Headache Neuropathy Pharyngitis Sores and thrush in the mouth Lymphadenopathy Rash Myalgia Nausea Vomiting Enlargement of liver and spleen
Give examples of conditions which can be indicators of HIV infection?
TB Pneumocystitis Cerebral toxoplasmosis Primary cerebral lymphoma Crytococcal meningitis Progressive multifocal leucencephalopathy Kapsoi's sarcoma Persistent crytosporidosis Cervical cancer Cytomegalovirus Non-hodgkin;s lymphoma
What is the aim of treatment in HIV infection?
To maintain an undetectable viral load
What is the definition of an undetectable viral load globally?
<200 copies per ml
What is the definition of an undetectable viral load in Scotland?
<40 copies per ml
When should antiretroviral treatment be started in HIV infection?
As soon as possible to reduce morbidity/mortality and reduce risk of onwards transmissions
What drugs are used in triple therapy against HIV?
2 nucleoside reverse transcriptase inhibitors plus a drug from another class (usually an integrase inhibitor)
What factors influence the choice of therapy in HIV patients?
Patient choice
Comorbidities
Interactions
Drug resistance
What are the possible short term side effects of HIV treatment?
Rash Hypersensitivity CNS side effects GI side effects Renal and septic effects
What are the possible long term toxicities of HIV infection?
Body shape changes (lipoatrophy, lipodystrophy) Renal Hepatic Lipid Bone
Why does antiretroviral treatment for HIV have so many. drug interactions?
It effects the CYP450 enzyme resulting in reduced/increased drug levels of other medications
Partner notification is carried out for all people following a HIV diagnosis. T/F?
True
How can HIV infection be prevented?
Use of condoms Treatment as prevention Post exposure prophylaxis Pre exposure prophylaxis Prevention of mother to child transmission Harm reduction measures
How soon after exposure does post exposure prophylaxis for HIV. need to be initiated?
72 hours
For how long is post exposure prophylaxis for HIV continued?
28 days
Breast-feeding should be avoided in HIV positive mothers. T/F?
True - there is no data on the safety of breastfeeding in HIV infection
How is a pregnant women with HIV managed to prevent transmission of HIV to the baby?
Antiretrovirals given to mother during pregnancy
Post exposure prophylaxis given to baby
P.jiroveci infection is an opportunistic infection which can occur in individuals with HIV. Give an account of the pathogenesis of this infection
It is an extracellular pathogen (fungus) which causes interstitial plasma cell pneumonia with foamy exudates int he alveoli
What are the symptoms of p.jorveci infection?
Progressive and disproportionate shortness of breath, fever, dry cough with failure to respond to usual antibiotic regimes
What are the possible complications of p.jiroveci infection?
Respiratory failure
Pneumothorax
What is the first line treatment for p.jiroveci infection?
Cotrimoxazole and steroid therapy
What signs of p.jiroveci infection may be seen on CXR?
Perihilar interstitial shadowing in moderate disease and white out in sever disease
