HIV Flashcards
HIV = AIDS. True/False?
False
HIV does not mean you have AIDS but it increases the risk of getting AIDS
What type of virus is HIV?
Retrovirus
Which immune receptors are the target of HIV infection?
CD4+ receptors
What effect does HIV attacking CD4 receptors have on the immune system?
Reduced circulating CD4 Reduced CD8 activation Reduced antibody class switching Chronic immune activation Basically, increases susceptibility to infection!
What is the normal range of CD4 cells?
500-1600 cells/mm3
What is meant by opportunistic infection?
Infection that would not normally occur in a healthy individual
At what points of infection does HIV rapidly replicate?
Early and late points
When do clinical presentations of HIV typically occur?
2-4 weeks after onset of infection
List some clinical features of HIV infection
Fever Maculopapular rash Myalgia Pharyngitis Headache Meningism
Is there a high risk of transmission of HIV?
Very high risk through normal routes (i.e. not airborne)
Asymptomatic HIV infection involves a latent/dormant virus. True/False?
False!
Infection is ongoing even though person is asymptomatic; still risk of transmission
What cause of pneumonia is a common opportunistic infection occurring in HIV/AIDS patients?
Pneumocystis jirovecii
How is pneumocystis jirovecii pneumonia diagnosed?
Bronchoalveolar lavage and immunofluorescence
+/- PCR
What is the treatment for pneumocystis jirovecii?
Co-trimoxazole
Cerebral toxoplasmosis is another opportunistic infection. What organism causes it?
Toxoplasma gondii
What happens pathologically in cerebral toxoplasmosis?
Chorioretinitis - multiple cerebral abscesses
Which animal/pet is particularly infamous for transferring toxoplasma to humans?
Cats
What is the CD4 threshold for cerebral toxoplasmosis?
CD4 less than 150
CMV is another opportunistic infection. What is the CD4 threshold for this?
CD4 less than 50
How does CMV usually present?
Reduced visual acuity
Floaters
Abdo pain, diarrhoea
List some opportunistic skin infections that may occur with HIV
Herpes zoster
Herpes simplex
Human papilloma virus
Weird ones - histoplasmosis, molluscum contagiosum
Which HIV strain is associated with neurocognitive impairment?
HIV-1
Which condition is caused by JC virus as an opportunistic inffection?
Progressive multifocal leukoencephalopathy
What is “Slim’s disease” in association with HIV?
HIV-associated wasting due to metabolic disorder, anorexia, malabsorption and/or hypogonadism
What is the most common AIDS-related cancer?
Kaposi’s sarcoma
Which organism causes Kaposi’s sarcoma?
Human herpes virus 8
How is Kaposi’s sarcoma treated?
HA anti-retroviral therapy
Local therapy
Systemic chemotherapy
Which AIDS-related cancer is caused by EBV?
Non-Hodgkins lymphoma
Which AIDS-related cancer is caused by HPV?
Cervical cancer
What are the 3 main modes of transmission of HIV?
Sexual
Parenteral
Mother-to-child
Is HIV more common in men who have sex with men or women who have sex with men who have sex with men?
Men who have sex with men
What sexual factors increase the risk of getting HIV?
Anoreceptive
Trauma
Genital ulceration
Concurrent STI
How might HIV be acquired parenterally?
Injection drug use
Infected blood products
Iatrogenic
Who should be tested for HIV?
Those in high prevalence areas
Screening of high-risk groups
Those with clinical indicators
What are high-risk groups for HIV?
Men who have sex with men Women who have sex with men who have sex with men Injecting drug users People living with people who have HIV Endemic areas
What markers of HIV are used to detect infection?
Antibody
Antigen (p24)
Viral RNA
List markers of HIV in order of first appearance
Viral load
Antigen
Antibody
What is the window period of 3rd generation antibody tests for HIV compared to 4th generation antibody tests?
20-25 days (3rd gen)
14-28 days (4th gen)
How do 4th gen antibody tests differ from 3rd gen antibody tests for HIV?
3rd gen: antibody only
4th gen: antibody + antigen
What is the BASHH guidance on a negative 4th gen antibody test with regards to HIV?
Negative antibody test performed 4 weeks after exposure is highly likely to exclude HIV infection
What rapid HIV tests can be done?
Fingerprick
Recent infection testing algorithm
Home sampling
Home testing
Which drug class has in vitro activity against HIV? Give an example of a drug under this class
Nucleoside analogues reverse transcriptase inhibitors (NRTI)
Zidovudine
What is highly-active anti-retroviral therapy (HAART)?
Combination of 3 drugs from at least 2 drug classes to which the virus is susceptible
Partner notification of HIV is a voluntary process. True/False?
True
There is no risk of HIV transmission with casual/household contact. True/False?
True
