STD 3 Flashcards
What are retroviridae?
Family of enveloped viruses with single stranded positive sense RNA
-> replicate in host cell through reverse transcription
Why is HIV called a lentivirus?
Long interval between initial infection and symptoms onset
What are the component of HIV virus?
- Viral RNA
- Lipid bilayer
- Nucleocapsid- P7
- Matrix- p17
- Caspid- p24
- Protease- p15
- Reverse transcriptase- p66
- Integrase- p31
- Envelope- Su gp12, TM gp41
What is the prevalence of HIV?
4.6%
-> 38 million people living with HIV (2019)
-> 6000 in scotland
What are the stages in HIV life cycle?
- Attachment
- Fusion- uncoating
- Reverse transcription- nuclear import
- Integration
- Transcription - nuclear export
- Translation- assembly of proteins
- Budding and maturation
What are the modes of transmission for HIV?
Paternal exposure (can be vertical at time of birth)
Blood transfusion
Sharing needles
Needle stick injury
Sexual exposure without condom use (oral, anal, vaginal)
What risk factors make HIV infection more likely?
Higher viral levels in plasma/ genital infections
Other STIs
What are the phases of HIV infection?
Primary infection- acute HIV syndrome, wide dissemination, seeding of lymphoid organs
Clinical latency
Constitutional symptoms
Opportunistic disease
Death
What are the features of HIV stage 1 (acute infection)?
Patient may be asymptomatic
Pt has persistent generalised lymphadenopathy in at least 2 sites (for longer than 6 months)
CD4+- at least 500 cells/ul
What are the features of HIV stage 2 (early or mildly symptomatic)?
Unexplained weight loss (<10% of total body weight)
Recurrent respiratory infections- sinusitis, bronchitis, otitis media, pharyngitis
Dermatological conditions
-> VZV flares
-> Angular cheilitis
-> Recurrent oral ulceration
-> papilar pruritic eruption
CD4+- 350-499/ul
What are the features of Stage 3 HIV (late or moderately symptomatic stage)?
Weight loss (>10%)
Unexplained diarrhoea
Pulmonary TB
Severe bacterial infections
-> Pneumonia
-> pyelonephritis
-> meningitis
-> bone and joint infections
-> bacteraemia
Candiasis
Hairy Leukoplakia
ANUG
CD4+- 200 to 349
What is considered AIDS (stage 4)?
<200 CD4+ cells/ul
What does AIDS stand for?
Acquired immunodeficiency syndrome
What conditions are considered AIDS-defining
- HIV wasting syndrome
- Pneumocystis pneumonia
- Recurrent severe or radiological bacterial pneumonia
- Extrapulmonary tuberculosis
- HIV encephalopathy
- CNS toxoplasmosis
- Chronic orolabial herpes simplex infection
- Oesophageal candidiasis
- Kaposi’s sarcoma
What conditions may arouse suspicion that patient has AIDS?
- CMV infections- retinitis, liver, spleen, LNs
- Extrapulmonary crytococcosis
- Disseminated endemic mycoses
- Disseminated non TB mycobacteria infection
- Tracheal, bronchial, pulmnory candiasis
- Visceral HSV
- Cerebral b-cell NHL
- HIV cardiomyopathy/nephropathy
What is the most prevalent opportunistic disease among people with HIV?
TB
What neoplastic conditions are caused by HIV?
NH/H lymphoma
Lip/oral cancer
Kaposi’s Sarcoma
Which type of fungal pathogens cause superficial fungal infection in HIV?
Candida
Which type of fungal pathogens cause invasive/deep oral pharyngeal fungal infections?
Histoplasma genus
Blastomyces genus
Aspergillus genus
Rhizopus, Rhizomucor, Mucor, Absidia, Cokeromyces, Apophysomyces Cunninghamella,
Saksenaea genus
Cryptococcus genus
Which viral infections are commonly superimposed on HIV infections?
Herpes Simplex Virus (HSV)
Varicella Zoster Virus (VZV)
Cytomegalovirus (CMV)
Epstein-Barr Virus (EBV)
Human Papilloma Virus (HPV)
Human Herpes Virus – 8
Which oral bacterial infections are common in HIV patients?
TB
Syphillis
How do TB oral lesions seen in HIV present?
Painful superficial lingual ulcer
-> circumscribed
-> crateriform aspect
-> Elevated
-> Indurated
How do secondary syphillis oral lesions seen in HIV present?
Mucous patched
-> raised plaques
-> erythematous base
-> serpentine white/redish outline
What conditions affecting the periodontium is HIV associated with?
Linear gingival erythema- distinct band around margin (does not respond to perio tx)
Necrotising gingivitis, periodontitis, stomatitis
How do mouth ulcers in HIV present?
Start off aphthous like- can be come necrotising stomatitis
Range in size
Persistent
Painful
Frequency increases with HIV progression
What issues can HIV cause in salivary glands?
Bilateral parotid enlargement
-> increased on HAART
Xerostomia- HIV related medication
-> caries
-> oral fungal infections
How does Kaposi’s Sarcoma present? (associated with HHV-8)
Red/blue/purple macular and nodular lesions
How is Kaposi sarcoma diagnosed?
Biopsy and pathology assessment
How does NHL appear clinically?
- Rapidly enlarging necrotic masses
- Ulcerated or nonulcerated masses
- Palate and gingivae most common sites
-> Prognosis is very poor
How is NHL diagnosed?
Biopsy and histological evaluation
How is NHL treated?
Aggressive oncology therapy
What antigens are used in HIV diagnostic testing in sandwich ELISA?
Recombinant and synthetic peptides
-> 99.5% specificity, 100% sensitivity
What antibodies does sandwich ELISA for HIV detect?
IgG and IgM for anti HIV1/2/group )
HIV1 p24 Ag
What are some examples of rapid tests for HIV?
Chembio HIV/HCV/syphilis- HIV Ab
Biolytical HIV1
What is used to manage HIV?
HAART- Highly active anti-retroviral therapy
-> reduces levels of viraemia
-> not always fully effective
-> long and short-term toxicity issues
What combination of drugs is used in HAART?
2 nucleoside reverse transcriptase inhibitors
1 of :
Integrase stand transfer inhibitor
Non-nucleoside reverse transcriptase inhibitor
Protease inhibitor
Plus pharmacokinetic enhancer- booster
-> Cobicistat
-> Ritonavir
What are some examples of NRTIs?
Tenofivir
Lamivudine and Emtricitabine
Abacavir
What are some examples of INSTI?
Dolutegravir
Raltegravir
Elvitegravir
What are some examples of NNRTI?
Efavirenz
Nevirapine
Rilpivirine
What are some examples of Protease inhibitors?
Darunavir
Atazanivir
What are some of the adverse orofacial side effects of HAART?
Erythema Multiforme
Xerostomia
Ulcers
Altered tast
Peri-oral paraethesia
Facial lipodystrophy
How are STIs prevented?
Abstinence
Condoms
Vaccination- Hep B, HPV
Reduce number of partners
Mutual monogamy
How is mother-child transmission of HIV prevented?
All HIV positive woman who are pregnant or breastfeeding should maintain viral suppression therapy
How quickly should PEP be taken?
ASAP after the exposure
-> no longer than 72 hours after
-> continue for 4 weeks to maximise chance of prevention
What is PrEP?
Pre-exposure prophylaxis- daily tenofovir/emtricitabine
-> given to high risk individuals
