respiratory infections and HIV

Question 1

name some opportunistic infections associated with low CD4 count 6

Answer 1

• shingles
• TB
• oral thrush
• PCP (pneumocytis pnuemonia)
• fungal meningitis
• cerebral toxoplasmosis

Question 2

what happens to patients who age with HIV? 9

Answer 2

• CVD
• cancer
• cognitive decline
• frailty
• chronic kidney disease
• polypharmacy
• chronic liver disease
• COPD
• diabetes mellitus

Question 3

what is a big clue for HIV?

Answer 3

getting oral candidiasis without being immunosuppressed

Question 4

what are the 3 questions to ask about someone with possible HIV?

Answer 4

• is the patient effective on cART
• what is the CD4
• do they have other comorbidities

Question 5

name some HIV related respiratory infections? 5

Answer 5

• PCP=pneumonia
• Bacterial pneumonias (CAP and HAP)- pneumococcal pneumonia, H influenza, staphylococcus aureus, atypical agents- C pneumonia, M pneumonia
• Fungal pneumonias- aspergillosis, cryptococcis, histoplasmosis
• Viral pneumonias- CMV pneumonitis, influenza
• TB

Question 6

describe the pathology of pneumocystis jivorveci pneumonia? 9

Answer 6

• P jiroveci
• Ubiquitous in environment
• Initial infection usually occurs in early childhood
• PCP may result from reactivation or new exposure
• In immunosuppressed patients, possible airborne spread
• Substantial decline in incidence in high income settings, owing prophylaxis and ART
• Most cases occur in patients unaware of their HIV infection, in those who are not in care and those with advanced aids (CD4 count <100)
• Before ART, PCP see in in 70-80% of AIDS patients
• with advanced immunosuppression, treated PCP is associated with a 20-40% mortality

Question 7

what are the risk factors for pneumocystis jivorveci pneumonia? 7

Answer 7

• CD4<200
• CD4 %<14%
• Prior PCP
• Oral thrush
• Recurrent bacterial pneumonia
• Unintentional weight loss
• High HIV RNA

Question 8

what are the clinical manifestations for PCP? 4

Answer 8

• Progressive exertional dyspnoea, fever, non-productive cough, chest discomfort
• Subacute onset, worsens over days-weeks
• Chest exam can be normal, or diffuse dry rales, tachypnoea, tachycardia
• Extrapulmonary disease seen rarely; occurs in any organ

Question 9

how would we diagnose PCP? 6

Answer 9

• Clinical presentation, blood tests, radiographs, suggestive but not diagnostic
• Organism cannot be cultured
• Definitive diagnosis should be sought
• Hypoxaemia: characteristic may be mild or severe
• LDH>500 is common but non-specific
• 1,3beta-D-glycan may be elevated

Question 10

what would be the CXR presentations for PCP? 4

Answer 10

• May be normal in early disease
• Typical: diffuse bilateral, symmetrical interstitial infiltrates
• May see atypical presentations, nodules, asymmetric disease, blebs, cysts, pneumothorax
• Cavitation, intrathoracic adenopathy and pleural effusion are uncommon

Question 11

how do we get a definitive diagnosis for PCP? 6

Answer 11

• Requires demonstrating organism
• Induced sputum
• Bronchoscopy with bronchoalveolar lavage
• Transbronchial biopsy
• Open-lung biopsy
• PCR`: high sensitivity for BAL sample, may not distinguish disease from colonisation

Question 12

describe primary prophylaxis for PCP? 5

Answer 12

• Initiate:
• Consider for:
• CD4%<14% or history of AIDS defining illness
• CD4 200-250 cells
• Discontinue:
• On ART with CD4>200 cells for over 3 months
• Reinitiate:
• CD4 decreases to <200

Question 13

what is the treatment fo PCP? 7

Answer 13

• 21 days for all treatment regimens
• Septrin is preferred treatment
• For patients who experience non-life threatening adverse events, consider desensitisation or dosage reduction
• Moderate-severe PCP= septrin: IV or oral in divided doses
• Mild-moderate PCP- oral septrin
• Adjust dosage for renal insufficiency
• Corticosteroids- give as early as possible (within 72 hours)

Question 14

what are the risk factors for PCP? 7

Answer 14

• Smoking
• HIV
• cART
• pollution
• age
• recreational drug use
• comorbidities

Question 15

explain respiratory infection in cART:

• high income settings CD4>250 5
• low income settings CD4<250 5

Answer 15

• bacterial pneumonia
• hospital acquired pneumonia
• other respiratory conditions: COPD, asthma, lung cancer
• TB
• COVID-19 pneumonitis
• All of the above plus
• PCP
• Fungal pneumonias
• TB
• Covid-19 pneumonitis

Question 16

what are the interventions to prevent people with HIV getting PCP? 6

Answer 16

• seasonal flu vaccine
• pneumovax vaccine
• COVID_19 vaccine
• Smoking cessation
• Substance abuse counselling
• cART