HIV & respiratory infections

Question 1

what chronic infections are you likely to get when your CD4 count is >350?

Answer 1

• community acquired pneumonia
• other URTI
• TB

Question 2

what chronic infections are you likely to get when your CD4 count is <350?

Answer 2

• PCP
• other HIV related pneumonias (fungal, viral:CMV, bacterial)
• TB

Question 3

what are the HIV related respiratory infections?

Answer 3

• PCP pneumonia
• bacterial pneumonias (CAP and HAP): pneumococcal pneumonia, H influenza, staphylococcus aureus, atypical agents
• fungal pneumonias: aspergillosis, cryptococcis, histoplasmosis
• viral pneumonias: CMV pneumonitis, influenza
• TB

Question 4

what is the epidemiology of Penumocytis jiroveci Pneumonia?

Answer 4

• ubiquitous in the environment
• initial infection usually occurs in early childhood
• PCP may result from reactivation or new exposure
• in immunosuppressed patients, possible airborne spread

Question 5

what are the risk factors of PCP?

Answer 5

• CD4 count <200 cells/micoliter
• CD4 percentage <14%
• prior PCP
• oral thrush
• recurrent bacterial pneumonia
• unintentional weight loss
• high HIV RNA

Question 6

what are the clinical manifestations of PCP?

Answer 6

• progressive exertional dyspnea, fever, nonproductive cough, chest discomfort
• subacute onset, worsens over days-weeks
• chest exam may be normal, or diffuse dry rales, tachypnea, tachycardia
• extrapulmonary disease seen rarely; occurs in any organ, associated with aerosolised pentamidine prophylaxis

Question 7

how do you diagnose PCP?

Answer 7

• clinical presentation, blood tests, radiographs suggestive but not diagnostic
• organism cannot be cultured, definitive diagnosis should be sought
• hypoxemia: characteristic, may be mild or severe
• LDH >500mg/dL is common but nonspecific
• CXR: may be normal in early disease, diffuse bilateral, symmetrical interstitial infiltrates, may see atypical presentations (nodules, asymmetric disease, blebs, cysts, pneumothroax)
• cavitation, intrathoracic adenopathy and pleural effusion are uncommon
• induced sputum
• bronchoscopy with bronchoalveolar lavage
• transbronchial biopsy
• open-lung biopsy

Question 8

what is the primary prophylaxis?

Answer 8

• initiate: CD4%<14% or history of AIDS-defining illness, CD4 200-250 cells/microliter if Q 3-month CD4 monitoring is not possible
• discontinue: on ART with CD4>200cells/microliter for >3months
• reinitiate: CD4 decreases to <200 cell/microliter

Question 9

how do you treat PCP?

Answer 9

• duration: 21 days for all treatment regimens
• preferred: septrin is treatment of choice
• adjunctive: corticosteroids

Question 10

what are the risk factors for PCP?

Answer 10

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

Question 11

what are the interventions for PCP?

Answer 11

• seasonal flu vaccine
• pneumovax vaccine
• COVID-19 vaccination
• smoking cessation
• substance abuse counselling
• cART