Over 1/3 of world's population is infected
Primary Infection
Usually contained by body via formation of tubercles
Hematogenous spread limited to areas with high O2 or blood flow (apical lung, vertebrae)
PPD positive
Reactivation Infection
More common in immunocompromised patients (AIDS, malignancy, DM, immunosupressive medications)
Miliary<unk> 
Disseminated<unk> 
Looks like millet seeds
Seen in patients with comorbid AIDS
Check HIV in patients suspected of<unk> 
PPD is positive in only 50% of cases
Usually contained by body via formation of tubercles
Hematogenous spread limited to areas with high O2 or blood flow (apical lung, vertebrae)
PPD positive
PPD positive
More common in immunocompromised patients (AIDS, malignancy, DM, immunosupressive medications)
Disseminated<unk> 
Looks like millet seeds
Seen in patients with comorbid AIDS
Check HIV in patients suspected of<unk> 
PPD is positive in only 50% of cases
Check HIV in patients suspected of<unk> 
AIDS<unk>  is 200-500x more common in AIDS population than general population
CD4 count
Increased risk when <500
Determines the clinical and radiographic presentations of<unk> 
Pediatric
More likely to progress early to active disease
Presentation more commonly that of primary<unk> 
>5yr - classic symptoms
<5yr - miliary<unk> , meningitis, cervical lymphadenitis, pneumonia that does not respond to usual antibiotics
Children are usually not infectious due to their weak cough<unk>  is 200-500x more common in AIDS population than general population
CD4 count
Increased risk when <500
Determines the clinical and radiographic presentations of<unk> 
Increased risk when <500
Determines the clinical and radiographic presentations of<unk> 
More likely to progress early to active disease
Presentation more commonly that of primary<unk> 
>5yr - classic symptoms
<5yr - miliary<unk> , meningitis, cervical lymphadenitis, pneumonia that does not respond to usual antibiotics
Children are usually not infectious due to their weak cough
Presentation more commonly that of primary<unk> 
Reaction considered positive in following situations:
>5 mm
HIV positive
Close contact with active<unk>  patient
Nodular or fibrotic changes on CXR
Immunosuppressed (TNF-alpha inhibitor, chemo, organ transplant)
>10 mm
Children < 4 yrs old
Healthcare/lab/prison employees and residents
Co-morbid conditions (dialysis, DM, blood/head/neck/lung malignancy, IV drug users)
People from high prevalence areas
>15 mm
Persons with no known risk factors for<unk> 
HIV positive
Close contact with active<unk>  patient
Nodular or fibrotic changes on CXR
Immunosuppressed (TNF-alpha inhibitor, chemo, organ transplant)
Children < 4 yrs old
Healthcare/lab/prison employees and residents
Co-morbid conditions (dialysis, DM, blood/head/neck/lung malignancy, IV drug users)
People from high prevalence areas
Persons with no known risk factors for<unk>
Tuberculosis
HIV neurologic complications
Aspergillosis
Toxoplasmosis
Sarcoidosis
Cryptococcosis
Histoplasmosis
AIDS Dementia