Virology

Question 1

BAL

• Description
• Indications

Answer 1

Bronchoalveolar lavage
- Diagnostic method for pathogenic infections in the lower airways

Bronchoscope is passed through airway, fluid is then passed then collected for investigations

Indications= diagnosis in immunocompromised

• Pneumonia in the ventilated
• ARDS

Question 2

Specificity

• Definition/ formula
• Implications in prevalence of disease

Answer 2

Proportion of people that accurately tests negatively
- TN/ TN+ FP

Lower specificity in a more prevalent disease means= more false positives
- May cause the implementation of necessary medical interventions

Question 3

Sensitivity

• Definition/ formula
• Implications in prevalence of disease

Answer 3

Proportion of people that accurately tests positive
- TP/ TP + FN

Lower sensitivity in a more prevalent disease means= more false negative
- May cause more late presentations/ exacerbations of diseases