TB today Flashcards
What is Tuberculosis (Tb)
Is an infectious disease of the respiratory tract.
How is Tb caused?
By the airborne spread of Mycobacterium tuberculosis.
What are the symptoms of Tb?
o Malaise (feeling of discomfort) o Weight loss o Night sweats o Cough o Haemoptysis o Breathlessness o Upper Zone crackles
What types of Tb are there?
Meningeal Gastrointestinal Pericardial Renal Septic arthritis Adrenal
How do you diagnose Tb?
Using a Ziehl Neeson stain and Acid Alcohol Fast Bacilli.
What colour s the ZN stain?
Pink
What is the role of PCR?
Used to pick up all smear positive cases and most culture positive cases. It can tell if the organism is resistant to rifampicin (antibiotic).
What are the histological features of Tb?
o Multinucleate giant cell granulomas
o Caseating necrosis
o Visible mycobacteria
Where does Tb predominantly occur and what can it lead too?
It predominantly occurs in the upper lobe and can lead to: cavity formation, tissue destruction, scarring and calcification.
What is Latent Tb?
Is symptom free and culture negative, and has a balance between the organism and your immune system. No presence of active Tb but there will be evidence of previous Tb.
What tests are used to detect previous exposure to Tb?
Interferon Gamma Release Assay and Mantoux tests.
-Mantoux tests cannot distinguish between Latent Tb, Cured TB, Active TB or BCG.
How can TB be prevented?
o Screening of high risk groups o Isolation of infectious individuals o BCG immunisation o Improved social measures o Notifying public health
Risk factors for developing pleural infections
o Diabetes mellitus o Immunosuppression o Gastro-oesophageal reflux o Alcoholism o IV drug abuse
