Pulmonary TB Flashcards
Definition?
Pulmonary tuberculosis (TB) is an infectious disease caused byMycobacterium tuberculosis.
RF?
• Infection • Birth in endemic country • HIV • Immunosuppressive meds • Silicosis Apical fibrosis
ddx?
• COVID-19-fever, cough, loss of taste and smell
• CAP-crackles and dyspnoea
• Lung cancer-constitutionals
• Non-TB mycobacteria-cavitation
• Fungal infection-travel
Sarcoidosis-intrathoracic lymphadenopathy and arthralgias
epidemiology?
Age:
Sex:
Ethnicity: Asia, Africa, Western Pacific
Aetiology?
M.TB/mycobacterium
CP?
• RFs • Cough • Fever • Anorexia • Weight loss • Malaise • Night sweats • Pleuritic chest pain • Haemoptysis Crackles, bronchial breath sounds, or amphoric breath sounds (distant hollow breath sounds heard over cavities).
Pathophysiology?
• M.TB are rod shaped, and needs oxygen as strict aerobes
• Waxy cell wall from mycolic acid that make them survive even after acidic environments
• Resists weak disinfections and survives on dry surfaces
• Transmitted via inhalation
• TB avoids mucociliary elevators
• Alveolar macrophages phagocytose M.TB but release protein so lysozyme cannot bind so it isn’t broken down and in fact proliferates
• After 3 wks- cell mediated immunity-create granulomas-tissue inside middle dies causes caseous necrosis-Ghon focus
• Ghon complex-ghon focus and caseating necrosis in LNs-subpleural and in lower lobes
• Ranke complex-fibrosis and calcification of Ghon complex
• TB can be killed off are dormant and walled off and can be reactivated in immunosuppression to spread to upper lobes where more oxygen is
Memory T cells release cytokines more caseating necrosis and cavitates and disseminates to the lungs (bronchopneumonia) or the vascular system causing systemic miliary TB
signs pulmonary TB?
• kidneys-pyuria • Meningitis • Lumbar vertebrae-pott disease • Adrenal glands-Addisons disease • Liver-hep Cervical LNs-scrophula
Investigations first line?
• CXR-fibronodular opacities in lobes, lymphadenopathy and or pleural effusion
• Sputum acid-fast bacilli smear-M.TB
• Sputum culture-gowth of M.TB-Ziehl Neesen stain-red vibrae
• FBC-raised WCC, low Hb
• NCA-positive for M.TB
Purified protein derivative intradermal skin test
I-Second line onwards?
- Bronchoscopy
- Empirical treatment
- CT
- Specific microbe assays
m-latent?
6 or 9 months of daily isoniazid, 3 months of weekly rifapentine plus isoniazid, or 3 months of daily isoniazid plus rifampicin.One month of daily rifapentine plus isoniazid or 4 months of daily rifampicin are alternative regimens
m-acute?
- Initial Phase-
- first-line treatment is isoniazid, rifampicin, pyrazinamide, and ethambutol
- Directly observed therapy or self-administered
- Continuation Phase
- The continuation phase is 18 weeks in duration and medication is given after completion of the initial phase
• Isoniazid resistance
Multidrug resistance
m if acute HIV?
• Intial phase • Continuation phase • Anti-TB therapy • Standardised or individualised long term regimen • Surgery • Intensive and continuation regimen • Surgery Consult if pregnant or hepatic dysfunction
prognosis?
RFs
few complications if treated well
complications?
• Transmission • IRIS • ARDS • Pneumothorax • Empyema • Bronchiectasis • Lung destruction • Right middle lobe syndrome haemoptysis
indications for vaccine?
- are born in areas of the UKwhere the rates of TB are high
- havea parent or grandparent who was born in a country wherethere’sa highrate ofTB
- Work with animals, fluids, refugees, prisoners and homeless people and healthcare workers
- Travelling to endemic areas/infected people
presentation of non-pulmonary TB?
- RF’s
- Enlarged LN
- Pleuritic chest pain
- Skeletal pain
- Urinary symptoms
- Abdominal swelling
- Abdominal pain
- Headache
ethical and legal consequences of TB therapy?
• Ethical-choices, wider effect on communities,
Legal-sanctions, health education, duty of HCP
DOT?
• A method of drug administration in which a health care professional watches as a person takes each dose of a medication.
Directly observed therapy (DOT) is used to ensure the person receives and takes all medications as prescribed and to monitor response to treatment.
multi-drug resistant TB?
• Resistance to isoniazid and rifampicin
• Can take up to 12 months to treat
Mutations or re-exposure to same /diff RF/causative agent
Screening?
Screening of risk groups allows the burden of disease in countries to be lowered
Mantoux test?
• Purified protein derivative of M.TB injected and measure mm of wheal/induration
Delayed type 4 hypersensitivity reaction via TH1 cells
Notification?
• Can result in outbreaks
Done via Enhanced TB Surveillance -paper or online forma
Traced?
• Household contacts or other close contacts
• In occupational exposures-current and former workers should be contacted
Immunocompromised contacts