Prevention

1. Prevention • BacilleCalmette Guerin (BCG) Vaccine • Live attenuated strain of Mycobacterium bovis; 1921 • Efficacy • Clinical trials UK: protective effect of 60 to 80%; • Trials elsewhere have shown variable results; efficacy the closer one gets to the equator • Meta-analysis Colditz et al. (1994) = 50 per cent effective • Most important protective benefits are in minimising the risk of death, meningitis and miliary disease in neonates and young children • WHO recommend  given to all children in countries highly endemic for TB Australian Recommendations: 1. Aboriginal neonates in areas of high incidence (e.g. NT, Far North Queensland, N WA & SA) 2. Individuals travelling to or living in areas with  prevalence of TB 3. Neonates born to parents with leprosy or a Fx of leprosy; 4. HCWs who may be at high risk of exposure to drug resistant cases

2. Very safe • Anaphylactoid reactions (rare); Most common is development of a localised abscess at the site of injection, especially if the vaccination is given too deeply • Immuno-compromised  risk for disseminated BCG infection • C/I: Positive TST of greater than 5-mm diameter in duration; Immunocompromised (HIV, corticosteroids, chemo, malignancies ); Pregnant (?); PHx TB; Febrile; Pt suffers from a generalised skin disease such as eczema and psoariasis Method • Tuberculin skin test (Manoux) is done first (except infants below 6 months where Hx of TB excluded) • C/I if reactive -  risk of severe local inflammation and scarring • Single intradermal injection at the insertion of the deltoid – other sites: risk of keloid formation

3. Infection Control • Isolation = Negative Pressure Rooms – prevent cross-contaminations from room to room • Generates negative pressure to allow air to flow into the isolation room but not escape from the room • Educate patient about transmission  cover mouth when coughing etc • Masks – special filter masks

4. Prophylaxis • Screen close contacts with tuberculin test +CXR • Tuberculin +ve, CXR –ve: nothing further • Pt with HIV, no BCG - isoniazidprophylaxis↓risk by 40% • Child with +ve tuberculin test treatment • Tuberculin –ve in children/young adults repeat in 6 wks; administer BCG if still –ve / treatment if +ve • Children <1y with family member with TB - isoniazid6/12 + BCG with strain resistant to isoniazid