Mantoux, BCG scar-1.pptx

Spotters

1. Spotters Dr Vichithra M Senior resident Department of Pediatrics WORLD TB DAY: MARCH 24

2. Spotter 1 Identify the spotter in the image? Ans. Tuberculin Syringe Other uses: Bcg vaccination, intradermal test dose administration, insulin administration. Strain used in PPD (purified protein derivative) ? Ans. RT23 strain How many TU of PPD used for TST? Ans. WHO: 5 units, RNTCP: 2 units Dose of PPD for TST? Ans. 0.1ml

3. Administration Site of administration? Ans. Left forearm on flexor aspect just below the elbow. What gauge needle is used and how much length? Ans. 27 gauge needle, ½ (half) inch length. Angle at which needle has to be inserted? Ans. 5 to 15 degree After injection, wheal of _____ mm is seen Ans. Normal is 6mm If no wheal what should be done? Ans. Readminister 2 inch from the 1 st site of administration.

4. Interpretation When and how will you interpret? Ans. Interpreted after 48 to 72 hours by checking the diameter of induration. Type of hypersensitivity reaction? Ans. Type 4 delayed hypersensitivity reaction. When it is considered positive? Ans. Greater than 10mm is positive What if child comes after 72 hours? Ans. Repeat once again on another arm What doses positive TST indicate? Ans. Person may or may not have infection . Test is done additional to significant risk factors.

5. Interference in BCG vaccine After what age you can do TST? Ans. After 1 year What happens to TST because of BCG vaccine? Ans. BCG vaccine – Mycobacterium bovis interferes with tuberculin skin test giving false interpretations.

6. Causes of False negativity Incorrect technique of administration or Interpretation Improper storage of tuberculin Immunodeficiency/suppression – Primary – Secondary like HIV infection, SAM, Immunosuppressive (e.g. steroids) Infections – Viral (e.g. measles, varicella) – Bacterial (e.g. Typhoid, leprosy, pertussis) Vaccinated with live viral vaccine (within 6 weeks) Neonatal patients Severe forms of TB

7. Causes of False positivity Incorrect technique of Interpretation BCG vaccination Infection with mycobacterium other than TB

8. Spotter 2 Identify? Ans. BCG scar Site? Ans. Left upper arm (deltoid insertion)

9. Vaccine Identify the person in image Ans. Albert Calmette Who and when discovered BCG vaccine? Ans. Albert Calmette and Camille Guerin ( BCG- Bacillus Calmette -Guerin), 1921 What is the type of vaccine used? Ans. Live attenuated vaccine Available form of vaccine? Ans. Lyophilized Strain used in BCG vaccine? Ans. Danish 1331 (used all over India) Other strain: Pasteur

10. More about vaccine Diluent used in vaccine? Ans. Normal Saline (powder form) How do you store vaccine? Ans. 2 to 8 degree (heat and light sensitive) How long you can keep an open vial? Ans. Upto 4 hours. Discarded after 4 hours Dose and route of BCG vaccine? Ans. 0.1ml intradermal (LBW or preterm: 0.05ml) Raise a wheal of ____ diameter Ans. 5 to 7 mm

11. Schedule and efficacy When will you give vaccine? Ans. NIS: @birth upto 1 year, IAP: @birth upto 5 years Is it given all over the world? Ans. Only in Endemic Regions Efficacy of the vaccine? Ans. Against extrapulmonary TB: 0 to 80%, Meningeal and milliary TB: 50 to 80%, Pulmonary TB: 40 to 50%

12. Vaccine reaction Papule: 2 - 3 weeks 4 – 8 mm size: 4 -6 weeks Ulcer and scar: 6 - 12 weeks

13. Adverse effects of vaccine Axillary lymphadenitis (Management: self resolving , rarely require antibiotics, persists more than 1 year excision biopsy required.) Disseminated BCGosis (In severe immunodeficient child, immunity vains by 6 to 8 weeks and develop disease due to vaccination) BCG IRIS with HIV (IRIS: Immune Reconstitution Inflammatory Syndrome)

14. Vaccine – more info With which vaccine BCG cannot be given? Ans. Measles Contraindication for BCG vaccine? Ans. Primary immunodeficiency, HIV positive babies BCG vaccine to child born to a mother who is HIV positive? Ans. If child is HIV positive: BCG NOT given, If child HIV negative or HIV status not know: BCG Given.

15. No BCG scar Should we revaccinate? Ans. 10% may not have scar. Revaccination not required. Is it normal? Ans. yes Extra points: Mother active pulmonary TB gave birth to child: Child investigations- CXR, Usg abdomen and gastric lavage– if negative: prophylaxis INH for 6months with Bcg vaccine; if positive: HREZ*2months and HRE*4months BCG protective against COVID 19: doubtful but still those vaccinated with BCG have reduced morbidity and mortality due to COVID 19