#Tuberculosis
Parajuli SB, 2026 (www.suryaparajuli.com.np)
Community Medicine (Kathmandu University) | MBBS 3rd Semester |
#πΉ Specific Learning Outcomes (SLOs)
At the end of the session, the learner will be able to:
Describe the burden and public health importance of Tuberculosis globally and in Nepal
Explain epidemiological determinants and transmission of TB
Classify TB based on diagnosis, site, treatment history, and drug resistance
Identify presumptive TB cases and discuss screening strategies
Explain the diagnostic approach including Xpert MTB/RIF, LPA, and DST
Discuss treatment of Drug Susceptible (DS) TB and Drug Resistant (DR) TB
Describe TB management in children and extrapulmonary TB
Explain prevention, infection control, and TB preventive treatment strategies
#π¦ Problem Statement
π TB remains one of the top infectious killers worldwide
β οΈ Caused by Mycobacterium tuberculosis
π« Primarily affects lungs (Pulmonary TB)
π§ Can affect other organs (Extrapulmonary TB)
π About one-fourth of the world population is infected
π Leading cause of death from a single infectious agent
π Curable and preventable disease
β οΈ Delayed diagnosis β transmission + DR-TB
#Nepal Situation
π FY 2079/80 (2022/23)
#Key Data
β’ Total notified TB cases: 37,447
β’ Case Notification Rate: 126 per 100,000
β’ Pulmonary TB: 73%
β’ Bacteriologically confirmed PTB: 79% of PTB
β’ Childhood TB: 8%
β’ Men affected nearly 2 times more than women
β’ DS-TB treatment success: 92%
β’ DR-TB treatment success: 82%
β οΈ Nearly 50% still miss diagnosis and care
#π¦ Definition β Tuberculosis
A communicable disease caused by
Mycobacterium tuberculosis complex
#Includes:
β’ M. tuberculosis (most common)
β’ M. bovis
β’ M. africanum
β’ M. caprae
and related organisms
#Spread by:
π¨ Airborne droplet nuclei from infectious patients
Mainly through coughing
#π¬ Epidemiological Determinants
#Agent Factors
π¦ Mycobacterium tuberculosis
β’ Acid-fast bacillus
β’ Slow growing
β’ Aerobic
β’ Intracellular pathogen
β’ Survives inside macrophages
β οΈ Drug resistance major concern
#π€ Host Factors
#High-risk groups
β’ PLHIV
β’ Diabetics
β’ Malnourished
β’ Smokers
β’ Alcohol users
β’ Cancer patients
β’ Steroid users
β’ Elderly
β’ Children
β’ Close contacts of TB patients
#π Environmental Factors
β’ Poverty
β’ Overcrowding
β’ Poor ventilation
β’ Malnutrition
β’ Migration
β’ Prisons
β’ Refugee camps
β’ Stigma
β’ Delayed healthcare access
#π Mode of Transmission
π¨ Airborne transmission
#Spread through:
β’ Coughing
β’ Sneezing
β’ Talking
β’ Singing
#Not spread by:
β Handshake
β Sharing food
β Clothes
#π Classification of TB
#Based on Diagnosis
β’ Presumptive TB
β’ Bacteriologically confirmed TB
β’ Clinically diagnosed TB
#Based on Site
β’ Pulmonary TB (PTB)
β’ Extrapulmonary TB (EPTB)
#π Classification of TB
#Based on Previous Treatment
β’ New case
β’ Relapse
β’ Failure
β’ Loss to follow-up
#Based on Drug Resistance
β’ Monoresistance
β’ Polyresistance
β’ Hr-TB
β’ RR-TB
β’ MDR-TB
β’ Pre-XDR
β’ XDR-TB
#π Presumptive TB
#Adult Criteria
β οΈ Cough β₯ 2 weeks
β οΈ Hemoptysis
β οΈ Fever + night sweats
β οΈ Weight loss
β οΈ Loss of appetite
β οΈ Contact with bacteriologically confirmed TB
β οΈ Chest X-ray suggestive of TB
#πΆ Pediatric Presumptive TB
β’ Persistent cough > 2 weeks
β’ Fever > 2 weeks
β’ Poor weight gain
β’ Weight loss
β’ Severe malnutrition
β’ Reduced activity
β’ Contact with infectious TB case
#π§ͺ WHO Recommended Diagnostic Tools
#Initial preferred test
#Xpert MTB/RIF / Ultra
β Detects MTB
β Detects Rifampicin resistance
β Rapid result
β Higher sensitivity
#Other tools
β’ Smear microscopy
β’ Culture
β’ LPA
β’ DST
β’ Chest X-ray
#π Interpretation of Xpert Results
#MTB detected + RR not detected
β‘ Start first-line regimen
#MTB detected + RR detected
β‘ Refer for DR-TB treatment
#MTB not detected
β‘ Further evaluation needed
#Invalid/Error
β‘ Repeat test
#π« Extrapulmonary TB
#Common Sites
β’ Lymph nodes
β’ Pleura
β’ CNS (TB meningitis)
β’ Bone & joints
β’ Spine
β’ Abdomen
β’ Pericardium
β’ Genitourinary system
β οΈ Severe EPTB requires longer treatment
#π DS-TB Treatment
#Standard Regimen
2HRZE/4HR
#Meaning
2 months:
H = Isoniazid
R = Rifampicin
Z = Pyrazinamide
E = Ethambutol
followed by
4 months:
H + R
#π Severe EPTB Treatment
#Example
TB meningitis
TB pericarditis
Miliary TB
Bone TB
#Regimen
2HRZE/7β10HRE
Steroids when indicated
#π Follow-up During Treatment
#Sputum Monitoring
#Month 2
End of intensive phase
#Month 5
Detect failure
#Month 6
Treatment outcome
β οΈ Positive smear at month 5 = Failure
#β οΈ Drug Resistant TB
#Types
#Hr-TB
Isoniazid resistant
#RR-TB
Rifampicin resistant
#MDR-TB
Resistance to H + R
#XDR-TB
Advanced resistance pattern
#π Hr-TB Regimen
6(H)RZE+Levofloxacin6(H)RZE + Levofloxacin6(H)RZE+Levofloxacin
Daily for 6 months
If FQ resistant:
6(H)RZE6(H)RZE6(H)RZE
#π¨ MDR/RR-TB
#Requires
β’ Xpert MTB/XDR
β’ LPA
β’ DST
β’ Referral to DR-TB center
#Newer regimens
β’ BPaL
β’ BPaLM
(Bedaquiline + Pretomanid + Linezolid Β± Moxifloxacin)
#πΆ TB in Children
#Important points
β’ Diagnosis is difficult
β’ Score chart useful
β’ Gastric aspirate may be needed
β’ Stool sample may be used
β’ SAM children require active screening
β οΈ TB meningitis needs urgent referral
#π₯ Infection Control
#Administrative
β’ Early diagnosis
β’ Fast treatment initiation
β’ Cough etiquette
#Environmental
β’ Ventilation
β’ Sunlight
β’ UV
#Personal
β’ Mask use
β’ N95 for healthcare workers
#π‘οΈ Prevention
#BCG Vaccine
πΆ Given at birth
Protects mainly against severe childhood TB
Especially:
β’ TB meningitis
β’ Miliary TB
#π TB Preventive Treatment (TPT)
#Given to
β’ Household contacts
β’ PLHIV
β’ High-risk children
#Purpose
Prevent progression from infection β disease
#π― Key Public Health Message
#Early detection + Correct treatment + Adherence
= TB control
#Missed diagnosis
= Continued transmission
#Poor compliance
= Drug resistance
#π References
National Tuberculosis Control Center, Nepal (2024)
Clinical Handbook of TB Management Protocols 2024
WHO TB Guidelines 2022
CDC Core Curriculum on Tuberculosis 2021
Parkβs Textbook of Preventive and Social Medicine
International Standards for TB Care (ISTC)
National TB Programme Nepal