Tuberculosis Epidemiology Malayalam | Agent, Host, Environment & Diagnostic Tests | NEET PG

ക്ഷയരോഗത്തിന്റെ (Tuberculosis) എപ്പിഡെമിയോളജി, എപ്പിഡെമിയോളജിക്കൽ ഡിറ്റർമിനന്റുകൾ, ഡയഗ്നോസ്റ്റിക് ടെസ്റ്റുകൾ: മലയാളത്തിൽ ലളിതമായി. NEET PG, NExT, AIAPGET, UPSC, Kerala PSC, MD എൻട്രൻസ്, MPH പരീക്ഷകൾക്ക്. Tuberculosis remains one of the most important public health problems in India, which carries about a quarter of the world's TB burden. This lecture, explained in Malayalam, covers the epidemiology of TB through the agent–host–environment model, the key epidemiological indices, and the diagnostic tests used under the National TB Elimination Programme (NTEP). It is one of the most frequently tested topics in Community Medicine (SPM) for NEET PG, NExT, AIAPGET, UPSC CMS, Kerala PSC and MD entrance exams. Related videos • NTEP Part 2: Strategy and Organisation: [paste link] TOPICS COVERED 1. Epidemiological determinants: Agent factors • Causative agent: Mycobacterium tuberculosis (human type); M. bovis (bovine type) • Discovered by Robert Koch in 1882 (World TB Day, 24 March, marks this) • Acid-fast bacilli: slow-growing, aerobic, resistant to drying • Source of infection: mainly sputum-positive pulmonary TB patients • Reservoir: human beings • Drug resistance: MDR-TB, pre-XDR and XDR-TB 2. Host factors • Age: affects all ages; the risk of disease is higher in young adults and the elderly • Sex: notified cases are higher in males • Nutrition: undernutrition is a major risk factor in India • HIV co-infection: the strongest single risk factor for progression from infection to disease • Diabetes, smoking, alcohol use, silicosis and immunosuppressive drugs • Previous TB and incomplete treatment 3. Environmental and social factors • Overcrowding and poor ventilation • Poverty, poor housing and low literacy • Occupational exposure: mining and silica dust • Migration, urban slums and prisons • Delayed health-seeking and stigma 4. Mode of transmission and natural history • Airborne spread through droplet nuclei from coughing, sneezing and talking • Incubation: weeks to months; the risk of disease is highest in the first 2 years after infection • Only about 5 to 10 percent of infected people develop disease in their lifetime (much higher with HIV) • One untreated sputum-positive patient can infect about 10 to 15 people in a year 5. Epidemiological indices of TB • Prevalence of infection (tuberculin test) • Incidence of infection: Annual Risk of Tuberculosis Infection (ARTI) • Prevalence of disease (case prevalence) • Incidence of disease (case incidence) • Mortality rate and case fatality 6. Diagnostic tests • Presumptive TB: cough for 2 weeks or more, fever, weight loss, night sweats, haemoptysis • Sputum smear microscopy: Ziehl-Neelsen staining and LED fluorescence microscopy • NAAT: CBNAAT (GeneXpert) and TrueNat, which detect TB and rifampicin resistance together • Culture: solid (LJ medium) and liquid (MGIT), the gold standard • Line Probe Assay (LPA) for drug-resistance testing • Chest X-ray: as a screening and supporting tool • Tuberculin Skin Test (Mantoux): 5 TU PPD, read after 48 to 72 hours • IGRA (Interferon Gamma Release Assay) and Cy-TB, the indigenous skin test • Universal Drug Susceptibility Testing (UDST) under NTEP QUICK EXAM POINTS • Best indicator of the TB problem and its trend in a community: Annual Risk of Tuberculosis Infection (ARTI) • Most important source of infection: sputum smear-positive pulmonary TB • Mantoux test: induration of 10 mm or more is positive; 5 mm or more is taken as positive in HIV-positive people • A positive tuberculin test shows infection, not disease • Gold standard for diagnosis: culture • CBNAAT and TrueNat give results within hours and detect rifampicin resistance • The strongest risk factor for TB disease among infected people: HIV infection • The main risk factor at population level in India: undernutrition WHO IS THIS FOR? MBBS, BHMS, BAMS and other AYUSH students, interns and graduates preparing for university exams, NEET PG, NExT, AIAPGET, UPSC CMS, Kerala PSC and MD entrance exams. Also useful for MPH, BPH, Social Medicine and Public Health students, and for anyone who wants to understand tuberculosis better. ABOUT THE INSTRUCTOR Dr. Shary Krishna B.S., MD (Homoeopathy), PhD (Public Health, Jawaharlal Nehru University, New Delhi). UGC-NET qualified in Social Medicine & Community Health. About three years of teaching experience in medical colleges. Subscribe and turn on notifications for more Community Medicine and National Health Programme lectures in Malayalam. Share with batchmates preparing for PG entrance and PSC exams. TB is curable. Diagnosis and treatment are free at all government health facilities in India. If you or someone you know has a cough for 2 weeks or more, please get tested. Disclaimer: This content is for educational and exam-preparation purposes only. It is not medical advice. Please consult a doctor for any health concern. #Tuberculosis #TBEpidemiology #CommunityMedicine #NTEP #NEETPG #AIAPGET #SPMMalayalam #KeralaPSC