Master PSM (Preventive Social Medicine)
for FMGE

Core Concepts

Preventive Social Medicine (PSM), also known as Community Medicine, focuses on health promotion, disease prevention, and addressing social determinants of health at a population level. Key principles include:

• Epidemiology: Study of disease distribution and determinants in populations.
• Health Indicators: Measures reflecting health status (e.g., IMR, MMR, CBR, CDR, U5MR, Life Expectancy).
• Levels of Prevention:
  • Primordial: Preventing emergence of risk factors (e.g., healthy lifestyle promotion in childhood).
  • Primary: Preventing onset of disease (e.g., vaccination, health education, sanitation).
  • Secondary: Early detection and prompt treatment (e.g., screening for cervical cancer, DOTS for TB).
  • Tertiary: Limiting disability, rehabilitation (e.g., physiotherapy after stroke).
• Screening: Presumptive identification of unrecognised disease using tests, examinations, or other procedures. Criteria for a good screening test: valid (sensitive & specific), reliable, simple, safe, acceptable, affordable.
• Study Designs:
  • Descriptive: Case reports, case series, cross-sectional (prevalence).
  • Analytical: Case-control (odds ratio), Cohort (relative risk, attributable risk), Ecological.
  • Experimental: RCTs (clinical trials), Field trials, Community trials.
• National Health Programs: Understanding their objectives, target groups, and key interventions (e.g., RMNCH+A, NVBDCP, NLEP, NTEP, NCD programs, IDSP).
• Demography: Study of population dynamics (fertility, mortality, migration). Stages of demographic transition.
• Iceberg Phenomenon of Disease: Only a small proportion of a disease is clinically apparent (tip of the iceberg); a large portion remains hidden (unreported cases, carriers, subclinical cases).

Clinical Presentation (Public Health Scenarios)

• Outbreak Investigation: Cluster of acute febrile illness, diarrhea, or rash in a community, suggestive of common source exposure or person-to-person transmission.
• High Maternal/Child Mortality: Persistent elevated rates of maternal deaths or under-5 child deaths in a geographical area, indicating gaps in RMNCH+A services.
• Nutritional Deficiencies: High prevalence of protein-energy malnutrition (PEM), anemia, or micronutrient deficiencies (e.g., Vitamin A deficiency) among specific vulnerable groups (children, pregnant women).
• Non-communicable Disease Burden: Rising prevalence of hypertension, diabetes, CVD, or cancers in an adult population, indicating lifestyle risk factors and need for NCD screening/management.
• Environmental Health Issues: High incidence of water-borne diseases (e.g., cholera, typhoid) linked to unsafe drinking water, or vector-borne diseases (e.g., dengue, malaria) due to poor sanitation and vector breeding sites.
• Vaccine-Preventable Disease Cases: Sporadic cases or clusters of measles, diphtheria, pertussis, or polio, signaling gaps in immunization coverage.

Diagnosis (Gold Standard for Public Health Problems)

In PSM, "diagnosis" refers to identifying the nature and extent of a community health problem or disease outbreak.

• Outbreak Confirmation:
  • Epidemiological Linkage: Demonstrating a statistically significant association of cases in time, place, and person.
  • Laboratory Confirmation: Isolation of causative agent from clinical samples (e.g., stool culture for cholera, RT-PCR for viral outbreaks) and environmental samples (e.g., water analysis).
• Disease Burden Assessment:
  • Surveillance Data Analysis: Systematic collection, analysis, interpretation, and dissemination of health data (e.g., IDSP data).
  • Community Surveys: Cross-sectional studies using standardized tools (e.g., NFHS for maternal & child health indicators, nutrition surveys).
• Nutritional Status:
  • Anthropometry: Weight-for-age, height-for-age, weight-for-height (Z-scores) against WHO growth standards. MUAC for severe acute malnutrition (SAM).
  • Biochemical Tests: Hemoglobin estimation for anemia, serum Vitamin A levels.
• Environmental Quality:
  • Water Quality Testing: For residual chlorine, pH, turbidity, and bacteriological parameters (e.g., E. coli, coliforms).
  • Vector Indices: Breteau index, House index for Aedes mosquitoes; Man hour density for anopheline mosquitoes.

Management (First Line Public Health Interventions)

Management in PSM involves population-level strategies for prevention, control, and health improvement.

• Immunization: Universal Immunization Program (UIP) schedule adherence, maintaining cold chain, awareness campaigns to increase coverage.
• Health Education & Promotion (IEC/BCC): Targeted Information, Education, and Communication (IEC) and Behavior Change Communication (BCC) activities for healthy lifestyles, hygiene, sanitation, and disease prevention.
• Environmental Sanitation: Provision of safe drinking water (chlorination, water purification), proper waste disposal (solid, liquid, biomedical), safe food handling practices.
• Vector Control: Anti-larval measures, anti-adult measures (spraying, fogging), personal protection (LLINs, repellents), environmental modification to reduce breeding sites.
• Nutritional Interventions: Promotion of Infant and Young Child Feeding (IYCF) practices, micronutrient supplementation (Vitamin A, iron-folic acid), deworming, management of severe acute malnutrition (SAM).
• Outbreak Control:
  • Case identification, isolation, and prompt treatment.
  • Contact tracing and prophylactic measures (e.g., vaccination, chemoprophylaxis).
  • Source identification and elimination (e.g., contaminated food/water source).
  • Risk communication to the public.
• National Health Programs Implementation: Strengthening program specific activities like DOTS for TB (NTEP), Integrated Management of Neonatal and Childhood Illness (IMNCI), early detection and referral for NCDs.

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