NATURAL HISTORY OF DISEASE

NATURAL HISTORY OF DISEASE

Iceberg Phenomenon of Disease

• Iceberg Phenomenon of disease: Disease in a community may be compared to an
iceberg

– Floating tip: What physician sees in community (Clinical cases)

– Vast submerged portionQ: Hidden mass of disease (Latent, inapparent, presymptomatic and undiagnosed cases and carriers)

– Line of demarcation (water surface): Is between apparent and inapparent

• ‘Epidemiologist is concerned with Hidden portion of iceberg’ whereas Clinician is concerned with Tip of iceberg

• ‘Screening is done for Hidden portion of Iceberg’ whereas diagnosis is done for tip of
iceberg

• Iceberg phenomenon of disease is not shown by -

– Rabies
– Tetanus
– Measles
– Rubella