ICEBERG PHENOMENON
| A | Apparent and inapparent | |
| B |
Symptomatic and asymptomatic |
|
| C |
Cases and carriers |
|
| D |
Diagnosed and undiagnosed |
Iceberg phenomenon differentiates:
| A |
Apparent and inapparent |
|
| B |
Symptomatic and asymptomatic |
|
| C |
Cases and carriers |
|
| D |
Diagnosed and undiagnosed |
The disease in the community is represented graphically through the phenomenon of iceberg.
Iceberg of disease
o Disease in a community may be compared with an iceberg.
o The floating tip of the iceberg represents what the physician sees in the community, i.e. clinical cases (Diagnosed case, symptomatic case of the clinically apparent case).
o The vast submerged portion of the iceberg represents the hidden mass of disease, i.e. latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community.
- The “waterline” represents the demarcation between apparent and inapparent disease.
- An epidemiologist is concerned with the hidden portion of the iceberg whereas the clinician is concerned with the tip of the iceberg.
- Screening is done for a Hidden portion of the iceberg whereas diagnosis is done for the tip of the iceberg.
o The iceberg phenomenon of disease is not shown by Rabies, Tetanus, Rubella, and Measles.
o The clinician concerned only with the tip of iceberg, i.e symptomatic cases that are seen in clinical treatment, this can result in inaccurate view of the nature and causes of a disease results because the minority of the cases are studied (hidden cases:- submerged portion of iceberg is not studied) –> Clinician’s Fallacy.
| A | It includes sub-clinical cases | |
| B |
It includes carriers |
|
| C |
It constitutes undiagnosed reservoir of infection |
|
| D |
Diagnosis can be made with available techniques |
Ans. is ‘D’ i.e., Diagnosis can be made with available techniques
Iceberg of disease
* Disease in a community may be compared with an iceberg.
* The floating tip of the iceberg represents what the physician sees in the community, i.e. clinical cases (Diagnosed case, symptomatic case of the clinically apparent case).
* The vast submerged portion of the iceberg represents the hidden mass of disease, i.e. latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community.
– The “waterline” represents the demarcation between apparent and inapparent disease.
– An epidemiologist is concerned with the hidden portion of the iceberg whereas the clinician is concerned with the tip of the iceberg.
– Screening is done for a Hidden portion of the iceberg whereas diagnosis is done for the tip of the iceberg.
* The iceberg phenomenon of disease is not shown by Rabies, Tetanus, Rubella, and Measles.
* The clinician concerned only with the tip of iceberg, i.e symptomatic cases that are seen in clinical treatment, this can result in inaccurate view of the nature and causes of a disease results because the minority of the cases are studied (hidden cases:- submerged portion of iceberg is not studied) –> Clinician’s Fallacy diseases with a great deal of subclinical infection (therefore have iceberg phenomenon) are :
- Polio
- Japanese encephalitis
- Influenza
- Mumps
- Hepatitis A and B
- Diphtheria
All show iceberg phenomenon except ‑
| A | Influenza | |
| B |
Polio |
|
| C |
Hepatitis |
|
| D |
Chicken pox |
Ans. is ‘D’ i.e., Chicken pox
Iceberg of disease
- Disease in a community may be compared with an iceberg.
- The floating tip of the iceberg represents what the physician sees in the community, i.e. clinical cases (Diagnosed case, symptomatic case of the clinically apparent case).
- The vast submerged portion of the iceberg represents the hidden mass of disease, i.e. latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community.
- The “waterline” represents the demarcation between apparent and inapparent disease.
- An epidemiologist is concerned with the hidden portion of the iceberg whereas the clinician is concerned with the tip of the iceberg.
- Screening is done for a Hidden portion of the iceberg whereas diagnosis is done for the tip of the iceberg.
- The iceberg phenomenon of disease is not shown by Rabies, Tetanus, Rubella, and Measles.
- The clinician concerned only with the tip of iceberg, i.e symptomatic cases that are seen in clinical treatment, this can result in inaccurate view of the nature and causes of a disease results because the minority of the cases are studied (hidden cases:- submerged portion of iceberg is not studied) –> Clinician’s Fallacy diseases with a great deal of subclinical infection (therefore have iceberg phenomenon) are :
- Polio
- Japanese encephalitis
- Influenza
- Mumps
- Hepatitis A and B
- Diphtheria
In chickenpox
–Inapparent infection is estimated to occur in no more than 5% of susceptible children”.
| A |
Symptomatic and asymptomatic cases |
|
| B |
Diagnosed and undiagnosed cases |
|
| C |
Apparent and inapparent cases |
|
| D |
Case and carriers |
Ans. is ‘c’ i.e., Apparent and inapparent cases
The “waterline” represents the demarcation between apparent and inapparent disease.
True regarding japanese encephalitis is except ‑
| A |
Man to man transmission is not reported |
|
| B |
Culicine mosquito s zoophilic |
|
| C |
Mortality is 80-90% |
|
| D |
Cases show up of iceberg |
Ans. is ‘c’ i.e. Mortality is 80-90%
- Mortality is 20-40% (not 80-90%).
About other options
- Man to man transmission is not seen.
o Cases show tip of iceberg -> Ratio of overt disease to inapparent infection varies from 1 : 1000.
o Culex is a zoophilic mosquito.
| A | Rabies | |
| B |
Polio |
|
| C |
JE |
|
| D |
Mumps |
Ans. is ‘a’ i.e., Rabies
Iceberg phenomenon of disease is not shown by rabies, tetanus and measles.
An infectious disease shows iceberg phenomenon. That means it has ‑
| A |
More case fatality rate |
|
| B |
More SAR |
|
| C |
More subclinical cases |
|
| D |
More complications |
Ans. is ‘C’ i.e., More subclinical cases
Iceberg of disease
Disease in a community may be compared with an iceberg.
The floating tip of the iceberg represents what the physician sees in the community, i.e. clinical cases (Diagnosed case, symptomatic case of the clinically apparent case).
The vast submerged portion of the iceberg represents the hidden mass of disease, i.e. latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community.
- The “waterline” represents the demarcation between apparent and inapparent disease.
- An epidemiologist is concerned with the hidden portion of the iceberg whereas the clinician is concerned with the tip of the iceberg.
- Screening is done for a Hidden portion of the iceberg whereas diagnosis is done for the tip of the iceberg.
The iceberg phenomenon of disease is not shown by Rabies, Tetanus, Rubella, and Measles.
The clinician concerned only with the tip of iceberg, i.e symptomatic cases that are seen in clinical treatment, this can result in inaccurate view of the nature and causes of a disease results because the minority of the cases are studied (hidden cases:- submerged portion of iceberg is not studied) → Clinician’s Fallacy
Diseases with a great deal of subclinical infection (therefore have iceberg phenomenon) are :
- Polio
- Japanese encephalitis
- Influenza
- Mumps
- Hepatitis A and B
- Diphtheria
| A | Mumps | |
| B |
Influenza |
|
| C |
Measles |
|
| D |
Polio |
Ans. is ‘c’ i.e., Measles
Iceberg of disease
o Disease in a community may be compared with an iceberg.
o The floating tip of the iceberg represents what the physician sees in the community, i.e. clinical cases (Diagnosed case, symptomatic case of the clinically apparent case).
o The vast submerged portion of the iceberg represents the hidden mass of disease, i.e. latent, inapparent, presymptomatic and undiagnosed cases and carriers in the community.
- The “waterline” represents the demarcation between apparent and inapparent disease.
- An epidemiologist is concerned with the hidden portion of the iceberg whereas the clinician is concerned with the tip of the iceberg.
- Screening is done for a Hidden portion of the iceberg whereas diagnosis is done for the tip of the iceberg.
o The iceberg phenomenon of disease is not shown by Rabies, Tetanus, Rubella, and Measles.
o The clinician concerned only with the tip of iceberg, i.e symptomatic cases that are seen in clinical treatment, this can result in inaccurate view of the nature and causes of a disease results because the minority of the cases are studied (hidden cases:- submerged portion of iceberg is not studied) –> Clinician’s Fallacy.
In some disease, a great deal of subclinical infection occurs
Polio, Japanese encephalitis, Influenza, Mumps, Hepatitis A and B, Diphtheria
