The Spectrum of Disease and The Iceberg Phenomenon - NEET PG PSM
Mar 28, 2023
Epidemics are sudden and widespread disease outbreaks in a particular community or region. Understanding the types of epidemics, such as common-source, propagated, and mixed epidemics is important for their control and management.
NEET PG may test your knowledge of the different epidemics and their management strategies. The topics of "Types of Epidemics," "Levels of Prevention of Disease," and "Iceberg Phenomenon of Disease" are particularly important for the NEET PG exam.
1. Literacy Rate 2. IMR 3. Life Expectancy at 1 year of age
1. Literacy Rate 2. Income 3. Life Expectancy at Birth
HDI
Literacy Rate is known by different synonymous
Education index
Enrolment ratio in schools
Knowledge
Mean years of School
Income measured in
Per capita (or) US $ PPP (Purchasing power parity)
Life expectancy is also known as longevity at birth or LE0 in HDI or LE1 in PQLI
Important Information
PQLI: 0 - 100; PQLI of India: 65
HDI: 0 - +1, HDI of India: 0.640, Rank: 129
Norway: HDI of 0.95 is the most developed country
MDPI (Multidimensional Poverty Index) has 3 Indicators further comprised of 10 sub-indicators
Health
Education
Living Standard
MDPI will define the person as poor, if there is deprivation in >33% of the indicators. It has 3 main Indicators which lie between 0 to +1. Based on MDPI India has a 27.9% poor population.
Below Poverty Line (BPL) Criteria
Rural
Urban
Caloric Intake (M/Imp)
< 2400 Kcal
< 2100 Kcal
Income Per Capita
< 32 Rs/Person/day
< 47 Rs/Person/day
Income (Ld bank)
< US $ 1.90: Extreme poverty
Based on Income per Capita, currently 29.5% of the Indian population is living below the poverty line.
Time Distribution of Disease
Short-term fluctuations: Epidemics
E.g.: Food poisoning, Bhopal Gas tragedy
Long-term fluctuation: Secular Trend
E.g.: Non-communicable disease (DH, CAD)
Periodic fluctuations
Seasonal Trend: Disease that increases every particular season
E.g.: Malaria, Dengue in the rainy season, RTI in winter season
Cyclical Trend: Fluctuations in every few years
E.g.
Measles, Rubella, Influenza
Measles every 2-3 years
Rubella every 5-8 years
Important Information
Influenza shows maximum change in trend due to antigenic shift/drift
Types of Epidemics
1. Single Exposure Point Source Epidemic (SEPSE)
Sudden Rise and Sudden Fall in no. of cases
Cluster of cases in a single incubation period.
E.g.: Staph food poisoning/Bhopal gas tragedy
2. Multiple Exposure Point Source Epidemic (MEPSE)
Sudden rise in no. of cases, but fall in no. of cases is not sudden but interrupted by multiple peaks.
These multiple peaks are known as secondary waves
E.g.
Contaminated Water Supply/Well in Village
HIV through Commercial Sex Worker
3. Propagated Epidemic
Person to-person transmission
Slow rise in population → Plateau → Slow fall
Absence of peak
E.g.: HIV, TB, Hep-A, Recurrence of Polio
Control of Disease
Control: Reduction in transmission so that it stops to be a public health problem.
It has 4 components
Reduction of incidence
Reduction of duration
Reduction of complications
Reduction of the financial burden of disease
Elimination: Complete interruption of transmission, but the organism is still present, so the disease can make a comeback. (Country/ Region)
Eradication: Complete extermination of the organism (World)
India has been declared free status of 2 diseases namely
Trachoma
Polio
Only Smallpox has been eradicated from the world on 8 May 1980
Only 2 strains of poliovirus have been eradicated and not the disease
P2: 20th September 2015
P3: October 2019
Levels of Prevention of Disease
Primordial: Before the emergence of risk factors
Examples of Primordial: Source reduction in Malaria (i.e. stranded water)
Primary: Risk factors present but no disease yet
Health promotion & specific protection
Primary can prevent
Examples of 1°: Vaccine and contraceptives; Mosquito Nets and Gambusia fish, masks, social distancing
Secondary: Disease has possibly started
Early diagnosis and treatment
Cannot prevent
Examples of 2°: PBS of Malaria, Sputum smears examination for TB, drug Remdesivir, Western blot for HIV, PAP smear, ATT, MDT (multi-drug therapy), ACT
Tertiary: Disease is in progression
Disability limitation and rehabilitation
Spectacles are also visual rehabilitation
Examples of 3°: Crutches in Polio, Spectacles
ICD-II (INTERNATIONAL CLASSIFICATION OF DISEASES)
It contains 3 Volumes and has 26 chapters along with chapter X, V.
I Volume: Tabulation list
II Volume: Reference guide
III Volume: Alphabetical Index
Chapter X: Extension quotes
Chapter V: Functional assessment
Revised every 10 years, right now 11th edition released in June 2018
Chapter 6: Mental behavioral and Neurodevelopmental disorders
It is a proportion, always expressed in percentage
TYPES OF SURVEILLANCE
Passive (90%): Patient reports to health system on its own
Active (8-10%): Seen in Malaria/ Polio/ TB/ Kala azar/ Leprosy/ RNTCP/ NLEP
Sentinel: To identify Hidden/ Missing cases, seen in HIV. The trend of a disease can be known
All are secondary levels of prevention
Previous Year Questions
Q. Food poisoning is an example of?(FMGE Dec 2017)
A. Point source epidemic
B. Propagated source epidemic
C. Common source epidemic
D. Pandemic
Q. A well of contaminated water resulting in an epidemic of acute watery diarrhea is a typical example of?(FMGE June 2018)
A. Common source single exposure epidemic
B. Common source continuous exposure epidemic
C. Slow epidemic
D. Propagated epidemic
Q. On Republic Day, a camp was organized, and people were screened for HTN by checking BP and for DM by checking their BMI and blood sugar level, level of prevention is?(FMGE Dec 2019)
A. Primary
B. Primordial
C. Secondary
D. Tertiary
Q. A man came for a checkup after his father had a cerebrovascular accident due to hypertension. What type of prevention is this?(FMGE Aug 2020)
A. Primordial
B. Primary
C. Secondary
D. Specific protection
Q. Interval between primary and secondary cases is known as? (NEET 2018)
A. Serial interval
B. Generation time
C. Incubation time
D. Lead time
Q. Long term changes/ sequelae of a disease are seen in?(FMGE Aug 2020)
A. Secular trend of a disease
B. Cyclical trend of a disease
C. Disease changing its traits according to herd immunity in the population
D. Disease changing the symptoms as per seasons
Q. Counseling and Screening is done for Tuberculosis is an HIV positive patient at ICTC center (NACP program). This is which level of prevention?(FMGE June 2022)
A. Primary
B. Secondary
C. Primordial
D. Tertiary
Q. TB sputum assessment comes under which type of mode of prevention? (FMGE June 2022)
A. Primary
B. Secondary
C. Primordial
D. Tertiary
Q. A person working in an industry lost his hand. He is unable to do his daily activities including writing and machine working. Which is an Impairment In this guy? (FMGE June 2022)
A. Accident in industry
B. Can't do his machine work
C. Loss of anatomical structure
D. Unemployment
To study this topic in depth and other PSM topics, download the PrepLadder app and find high-quality preparation content. for NEET PG exam.
PrepLadder Medical
Get access to all the essential resources required to ace your medical exam Preparation. Stay updated with the latest news and developments in the medical exam, improve your Medical Exam preparation, and turn your dreams into a reality!