What is the difference between communicable and non-communicable diseases?

Communicable (Infectious) Diseases: Can spread from person to person through pathogens (bacteria, viruses, fungi, parasites). Examples: Tuberculosis, Malaria, COVID-19, Cholera. Non-Communicable Diseases (NCDs): Cannot spread person to person; caused by lifestyle, genetics, environment. Examples: Diabetes, Heart disease, Cancer, Hypertension.

What is the Universal Immunisation Programme (UIP) in India?

The Universal Immunisation Programme (UIP) was launched in India in 1985 to provide free vaccines to children and pregnant women. It covers BCG, OPV, DPT, Hepatitis B, Measles, IPV, Pentavalent, PCV, Rotavirus vaccines, and Tetanus Toxoid for pregnant women. India achieved polio-free status in 2014.

What diseases do different mosquitoes transmit?

Anopheles mosquito: Malaria (Plasmodium parasite), Filariasis. Aedes mosquito: Dengue fever, Chikungunya, Zika virus, Yellow fever. Culex mosquito: Japanese Encephalitis (brain fever), Filariasis. In Tamil Nadu, Dengue and Chikungunya (Aedes) and Malaria (Anopheles) are significant public health concerns.

Health, Nutrition and Diseases — TNPSC Group II/IIA Science

Overview

Health and nutrition questions in TNPSC Group 2/2A cover vitamins and their deficiency diseases, communicable diseases, vector-borne diseases, vaccination programmes, and health organizations. This is a high-scoring section if you memorise the vitamin-disease connections and disease-vector connections.

Vitamins

Fat-Soluble Vitamins (Stored in body)

Vitamin	Chemical Name	Source	Deficiency Disease
A	Retinol	Milk, eggs, fish oil, carrots, green leafy vegetables	Night blindness, Xerophthalmia
D	Calciferol	Sunlight (skin synthesis), fish oil, egg yolk, fortified milk	Rickets (children), Osteomalacia (adults)
E	Tocopherol	Vegetable oils, nuts, green vegetables	Infertility, muscle weakness, haemolysis of RBCs
K	Phylloquinone	Green leafy vegetables, liver	Impaired blood clotting (haemorrhage)

Water-Soluble Vitamins (Not stored; regular intake needed)

Vitamin	Chemical Name	Source	Deficiency Disease
B1	Thiamine	Whole grains, legumes, pork	Beri-beri (nervous system, heart)
B2	Riboflavin	Milk, eggs, meat, green vegetables	Ariboflavinosis (cracks at mouth corners, skin problems)
B3	Niacin	Meat, fish, peanuts, whole grains	Pellagra (3D's: Dermatitis, Diarrhoea, Dementia)
B6	Pyridoxine	Meat, fish, potatoes, fortified cereals	Anaemia, peripheral neuropathy
B9	Folic acid	Green leafy vegetables, legumes, fortified foods	Neural tube defects in fetus, Megaloblastic anaemia
B12	Cyanocobalamin	Animal products (meat, dairy, eggs)	Pernicious anaemia, nerve damage
C	Ascorbic acid	Citrus fruits (lemon, orange), guava, amla	Scurvy (bleeding gums, joint pain)

Memory Aid for Vitamin Deficiency Diseases

Vitamin	Disease
A	Night Blindness
B1	Beri-Beri
B3	Pellagra (3 Ds)
B9	Neural Tube Defects
B12	Pernicious Anaemia
C	Scurvy
D	Rickets (children)
K	Haemorrhage

Minerals for Health

Mineral	Function	Source	Deficiency
Calcium (Ca)	Bones, teeth, muscle	Milk, dairy, green vegetables	Osteoporosis, rickets
Iron (Fe)	Haemoglobin production	Red meat, spinach, lentils	Anaemia (iron deficiency)
Iodine (I)	Thyroid hormone production	Seafood, iodised salt	Goitre, hypothyroidism
Sodium (Na)	Fluid balance, nerve function	Salt, processed foods	Hyponatraemia
Fluorine (F)	Dental health	Fluoridated water, toothpaste	Dental caries (excess = fluorosis)
Zinc (Zn)	Immune function, growth	Meat, shellfish, legumes	Growth retardation, immune weakness

Types of Diseases

Based on Spread

Type	Description	Examples
Communicable (Infectious)	Spread by pathogens	TB, Malaria, Cholera, COVID-19, Typhoid
Non-Communicable (NCDs)	Not contagious; lifestyle/genetics	Diabetes, Cancer, Heart disease, Hypertension

Based on Pathogen

Pathogen	Disease	Transmission
Bacteria	TB, Typhoid, Cholera, Tetanus	Air, water, food, contact
Virus	COVID-19, HIV/AIDS, Influenza, Dengue, Polio, Hepatitis B	Air, blood, vector
Protozoa	Malaria, Amoebic dysentery, Kala-azar	Vector, water
Fungi	Ringworm, Athlete's foot	Direct contact
Helminths (Worms)	Filariasis (elephantiasis), Roundworm, Tapeworm	Vector, food

Vector-Borne Diseases

Mosquito-Borne Diseases (Most Important for TNPSC)

Mosquito	Disease	Pathogen
Anopheles (female)	Malaria	Plasmodium (protozoan)
Aedes aegypti	Dengue fever	Dengue virus
Aedes aegypti	Chikungunya	Chikungunya virus
Aedes aegypti	Zika virus	Zika virus
Culex	Japanese Encephalitis	JE virus
Culex + Anopheles	Lymphatic Filariasis (Elephantiasis)	Wuchereria bancrofti

Other Vector-Borne Diseases

Vector	Disease	Pathogen
Sandfly	Kala-azar (Visceral Leishmaniasis)	Leishmania donovani
Tse-tse fly	Sleeping sickness	Trypanosoma
Rat flea	Plague	Yersinia pestis
Housefly	Typhoid, Cholera, Diarrhoea	Various

Important Communicable Diseases

Malaria

Pathogen: Plasmodium (4 types: P. falciparum — most dangerous; P. vivax — most common)
Vector: Female Anopheles mosquito
Symptoms: Cyclic fever and chills, anaemia
Diagnosis: Blood smear test, RDT
Treatment: Chloroquine (for P. vivax), Artemisinin combination (for P. falciparum)
Prevention: Mosquito nets (bed nets), repellents, eliminate stagnant water

Tuberculosis (TB)

Pathogen: Mycobacterium tuberculosis (bacteria)
Transmission: Airborne droplets (coughing, sneezing)
Symptoms: Persistent cough, blood in sputum, fever, weight loss
Diagnosis: Chest X-ray, sputum culture, Mantoux test
Treatment: DOTS (Directly Observed Treatment, Short-course) — 6 months
Prevention: BCG vaccine at birth
India: Highest TB burden in world (~2.5 million cases/year)

Dengue Fever

Pathogen: Dengue virus (4 serotypes)
Vector: Aedes aegypti mosquito (bites in daytime)
Symptoms: High fever, severe headache, pain behind eyes, rash, joint pain
Warning signs: Thrombocytopenia (low platelets), bleeding
No specific treatment: Supportive care; maintain hydration; paracetamol (not aspirin)
Prevention: Eliminate stagnant water; use mosquito repellent; wear full clothes

COVID-19

Pathogen: SARS-CoV-2 virus
Transmission: Respiratory droplets, aerosols
Vaccines: Covishield (India, AstraZeneca), Covaxin (Bharat Biotech), Corbevax, ZyCoV-D (DNA vaccine)
WHO declared pandemic: March 11, 2020

Vaccination and Immunisation

Types of Vaccines

Type	Examples
Live attenuated	BCG, Oral Polio (OPV), MMR, Chickenpox
Inactivated (Killed)	Hepatitis A, Rabies, IPV (Inactivated Polio)
Toxoid	DPT (Diphtheria, Pertussis, Tetanus)
Subunit	Hepatitis B, HPV
mRNA	COVID-19 (Pfizer, Moderna)
DNA	ZyCoV-D (COVID-19)

Universal Immunisation Programme (UIP)

Vaccine	Prevents	Given at
BCG	Tuberculosis	Birth
Oral Polio (OPV)	Polio	Birth, 6, 10, 14 weeks, boosters
Hepatitis B	Hepatitis B	Birth, 6, 10, 14 weeks
DPT/Pentavalent	Diphtheria, Pertussis, Tetanus, Hib, HepB	6, 10, 14 weeks
Measles/MR	Measles, Rubella	9–12 months, 16–24 months
JE	Japanese Encephalitis	9–12 months (endemic districts)
Rotavirus	Rotavirus diarrhoea	6, 10, 14 weeks

Polio-free India: Certified on March 27, 2014 by WHO

Key Health Organisations

Organisation	Full Form	Headquarters	Founded
WHO	World Health Organization	Geneva, Switzerland	1948
UNICEF	UN Children's Fund	New York, USA	1946
AIIMS	All India Institute of Medical Sciences	New Delhi	1956
ICMR	Indian Council of Medical Research	New Delhi	1911
PGI	Postgraduate Institute (Chandigarh)	—	1962

WHO Director-General: Tedros Adhanom Ghebreyesus (2017–) World Health Day: April 7 (WHO founding)

Key Facts for TNPSC Group II/IIA

Vitamin A deficiency: Night blindness; found in carrots, milk, green leafy vegetables
Vitamin C deficiency: Scurvy (bleeding gums); found in citrus fruits, guava, amla
Vitamin D deficiency: Rickets (children); synthesised by skin from sunlight
Iron deficiency: Anaemia — most common nutritional deficiency in India
Iodine deficiency: Goitre; prevented by iodised salt
Anopheles mosquito: Malaria; Aedes mosquito: Dengue, Chikungunya, Zika
BCG vaccine: Prevents tuberculosis; given at birth
India polio-free: March 27, 2014
DOTS: Treatment for tuberculosis; 6-month course
WHO headquartered: Geneva, Switzerland; founded April 7, 1948

Previous Year MCQ Patterns

Q: Night blindness is caused by deficiency of which vitamin? a) Vitamin C b) Vitamin A c) Vitamin D d) Vitamin B12

Answerb) Vitamin A — Night blindness (nyctalopia) is caused by Vitamin A (Retinol) deficiency. Vitamin A is essential for the production of rhodopsin, a pigment in the rod cells of the retina that is needed for vision in low light. Severe deficiency can lead to xerophthalmia (dry eyes) and total blindness.

Q: Which mosquito is the vector for Dengue fever? a) Culex b) Anopheles c) Aedes aegypti d) Mansonia

Answerc) Aedes aegypti — Dengue fever is transmitted by the Aedes aegypti mosquito, which bites during the daytime (unlike Anopheles which bites at night). Aedes also transmits Chikungunya and Zika virus. Anopheles transmits malaria; Culex transmits Japanese Encephalitis.

Q: Rickets in children is caused by deficiency of: a) Vitamin A b) Vitamin B12 c) Vitamin C d) Vitamin D

Answerd) Vitamin D — Rickets is a skeletal deformity in children caused by Vitamin D deficiency, which leads to improper calcium absorption and soft, weak bones. Vitamin D is synthesised by the skin when exposed to sunlight. In adults, the same deficiency causes osteomalacia (soft bones).

Frequently Asked Questions

Fat-soluble vitamins are A, D, E, and K (remembered as ADEK). They are stored in body fat and liver. Vitamin A (Retinol): Night blindness, dry skin. Vitamin D (Calciferol): Rickets in children, osteomalacia in adults. Vitamin E (Tocopherol): Antioxidant, infertility. Vitamin K (Phylloquinone): Blood clotting.