Health & Disease
Health questions divide cleanly: communicable diseases with their pathogen and vector, non-communicable diseases with their risk factors, and the national programmes that address each. Learn the disease with its carrier attached.
Mental model
Sort every disease by its CAUSE first, because the cause dictates the cure: virus (no antibiotic works — vaccine or antiviral), bacterium (antibiotic), protozoan (malaria, kala-azar), worm, or deficiency/lifestyle. Then attach the vector where there is one — Anopheles mosquito for malaria, Aedes for dengue and chikungunya, Culex for filariasis. Cause → vector → cure is the triplet the examiner scrambles.
Associations
A short trigger on the left, everything it pulls with it on the right.
Anopheles malaria, Aedes dengue, Culex filaria.
Three mosquitoes, three diseases. Aedes also carries chikungunya and Zika, and bites in daylight, while Anopheles bites at night — a detail that often decides a question about prevention advice.
Bacteria yield to antibiotics; viruses do not.
Tuberculosis, cholera and typhoid are bacterial and treatable with antibiotics. Influenza, dengue, measles and COVID-19 are viral, and antibiotics do nothing for them — a distinction the exam tests directly and public health messaging repeats constantly.
Things to remember
The night-before list. Short enough to recall cold.
- 1Malaria is caused by a Plasmodium parasite transmitted by the female Anopheles mosquito.
- 2Dengue and chikungunya are spread by the Aedes mosquito, which breeds in clean stagnant water and bites during the day.
- 3Tuberculosis is a bacterial disease of the lungs spread through the air; India runs a national elimination programme for it.
- 4Iodine deficiency causes goitre, and iron deficiency causes anaemia — the two most common micronutrient deficiencies in India.
- 5The Universal Immunisation Programme provides free vaccination against a specified set of childhood diseases.
- 6Non-communicable diseases such as diabetes, hypertension and cardiovascular disease now account for the largest share of India's disease burden.
In detail
- Malaria is caused by the Plasmodium protozoan and spread by the female Anopheles mosquito; dengue and chikungunya are viral and spread by the Aedes mosquito, which bites during the day.
- Tuberculosis is bacterial, caused by Mycobacterium tuberculosis, and mainly affects the lungs; India runs a national TB elimination programme against it.
- Antibiotics act only on bacteria, not viruses; taking them for viral illness drives antimicrobial resistance.
- Iodine deficiency causes goitre, iron deficiency causes anaemia, and both are addressed through fortification and supplementation programmes.
- Smallpox is the one human disease declared eradicated worldwide; polio is tackled in India through the oral polio vaccine under the pulse polio programme.
Where people slip
- Antibiotics do not work against viral infections. An option prescribing them for dengue or influenza is wrong.
Check yourself
Nothing here is scored — it will not change your mastery figures.
Dengue fever is transmitted by which mosquito?
From the question bank
Which vitamin is abundantly found in citrus fruits like oranges and lemons?
From the question bank
Where is the headquarters of the World Health Organization (WHO) located?
Books to read
- NCERT Class XII — Biology
- India Year Book — Publications Division, Government of India
- Lucent's General Knowledge
Official sources
Hand-checked official domains only — the notes above carry no links of their own.