Biology · Human Health and Diseases · NEET
Typhoid (Salmonella typhi), amoebiasis (Entamoeba histolytica) and ascariasis (Ascaris) spread through food and water contaminated with the pathogen. NCERT groups these three together as food- and water-borne. This is why clean drinking water and proper waste disposal stop them. For NEET, remember this trio together.
Pneumonia (Streptococcus, Haemophilus) and the common cold (rhino viruses) are air-borne. They spread through droplets or aerosols released when an infected person coughs or sneezes, or by close contact with the patient or their belongings. NCERT lists pneumonia and common cold as the two main air-borne examples.
Malaria (female Anopheles mosquito) and filariasis/elephantiasis (female mosquito carrying Wuchereria) spread through insect vectors. Dengue and chikungunya spread through Aedes mosquitoes. A vector is a carrier that transfers the pathogen from one host to another. Controlling mosquito breeding places stops these diseases.
Typhoid is water-borne (and food-borne), NOT air-borne. Salmonella typhi enters the small intestine through food and water contaminated with the pathogen. NEET options often place typhoid with air-borne diseases as a trap, so always tag typhoid as food/water-borne.
Amoebiasis spreads when houseflies act as mechanical carriers, transferring the parasite Entamoeba histolytica from contaminated food and faeces to healthy food, contaminating it. Note: the housefly here is a mechanical carrier, not a true biological vector like the malaria mosquito. NEET tests this housefly-amoebiasis link often.
AIDS is NOT air-borne and does not spread by touch, food, water, or mosquito bite. HIV spreads through sexual contact, infected blood/blood products, sharing infected needles, and from an infected mother to her child (placenta or breast milk). This is why casual contact with an AIDS patient is safe.
In which disease does mosquito transmitted pathogen cause chronic inflammation of lymphatic vessels?
Which of the following diseases is not sexually transmitted?
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Contaminated food/water, air (droplets and close contact), insect vectors, and sexual contact/blood. Use the hook FAVS: Food-water, Air, Vector, Sexual/blood.
A vector is a living carrier, usually an insect like a mosquito, that transfers a pathogen from an infected host to a healthy host. The female Anopheles mosquito is the vector for malaria; Aedes for dengue and chikungunya.
All three are transmitted through food and water contaminated with the pathogen. Because they share the same route, the same prevention (clean water, hygiene, proper waste disposal) works for all three. NEET often asks which diseases share a route.
No. HIV does not spread by mosquito bite, touch, food, water, or air. It spreads only through sexual contact, infected blood, shared needles, and from mother to child. This is a very common NEET trap.
The common cold is air-borne. It spreads through droplets and by close contact with an infected person or their belongings, along with pneumonia.
