Which one of the following diseases is non-infectious?

The correct answer is Option (4) → Elephantiasis

Note 1: None of the given options appears to be correct, as explained below. As per NCERT, elephantiasis is an infectious disease, spread by mosquitoes.

An infectious disease is caused by a pathogen and can pass from an infected person to a healthy one, through air, water, food, contact or a vector such as a mosquito. A non-infectious disease, such as cancer, cannot pass from one person to another.

Option (1) Cholera — An infectious disease. It is caused by a bacterium and spreads through contaminated water and food.

Option (2) Pneumonia — An infectious disease. Bacteria such as Streptococcus pneumoniae and Haemophilus influenzae infect the alveoli of the lungs. A healthy person gets it by inhaling droplets from an infected person or by sharing glasses and utensils.

Option (3) Tuberculosis — An infectious disease. It is caused by the bacterium Mycobacterium tuberculosis and spreads through the air when an infected person coughs.

Option (4) Elephantiasis — The answer given here; an infectious disease as per NCERT. The filarial worm passes from person to person through the bite of a mosquito, so the disease is infectious even though it needs a vector.

Note 2: The same question was also asked in CUET (UG) 2025 on 03-06-2025 (Slot 2).

NCERT Extract:
Common Diseases in Humans – “… Wuchereria (W. bancrofti and W. malayi), the filarial worms cause a slowly developing chronic inflammation of the organs in which they live for many years, usually the lymphatic vessels of the lower limbs and the disease is called elephantiasis or filariasis (Figure 7.2). The genital organs are also often affected, resulting in gross deformities. The pathogens are transmitted to a healthy person through the bite by the female mosquito vectors.”