Which disease is not the sexually transmitted infection?

The correct answer is Option (2) → Elephantiasis

Sexually transmitted infections (STIs) are infections passed from one person to another through sexual intercourse. They are also called venereal diseases (VD) or reproductive tract infections (RTI).

Option (1) Chlamydiasis — A sexually transmitted infection. Chlamydiasis is one of the common STIs that NCERT lists. It spreads through sexual contact, and it can be cured if it is detected early and treated properly.

Option (2) Elephantiasis — Not a sexually transmitted infection. Elephantiasis is a worm disease of the lymphatic vessels, carried from person to person by mosquitoes. Sexual contact plays no part in passing it on.

Option (3) Trichomoniasis — A sexually transmitted infection. Trichomoniasis is also in NCERT’s list of common STIs. It passes between partners during sexual intercourse.

Option (4) Gonorrhoea — A sexually transmitted infection. Gonorrhoea is one of the best-known STIs, spread by sexual contact with an infected person. It is completely curable if treated early.

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.”
Sexually Transmitted Infections (STIs) – “Infections or diseases which are transmitted through sexual intercourse are collectively called sexually transmitted infections (STI) or venereal diseases (VD) or reproductive tract infections (RTI). Gonorrhoea, syphilis, genital herpes, chlamydiasis, genital warts, trichomoniasis, hepatitis-B and of course, the most discussed infection in the recent years, HIV leading to AIDS are some of the common STIs.”