Question

Which has been eradicated?
A. Plague
B. Kala-Azar
C. Smallpox
D. Poliomyelitis

Answer 1

Hint: Eradication of a disease refers to its complete removal from the human species, such that its cases stop coming up. In addition, due to the easily available vaccine of the disease that was discovered by Edward Jenner, humans have developed immunity to that disease.

Complete answer:Plague/Bubonic Plague:
It is also known as the Black death. The pathogen is Yersinia pestis. It is mainly a disease of rodents, but sometimes it affects humans also. It spreads in the rat community through the rat flea known as Xenopsylla. It is characterized by a high fever and the formation of a lump called bubo in the groin or the armpit. Red patches appear in the skin which ultimately becomes black and leads to death.
-Kala-Azar:
It is also known as Black fever. It is caused by the infection of the Leishmania parasite. Its vector is a sandfly. The common symptoms include fever, loss of weight. There is swelling observed on the Liver and Spleen because it affects the internal organs like the Liver, Spleen, and Bone marrow.
-Smallpox:
It was discovered by Edward Jenner. It is caused by the smallpox virus known as the Variola virus. It is present in the oral and the nasal discharges of the patients and gets ejected out during coughing, sneezing, etc., to affect healthy people. It is highly infectious and is characterized by symptoms like high fever, chills, backache, headache, etc. On the third day of illness rash is observed which changes into papules, and then vesicles containing fluids. Vaccination for this disease is easily available nowadays. It has been eradicated from the world.
-Poliomyelitis:
It is also known as infantile paralysis. This disease mainly spreads through the intestinal discharges. Poliovirus reaches the spinal cord and the nervous system via the alimentary canal. Its incubation period is 7-14 days. Stiffness of the neck is an important symptom. Paralysis is followed by chills, and pain all over the body.
Thus, smallpox has been eradicated from the world.
Hence, the correct answer is option C.

Note: Polio has been completely eradicated from our country. Until 2009, India had almost half the number of Polio cases. However, in 2014, it was declared Polio-free due to the consistent efforts of the government, WHO, UNICEF, and other premier organizations.