Question

A parasitic disease, which is not transmitted through bite of insect vector is
A. Filariasis
B. Malaria
C. Leishmaniasis
D. Ascariasis

Answer 1

A vector can be understood as an organism that has the ability to spread a disease, but does not cause the disease by itself. It carries the pathogen from one host to the next. It is a major component in the spread of various infectious diseases.

Complete answer:
Many infectious diseases are spread through insect vectors such as mosquitoes. But Ascariasis is a disease caused by a pathogenic worm known as Ascaris, which enter into the human body through the soil or water contaminated with human feces which has the eggs of the pathogen. Thus the spread of the disease is through human feces containing the organism into the soil, from where it enters into the next organism and the cycle continues.
Considering the other given options:
Filariasis is an infectious disease caused by a roundworm known as Wuchereria bancrofti, the spread of this disease is through the bite of mosquitoes, which transmit the larvae from one host to the next. Thus it is a disease spread by an insect vector.
Malaria is a protozoan infectious disease, which is transmitted by a female Anopheles mosquito that acts as a vector, hence it is also transmitted by an insect vector.
Leishmaniasis is transmitted through the bite of flies known as Phlebotomine sand flies. Thus it is also transmitted by an insect vector.

So, the correct answer is “Option D”. As the rest of the diseases have spread through an insect vector.

Note:
Ascariasis is found to commonly infect children, and the individuals residing in unhygienic areas, without access to clean food or drinking water. This disease is characterized by watery stools and dehydration causing weakness. On getting severe it can cause perforations in the walls of the small intestine which is fatal.