Question

A disease spread indirectly through a vector is
a) Sleeping sickness
b) Malaria
c) Kala-azar
d) All of the above

Answer 1

A disease is caused by the infection caused due to due transmission of the infectious agents into a healthy human body. These infectious agents are usually carried by various organisms which are known as vectors. These vectors act as a carrier of the disease. The disease can be caused by direct transmission or indirect transmission.

Complete answer:
Sleeping sickness is a disease caused by the tsetse fly. It is also known as African trypanosomiasis. It is a parasitic disease. The common symptoms of this disease are fever, headache, irritability, fatigue, and disturbed sleeping patterns. Some people can develop neurological disbalance as the disease progresses. It can be fatal if left untreated.
Malaria is caused by the vector mosquito. Only the Aedes mosquito is capable of transmitting the infections. It is caused due to the parasite Plasmodium vivax. The other species of plasmodium cause various types of malaria which can be fatal. It leads to jaundice and anemia in people infected by it due to the loss of red blood cells. If taken properly, it can be treated easily.
Kala-azar is a disease that is caused due to Leishmania parasites. It is spread through the sandflies. It affects the spleen, liver, and bone marrow of the person who gets the infection. The most common symptoms may include weight loss and swelling of the liver and spleen. It also leads to the darkening of the skin that is why it is also called black fever.

So, the answer is option D.

Note:
The prevention of the vector transmitted disease lies in the hygiene maintained in our surroundings. The use of nets on the windows and doors help in preventing the vectors to reach the healthy individual. One should also take care of the diet that one takes.