Hepatitis-$B$ and $HIV$ spread through:

$AIDS$ is caused by which type of virus?

Which enzyme is responsible for integrating the viral $DNA$ (formed after reverse transcription of viral $RNA$) into the host cell $DNA$?

In an $HIV$ infected person,the $HIV$ produced in macrophages enters which cells to replicate and produce its progeny?

In India,the $HIV$ virus was first reported in:

The immune system of a person is suppressed. In the $\text{ELISA}$ test,he was found positive to a pathogen.
$(a)$ Name the disease the patient is suffering from.
$(b)$ What is the causative organism?
$(c)$ Which cells of the body are affected by the pathogen?