I say no for the nomad peple because their food, for example, is various, they can married with different persons with are not part of theyr tribe or grup.
An agrarian society due to his work in agriculture, therefore fresh air, physical effort, can be healthyer than a rural society.
On the other hand, a hunter- gatherer society is a primitive society and can be exposed to a disease by eating infested meal but this is not quite a danger.
Disease is easier to spread in agrarian society.
The reason why it spreads easier in the agrarian society is because within this society the people depend on each other for goods and other services, and this leads to the spread of diseases.
hope this helps
what is the other part to the question