This lifeform is found widely in Eurasia. This lifeform is found widely in the Indo-Australian region. This lifeform is widespread in North America. This lifeform is found widely in the New World tropics. This lifeform is common in suitable environments.
This genus cases Aids. This lifeform is tansmitted from human to human though blood or sexual secretions. This is frequently referred to as HIV-1 or HIV-2 and is a serious health threat.
Viruses are the most primitive of lifeforms.