• Statement 1 is correct: Cytomegalovirus (CMV) is also known as Human Herpesvirus 5 (HHV-5). It is a common herpes virus that often causes natural infections in childhood and remains asymptomatic in patients with normal immunity. 

• Once infected, the virus is retained in the body for life. Most people don’t realise that they have been infected by CMV because it rarely causes problems in healthy people. 
• The symptoms usually surface only when carriers become immuno-compromised, such as those suffering from cancer, AIDS, or those who have recently had transplants. 

• Statement 2 is correct: Expecting mothers who develop an active CMV infection during pregnancy can pass on the virus to their babies, which is known as congenital CMV. Children born with it may or may not show symptoms. 
• Statement 3 is incorrect: Humans cannot be infected by animal strains of CMV. 

Source: Article