Final answer:
Toxoplasmosis, caused by Toxoplasma gondii, is a significant infection that can cause severe complications in immunocompromised people and during pregnancy. CMV is another infectious agent that can cause infectious mononucleosis and poses a threat to the immunocompromised.
Step-by-step explanation:
Toxoplasmosis is a protozoal infection primarily caused by Toxoplasma gondii. It particularly poses risks to immunocompromised individuals and can affect developing fetuses when a mother contracts the infection during pregnancy. This condition is noteworthy among various infections that can cause complications in these sensitive populations, alongside others like syphilis (Treponema pallidum), varicella (Varicella-zoster virus), rubella, and HIV (Retrovirus).
Another notable infection in immunocompromised patients is Cytomegalovirus (CMV). It is caused by human herpesvirus 5 and can lead to infectious mononucleosis, with potential severe complications in persons with weakened immune systems. The Toxoplasma gondii infection, while often asymptomatic, can become problematic when reactivated under conditions of immunocompromise, leading to severe illnesses such as encephalitis or retinitis.