It depends what you mean by 'amoeba'. I don't know of any reports
from the genus Amoeba but viruses and virus like particles have
been reported in the amebae Entamoeba and Naegleria. You might want
to consult the reviews below. I am not aware of viruses in Paramecium
except for bacteriophages that infect the bacterial symbionts (kappa)
of paramecia.
Graham
Wang AL; Wang CC
Viruses of the protozoa.
Annual Review of Microbiology 1991;45:251-63
Diamond LS; Mattern CF
Protozoal viruses.
Advances in Virus Research 1976;20:87-112
______________________________________________
C. Graham Clark, Ph.D.
Laboratory of Parasitic Diseases,
National Institutes of Health,
Bethesda, MD 20892-0425
Tel:301-496-4740
FAX:301-402-4941
e-mail:cge at cu.nih.gov