Simian foamy viruses (SFVs) are highly prevalent in a variety of nonhuman p
rimate species ranging from prosimians to apes, SFVs possess a broad host r
ange, and human infections can occur by cross-species transfer (W, Heneine
et al., Nat, Med, 4:403-407, 1998). Retrovirus screening of potential sourc
es of infection, such as laboratory research animals and simian-derived bio
logical products, could minimize human exposure to SFVs by reducing the ris
k of potential retrovirus infection in humans. We describe a variety of sen
sitive assays for SFV isolation and detection which were developed with a p
rototype strain of SFV serotype 2, The Mns dunni cell line (M, R, Lander an
d S. K, Chattopadhyay, J. Virol, 52:695-698, 1984) was found to be highly s
ensitive for SFV production on the basis of various general and specific re
trovirus detection assays such as reverse transcriptase assay, transmission
electron microscopy, immunofluorescence assay, and Western blotting. A hig
hly sensitive PCR assay was developed on the basis of the sequences in prim
ary SFV isolates obtained from pig-tailed macaques (Macaca nemestrina) and
rhesus macaques (Macaca mulatta). Analysis of naturally occurring SFV infec
tion in macaques indicated that analysis by a combination of assays, includ
ing both highly sensitive, specific assays and less sensitive, broadly reac
tive assays, is important for evaluation of retrovirus infection.