Evolution of poliovirus type I during 5.5 years of prolonged enteral replication in an immunodeficient patient

Poliovirus type 1 was isolated from an immunodeficient patient 4 days after onset of paresis (IS1) and after 5.5 years of prolonged enteral virus repl ication (152). Antigenic characterization revealed that IS1 was Sabin 1-lik e, whereas IS2 reacted like poliovirus 1 Mahoney. Complete genomic sequenci ng demonstrated the phylogenetic relationship (94.9% identity) of IS1 and I S2, which differed from the most closely related Sabin 1 by 5.4 and 8.3%, r espectively. Both isolates had revertant-like mutations at nucleotides 480 and 6203. Deduced amino acid sequences indicated significant changes betwee n IS1 and IS2 at the neutralizing antigenic site 1. Prolonged enteral repli cation, evolution, and shedding of poliovirus by immunodeficient patients s hould be considered in the poliovirus eradication strategy. (C) 1999 Academ ic Press.