The compound of Formula IIIe for use in the treatment of a host in need thereof infected with an RNA virus other than HCV: or a pharmaceutically acceptable salt thereof; wherein: Y is NR 1 R 2 ; R 1 is methyl; R 2 is hydrogen; R 3 is hydrogen, , diphosphate, triphosphate, a carbonyl linked amino acid, or -C(O)R 3C ; R 3A is selected from O - , OH, an -O- aryl, an -O- heteroaryl, and an heterocyclyl; R 3B is selected from O - , OH, an N-linked amino acid, and an N-linked amino acid ester; R 3C is alkyl, alkenyl, alkynyl, -(C 0 -C 2 )(cycloalkyl), -(C 0 -C 2 )(heterocyclo), -(C 0 -C 2 )(aryl), -(C 0 -C 2 )(heteroaryl), -O-alkyl, -O-alkenyl, -O-alkynyl, -O-(C 0 -C 2 )(cycloalkyl), -O-(C 0 -C 2 )(heterocyclo), -O-(C 0 -C 2 )(aryl), -O-(C 0 -C 2 )(heteroaryl), -S-alkyl, -S-alkenyl, -S-alkynyl, -S-(C 0 -C 2 )(cycloalkyl), -S-(C 0 -C 2 )(heterocyclo), -S-(C 0 -C 2 )(aryl), or -S-(C 0 -C 2 )(heteroaryl); R 7 is hydrogen, C 1-6 alkyl, C 3-7 cycloalkyl, heteroaryl, heterocyclyl, or aryl; R 8 is hydrogen or C 1-6 alkyl; R 9a and R 9b are independently selected from hydrogen, C 1-6 alkyl, cycloalkyl, -(CH 2 ) c (NR 9' ) 2 , C 1-6 hydroxyalkyl, -CH 2 SH, -(CH 2 ) 2 S(O)Me, -(CH 2 ) 3 NHC(=NH)NH 2 , (1H-indol-3-yl)methyl, (1H-imidazol-4-yl)methyl, -(CH 2 )CCOR 9" , aryl and aryl(C 1-3 alkyl)-; R 9' is independently hydrogen or C 1-6 alkyl; R 9" is -OR 11 or -N(R 11' ) 2 ; R 10 is hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, heterocycloalkyl, aminoacyl, aryl, heteroaryl, aryl, or heteroaryl; R 11 is C 1-6 alkyl, cycloalkyl, C 2-6 alkynyl, C 2-6 alkenyl, or acyl; R 11' is hydrogen, C 1-6 alkyl, cycloalkyl, C 2-6 alkynyl, C 2-6 alkenyl, or acyl; and c is 1 to 6; wherein the virus is from the Flaviviridae family. Y is NR 1 R 2 ; R 1 is methyl; R 2 is hydrogen; R 3 is hydrogen, , diphosphate, triphosphate, a carbonyl linked amino acid, or -C(O)R 3C ; R 3A is selected from O - , OH, an -O- aryl, an -O- heteroaryl, and an heterocyclyl; R 3B is selected from O - , OH, an N-linked amino acid, and an N-linked amino acid ester; R 3C is alkyl, alkenyl, alkynyl, -(C 0 -C 2 )(cycloalkyl), -(C 0 -C 2 )(heterocyclo), -(C 0 -C 2 )(aryl), -(C 0 -C 2 )(heteroaryl), -O-alkyl, -O-alkenyl, -O-alkynyl, -O-(C 0 -C 2 )(cycloalkyl), -O-(C 0 -C 2 )(heterocyclo), -O-(C 0 -C 2 )(aryl), -O-(C 0 -C 2 )(heteroaryl), -S-alkyl, -S-alkenyl, -S-alkynyl, -S-(C 0 -C 2 )(cycloalkyl), -S-(C 0 -C 2 )(heterocyclo), -S-(C 0 -C 2 )(aryl), or -S-(C 0 -C 2 )(heteroaryl); R 7 is hydrogen, C 1-6 alkyl, C 3-7 cycloalkyl, heteroaryl, heterocyclyl, or aryl; R 8 is hydrogen or C 1-6 alkyl; R 9a and R 9b are independently selected from hydrogen, C 1-6 alkyl, cycloalkyl, -(CH 2 ) c (NR 9' ) 2 , C 1-6 hydroxyalkyl, -CH 2 SH, -(CH 2 ) 2 S(O)Me, -(CH 2 ) 3 NHC(=NH)NH 2 , (1H-indol-3-yl)methyl, (1H-imidazol-4-yl)methyl, -(CH 2 )CCOR 9" , aryl and aryl(C 1-3 alkyl)-; R 9' is independently hydrogen or C 1-6 alkyl; R 9" is -OR 11 or -N(R 11' ) 2 ; R 10 is hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, C 3-7 cycloalkyl, heterocycloalkyl, aminoacyl, aryl, heteroaryl, aryl, or heteroaryl; R 11 is C 1-6 alkyl, cycloalkyl, C 2-6 alkynyl, C 2-6 alkenyl, or acyl; R 11' is hydrogen, C 1-6 alkyl, cycloalkyl, C 2-6 alkynyl, C 2-6 alkenyl, or acyl; and c is 1 to 6; <EOS>