Neurotropism of a high-passage XJ strain of Junín virus.

Guinea pig infection with a highly passaged XJ prototype strain of Junín virus by the intramuscular route (IM) was carried out in order to study viral tropism modification in this host. The neurotropism of this strain was demonstrated by viral isolation, meningitis, and by the presence of Junín antigens as shown by immunofluorescence. These events, not previously observed with the same lower-passaged strain, revealed the appearance of neurotropism after multiple passages in guinea pigs.