Rocio
virus (ROCV) is an encephalitic
flavivirus endemic to
Brazil. Experimental
flavivirus infections have previously demonstrated a
persistent infection and, in this study, we investigated the persistence of ROCV
infection in
golden hamsters (
Mesocricetus auratus). The
hamsters were infected intraperitoneally with 9.8
LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various
time points over a 120-day period to collect of
blood,
urine and organ samples. The viral titres were quantified by real-
time-
polymerase chain reaction (qRT-
PCR). The specimens were used to infect
Vero cells and ROCV
antigens in the
cells were detected by immunefluorescence assay. The levels of
antibodies were determined by the haemagglutination inhibition
technique. A histopathological examination was performed on the
tissues by
staining with haematoxylin-
eosin and detecting
viral antigens by
immunohistochemistry (IHC). ROCV induced a strong
immune response and was pathogenic in
hamsters through neuroinvasion. ROCV was recovered from
Vero cells exposed to samples from the
viscera,
brain,
blood,
serum and
urine and was detected by qRT-
PCR in the
brain,
liver and
blood for three months after
infection. ROCV induced histopathological changes and the expression of
viral antigens, which were detected by IHC in the
liver,
kidney,
lung and
brain up to four months after
infection. These findings show that ROCV is pathogenic to
golden hamsters and has the capacity to cause
persistent infection in
animals after intraperitoneal
infection.