INTRODUCTION:

Ilheus virus (ILHV) is a Brazilian arbovirus belonging to the Flaviviridae family and Flavivirus genus. The virus is clinically classified as encephalitogenic, and is known to cause infection persistence.

OBJECTIVE:

To investigate persistent infection by ILHV in golden hamsters (Mesocricetus auratus).

MATERIALS AND METHODS:

Hamsters were infected intraperitoneally with ILHV (9.6 LD50/0.02 mL), anaesthetised, and sacrificed up to the 120th day post-infection, for blood, urine, and tissue sampling. Viral titers were measured for ILHV using reverse transcription followed by real-time reverse transcription polymerase chain reaction (qRT-PCR) performed on biological samples, which were used to infect VERO cells; viral replication was confirmed by immunofluorescence. Serum antibody levels were determined using hemagglutination inhibition technique; tissue alterations were observed through histopathological examination of hematoxylin-eosin-stained tissues; viral antigens were detected using immunohistochemistry.

RESULTS:

A strong immune response was induced by ILHV, in addition to its pathogenicity in hamsters and neural invasion. The virus was isolated from VERO cells in the viscera, brain, blood, serum, and urine of infected hamsters and detected by qRT-PCR in the brain, liver, and blood at 30, six, and 15 days post-infection, respectively. Histopathological alterations and detection of viral antigens in the liver, kidney, and lung samples occurred 30 days after infection; in the brain, they were detected up to four months after infection.

CONCLUSION:

These results indicate that ILHV is pathogenic to golden hamsters and causes persistent infection in peripherally infected hamsters.