Pathogenesis of guinea pig adenovirus infection.

Background and purpose: The existence of guinea pig adenovirus (GPAdV) has been suspected on the basis of histopathologic findings, but the virus has not yet been isolated. In susceptible animals, it may cause severe bronchopneumonia and death. Adenovirus-like inclusion bodies have been observed in the lungs of animals with clinical disease. Prevalence of the infection is unknown. Recently, a polymerase chain reaction (PCR) assay was described that was able to selectively detect GPAdV.

Methods: To investigate the pathogenesis of GPAdV, we inoculated eight guinea pigs with GPAdV; eight control animals were sham inoculated. The PCR assay was used to trace the infection. In a second experiment, transmission of GPAdV from an experimentally infected animal to five immune-naive cohorts was examined.

Results: None of the infected animals developed clinical disease. The GPAdV could be detected by PCR analysis of nasal-swab specimens on days 6 through 15 after infection. Infective virus could be recovered from the nasal mucosa during this period (as determined by inoculation of immune-naive animals). The virus was transmitted from an experimentally infected animal to two of five immune-naive cage mates.

Conclusion: The GPAdV may cause transient subclinical upper respiratory tract infection that may descend to the lungs.