Chronic neurologic disease in Junín virus-infected rats

Area of Science:

• Neuroscience
• Virology
• Immunology

Background:

• Junín virus (JUNV) is a New World arenavirus responsible for Argentine hemorrhagic fever.
• Persistent viral infections of the central nervous system (CNS) can lead to chronic neurological disorders.

Purpose of the Study:

• To investigate if Junín virus persistence in the rat CNS can induce late-onset neurological disease.

Main Methods:

• Newborn rats were intracerebrally inoculated with the XJ strain of Junín virus.
• Animals were monitored for clinical signs, mortality, and viral persistence at different time points post-inoculation.
• Histopathological analysis, including detection of viral antigen and inflammatory markers, was performed.

Main Results:

• Three distinct phases were observed: acute disease (up to 30 days post-inoculation) with 5% mortality, an intermediate phase (up to 280 days) with subclinical signs but evident viral persistence, and a chronic phase with neurological syndrome.
• The chronic phase was characterized by severe inflammation, presence of viral antigen in neurons, and virus recovery via co-culture.
• Late neurologic disease correlated with the failure to effectively clear the virus from the brain.

Conclusions:

• Junín virus persistence in the rat CNS can lead to the development of late-onset neurological disease.
• Chronic neurological complications appear to result from sustained viral presence and subsequent long-lasting immunologic stimulation.
• Animal models are crucial for understanding the pathogenesis of persistent viral CNS infections and associated late-onset diseases.