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Updated: May 7, 2026
Arbovirus Infections As Screening Tools for the Identification of Viral Immunomodulators and Host Antiviral Factors
Published on: September 13, 2018
Experimental infections of Oryzomys couesi with sympatric arboviruses from Mexico
Eleanor R Deardorff1, Naomi L Forrester, Amelia P Travassos da Rosa
1Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.
Abstract:
Coues rice rat (Oryzomys couesi), a species abundant throughout Central America, was evaluated experimentally for the ability to serve as an amplifying host for three arboviruses: Patois (Bunyaviridae, Orthobunyavirus), Nepuyo (Orthobunyavirus), and Venezuelan equine encephalitis virus subtype ID (Togaviridae, Alphavirus). These three viruses have similar ecologies and are known to co-circulate in nature. Animals from all three cohorts survived infection and developed viremia with no apparent signs of illness and long-lasting antibodies. Thus, O. couesi may play a role in the general maintenance of these viruses in nature.
Insights
The Coues rice rat (Oryzomys couesi) can amplify arboviruses like Patois, Nepuyo, and Venezuelan equine encephalitis virus without showing illness. This suggests the rodent plays a role in maintaining these viruses in Central American ecosystems.
Area of Science:
- Arthropod-borne viral diseases
- Zoonotic disease ecology
- Mammalian host-pathogen interactions
Background:
- Arboviruses such as Patois, Nepuyo, and Venezuelan equine encephalitis virus circulate in Central America.
- The Coues rice rat (Oryzomys couesi) is a common rodent species in this region.
- Understanding potential amplifying hosts is crucial for arbovirus surveillance and control.
Purpose of the Study:
- To experimentally assess the Coues rice rat's capacity to act as an amplifying host for Patois, Nepuyo, and Venezuelan equine encephalitis virus ID.
- To determine if Oryzomys couesi exhibits clinical signs of illness or develops immunity following infection with these arboviruses.
Main Methods:
- Cohorts of Oryzomys couesi were experimentally infected with Patois virus, Nepuyo virus, or Venezuelan equine encephalitis virus ID.
- Animals were monitored for clinical signs, viremia, and antibody development post-infection.
Main Results:
- All infected Oryzomys couesi survived the experimental infections.
- Animals developed viremia without apparent signs of illness.
- Long-lasting antibodies were detected in surviving rodents, indicating an immune response.
Conclusions:
- The Coues rice rat (Oryzomys couesi) is a competent amplifying host for Patois, Nepuyo, and Venezuelan equine encephalitis virus ID.
- Oryzomys couesi may play a significant role in the natural maintenance and transmission cycles of these co-circulating arboviruses.
- The lack of clinical signs in infected rodents highlights their potential importance in enzootic transmission dynamics.
