Spatial and Temporal Dynamics of Lymphocytic Choriomeningitis Virus in Wild Rodents, Northern Italy

Valentina Tagliapietra,Olli Vapalahti,Liina Voutilainen,Heikki Henttonen,Juha Laakkonen,Heidi C Hauffe,Annapaola Rizzoli,Roberto Rosà,Antti Vaheri

doi:10.3201/eid1507.01524

Abstract

Abstract We determined the prevalence of infection with lymphocytic choriomeningitis virus (LCMV) among small mammals in northern Italy and analyzed long-term dynamics of LCMV in a rodent population in the province of Trento. LCMV is circulating among the most widespread and common wild rodent species in this area (Apodemus flavicollis, Myodes glareolus, and Microtus arvalis); overall prevalence is 6.8%. During 2000–2006, intensive monitoring of LCMV in a population of yellow-necked mice (A. flavicollis) showed a positive correlation between prevalence of infection and rodent density. At the individual level, weight and sex appeared to correlate with antibody prevalence, which suggests that horizontal transmission of LCMV occurs principally among heavier, older males and occurs during fighting. Isolation and genetic characterization of this virus will be the crucial next steps for a better understanding of its ecology.

Highlights

We determined the prevalence of infection with lymphocytic choriomeningitis virus (LCMV) among small mammals in northern Italy and analyzed long-term dynamics of LCMV in a rodent population in the province of Trento
Several wild rodent species are seropositive for LCMV: Mus spretus (Algerian mouse), Apodemus agrarius, A. flavicollis, A. sylvaticus, A. mystacinus, Micromys minutus, Microtus levis
Antibodies were detected in all species except A. agrarius and A. sylvaticus

Summary

Introduction

We determined the prevalence of infection with lymphocytic choriomeningitis virus (LCMV) among small mammals in northern Italy and analyzed long-term dynamics of LCMV in a rodent population in the province of Trento. LCMV is circulating among the most widespread and common wild rodent species in this area (Apodemus flavicollis, Myodes glareolus, and Microtus arvalis); overall prevalence is 6.8%. During 2000–2006, intensive monitoring of LCMV in a population of yellow-necked mice (A. flavicollis) showed a positive correlation between prevalence of infection and rodent density. Viral hemorrhagic fevers caused by arenaviruses pose serious human public health risks and cause devastating and often lethal disease. These diseases include Lassa hemorrhagic fever in West Africa, Junín hemorrhagic fever in Argentina, Machupo and Chapare hemorrhagic fevers in Bolivia, Guanarito hemorrhagic fever in Venezuela, and Sabià hemorrhagic fever in Brazil. Immunocompromised persons are susceptible to infection with LCMV; deaths caused by LCMV in organ transplant recipients have been reported [21]

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Conclusion