Modelling relative abundance of Oligoryzomys flavescens, an Orthohantavirus reservoir, in an endemic hantavirus pulmonary syndrome zone

Abstract

Hantavirus pulmonary syndrome (HPS) is a zoonotic emerging infectious disease caused by New World orthohantaviruses (family Hantaviridae) hosted by rodents of the family Cricetidae. In Argentina, one of its main hosts is the sigmodontine rodent Oligoryzomys flavescens, a widely distributed mouse of the Pampas, Delta and Espinal ecoregions of central‐east Argentina. Because the abundance of the reservoir and its proportion in the rodent community affects both virus prevalence and human exposure risk, its estimation throughout its known geographical distribution is of key importance for the design of public health strategies to prevent HPS. The aim of this study was therefore to model the relative abundance of O. flavescens in most of the Pampas ecoregion within Buenos Aires Province, Argentina, where hantavirus pulmonary syndrome is endemic. To do this we used owl‐pellet samples collected between 2006 and 2008 from 51 sites distributed throughout most of Buenos Aires province. Mammalian prey in each pellet was identified to the lowest possible taxonomic level by examination of the skulls, dentaries and molars. We modelled the frequency of O. flavescens found in each sample as a function of climatic, environmental, and topographic data of each site. The two best models were applied to a Geo referential Information System to build maps of estimated frequency (as a proxy of relative abundance) within Buenos Aires province. Estimated relative abundance of O. flavescens in Buenos Aires province was significantly associated with annual mean temperature, annual precipitation and presence of freshwater bodies, and varied among sub‐regions, with the Inland and Rolling Pampas being the regions with highest frequencies. Knowing in which areas O. flavescens abundance is expected to be higher can be used to concentrate limited sanitary efforts in those areas that are most needed in order to reduce transmission and increase detection.

Filling the gaps in the Argentinian distribution of orthohantavirus: First finding of Lechiguanas virus in rodents from Corrientes, Argentina

“…In Argentina, the species was recorded in eight provinces of the northeast and central east of the country (Gómez Villafañe et al, 2019; Figure 3). O. flavescens is one of the most abundant species in extensive marsh areas of the region (Fabri et al, 2003; Maroli et al, 2022; Pardiñas et al, 2005; Vadell et al, 2011, 2023), the numerically dominant in our sampling and a well‐known reservoir of the LECV in the central region of Argentina (González‐Ittig et al, 2014; Hercolini et al, 2018; Maroli et al, 2022; Muschetto et al, 2018; Palma et al, 2012; Vadell et al, 2011) and Uruguay (Delfraro et al, 2003). In addition, the high similarity with the hantavirus found in a human case in Misiones province (Figures 2 and 3) suggests that the transmitting reservoir in that human case would also be O. flavescens .…”