Diversity among Tacaribe serocomplex viruses (family Arenaviridae) naturally associated with the Mexican woodrat (Neotoma mexicana).

The results of analyses of glycoprotein precursor and nucleocapsid protein gene sequences indicated that an arenavirus isolated from a Mexican woodrat (Neotoma mexicana) captured in Arizona is a strain of a novel species (proposed name Skinner Tank virus) and that arenaviruses isolated from Mexican woodrats captured in Colorado, New Mexico, and Utah are strains of Whitewater Arroyo virus or species phylogenetically closely related to Whitewater Arroyo virus. Pairwise comparisons of glycoprotein precursor sequences and nucleocapsid protein sequences revealed a high level of divergence among the viruses isolated from the Mexican woodrats captured in Colorado, New Mexico, and Utah and the Whitewater Arroyo virus prototype strain AV 9310135, which originally was isolated from a white-throated woodrat (Neotoma albigula) captured in New Mexico. Conceptually, the viruses from Colorado, New Mexico, and Utah and strain AV 9310135 could be grouped together in a species complex in the family Arenaviridae, genus Arenavirus.

Demographic factors associated with prevalence of antibody to Sin Nombre virus in deer mice in the western United States.

We used long-term data collected for up to 10 yr (1994-2004) at 23 trapping arrays (i.e., webs and grids) in Arizona, Colorado, Montana, and New Mexico to examine demographic factors known or suspected to be associated with risk of infection with Sin Nombre virus (SNV) in its natural host, the deer mouse (Peromyscus maniculatus). Gender, age (mass), wounds or scars, season, and local relative population densities were statistically associated with the period prevalence of antibody (used as a marker of infection) to SNV in host populations. Nevertheless, antibody prevalence and some of the risk factors associated with antibody prevalence, such as relative population density, gender bias, and prevalence of wounding, varied significantly among sites and even between nearby trapping arrays at a single site. This suggests that local microsite-specific differences play an important role in determining relative risk of infection by SNV in rodents and, consequently, in humans. Deer mouse relative population density varied among sites and was positively and statistically associated with infection prevalence, an association that researchers conducting shorter-term studies failed to demonstrate. Both wounding and antibody prevalence increased with mass class in both males and females; this increase was much more pronounced in males than in females and wounding was more frequent in adult males than in adult females. Prevalence of wounding was greatest among seropositive deer mice, regardless of mass class, but many deer mice without detectable wounds or scars eventually became infected. Many of these patterns, which will be useful in the development of predictive models of disease risk to humans, were only detected through the application of data collected over a long (10-yr) period and with abundant replication.

Epizootiology of arenaviral infections in the white-throated woodrat (Muridae: Sigmodontinae) and other woodrats in Arizona.

The purpose of this study was to extend and refine our knowledge of the geographical distribution and natural host relationships of the arenaviruses associated with woodrats indigenous to Arizona. Antibody to a Tacaribe serocomplex virus was found in 112 of 1,250 white-throated woodrats, five of 208 Mexican woodrats, one of 114 Stephen's woodrats, and none of 862 other rodents captured at 51 sites in 10 counties in Arizona. Of the 112 antibody-positive white-throated woodrats, 109 (97.3%) were captured within extensive, dense patches of prickly pear cactus and cane cholla in three counties in mid-central Arizona. Analysis of the serological and zoographical data suggested that white-throated woodrats usually become infected early in life and that the distribution of antibody-positive white-throated woodrats in Arizona is not linked to a specific biome.

Diversity among tacaribe serocomplex viruses (family Arenaviridae) naturally associated with the white-throated woodrat (Neotoma albigula) in the southwestern United States.

Bayesian analyses of glycoprotein precursor and nucleocapsid protein gene sequences indicated that arenaviruses naturally associated with white-throated woodrats in central Arizona are phylogenetically closely related to the Whitewater Arroyo virus prototype strain AV 9310135, which originally was isolated from a white-throated woodrat captured in northwestern New Mexico. Pairwise comparisons of glycoprotein precursor and nucleocapsid protein amino acid sequences revealed extensive diversity among arenaviruses isolated from white-throated woodrats captured in different counties in central Arizona and extensive diversity between these viruses and Whitewater Arroyo virus strain AV 9310135. It was concluded that the viruses isolated from the white-throated woodrats captured in Arizona represent 2 novel species (Big Brushy Tank virus and Tonto Creek virus) and that these species should be included with Whitewater Arroyo virus in a species complex within the Tacaribe serocomplex (family Arenaviridae, genus Arenavirus).