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Abstract: In our recent epidemiological survey conducted in Mexico for hantavirus infection, we identified three distinct viruses circulating in Mexican wild rodents, namely Montano virus (MTNV), Huitzilac virus (HUIV), and Carrizal virus (CARV). To gain a detailed understanding of hantavirus epidemiology and its associated hosts, 410 rodents were captured at eight collecting points in Morelos and Guerrero, Mexico, and examined for hantavirus seroprevalence, the presence of viral RNA, and rodent host species identification using cytochrome b gene sequences. Of the 32 species captured, seven species were positive for hantavirus: Peromyscus beatae (31/127; 24.4%), Reithrodontomys sumichrasti (6/15; 40%), Reithrodontomys megalotis (2/25; 8%), Peromyscus aztecus evides (1/1; 100%), Peromyscus megalops (1/41; 2.4%), Megadontomys thomasi (1/9; 11.1%), and Neotoma picta (1/6; 16.7%), with an overall prevalence of 10.5%; virus genome persisted in the majority of seropositive rodents. Nucleotide sequence and phylogenetic analysis showed that the viruses belonged mainly to the three lineages previously identified. The data showed that MTNV and CARV were primarily carried by P. beatae and R. sumichrasti, respectively. In addition, the data revealed an apparent complex interaction between hantaviruses and their hosts, suggesting active transmission and/or spillover infections within sympatric rodent species. [Copyright &y& Elsevier]

To investigate if non-hematophagous bats play a role in outbreaks of rabies and blue eye disease (LPMV), we studied the seroprevalence against both agents in several species of non-hematophagous bats on the sub-tropical Pacific coast of the state of Colima, Mexico. The survey covered a predominantly agricultural area (disturbed), and an area dominated by semideciduous dry forest (undisturbed). A total of 151 non-hematophagous bats of 16 species were captured from the two areas. Fifty-six (37%) had antirabic antibodies (Ab) while 87 (58%) did not and 8 samples (5%) had to be discarded because of hemolysis. A much lower (P<0.05) prevalence of antirabic Ab was found in bats caught in disturbed areas (22.7%) compared with those from undisturbed areas (51.9%). The presence of antirabic Ab was not related to sex, genera or feeding habits. The higher prevalence found in bats in the undisturbed area may be the result of more frequent interspecies encounters. Of the 108 sera analyzed for antibodies against LPMV, only one was positive (a male Rhogeessa parvula major, captured in the undisturbed area). This suggests that bats in the surveyed localities do not play a role in the epidemiology of LPMV. [Copyright &y& Elsevier]

Abstract: A variety of hantaviruses are harbored by rodents in North and South America, some of which can cause hantavirus pulmonary syndrome. To obtain greater evolutionary insight into hantaviruses in the Americas, a total of 211 rodents were captured in the Mexican states of Guerrero and Morelos in 2006. Anti-hantavirus antibodies were detected in 27 of 211 serum samples (12.8%) by ELISA. The distribution of seropositive rodents was: 17 Peromyscus beatae, 1 Megadontomys thomasi, 1 Neotoma picta, 6 Reithrodontomys sumichrasti, and 2 Reithrodontomys megalotis. The hantavirus small (S), medium (M), and large (L) genome segments from P. beatae, R. sumichrasti, and R. megalotis were amplified and the sequences covering the open reading frames were determined. The hantaviruses from P. beatae, R. sumichrasti, and R. megalotis were provisionally designated Montano (MTN), Carrizal (CAR), and Huitzilac (HUI), respectively. The M segment amino acid identities among the Mexican hantaviruses were 80.8–93.0%. When these M segments were compared to those of known hantaviruses, MTN virus was most closely related to Limestone Canyon (LSC) virus (88.9% amino acid identity), while the CAR and HUI viruses were most closely related to El Moro Canyon (ELMC) virus (90–91% identity). Phylogenetic analysis revealed that the MTN, CAR, and HUI viruses occupy a monophyletic clade with the LSC, ELMC, and Rio Segundo viruses, which are harbored by Peromyscus boylii, R. megalotis, and Reithrodontomys mexicanus, respectively. The data obtained in this study provide important information for understanding the evolution of hantaviruses in the Americas. [Copyright &y& Elsevier]

Abstract: Hantaviruses can cause two serious illnesses when transmitted from their rodent reservoirs to humans; hantavirus pulmonary syndrome (HPS) in the New World and hemorrhagic fever with renal syndrome in the Old World. Cases of HPS were first recognized in the Americas in small, focal outbreaks in rural populations in the Southwestern USA in 1993. Since that time, outbreaks as well as sporadic cases of HPS have been recognized throughout the Americas. Remarkably, HPS cases have not been reported in Mexico. Mexico is one of the most biodiverse regions in the world and this is reflected in the species diversity of the peromyscine, sigmodontine and oryzomyine rodents; all potential hosts of hantaviruses. Hence, we collected and surveyed several rodent species in Western Mexico and identified three previously unrecognized rodents with antibodies to hantaviral antigens: Oryzomys couesi, Sigmodon mascotensis and Baiomys musculus. The S and M segments cloned from O. couesi and S. mascotensis, referred to herein as Playa de Oro (ORO) virus, showed strongest similarity to Bayou and Catacamas viruses with 92/93% and 92/92% similarity based on S/M amino acid sequences, respectively. This and phylogenetic analysis of the M and S segments suggests that ORO virus is a unique genotype within Hantavirus. [Copyright &y& Elsevier]

This study is the first work that compares rodent communities in a deciduous forest in Mexico. It documents differences between sites experiencing different degrees of disturbance caused by firewood and lumber extraction, and cattle grazing; a relatively undisturbed site (Site 1) and another more disturbed site (Site 2) in southeastern Morelos State. In each site we captured six species of rodents. Though habitat disturbance did not modify diversity or evenness of rodent species, the total number of individuals captured in Site 1 (n = 319) was greater than in Site 2 (n = 90). Effects of habitat fragmentation were expressed in significant differences in population density, age structure and microhabitat preference between two sites for Baiomys musculus, Peromyscus levipes and P. melanophrys. The disturbance of deciduous forest appears to be the principal factor explaining differences in demographic parameters of rodent species between the two study sites, as these two sites have the same climate, similar soils, and topography which differ only slightly. [ABSTRACT FROM AUTHOR]