NEW DATA ON THE THREATENED Cerradomys goytaca (RODENTIA, CRICETIDAE) / Nuevos datos sobre el amenazado Cerradomys goytaca (RODENTIA, CRICETIDAE)

ABSTRACT Cerradomys goytaca is a cricetid rodent endemic to "Restinga" formations from southeastern Atlantic Forest. It is known from only five localities, and it is considered endangered of extinction. Herein, we furnish new data on C. goytaca from an additional locality in Rio de Janeiro state. The present record provides new data on habitat and represents the westernmost geographic limit of this poorly known species.

RESUMEN Cerradomys goytaca es un roedor cricetideo endémico de las formaciones de Restinga del sureste de la Selva Atlantica. Es conocido solo en cinco localidades, y se considera en peligro de extinción. Aquí, proporcionamos nuevos datos sobre C. goytaca de una localidad adicional en el estado de Río de Janeiro. El presente registro proporciona nuevos datos del hábitat y representa el límite geográfico más occidental de esta especie poco conocida.

Anestesia de roedores sigmodontinos en condiciones de campo / Anesthesia in Sigmodontinae Rodents Living out in the Countryside

Resumen Algunas investigaciones de mamíferos silvestres requieren del uso de métodos que faciliten la manipulación de los individuos en condiciones de campo, sin afectar negativamente a los animales o a los investigadores. Dentro de estos métodos, se encuentra la inmovilización química, la cual no ha sido muy documentada en roedores silvestres de la subfamilia Sigmodontinae (Cricetidae). Por ello, en esta investigación se evaluó el uso de éter dietílico inhalado para manipular roedores sigmodontinos en campo, comparando el tiempo de inducción y el tiempo de recuperación de la anestesia entre especies, sexos y tipos de ambientes. Se capturaron y anestesiaron un total de 289 individuos de seis especies en el Parque Nacional Natural Chingaza. El tiempo de inducción de la anestesia fue diferente entre Microryzomys minutus, Neomicroxus bogotensis, Thomasomys laniger y Thomasomys niveipes (F3; 552 = 9,36; p < 0,05); de igual forma, el tiempo de recuperación de la anestesia fue diferente entre dichas especies (H = 9,59; p = 0,022). No se encontraron diferencias en los tiempos de inducción y recuperación de la anestesia entre sexos, ni entre ambientes. La mortalidad total fue de 4,5 %. No se observaron secreciones mucosas, vómito o complicaciones cardíacas o respiratorias en los individuos anestesiados. Los individuos fueron recapturados y no se evidenciaron alteraciones en su comportamiento o aspecto físico que indicaran una afectación por la anestesia o manipulación en capturas previas. La anestesia inhalada con éter dietílico puede ser una opción rápida y segura para inmovilizar y manipular sigmodontinos durante procedimientos cortos en campo dentro de estudios poblacionales o programas de monitoreo en vida silvestre.

Abstract Some researches in wild mammals require methods that enable to handle the animals living in wild conditions, without affecting negatively the animals, or the researchers. These methods include the chemical immobilization, which has not been enough documented when handling wild rodents of the Sigmodontinae subfamily (Cricetidae). Therefore, this research evaluated the use of diethyl ether when handling Sigmodontinae rodents out in the countryside. It compared the induction time to the anesthesia recovery time between species, genders, and type of environments. A total of 289 animals were caught and anesthetized from six species in the Chingaza National Natural Park. The anesthesia induction times were different between Microryzomys minutus, Neomicroxus bogotensis, Thomasomys laniger y Thomasomys niveipes (F3; 552 = 9.36; p < 0.05). Likewise, the anesthesia recovery times were different between the same species (H = 9.59; p = 0.022). No difference was found in the induction times and the anesthesia recovery times between genders, neither for the types of environment. Total mortality was 4.5%. None mucosal secretions, vomit, or cardiac/respiratory complications were observed in the anesthetized animals. These subjects were caught again and they did not show any alterations in their behavior or physical aspect indicating affection derived either from the anesthesia or the previous handling under captivation. Anesthesia with diethyl ether can be a quick and safe choice when it comes to immobilize and handle Sigmodontinae rodents during short procedures out in the countryside, when carrying out population studies or wildlife monitoring programs.

Brote de síndrome pulmonar por hantavirus, Tucumán, Argentina / Outbreak of hantavirus pulmonary syndrome in Tucumán, Argentina

Se describe un brote de síndrome pulmonar por hantavirus en el departamento de Burruyacú, provincia de Tucumán. La detección en 2016 de un caso de hantavirosis en una joven de 23 años -en ese momento considerado el primero ocurrido en dicha provincia- promovió un estudio epidemiológico exhaustivo, que permitió detectar retrospectivamente otro caso ocurrido en un niño de 5 años, un mes antes, en el mismo departamento. La infección fue confirmada por serología en ambos casos (caso 1 en muestras de 4 y 7 días de evolución, caso 2 en muestra a los 4 días). En ambos casos el genotipo viral fue caracterizado como HU39694 y los contactos fueron serológicamente negativos. En las áreas fueron identificados roedores pertenecientes a los géneros Akodon y Calomys y a la especie Mus musculus, pero no a Oligoryzomys, el reservorio habitual del genotipo HU39694. Tampoco se detectaron anticuerpos anti-hantavirus en suero de los roedores capturados. La ausencia de registro de viajes a área endémica de este genotipo y los hábitos recreacionales de los pacientes, sumados a los resultados serológicos negativos para hantavirus en los contactos, permiten inferir la posible exposición de los pacientes a fluidos de roedores infectados durante actividades recreativas o sociales al aire libre en sus respectivas áreas de residencia. En conclusión, se demuestra la circulación en Tucumán del genotipo viral HU39694, hasta ahora considerado restringido a la región pampeana central. Se extiende así a Tucumán el área endémica de hantavirosis, pero no se identificó el reservorio en el área.

We describe an outbreak of hantavirus pulmonary syndrome in the Burruyacú Department, Province of Tucumán. The detection in 2016 of a case of hantavirosis affecting a 23-year-old woman, considered at that time to be the first case occurred in that province, promoted a thorough epidemiological study. The investigation allowed the retrospective detection of another case occurred one month earlier in a 5-year-old child in the same Department. In both cases, the infection was confirmed by serology (case 1 at days 4 and 7 of disease onset, case 2 at day 4) and the viral genotype was characterized as HU39694. The contacts of both cases were serologically negative for hantavirus. The rodents captured in the area belonged to genus Akodon, genus Calomys and species Mus musculus. Oligoryzomys, the known reservoir for this viral genotype, was not found. Specific anti-hantavirus antibodies were not detected in the captured rodents. Given that the patients had not visited hantavirus endemic areas and their contacts were negative for hantavirus, we infer that the patients were locally exposed to fluids of infected rodents during their usual social or recreational outdoor activities. In conclusion, we demonstrate that hantavirus HU39694 -a genotype until now considered to be restricted to the Central Pampas of the country- is circulating in the North Western province of Tucumán. The endemic area of hantavirosis is thus expanded to this province but the viral reservoir in the area has not yet been identified.

Characterisation of the vascular pathology in Sigmodon hispidus (Rodentia: Cricetidae) following experimental infection with Angiostrongylus costaricensis (Nematoda: Metastrongylidae)

BACKGROUND Angiostrongylus costaricensis is a nematode that causes human abdominal angiostrongyliasis, a disease found mainly in Latin American countries and particularly in Brazil and Costa Rica. Its life cycle involves exploitation of both invertebrate and vertebrate hosts. Its natural reservoir is a vertebrate host, the cotton rat Sigmodon hispidus. The adult worms live in the ileo-colic branches of the upper mesenteric artery of S. hispidus, causing periarteritis. However, there is a lack of data on the development of vasculitis in the course of infection. OBJECTIVE To describe the histopathology of vascular lesions in S. hispidus following infection with A. costaricensis. METHODS Twenty-one S. hispidus were euthanised at 30, 50, 90 and 114 days post-infection (dpi), and guts and mesentery (including the cecal artery) were collected. Tissues were fixed in Carson’s Millonig formalin, histologically processed for paraffin embedding, sectioned with a rotary microtome, and stained with hematoxylin-eosin, resorcin-fuchsin, Perls, Sirius Red (pH = 10.2), Congo Red, and Azan trichrome for brightfield microscopy analysis. FINDINGS At 30 and 50 dpi, live eggs and larvae were present inside the vasa vasorum of the cecal artery, leading to eosinophil infiltrates throughout the vessel adventitia and promoting centripetal vasculitis with disruption of the elastic layers. Disease severity increased at 90 and 114 dpi, when many worms had died and the intensity of the vascular lesions was greatest, with intimal alterations, thrombus formation, iron accumulation, and atherosclerosis. CONCLUSION In addition to abdominal angiostrongyliasis, our data suggest that this model could be very useful for autoimune vasculitis and atherosclerosis studies.

Experimental infection of Rio Mamore hantavirus in Sigmodontinae rodents

This study shows an experimental spillover infection of Sigmodontinae rodents with Rio Mamore hantavirus (RIOMV). Necromys lasiurus and Akodon sp were infected with 103 RNA copies of RIOMV by intraperitoneal administration. The viral genome was detected in heart, lung, and kidney tissues 18 days after infection (ai), and viral excretion in urine and faeces began at four and six ai, respectively. These results reveal that urine and faeces of infected rodents contain the virus for at least 18 days. It is possible that inhaled aerosols of these excreta could transmit hantavirus to humans and other animals.

New host, geographic records, and histopathologic studies ofAngiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

Estudo da evolução das lesões vasculares presentes na angiostrongilíase abdominal experimental em Sigmodon hispidus (Rodentia: Cricetidae) / Study of the vascular lesions evolution which present in experimentalabdominal angiostrongyliasis in Sigmodon hispidus (Rodentia: Cricetidae)

Introdução: O Angiostrongylus costaricensis é um nematódeo que causa aangiostrongilíase abdominal. O ciclo de vida deste parasita envolve um hospedeiro invertebrado (intermediário) e um hospedeiro vertebrado mamífero (definitivo). Na natureza, um dos principais hospedeiros definitivos deste parasita é o roedor Sigmodon hispidus. O nematódeo instala-se na artéria mesentérica superior do hospedeiro definitivo, causando inicialmente uma periarterite e o sinofílica e posteriormente um trombo. Histopatologicamente, uma tríade de achados fundamentais define esta patologia: massivo infiltrado e o sinofílico; vasculiteeosinofílica e reação granulomatosa. Apesar da importância clínica, pouco se sabe a cerca dessa patologia. Objetivos: Caracterizar as lesões histopatológicas do território vascular e intestinal; acompanhar a dinâmica hematológica periférica e central; avaliar colesterolemia total e a presença de bactérias na lesão de S. hispidusinfectados com A. costaricensis. Material e Métodos: S. hispidus infectados com A. costaricensis foram eutanasiados em 30, 50, 90 e 114 dpi e foram coletados o intestino e mesentério (incluindo a artéria cecal). Os tecidos foram fixados emformalina Millonig de Carson e, histologicamente processados para microscopia de luz ou imunohistoquímica. O sangue também foi coletado através de punção cardíaca ou do plexo braquial e utilizado para realização de hemograma e análise da colesterolemia total e análise microbiológica. A lesão local também foi coletada para análise microbiológica. Resultados e discussão:...

Introduction: Angiostrongylus costaricensis is a roundworm which causes theabdominal angiostrongyliasis. This parasite’s life cycle involves an invertebrate host(intermediary) and a vertebrate host (definitive). In nature, the usual definitive host forthis parasite is the rodent Sigmodon hispidus. Adult worms install in the uppermesenteric artery of the definitive host, causing in the beginning an eosinophilicpolyarteritis and then a thrombus. Histopathologically, a triad of essential findingdefines this pathology as: massive eosinophilic infiltrate; eosinophilic vasculitis andthe granulomatous reaction. Despite the clinical importance, we know just a fewabout this pathology. Objectives: To characterize the histopathological lesions of thevascular and intestinal territories; to follow the peripheral and central hematologicdynamics; to evaluate the total cholesterol and the bacteria presence in the lesion onthe infected S. hispidus by A. costaricensis. Material and Methods: S. hispidusinfected by A. costaricensis were euthanized in 30, 50, 90 and 114 dpi and werecolected the intestine and mesentery (including the cecal artery). Tissues were fixedin Carson’s Millonig formalin and, histopathologically processed to light microscopy orimmunohistochemistry. The blood was also gathered through the cardiac puncture orfrom the brachial plexus and used to the CBC conduction and analysis of totalcholesterol and microbiological analysis. The local lesion was also gathered tomicrobiological analysis. Results and discussion:...

Dieta de roedores sigmodontinos (Cricetidae) en los bosques montanos tropicales de Huánuco, Perú

Se analizó el contenido estomacal de cinco especies de roedores sigmodontinos: Akodon orophilus, Microryzomys altissimus, M. minutus, Thomasomys notatus y T. kalinowskii, procedentes de los bosques montanos de Huánuco, Perú (2564 - 3850 m de altitud). Concluimos que A. orophilus es insectívora por haber presentado un alto volumen de artrópodos (adultos y larvas) en el contenido estomacal (90,1%); mientras que T. notatus y T. kalinowskii son principalmente herbívoras por el alto volumen de materia vegetal, 89% y 67,75% respectivamente; y que M. altissimus y M. minutus son omnívoras por presentar volúmenes similares tanto para vegetales como para artrópodos. Thomasomys kalinowskii es considerada generalista por la mayor amplitud de nicho (4,61), mientras A. orophilus es considerada especialista por el menor valor (1,70). Akodon orophilus mostró una preferencia por el consumo de artrópodos adultos al tener un bajo coeficiente de variación (CV= 20%) y también un significativo aumento en el consumo de larvas de artrópodos en la época húmeda, siendo la única especie con variación estacional en la dieta. Por otro lado, la sobreposición de nicho fue menor a 0,75 en el 80% de los pares de especies comparados, indicando una baja similitud en la dieta. La mayor similitud en la dieta se observó entre M. altissimus - T. notatus (0,822) y M. minutus - T. kalinowskii (0,816). Se concluye que estos roedores sigmodontinos, simpátricos en los bosques montanos de Huánuco, exhiben dietas disímiles, probablemente como una estrategia para evitar o aminorar la competencia interespecífica

We analyzed the stomach contents of five species of sigmodontine rodents: Akodon orophilus, Microryzomys altissimus, M. minutus, Thomasomys notatus, and T. kalinowskii, from mountain forests of Huánuco, Perú (2564 - 3850 m). We found that A. orophilus is an insectivorous species because the high volume of arthropods (adults and larvae) in the stomach contents (90.1%); T. notatus and T. kalinowskii are primarily herbivorous because they had a high volume of plant material of 89% and 67.75% respectively; whereas M. altissimus and M. minutus are omnivorous because they presented similar volume percentages for plants and arthropods. T. kalinowskii is considered a generalist species because it had the highest niche breadth (4.61), whereas A. orophilus is considered a specialist because it had the lowest value (1.70). Akodon orophilus registered a low coefficient of variation (CV= 20%) showing a preference for consuming adult arthropod, and also a significatively high consumption of arthropod larvae in the wet season, being the only species with a seasonal variation in the diet. On the other hand, the niche overlap was less than 0.75 in 80% of species pairs indicating low similarity in the diet, but greater than 0.75 between M. altissimus - T. notatus (0.822) and M. minutus - T. kalinowskii (0.816) suggesting a higher diet similarity. We conclude that these sigmodontine rodents, sympatric in the montane forests of Huánuco, exhibit dissimilar diets, probably as a strategy to prevent or lessen interspecific competition

Distribution of Oecomys catherinae Thomas, 1909 (Rodentia: Cricetidae) in northeastern Brazil with karyotypical and morphometrical notes / Distribuição de Oecomys catherinae Thomas, 1909 (Rodentia: Cricetidae) no nordeste do Brasil com notas morfométricas e cariotípicas

The genus Oecomys Thomas, 1906 is currently composed of 16 species with unclear taxonomy and poorly known geographic limits. O. catherinae Thomas, 1909 is known to occur within the Brazilian Atlantic Forest from the states of Santa Catarina to Pernambuco (where the northernmost previously known specimen of Oecomys in the Atlantic forest was recorded), and along riverine forest into the Cerrado. To gain a greater understanding of its geographical and ecological distribution (mainly in Northeastern Brazil) and of its taxonomic characterization, we provide a short review of karyotypical and morphometrical data from specimens collected within the distribution range of the species. Specimens presented 2n = 60 and AN varying between 62 and 64. A table with external and cranial measurements of the analyzed specimens is provided. In this paper we also report the presence of O. catherinae in the semi-deciduous forests of the state of Paraíba, representing the northernmost records of the species in the Atlantic forest and thereby extending its known geographical limits.

Oecomys Thomas, 1906 é um gênero atualmente composto por 16 espécies reconhecidas que apresentam taxonomia e distribuições geográficas ainda incertas. O. catherinae Thomas, 1906 é a espécie que ocorre ao longo da Floresta Atlântica brasileira dos estados de Santa Catarina a Pernambuco, onde se encontra o registro prévio mais ao norte para Oecomys na Floresta Atlântica, e ao longo de florestas de galeria no Cerrado. Pretendendo esclarecer aspectos relacionados à distribuição geográfica e ecológica de O. catherinae, com ênfase na região nordeste do Brasil, e auxiliar na sua caracterização taxonômica, fornecemos um breve resumo de dados morfométricos e cariotípicos de indivíduos coletados em diversos trabalhos ao longo da área de ocorrência da espécie. Os espécimens apresentaram 2n = 60 e NA variando entre 62 e 64. Uma tabela de medidas corporais externas e cranianas dos indivíduos analisados é fornecida. Também registramos pela primeira vez a presença de O. catherinae nas florestas semi-deciduais do estado da Paraíba, sendo atualmente os registros mais ao norte da espécie na Floresta Atlântica, estendendo os limites geográficos conhecidos para a espécie.

The use of PCR-RFLP as an identification tool for three closely related species of rodents of the genus Akodon (Sigmodontinae, Akodontini)

Three cryptic species of the rodent Akodon (A. cursor, A. montensis and Akodon sp.) were analyzed. The two former species are sympatric in the Brazilian states of São Paulo, Rio de Janeiro and Minas Gerais, where hybrids have already been found. The third species, Akodon sp., occurs in an isolated area in Central Brazil. The identification of these species is difficult by the need of living animals. At present, karyotyping is the only method used in the identification of specimens. We used PCR-RFLP of the mitochondrial cytochrome gene to test the distinctiveness of the three species, which was confirmed by the absence of shared species-specific haplotypes. We also detected a geographical pattern of haplotypes distribution with highly polymorphic populations of A. cursor from Espírito Santo and of A. montensis from Rio Grande do Sul.

Identificação das espécies de roedores reservatórios de hantavírus no sul e sudeste brasileiro: (Nota Prévia) / Identification of hantavirus rodent reservoirs species in south and southeastern Brazil: (Previous Note)

BACKGROUNS: Hantavirus is a genus belonging to the Bunyaviridae family. Human infection occurs mainly by inhalation of aerosols formed from wild rodent droppings. The objectives of this study were to identify the species of rodent reservoirs of hantavirus that cause the cardiopulmonary syndrome in the southern and southeastern regions of Brazil; to understand the eco-epidemiology of this virus and the wild rodents' systematics. MATERIAL AND METHODS: Rodents were captured using Sherman traps distributed throughout natural environments and around human settlements in localities were hantavirus cardiopulmonary syndrome was detected. After species identification, biometric measures were taken of each animal. Samples of blood, liver, kidney, spleen, heart and lung were preserved in liquid nitrogen and sent to the laboratory. Blood samples were tested for IgG antibodies for hantavirus using an enzyme-linked immunosorbent assay (ELISA). Voucher specimens are available at the Instituto Adolfo Lutz collection. RESULTS: A total of 4,069 rodents, belonging to 22 species, were captured. From these rodents, 201 had IgG antibodies for hantavirus. The number of positive specimens per number of captured rodents according to the natural environments studied is the following: a) Mainland: Bolomys lasiurus (130/1187), Oximicterus ruttilans (1/6), Thalpomys lasiotis (0/2), Oligoryzomys stramineus (0/1), Oryzomys nitidus (0/24), Pseudoryzomys simplex (0/14), Calomys tener (22/910), Calomys callosus (2/107); b) Atlantic rainforest: Bolomys sp (1/51), Brucepattersonius soricinus (0/16), Oximicterus quaestor (0/15), Thaptomys nigrita (1/59), Delomys dorsalis (0/1), Delomys sublineatus (0/4) Oligoryzomys delticola (0/5), Oryzomys capito (0/3), Oryzomys ratticeps (0/7), Calomys laucha (0/26); c) Both habitats: Akodon sp (14/910), Oligoryzomys nigripes (28/360), Rattus rattus (0/9), Mus musculus (2/352). Oligoryzomys nigripes was more frequent in the Atlantic rainforest. Bolomys lasiurus showed the highest capture index (44%) and the highest antibody prevalence among mainland species (10.9%). In the Atlantic rainforest, Akodon sp was the most captured species (45,4%) and Oligoryzomys nigripes showed the highest antibody prevalence (7,8%). CONCLUSIONS:Antibody prevalence indicates Bolomys lasiurus as the reservoir of hantavírus in the mainland regions of São Paulo and Minas Gerais and Oligoryzomys nigripes in the Atlantic rainforest of São Paulo, Rio Grande do Sul, Paraná and Santa Catarina. Species belonging to the genus Akodon and Calomys showed lower prevalence, and complementary studies are needed to clarify their role in hantavirus epidemiology.

DELINEAMENTO DO PROBLEMA: Os hantavirus formam um gênero da família Bunyaviridae . A infecção humana ocorre, principalmente, pela inalação de aerossóis formados a partir de excretas de roedores silvestres infectados. Os objetivos deste trabalho foram identificar as espécies de roedores reservatórios de hantavírus causadores de síndrome cardiopulmonar nas regiões Sul e Sudeste do Brasil; e compreender a ecoepidemiologia desses vírus e a sistemática de roedores silvestres. MATERIAL E MÉTODOS: Em locais onde ocorreram casos de síndrome cardiopulmonar por hantavírus, foram realizadas capturas de roedores silvestres com auxílio de armadilhas tipo Sherman, distribuídas nos diversos biomas e ambientes domiciliares, peridomiciliares e silvestres. Após identificação sistemática da espécie, medidas biométricas foram tomadas de cada animal. Amostras de sangue, fígado, rim, baço, coração e pulmão foram conservadas em nitrogênio líquido e levadas para o laboratório. O sangue foi testado pela técnica imunoenzimática (ELISA) para detecção de anticorpos IgG para hantavírus. As carcaças dos roedores foram depositadas na coleção do Instituto Adolfo Lutz. RESULTADOS: Foram capturados 4.069 roedores, de 22 espécies. Desses, 201 roedores apresentaram anticorpos IgG para hantavírus. As espécies e os respectivos números de roedores positivos por capturados, de acordo com os biomas estudados foram: a) cerrado: Bolomys lasiurus (130/1187), Oximicterus ruttilans (1/6), Thalpomys lasiotis (0/2), Oligoryzomys stramineus (0/1), Oryzomys nitidus (0/24), Pseudoryzomys simplex (0/14), Calomys tener (22/910), Calomys callosus (2/107), b) Mata Atlântica: Bolomys sp (1/51), Brucepattersonius soricinus (0/16), Oximicterus quaestor (0/15), Thaptomys nigrita (1/59), Delomys dorsalis (0/1), Delomys sublineatus (0/4) Oligoryzomys delticola (0/5), Oryzomys capito (0/3), Oryzomys ratticeps (0/7), Calomys laucha (0/ 26); c) nos dois biomas: Akodon sp (14/910), Oligoryzomys nigripes (28/360), Rattus rattus (0/9), Mus musculus (2/352). Oligoryzomys nigripes foi consideravelmente mais freqüente na mata atlântica. Bolomys lasiurus apresentou maior índice de captura (44%) e de prevalência de anticorpos entre espécies de cerrado (11%), enquanto na mata atlântica, Akodon sp foi a mais capturada (45%) e Oligoryzomys nigripes apresentou maior soropositividade (8%). CONCLUSÕES: Baseando-se na prevalência de anticorpos, Bolomys lasiurus foi identificado como reservatório de hantavírus nas regiões de cerrado de São Paulo e Minas Gerais e Oligoryzomys nigripes nas regiões de mata atlântica de São Paulo, Rio Grande do Sul, Paraná e Santa Catarina. Espécies do gênero Akodon e Calomys mostraram baixas soroprevalências e requerem novos estudos para esclarecer seu papel na epidemiologia do hantavírus.