| failure of cryptorchidism to suppress fertility in a tropical rodent. | the cane mouse (zygodontomys brevicauda) breeds year-round on the hot llanos of venezuela, only 8 degrees above the equator. the reproductive responses of the males of this species to heat were compared with those of a temperature zone rodent, the white-footed mouse (peromyscus leucopus). when tested at different ambient temperatures, the movement of the testis in relation to the scrotum was similar in the two species, but the cane mouse's testis proved to be much more resistant to maintenance a ... | 1993 | 8100454 |
| field studies on the epidemiology of venezuelan hemorrhagic fever: implication of the cotton rat sigmodon alstoni as the probable rodent reservoir. | during february 1992, field studies on the epidemiology of venezuelan hemorrhagic fever (vhf) were carried out in a rural area of portuguesa state in central venezuela. the objective of this work was to determine the prevalence of infection with guanarito virus, the etiologic agent of vhf, among wild rodents and humans living within an endemic focus of the disease. a total of 234 rodents, representing nine different species, were collected and their spleens were cultured for virus. thirty-one gu ... | 1993 | 8395143 |
| isolation, characterization and geographic distribution of caño delgadito virus, a newly discovered south american hantavirus (family bunyaviridae). | rodents collected from the venezuelan llanos (plains) during field studies of viral hemorrhagic fever were tested for evidence of hantavirus infection. hantavirus antibody was found in one (7.7%) of 13 oryzomys bicolor, one (3.4%) of 29 rattus rattus, 10 (6.0%) of 166 sigmodon alstoni and one (2.2%) of 45 zygodontomys brevicauda. hantavirus-specific rna was detected in lung tissues from four antibody-positive rodents: two s. alstoni from portuguesa state and one s. alstoni each from cojedes and ... | 1997 | 9498614 |
| hantavirus pulmonary syndrome in panama: identification of novel hantaviruses and their likely reservoirs. | hantavirus pulmonary syndrome (hps), a severe respiratory disease with high mortality caused by rodent-borne hantaviruses, has previously been identified in the united states and canada as well as central and southern south america. in late 1999 and early 2000, an outbreak of acute illness compatible with hps was reported in los santos, panama, with the death of 3 of the 12 (25%) suspected cases. hantavirus-specific antibodies were detected in patient sera, and virus rna was detected by reverse ... | 2000 | 11062031 |
| serosurvey of wild rodents for hantaviruses in panama, 2000-2002. | five hundred fifty-six samples representing 24 species of small mammals (two species of marsupials and 22 rodents) were collected in panama between february 2000 and july 2002. the samples were examined for antibodies to hantaviruses by means of enzyme-linked immunosorbent assay or immunoblot assays. the serologic results indicated that several rodent species might act as hantaviral reservoirs in panama: costa rican pygmy rice rat (oligoryzomys fulvescens costaricensis), four positive of 72 test ... | 2004 | 15137495 |
| community ecology of small mammal populations in panamá following an outbreak of hantavirus pulmonary syndrome. | in late 1999 and early 2000, an outbreak of hantavirus pulmonary syndrome (hps) occurred in and around los santos, on the azuero peninsula of southwestern panamá. this hps episode, resulting in 22% case fatality, was linked to the costa rican pigmy rice rat, oligoryzomys fulvescens costaricensis, which harbored a then undescribed hantavirus, choclo virus. in addition, cherrie's cane rat, zygodontomys brevicauda cherriei, was identified as carrying a distinct hantavirus, calabazo virus with no kn ... | 2004 | 15266755 |
| outbreak of hantavirus pulmonary syndrome, los santos, panama, 1999-2000. | an outbreak of hantavirus pulmonary syndrome occurred in the province of los santos, panama, in late 1999 and early 2000. eleven cases were identified; 9 were confirmed by serology. three cases were fatal; however, no confirmed case-patient died. case-neighborhood serologic surveys resulted in an overall hantavirus antibody prevalence of 13% among household and neighborhood members from the outbreak foci. epidemiologic investigations did not suggest person-to-person transmission of hantavirus in ... | 2004 | 15498167 |
| diffusion and home range parameters from rodent population measurements in panama. | simple random walk considerations are used to interpret rodent population data collected in hantavirus-related investigations in panama regarding the short-tailed cane mouse, zygodontomys brevicauda. the diffusion constant of mice is evaluated to be of the order of (and larger than) 200 meters squared per day. the investigation also shows that the rodent mean square displacement saturates in time, indicating the existence of a spatial scale which could, in principle, be the home range of the rod ... | 2005 | 15998498 |
| modeling hantavirus reservoir species dominance in high seroprevalence areas on the azuero peninsula of panama. | habitat fragmentation commonly influences distribution of zoonotic disease reservoirs. in panama, populations of rodent hosts of hantaviruses are favored by small habitat fragments isolated by agricultural lands. we expected a similar relationship between landscape characteristics and host distribution at fine geographical scales in southern panama. the relative abundance of zygodontomys brevicauda, the primary host for "calabazo" virus, and other rodents was assessed at 24 sites within the azue ... | 2006 | 16760528 |
| genetic diversity between and within the arenavirus species indigenous to western venezuela. | the results of analyses of z, rna-dependent rna polymerase, glycoprotein precursor, and nucleocapsid protein gene sequence data suggested that guanarito virus was the most common cause of venezuelan hemorrhagic fever in a 7-year period in the 1990s and that the evolution of pirital virus in association with sigmodon alstoni (alston's cotton rat) has occurred at a significantly higher rate than the evolution of guanarito virus in association with zygodontomys brevicauda (short-tailed cane mouse) ... | 2008 | 18586298 |
| hantavirus infection and habitat associations among rodent populations in agroecosystems of panama: implications for human disease risk. | hantavirus cardiopulmonary syndrome (hcps), which is caused by infection with choclo virus, is uncommon in panama, yet seropositivity among rural residents is as high as 60%. to clarify the environmental risk factors favoring rodent-to-human transmission, we tested serum from 3,067 rodents captured over a five-year period for antibodies against recombinant n protein of hantavirus by enzyme immunoassay and strip immunoblot. among 220 seropositive rodents, oligoryzomys fulvescens, the reservoir of ... | 2009 | 19556568 |
| epidemiology of emergent madariaga encephalitis in a region with endemic venezuelan equine encephalitis: initial host studies and human cross-sectional study in darien, panama. | neurotropic arboviral infections are an important cause of encephalitis. a zoonotic, vector-borne alphavirus, madariaga virus (madv; formerly known as south american eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in darien, panama, where the genetically similar venezuelan equine encephalitis virus (veev) is endemic. we report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of madv and veev ecology and epidemi ... | 2016 | 27101567 |
| phylogenetic relationship of necoclí virus to other south american hantaviruses (bunyaviridae: hantavirus). | the results of a previous study suggested that cherrie's cane rat (zygodontomys cherriei) is the principal host of necoclí virus (family bunyaviridae, genus hantavirus) in colombia. bayesian analyses of complete nucleocapsid protein gene sequences and complete glycoprotein precursor gene sequences in this study confirmed that necoclí virus is phylogenetically closely related to maporal virus, which is principally associated with the delicate pygmy rice rat (oligoryzomys delicatus) in western ven ... | 2015 | 26186516 |
| feeding success of lutzomyia evansi (diptera: psychodidae) experimentally exposed to small mammal hosts in an endemic focus of leishmania chagasi in northern colombia. | lutzomyia evansi is the vector of leishmania chagasi in northern colombia. differences in feeding success were revealed, when this phlebotomine sand fly was fed on five species of small mammal hosts from an endemic focus of visceral leishmaniasis. in each trial, 50 female sand flies were provided access to similar-sized depilated areas of the hind foot of each of 44 individual mammals and allowed to feed for 30 minutes. the number of engorged sand flies was counted at the end of each trial and c ... | 2003 | 14968917 |
| experimental infection of the cane mouse zygodontomys brevicauda (family muridae) with guanarito virus (arenaviridae), the etiologic agent of venezuelan hemorrhagic fever. | chronic infections in specific rodents appear to be crucial to the long-term persistence of arenaviruses in nature. the cane mouse, zygodontomys brevicauda, is a natural host of guanarito virus (family arenaviridae), the etiologic agent of venezuelan hemorrhagic fever. the purpose of this study was to elucidate the natural history of guanarito virus infection in z. brevicauda. thirty-nine laboratory-reared cane mice each were inoculated subcutaneously with 3.0 log10 plaque-forming units of the g ... | 1999 | 10479119 |
| natural rodent host associations of guanarito and pirital viruses (family arenaviridae) in central venezuela. | the objective of this study was to elucidate the natural rodent host relationships of guanarito and pirital viruses (family arenaviridae) in the plains of central venezuela. ninety-two arenavirus isolates from 607 animals, representing 10 different rodent species, were characterized to the level of serotype. the 92 isolates comprised 19 guanarito virus strains and 73 pirital virus strains. the 19 guanarito virus isolates were from zygodontomys brevicauda; 72 (98.6%) of the 73 pirital virus isola ... | 1999 | 10463688 |
| dynamics of leishmania chagasi infection in small mammals of the undisturbed and degraded tropical dry forests of northern colombia. | the infection rate with leishmania chagasi and the population dynamics of small mammals were studied in an undisturbed forest reserve (colosó) and an area of highly degraded forest (san andrés de sotavento [sas]) in northern colombia, both endemic for visceral leishmaniasis. live trapping of mammals was done every month, and species, age, sex and reproductive status determined. l. chagasi was detected in samples of skin or spleen by the polymerase chain reaction, after extraction of deoxyribonuc ... | 1998 | 9861395 |
| isolation and characterization of pirital virus, a newly discovered south american arenavirus. | specific rodent species are principal hosts for each of the well-characterized members of the virus family arenaviridae. guanarito virus (arenaviridae) is the etiologic agent of venezuelan hemorrhagic fever. a previous study on the epidemiology of venezuelan hemorrhagic fever revealed extensive arenavirus infection (presumed to be caused by guanarito virus) in two rodent species. sigmodon alstoni and zygodontomys brevicauda, collected from the region of venezuela in which the disease is endemic. ... | 1997 | 9180606 |
| acceleration and deceleration of sexual maturation by social cues in a tropical rodent zygodontomys brevicauda. | the effects of social cues from adult conspecifics on the rate of sexual maturity were studied in a tropical rodent, the cane mouse (zygodontomys brevicauda), in the laboratory. several aspects of the biology of this species have suggested that it might be atypical in that young females may not accelerate or decelerate their rate of reproductive development in response to social cues. this hypothesis was tested by housing 16-day-old females with an adult male, an adult female, or alone, and repr ... | 1994 | 7861401 |
| lack of reproductive photoresponsiveness and correlative failure to respond to melatonin in a tropical rodent, the cane mouse. | cane mice (zygodontomys brevicauda) are year-round breeders in venezuela. as shown previously, these animals are not reproductively responsive to variation in photoperiod. in the present experiments, male cane mice were maintained on long or short day lengths (16l:8d or 8l:16d, respectively) and challenged with each of three experimental treatments known to "unmask" reproductive photoresponsiveness in laboratory rats: olfactory bulbectomy, prolonged food restriction, and exposure as neonates to ... | 1992 | 1536900 |
| receptor determinants of zoonotic transmission of new world hemorrhagic fever arenaviruses. | transferrin receptor 1 (tfr1) is a cellular receptor for the new world hemorrhagic fever arenaviruses machupo (macv), junín (junv), and guanarito (gtov). each of these viruses is specifically adapted to a distinct rodent host species, but all cause human disease. here we compare the ability of these viruses to use various mammalian transferrin receptor 1 (tfr1) orthologs, including those of the south american rodents that serve as reservoirs for macv, junv, and gtov (calomys callosus, calomys mu ... | 2008 | 18268337 |
| photoperiod, melatonin secretion, and sexual maturation in a tropical rodent. | descendants of a sample of cane mice (zygodontomys brevicauda) trapped at 8 degrees latitude in venezuela were tested for reproductive photoresponsiveness. this species breeds continuously, year around, despite living in a seasonally harsh habitat. at 50 days of age there were no differences in the weights of the testes or seminal vesicles or in sperm counts of males born and reared on 16l:8d, 13l:11d, 11l:13d, or 8l:16d photoperiods, although there were small differences in body weight. females ... | 1990 | 2291910 |
| husbandry, reproduction and postnatal development of the neotropical muroid rodent zygodontomys brevicauda. | laboratory colonies of the neotropical muroid rodent zygodontomys brevicauda have been employed in studies of arbovirus epidemiology and are currently the subjects of experimental research on tropical mammalian reproductive physiology and evolutionary quantitative genetics. captive-bred litters typically consist of 4 or 5 pups weighing 3-4 g each at birth. adults 20-40 weeks old average 60-80 g with some sexual dimorphism. females are sexually mature at 3-4 weeks of age, males at 6-8 weeks. ovul ... | 1992 | 1548845 |
| divergence in zygodontomys (rodentia: sigmodontinae) and distribution of amazonian savannas. | northern south america presents a diverse array of nonforest or savanna-like ecosystems that are patchily distributed. the distribution of these open habitats has been quite dynamic during quaternary glacial-interglacial cycles; yet, the relevance of climatically driven vicariance events to the diversification of nonforest amazonian vertebrates remains poorly known. we analyzed karyologic and mitochondrial dna sequence data of the genus zygodontomys, a small cricetid rodent distributed throughou ... | 2009 | 19066316 |
| reproduction, development and behavior of captive oryzomys laticeps and zygodontomys brevicauda in trinidad. | | 1967 | 4228091 |
| new species and records of the mite genus prolistrophorus (acariformes: listrophoridae) from rodents of the subfamily sigmodontinae (rodentia: cricetidae). | six fur-mite species of the genus prolistrophorus fain, 1970 (acariformes: listrophoridae) were recorded from central and south american rodents of the subfamily sigmodontinae (rodentia: cricetidae). among them, prolistrophorus (aprolistrophorus) parabidentatus sp. nov. from akodon azarae from argentina and prolistrophorus (aprolistrophorus) tylomys sp. nov. from tylomys nudicaudus from guatemala are described as new for science. new hosts are recorded for the following species: prolistrophorus ... | 2014 | 25236266 |
| maripa hantavirus in french guiana: phylogenetic position and predicted spatial distribution of rodent hosts. | a molecular screening of wild-caught rodents was conducted in french guiana, south america to identify hosts of the hantavirus maripa described in 2008 in a hantavirus pulmonary syndrome (hps) case. over a 9-year period, 418 echimyids and murids were captured. viral rna was detected in two sigmodontine rodents, oligoryzomys fulvescens and zygodontomys brevicauda, trapped close to the house of a second hps case that occurred in 2009 and an o. fulvescens close to the fourth hps case identified in ... | 2014 | 24752689 |
| prevalence of antibody to hantaviruses in humans and rodents in the caribbean region of colombia determined using araraquara and maciel virus antigens. | we tested sera from 286 agricultural workers and 322 rodents in the department of córdoba, northeastern colombia, for antibodies against two hantaviruses. the sera were analysed by indirect elisa using the lysate of vero e6 cells infected with maciel virus (macv) or the n protein of araraquara virus (arav) as antigens for the detection of antibodies against hantaviruses. twenty-four human sera were igg positive using one or both antigens. we detected anti-macv igg antibodies in 10 sera (3.5%) an ... | 2013 | 23579795 |
| transmission of guanarito and pirital viruses among wild rodents, venezuela. | samples from rodents captured on a farm in venezuela in february 1997 were tested for arenavirus, antibody against guanarito virus (gtov), and antibody against pirital virus (pirv). thirty-one (48.4%) of 64 short-tailed cane mice (zygodontomys brevicauda) were infected with gtov, 1 alston's cotton rat (sigmodon alstoni) was infected with gtov, and 36 (64.3%) of 56 other alston's cotton rats were infected with pirv. the results of analyses of field and laboratory data suggested that horizontal tr ... | 2011 | 22172205 |