RESUMO
Common vampire bats (Desmodus rotundus) are a key rabies vector in South America. Improved management of this species requires long-term, region-specific information. To investigate patterns of demography and dispersal, we analysed 13 642 captures of common vampire bats in Northern Argentina from the period 1969-2004. In contrast with findings from more tropical regions, we found reproductive seasonality with peak pregnancy in September and peak lactation in February. Curiously, sex ratios were consistently male-biased both in maternity roosts and at foraging sites. Males comprised 57% of 9509 adults caught at night, 57% of 1078 juveniles caught at night, 57% of 603 juveniles caught in roosts during the day, and 55% of 103 newborns and mature fetuses. Most observed roosts were in man-made structures. Movements of 1.5-54 km were most frequent in adult males, followed by young males, adult females and young females. At night, males visited maternity roosts, and non-pregnant, non-lactating females visited bachelor roosts. Males fed earlier in the night. Finally, we report new longevity records for free-ranging vampire bats: 16 and 17 years of age for a female and male, respectively. Our results are consistent with model predictions that sex-biased movements might play a key role in rabies transmission between vampire bat populations.
RESUMO
During rabies outbreaks in cattle (paralytic rabies) in Argentina associated with the common vampire bat Desmodus rotundus, rabies was observed in marsh deer (Blastocerus dichotomus), red brocket deer (Mazama americana), capybara (Hydrochoerus hydrochaeris), savanna fox (Cerdocyon thous), and great fruit-eating bat (Artibeus lituratus). Rabies could constitute a threat to the survival of marsh deer in places where they live in small groups, and infection of both great fruit-eating bats and savanna fox represent a risk for humans; both species exhibit aggressiveness and fury when infected.
Assuntos
Doenças dos Bovinos/epidemiologia , Quirópteros/virologia , Reservatórios de Doenças/veterinária , Raiva/veterinária , Animais , Animais Domésticos/virologia , Animais Selvagens/virologia , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/transmissão , Cervos/virologia , Surtos de Doenças/veterinária , Reservatórios de Doenças/virologia , Feminino , Raposas/virologia , Masculino , Raiva/epidemiologia , Raiva/transmissãoRESUMO
OBJECTIVE: To evaluate live attenuated Brucella abortus RB51, killed B suis cells, O-polysaccharide (OPS) from B abortus 1119-3 and OPS from B suis 1330, for protection of swine against B suis challenge exposure under farm conditions. ANIMALS: 10 infected boars, 160 unvaccinated control sows and their 1,040 progeny, and 610 vaccinated sows and their 6,600 progeny. PROCEDURE: Gilts (45 to 65 days or 4 to 6 months old) were vaccinated or not vaccinated. For the latter gilts, additional variables studied were dose, number of doses, and delivery route. Mature gilts were mated with 4 infected boars, then serologic reaction to Brucella spp, results of bacteriologic culture of vaginal secretions, presence of abortion, and litter size were assessed. Various tissues obtained from aborted fetuses were obtained for culture of Brucella spp. RESULTS: About 40% of unvaccinated control gilts seroconverted to Brucella spp, 27% were positive for OPS precipitation by use of agar gel immunodiffusion, 23% aborted their fetuses, and the remaining gilts had litters of 5 to 8 pigs. Killed B suis cells provided the following protection: 25% of vaccinates were seropositive, 5% had positive results of agar gel immunodiffusion, 5% aborted, and the remaining gilts had litters of 7 to 8 pigs. Gilts that received live RB51 or OPS vaccine were protected. Serologic reactions were always negative, abortion did not occur (i.e., 100% were protected), and litter size was 10 to 12 pigs. CONCLUSIONS: Live attenuated B abortus RB51 or purified OPS was effective in protecting gilts against B suis infections. Dose (10(6) to 10(9) cells, 100 to 500 micrograms, respectively), number of doses (1 or 3), or route (IM or PO) made little difference. Further research is required to determine why these 2 vaccine candidates are similar in protection effectiveness and whether they can be used after infection as a treatment.
Assuntos
Vacina contra Brucelose/administração & dosagem , Brucella abortus/imunologia , Brucelose/veterinária , Complicações Infecciosas na Gravidez/veterinária , Doenças dos Suínos/prevenção & controle , Animais , Anticorpos Antibacterianos/análise , Antígenos de Bactérias/imunologia , Brucella abortus/isolamento & purificação , Brucelose/microbiologia , Brucelose/prevenção & controle , Feminino , Imunodifusão/veterinária , Masculino , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/prevenção & controle , Sêmen/microbiologia , Suínos , Doenças dos Suínos/microbiologia , Vacinação/veterinária , Vacinas Atenuadas/administração & dosagem , Vacinas de Produtos Inativados/administração & dosagem , VenezuelaRESUMO
Studies of pregnancy and lactation in vampire bats (Desmodus rotundus) in northern Argentina over a 4 yr period showed an inverse relationship between prevalence of pregnancy and lactation, the consequence of birth and onset of lactation, which was correlated with the wet season. The seasonal influx of young susceptibles into the vampire population in the wet season coincided with the well known increase in vampire transmitted rabies in that season.
Assuntos
Doenças dos Bovinos/epidemiologia , Quirópteros/fisiologia , Lactação/fisiologia , Prenhez/fisiologia , Raiva/veterinária , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/transmissão , Vetores de Doenças , Feminino , Masculino , Gravidez , Prevalência , Raiva/epidemiologia , Raiva/transmissão , Chuva , Estações do AnoRESUMO
A bacteriologic and serologic study was conducted on two ranches in the states of Apure and Guarico, Venezuela for brucellosis in collared peccaries (Tayassu tajacu). One hundred thirty-nine peccaries were necropsied and tissues were cultured. Forty-three isolations of Brucella suis biovar 1, were made from lymph nodes and spleens of 25 males and 18 females. Antibody to Brucella sp. was detected in sera from 122 animals by the rapid plate agglutination, standard tube agglutination, 2-mer-captoethanol, rivanol, complement fixation and card tests. Young animals had infection and reactor rates nearly as high as the older animals indicating most were infected at a relative early age. Results suggest that this species may transmit brucellosis when living with domestic animals. This is the first report of B. suis biovar 1 from collared peccaries in Venezuela.
Assuntos
Artiodáctilos/microbiologia , Brucelose/veterinária , Fatores Etários , Animais , Anticorpos Antibacterianos/sangue , Brucella/imunologia , Brucella/isolamento & purificação , Brucelose/epidemiologia , Feminino , Linfonodos/microbiologia , Masculino , Prevalência , Baço/microbiologia , Venezuela/epidemiologiaRESUMO
A virus isolated from the blood of a febrile horse in Argentina was identified as a strain of Kairi virus. This is the fifth Bunyamwera serogroup virus isolated from livestock and wild animals in the Americas. Bunyamwera serogroup viruses have been isolated from febrile humans in the Americas and Africa.
Assuntos
Vírus Bunyamwera/isolamento & purificação , Infecções por Bunyaviridae/veterinária , Bunyaviridae/isolamento & purificação , Doenças dos Cavalos/microbiologia , Animais , Argentina , Infecções por Bunyaviridae/microbiologia , Cavalos , Testes de Neutralização , Células VeroAssuntos
Controle de Roedores/métodos , Animais , México , Camundongos , Ratos , Controle de Roedores/instrumentaçãoRESUMO
A pesar de los crecientes problemas que causan en todo el mundo las poblaciones de roedores comensales, se carece de metodos para evaluar la eficacia de las medidas de lucha contra esos animales. En este articulo se describe un importante progreso en la evaluacion de programas para combatir los roedores
Assuntos
Animais , Ratos , Controle de Roedores , MéxicoRESUMO
Dogs were fed larvae of Echinococcus granulosus (Batsch, 1786) recovered from sheep in Argentina. The morphological characteristics of strobilae recovered from dogs at 28, 60 and 76 days postexposure were compared with those of Echinococcus spp. recovered from naturally infected foxes, Dusicyon clupaeus (Molina) and D. griseus (Gray), and those of worms reared in dogs from larvae in European hares, Lepus europaeus (L.). Only slight differences were observed in characters of taxonomic importance and it was concluded that all cestodes represented a single species, E. granulosus. The results are discussed as they bear on the speciation controversy and the potential epidemiology importance of Dusicyon spp. as hosts of E. granulosus. It was suggested that E. patagonicus Szidat, 1960 previously described from D. culpaeus is conspecific with E. granulosus. E. cepanzoi Szidat, 1971 is probably also a synonym of E. granulosus and the subspecies E. g. dusicyontis Blood and Lelijveld, 1969, is rejected on the grounds that there is no evidence for host specificity and ecological or other segregation from the nominate form. Foxes appear to become infected from scavenging on dead sheep in localities where E. granulosus is endemic in domestic animals. There is still no evidence that E. granulosus is maintained in Argentina in sylvatic cycles.
Assuntos
Equinococose/transmissão , Echinococcus/anatomia & histologia , Raposas/parasitologia , Animais , Argentina , Cães , Echinococcus/classificação , Ecologia , Lagomorpha/parasitologia , Ovinos , Especificidade da EspécieRESUMO
In an outbreak of bovine rabies in Argentina, a study was made of vampire bats (Desmodus rotundus) and wild carnivores. Rabies antibody rates of high prevalence were found in the bats, foxes (Dusicyon gymnocercus) and skunks (Conepatus chinga). The outbreak was part of an extensive continuing epizootic of vampire transmitted bovine rabies which may have also involved other vectors in the area of this study. Consumption of dead and dying bats by the carnivores is the suggested means of passage of rabies virus from vampire bats to foxes and skunks. Given optimum conditions it is conceivable that some outbreaks in carnivores may begin in this way.
Assuntos
Anticorpos Antivirais/análise , Carnívoros/imunologia , Doenças dos Bovinos/epidemiologia , Vírus da Raiva/imunologia , Raiva/veterinária , Animais , Argentina , Bovinos , Doenças dos Bovinos/imunologia , Quirópteros/imunologia , Raposas/imunologia , Mephitidae/imunologia , Testes de Neutralização , Gambás/imunologia , Raiva/epidemiologia , Raiva/imunologia , Roedores/imunologiaRESUMO
Vampire bat populations were opportunely sampled before, during, and at varying intervals after outbreaks of bovine rabies. The captured bats were examined for rabies neutralizing antibody and virus. In all, sera from 1,024 vampire bats were tested for antibody, and tissues from these bats plus 83 others were tested for virus. Neutralizing antibody only rarely appeared in vampire serum samples taken before bovine rabies outbreaks, and only low percentages of samples positive for rabies antibody were obtained from bats captured during bovine outbreaks. In contrast, varying percentages of positive samples (including some high percentages) were taken from bats captured at various intervals after bovine outbreaks. Only eleven rabies virus isolations were obtained in the course of this study. In each case the virus came from a bat captured just before or during a bovine outbreak. The authors suggest that rabies virus behaves in vampire populations the way diverse infectious agents typically behave in other hosts. That is, the virus infects many individuals; some die and others survive to demonstrate their exposure through the appearance of anitbody. The disease disappears from the bat population in time and does not return until a sufficient number of susceptible bats have re-entered the population.