Transmission de rabia a roedores por la ingestion de tejidos extraidos de animales naturalmente infectados / Rabies transmission to rodents after ingestion of naturally infected tissues

Se describen 7 ensayos en los que calomys musculinus y Mus musculus alimentados con tejido extraídos de perros, bovinos y vampiros naturalmente infectados de rabia. Los tejidos no fueron sometidos a ningún tipo de manipulación previa en el laboratorio. Se administraron directamente y los roedores los consumieron en forma voluntaria. Sobre 132 animales que ingirieron los distintos tejidos infectados, 3 contrajeron rabia (2,3%) y hubo seroconversión en 22 de los 128 sobrevivientes (17,2%). La possibilidad de contraer rabia por el consumo de tejido naturalmente infectados indicaría que los roedores pueden actuar como reservorios del virus, dado que la ingestión de cadáveres es una fuente de alimentación normal para muchas especies. Además, puede constituir un puente para el pasaje del virus rábico entre los carnívoros, ya que en muchos ecosistemas son la principal presa de estos animales. Es decir, que se trata de dos situaciones en las que aumenta el riesgo de infección al hombre por modedura de roedores

Transmission de rabia a roedores por la ingestion de tejidos extraidos de animales naturalmente infectados / Rabies transmission to rodents after ingestion of naturally infected tissues

Se describen 7 ensayos en los que calomys musculinus y Mus musculus alimentados con tejido extraídos de perros, bovinos y vampiros naturalmente infectados de rabia. Los tejidos no fueron sometidos a ningún tipo de manipulación previa en el laboratorio. Se administraron directamente y los roedores los consumieron en forma voluntaria. Sobre 132 animales que ingirieron los distintos tejidos infectados, 3 contrajeron rabia (2,3%) y hubo seroconversión en 22 de los 128 sobrevivientes (17,2%). La possibilidad de contraer rabia por el consumo de tejido naturalmente infectados indicaría que los roedores pueden actuar como reservorios del virus, dado que la ingestión de cadáveres es una fuente de alimentación normal para muchas especies. Además, puede constituir un puente para el pasaje del virus rábico entre los carnívoros, ya que en muchos ecosistemas son la principal presa de estos animales. Es decir, que se trata de dos situaciones en las que aumenta el riesgo de infección al hombre por modedura de roedores (AU)

[Rabies transmission to rodents after ingestion of naturally infected tissues]. / Transmisión de rabia a roedores por la ingestión de tejidos extraídos de animales naturalmente infectados.

We describe seven trials in which Calomys musculinus and Mus Musculus were fed with naturally rabies-infected tissues extracted from vampire bats, dogs, and bovines. The tissues were not subjected to any kind of previous laboratory handling and were administered directly in Petri dishes; rodents ate them voluntarily. The only infectious tissues were bovine brains taken from outbreaks transmitted by vampire bats (Table 1). It was possible to infect the two species of tested rodents, and there was no relationship between infection and amount of virus ingested. From the total number of 132 animals that ingested different kinds of rabies-infected tissues, 3 died of rabies infection. From 128 survivors of all the exposed mice, 22 presented seroconversion to rabies. In the infected Calomys musculinus there was evident nervous symptomatology consisting in excitability, aggressiveness, paralysis and isolation of rabies virus from their salivary glands. The possibility that rodents become rabies infected by the ingestion of naturally infected tissues would indicate that they may constitute a reservoir for rabies because cadaver ingestion is a natural feeding source for many species. Furthermore they may permit the passage of rabies virus in carnivorous, animals since they are an important prey for them. The present observations indicate two situations which may increase rabies risks to man through rodent bites.

Transmisión de rabia a roedores por la ingestión de tejidos extraídos de animales naturalmente infectados. / [Rabies transmission to rodents after ingestion of naturally infected tissues]

We describe seven trials in which Calomys musculinus and Mus Musculus were fed with naturally rabies-infected tissues extracted from vampire bats, dogs, and bovines. The tissues were not subjected to any kind of previous laboratory handling and were administered directly in Petri dishes; rodents ate them voluntarily. The only infectious tissues were bovine brains taken from outbreaks transmitted by vampire bats (Table 1). It was possible to infect the two species of tested rodents, and there was no relationship between infection and amount of virus ingested. From the total number of 132 animals that ingested different kinds of rabies-infected tissues, 3 died of rabies infection. From 128 survivors of all the exposed mice, 22 presented seroconversion to rabies. In the infected Calomys musculinus there was evident nervous symptomatology consisting in excitability, aggressiveness, paralysis and isolation of rabies virus from their salivary glands. The possibility that rodents become rabies infected by the ingestion of naturally infected tissues would indicate that they may constitute a reservoir for rabies because cadaver ingestion is a natural feeding source for many species. Furthermore they may permit the passage of rabies virus in carnivorous, animals since they are an important prey for them. The present observations indicate two situations which may increase rabies risks to man through rodent bites.

Probability of introducing diseases because of false negative test results.

The use of diagnostic tests for the selection of healthy individual persons or animals for inclusion in certain groups carries with it an inherent risk of including those with infections because they falsely reacted negatively. The factors of sensitivity of the test, prevalence of the disease, and the size of the group all influence the degree of such risk. The probability of including an infected individual person or animal can be calculated combining conditional probability and the binomial distribution.

Review of hospital cases in the assessment of hydatidosis as a health problem in the Argentine Province of Chubut.

A retrospective survey of hospital cases to obtain baseline data on hydatid disease in the northwest of the Province of Chubut, Argentina, from 1973 to 1979 revealed annual mean rates that varied between 13.4 and 75.8 confirmed new cases per 100.000 population. Inclusion of data on parasitologically confirmed non-surgical cases and on the geographic origin of patients permitted a more accurate estimate of cases in the four Departments comprised in the study area. Information on cyst location, clinical status at admission, mortality, number of re-operations and length of hospitalization was obtained to assess the public health impact of hydatidosis within the area. The criteria established and methods used to collect this information are described and discussed.

Rabia urbana: el problema de las lesiones por mordedura de perro. / Urban rabies: the problem of lesions by dog bites

Tanto la rabia humana como la canina constituyen un problema de caracter esencialmente urbano, presente en casi todos los paises de America Latina y el Caribe, que se agudiza en los suburbios o zonas perifericas de ciudades grandes y medianas.Los perros representan mas del 94,0% en los casos de rabia animal y son los transmisores de casi todos los casos humanos. Ademas, se estima que la poblacion canina de America Latina y el Caribe comprende entre 29 y 47 millones de animales, con una relacion de 1 a 8, o de 1 a 13 perros por habitante. Por otra parte, las mordeduras de perros no solo constituyen la causa de la gran mayoria de casos de rabia humana, sino tambien de gran cantidad de heridas que requieren tratamiento antirrabico preventivo, como atencion medica y o quirurgica. Teniendo en cuenta estas razones, se decidio efectuar una investigacion epidemiologica del problema efectuar una investigacion epidemiologica del problema en una zona altamente poblada e industrializada de Argentina, en Avellaneda, provincia de Buenos Aires