Murciélagos hematófagos como reservorios de la rabia / Hematophagous bats as reservoirs of rabies

La rabia continua siendo un desafío para las autoridades de salud pública y una limitante para la industria ganadera en América Latina. Caninos silvestres y domésticos, así como murciélagos hematófagos son las principales especies transmisoras y reservorios de la enfermedad. Actualmente, se observa variaciones en el perfil epidemiológico de la rabia, donde la especie de murciélago hematófago Desmodus rotundus se constituye en la principal especie transmisora. A lo largo del tiempo se ha acumulado conocimiento sobre la ecología, biología y comportamiento de esta especie y sobre la historia natural de la rabia, lo cual debe conducir a una continua evolución de los métodos de control poblacional de D. rotundus, prevención y técnicas de diagnóstico. Aún se desconoce la relación ecológica de esta especie con otras hematófagas y no hematófagas, y queda mucho por mejorar en los sistemas de notificación y vigilancia epidemiológica, así como crear una mayor conciencia entre los ganaderos ante el tema. La comprensión del impacto que las modificaciones ambientales inducidas por el hombre ejercen sobre la dinámica de infección del virus de la rabia en los murciélagos debe ser motivo de investigaciones posteriores. Esto requerirá la combinación de estudios de campo con modelos matemáticos y nuevas herramientas diagnósticas. La presente revisión pretende presentar los aspectos más relevantes sobre el rol de los murciélagos hematófagos como reservorios y transmisores del virus de la rabia.

Rabies continues to be a challenge for public health authorities and a constraint to the livestock industry in Latin America. Wild and domestic canines and vampire bats are the main transmitter species and reservoirs of the disease. Currently, variations observed in the epidemiological profile of rabies, where the species of hematophagous bat Desmodus rotundus constitutes the main transmitting species. Over the years, knowledge has accumulated about the ecology, biology and behavior of this species and the natural history of rabies, which should lead to continuous development of methods of population control of d. Rotundus as well as prevention and diagnostic tools for rabies. Ecological relationships of this species with other hematophagous and non-hematophagous bats is unknown, and there is much room for improvement in reporting systems and surveillance, as well as creating greater awareness among the farming community. Understanding the impact of human-induced environmental changes on the rabies virus in bats should be cause for further investigation. This will require a combination of field studies with mathematical models and new diagnostic tools. This review aims to present the most relevant issues on the role of hematophagous bats as reservoirs and transmitters of the rabies virus.

Multiple substitutions in biologically active domains ofrabies virus glycoprotein can be related to pathogenicprofile / Múltiplas substituições em domínios biologicamente ativos da glicoproteína do vírusrábico podem estar relacionadas com o perfil patogênico

Pathogenic profile of a rabies virus isolated from an insectivorous bat Lasiurus ega was compared with a rabies fixedvirus strain (CVS/32) in hamster and mouse. Incubation and clinical periods, clinical manifestation and death rateswere compared. Challenge of hamsters with L. ega was performed using: 10 2,611-4,021 LD50 /0,05 mL;. For CVS were used10 3,7-4,7 LD50 /0,05 mL. Were tested intramuscular (IM), intradermal (ID), intranasal (IN), epidermal abrasion (EA)inoculation routes. Viral antigen in brains was confirmed by Direct Immunofluorescence Test. Mortality percentagesobserved with L. ega rabies virus isolate were the following in hamster: 3,5 % IM, 10,710% IN; in mice: 50.0% IM, 30.0%IN. Furious rabies was predominant. Mortality percentages observed with CVS/32 in hamster: 12.5% IM, 62.5% ID,12.5% IN; in mice 100.0% IM, 70.0% ID, 10.0% IN. Paralytic rabies was found with this strain in both animal models.Epidermic abrasion was not a suitable challenge route. Incubation period was 5-7 days for CVS and 11-16 days for L. egaisolate, meanwhile clinical periods were comprehended between 4–7 days for both viruses. Several substitutions weredetected at antigenic domains of glycoprotein: AI (position 231), AII (34–42 and 198-200), domain of fusion dependenton low pH (102–179), transmembrane domain (440–461) and residue 242. These viruses showed contrasting biologicalbehaviors that can be linked to those substitutions at antigenic domains previously described.

O perfil patogênico de um vírus da raiva isolado de um morcego insetívoro Lasiurus ega foi comparado com o de vírusfixo de raiva (CVS/32) em hamster e camundongo, determinando os períodos de incubação e clínico, manifestaçãoclínica e mortalidade. Os animais foram desafiados com 10 2,611 - 4,021 DL50 /0,05 mL do isolado de L. ega e 10 3,7- 4,7 LD50 /0,05 mL do CVS/32, usando as vias: intramuscular (IM), intradermica (ID), intranasal (IN) e abrasão epidermica (AE).A presença do antígeno viral foi confirmada pela prova de imunofluorescência direta. As porcentagens de mortalidadeobservadas com o isolado de L. ega foram as seguintes em hamster: 3,5% IM, 10,71% IN; em camundongo: 50.0%IM, 30.0% IN. A forma furiosa da doença foi predominante. As porcentagens de mortalidade observadas com o vírusCVS/32 em hamster foram as seguintes: 12.5% IM, 62.5% ID, 12.5% IN; em camundongo 100.0% IM, 70.0% ID,10.0% IN. Com este vírus foi observada raiva paralitica. A via AE mostrou-se inadequada para induzir doença. Operíodo de incubação foi de 5–7 dias para o CVS/32 e 11-16 dias para o isolado de L. ega, entre tanto os períodosclínicos oscilaram entre 4–7 dias para ambos os vírus. Varias substituições foram achadas em domínios antigênicos daglicoproteína: AI (posição 231), AII (34–42 e 198-200), domínio de fusão dependente de baixo pH (102–179), domínioda transmembrana (440–461) e resíduo 242. Esses vírus mostraram comportamentos biológicos distintos o que poderiaestar ligado às substituições nos domínios antigênicos anteriormente descritos.