Rabies in Callithrix sp. in the urban area of Niterói, Rio de Janeiro, Brazil

Abstract In Brazil, rabies occurs mainly within an urban cycle, in which dogs and bats are reservoirs. This paper aims to report the occurrence of rabies in Callithrix sp. in Niterói, Rio de Janeiro, Brazil. In June 2019 a hybrid specimen was referred for diagnosis. The Direct Fluorescent Antibody, Mouse Inoculation, and Polymerase Chain Reaction tests were positive. A phylogenetic analysis was compatible with antigenic variant 3, characteristic of Desmodus rotundus. New studies should be undertaken to elucidate the real role of callitrichids in the urban rabies cycle.

Risco de transmissão do vírus da raiva oriundo de sagui (Callithrix jacchus), domiciliado e semidomiciliado, para o homem na região metropolitana de Fortaleza, estado do Ceará / Risks of transmitting rabies virus from captive domiciliary common marmoset (Callithrix jacchus) to human beings, in the metropolitan region of Fortaleza, state of Ceará, Brazil

INTRODUÇÃO: Uma variante do vírus da raivafoi identificadaem associação a casos de raiva humanos, no Estado do Ceará, transmitidos por saguis (Callithrix jacchus), primatas frequentemente criados como animais de estimação. Essa variante não apresenta proximidade antigênica ou relação genética com as variantes do vírus encontradas em morcegos e mamíferos terrestres das Américas. O objetivo do estudo foi avaliar os fatores de risco de transmissão do vírus da raiva oriundo de sagui (C. jacchus), criado como animal de estimação, para o homem na região metropolitana de Fortaleza, Ceará. MÉTODOS: Foi aplicado um questionário estruturado aos criadores de saguis, residentes nos municípios de Aquiraz e Maranguape, Ceará, enfocando o manejo e a interação desses primatas com humanos. Para avaliação da ocorrência de antígenos rábicos, através do teste de imunofluorescência direta (IFD), foram coletadas amostras de saliva dos saguis domiciliados e semidomiciliados. Com base nos resultados obtidos desses espécimes, foram analisadas amostras de sistema nervoso central (SNC). RESULTADOS: Na análise dos questionários, observou-se a proximidade dos criadores de saguis durante o manejo desses animais nos domicílios, bem como, seus conhecimentos limitados sobre a raiva, demonstrando haver risco quanto à transmissão do vírus. De 29 amostras de saliva de saguis reavaliadas, uma (3,4 por cento) apresentou reação de IFD positiva. De 11 amostras de SNC, três (27,3 por cento) apresentaram positividade. CONCLUSÕES: Os dados laboratoriais estão de acordo com os achados dos questionários, confirmando haver risco da transmissão do vírus da raiva devido à convivência de humanos com saguis (C. jacchus).

INTRODUCTION: In the State of Ceará, a new variant of the rabies virus was identified associated with cases of human rabies transmitted by common marmosets (Callithrix jacchus), which are frequently kept as pets. This new variant does not present antigenic proximity or genetic relationship to variants of the virus isolated from bats and terrestrial mammals from the American continent. The present study aimed to evaluate the risk factors of rabies virus transmission from common marmosets (C. jacchus) maintained as pets in the metropolitan region of Fortaleza, State of Ceará, Brazil, to human beings. METHODS: A questionnaire focusing on animal management and interaction between humans and primates was applied to individuals who had marmosets in the municipalities of Aquiraz and Maranguape. In order to evaluate the presence of rabies antigens by direct immunofluorescence test (DIF), samples of saliva were collected from domiciliary captive marmosets. Based on the detection of rabies antigens, biopsy samples of central nervous system (CNS) were analyzed. RESULTS: Analysis of questionnaire data verified that a close relation exists between humans and their pet marmosets, especially during management practices. Additionally, these people showed minimal knowledge regarding rabies, which represents a greater risk of infection. Of the 29 saliva samples evaluated, one (3.4 percent) was positive for DIF reaction and of the 11 CNS samples, three (27.3 percent) were positive. CONCLUSIONS: Laboratory data are in agreement with the questionnaire findings, which confirm an increased risk of rabies virus transmission due to the close relation between humans and marmosets.

Rabies virus viability after short-term cryopreservation using cryoprotectant agents

Rabies virus cryopreservation has been succinctly described in the scientific literature. The major researches about viral conservation emphasize the rabies diagnosis in decomposed samples. For now few information has been available concerning the use of cryoprotectants for rabies virus cryopreservation. This study aimed at assessing the viability of rabies virus after freezing/thawing procedures and investigating the effect of different concentrations of dimethyl sulphoxide (DMSO), glycerol (GLY), polyethyleneglycol (PEG) and sucrose (SUC) on rabies virus cryopreservation. Virus viability was assessed by virus isolation based on mouse inoculation test, titration and immunofluorescent antibody assay before and after 30 days of freezing procedures. The rabies virus samples after being exposed to cryopreservation without adding a cryoprotectant, its viability showed to be lower than that observed in samples exposed to other treatments. After 30 days of freezing procedure, the viability of cryopreserved samples using DMSO, GLY or PEG was lower than that observedin fresh samples. In addition, the use of sucrose at 10 or 68 concentrations induced positive effects on the viral particles viability after a short-term cryopreservation.

Cervical medulla as laboratory diagnosis material for rabies

Rabies is a contagious, neurotropic zoonosis associated with abandoned street dogs and low immunity. The disease has a reduced laboratory diagnosis rate because it is difficult to gather and transport sample material (brain). Based on this challenge, we studied the cervical medulla (CNS) as the pathway of de Rabies virus from the body to the brain. The cervical medulla was an ideal candidate for our study because its anatomy and location make it an easy material to gather. Our objective was to analyse the use of cervical medulla in the laboratory diagnosis of Rabies. Rabies viruses were intramuscularly inoculated into five Rattus species. After death, the brain and cervical medulla of each animal were intra-cerebrally macerated and inoculated. 100% positive for Rabies using the direct immunofluorescence (DIF) test and intracerebral inoculation. Overall, there was agreement between the analyses of the brains and the cervical medullas. Therefore, we propose the use of cervical medulla as a material for the laboratory diagnosis of Rabies.

Rabies transmitted by vampire bats to humans: an emerging zoonotic disease in Latin America? / La rabia transmitida por murciélagos vampiros a humanos: ¿una zoonosis emergente en América Latina?

Human rabies transmitted by vampire bats reached new heights in Latin America in 2005. A total of 55 human cases were reported in several outbreaks, 41 of them in the Amazon region of Brazil. Peru and Brazil had the highest number of reported cases from 1975 to 2006. In Peru, outbreaks involving more than 20 cases of bat-transmitted human rabies were reported during the 1980s and 1990s. During this period, a smaller number of cases were reported from outbreaks in Brazil. A comparison of data from field studies conducted in Brazil in 2005 with those from the previous decade suggests similar bat-bite situations at the local level. The objective of this study was to review the epidemiological situation and, on the basis of this information, discuss possible factors associated with the outbreaks. Prevention and control measures already recommended for dealing with this problem are also reviewed, and some further suggestions are provided.

La rabia en humanos transmitida por murciélagos vampiros aumentó en América Latina en 2005. Se notificaron varios brotes con un total de 55 personas enfermas, 41 de ellas en la región amazónica de Brasil. Perú y Bolivia acumularon el mayor número de casos notificados entre 1975 y 2006. En Perú se informaron brotes de más de 20 personas con rabia transmitida por murciélagos en las décadas de 1980 y 1990. En ese período se informó un número menor de casos en los brotes de Brasil. Al comparar los datos de estudios de campo realizados en Brasil en 2005 con los obtenidos en décadas anteriores se observaron situaciones similares en cuanto a los casos de mordidas por murciélagos a nivel local. En este estudio se presenta una revisión de la situación epidemiológica y, a partir de esa información, se discuten los posibles factores asociados con los brotes. Se revisan también las medidas de prevención y control ya recomendadas para hacer frente a este problema y se ofrecen algunas recomendaciones adicionales.

Relato de infecção natural de morcegos por flagelados tripanosomatideos em diferentes municípios do Estado do Rio de Janeiro / Report on natural infection of bats by trypanosomatid flagellates in different municipalities in the State of Rio de Janeiro

Este trabalho objetivou avaliar a infecção natural de morcegos por tripanosomatídeos. Foram examinados, por hemocultura, 86 exemplares de diferentes gêneros, sendo 22 (25,58 por cento) amostras isoladas de Desmodus rotundus e Lonchorhina aurita. Os resultados obtidos contribuem para o conhecimento da ocorrência de tripanosomatídeos em morcegos no Estado do Rio de Janeiro.

This study aimed to evaluate natural infection of bats by trypanosomatids. Using blood culturing, 86 specimens from different genera were examined, and 22 samples (25.58 percent) of Desmodus rotundus and Lonchorhina aurita were isolated. These results contribute towards knowledge of the occurrence of trypanosomatids in bats in the State of Rio de Janeiro.

Resposta imune produzida por vacinas anti-rábicas em sagüis (Callithrix sp) / Immune response produced by rabies vaccines in marmosets (Callithrix sp)

Visando avaliar a resposta imunológica produzida por vacinas anti-rábicas em primatas nao humanos neotropicais, trinta sagüis (Callithrix sp) foram divididos em cinco grupos de seis indivíduos e submetidos a cinco diferentes esquemas de vacinaçäo anti-rábica, utilizando-se duas vacinas animais distintas existentes no mercado. A primeira produzida em cérebro de camundongos lactentes (Fuenzalida e Palacios), e a segunda, em cultura de células NIL-2. Acompanhamento sorológico pós-vacinal foi realizado periodicamente. Os resultados mostraram que a vacina Fuenzalida e Palacios näo foi eficaz para a proteçäo dos animais, utilizando-se uma única dose ou mesmo com o reforço. Porém, os sagüis apresentaram anticorpos detectáveis, ao adotar-se o esquema semelhante ao de pré-exposiçäo indicado para os seres humanos, e apenas um animal contraiu raiva após o desafio viral. Por outro lado, a vacina produzida em cultura de células NIL-2 produziu elevados títulos de anticorpos em todos os animais imunizados e todos os animais resistiram ao desafio viral