Mycobacterium leprae in six-banded (Euphractus sexcinctus) and nine-banded armadillos (Dasypus novemcinctus) in Northeast Brazil

Human beings are the main reservoir of the causative agent of leprosy, Mycobacterium leprae. In the Americas, nine-banded armadillos (Dasypus novemcinctus) also act as a reservoir for the bacillus. In the state of Ceará (CE), which is located in Northeast Brazil and is an endemic area of leprosy, there are several species of armadillos, including D. novemcinctus and Euphractus sexcinctus (six-banded armadillo). Contact between humans and armadillos occur mainly through hunting, cleaning, preparing, cooking and eating. This study identified M. leprae DNA in the two main species of armadillos found in Northeast Brazil. A total of 29 wild armadillos (27 D. novemcinctus and 2 E. sexcinctus) were captured in different environments of CE countryside. Samples from the ear, nose, liver and spleen from each of these animals were tested by a nested M. leprae-specific repetitive element polymerase chain reaction assay. The samples that tested positive were confirmed by DNA sequencing. M. leprae was detected in 21% (6/29) of the animals, including five D. novemcinctus and one E. sexcinctus. This is the first Brazilian study to identify the presence of a biomarker of M. leprae in wild armadillos (D. novemcinctus and E. sexcinctus) in a leprosy hyperendemic area where there is continuous contact between humans and armadillos.

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.