Fifty Years of the National Rabies Control Program in Brazil under the One Health Perspective.

In 1973, the National Rabies Program was created in Brazil through an agreement between the Ministry of Health and Agriculture. Since its beginning, it developed integrated action through access to free post-exposure prophylaxis (PEP) for people at risk, dog vaccination campaigns, a joint surveillance system, and awareness. This study aims to describe human rabies in Brazil under the One Health perspective in recent decades, including achievements in the control of dog-mediated cases and challenges in human cases transmitted by wild animals. This paper also explores possible drivers of human rabies in the Northeast Region with half of the cases. The first part of this study was descriptive, presenting data and examples by periods. Statistical analysis was performed in the last period (2010-2022) to explore possible drivers. Dog-mediated human cases decreased from 147 to 0, and dog cases decreased from 4500 to 7. A major challenge is now human cases transmitted by wild animals (bats, non-human primates, and wild canids). Most current human cases occur in municipalities with a tropical and subtropical moist broadleaf forest biome and a Gini index higher than 0.5. In the multivariable analysis, an association with temperature was estimated (OR = 1.739; CI95% = 1.181-2.744), and primary healthcare coverage (OR = 0.947; CI95% = 0.915-0.987) was identified as a protector. It is possible to significantly reduce the number of dog-mediated human rabies cases through the efforts presented. However, Brazil has wildlife variants of the rabies virus circulating. The association of human cases with higher temperatures in the Northeast is a concern with climate change. To reduce human cases transmitted by wild animals, it is important to continue distributing free PEP, especially in remote at-risk areas in the Amazon Region, and to increase awareness.

Knowledge, Attitudes and Practices Regarding Sylvatic Rabies among High-Risk Households in Ceará State, Brazil.

Rabies transmitted by sylvatic populations has become an increasing concern in Brazil. A total of 113 participants with a history of contact with sylvatic populations were interviewed in 27 municipalities of Ceará State in northeast Brazil. Questionnaires included questions on knowledge, attitudes and practices (KAP) regarding sylvatic rabies. Most of the respondents (92%) knew about rabies and confirmed at least one species that transmitted the disease (79.6%). Of these respondents, 69% mentioned monkeys, and 67.2% mentioned dogs. However, 16% of the respondents listed an incorrect species. In general, knowledge on the symptoms and signs and on prevention measures was weak. The majority raised pets (93.8%), most commonly dogs and cats, and, of all the pets, 85.7% were claimed to be vaccinated against rabies. A total of 67.3% reported the appearance of free-living wild animals around their houses, mostly marmosets and wild canids; 18.3% reported that sylvatic populations had attacked animals or humans. Seventy-three percent had raised or still were raising wild animals as pets, mostly capuchin monkeys (79.5%) and marmosets (24.1%). This is the first KAP study on sylvatic rabies in Brazil. The data indicate important knowledge gaps and risk behavior within a high-risk population. There is a need for strengthening and improving sylvatic rabies surveillance and control, combined with the intensification of education and information campaigns.

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

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.

Increased detection of rabies virus in bats in Ceará State (Northeast Brazil) after implementation of a passive surveillance programme.

The intensification of dog, cat and livestock vaccination campaigns significantly reduced rabies cases in humans and domestic animals in Ceará State, Brazil. However, sylvatic animals-bats (order Chiroptera), wild canids, raccoons and non-human primates- remain as reservoirs for the virus. Our hypothesis is that surveillance and monitoring of rabies virus in bats, especially passive surveillance, is of fundamental importance, besides the implementation of health education and strengthening of surveillance actions in humans exposed to aggressions. Thus, we assessed the occurrence of rabies virus in animals focusing on bats, before and after launching of the Sylvatic Rabies Surveillance Program in 2010. Surveillance data from the 184 municipalities of Ceará State were analysed, collected during the periods 2003-2010 (active surveillance) and 2011-2016 (passive surveillance), respectively. A total of 13,543 mammalian samples were received for rabies diagnosis from 2003 to 2016. Of these, 10,960 were from dogs or cats (80.9%), 1,180 from bats (8.7%), 806 from other sylvatic animals (foxes, marmosets, raccoons; 6.0%) and 597 from herbivores (cattle, goats, sheep, equines, pigs; 4.4%). A total of 588 (4.3%) samples were positive for rabies. About 8.4% (99/1,180) of the bat samples were infected with rabies virus, 92 (92.9%) of these were from non-haematophagous bat species and 7 (7.1%) from haematophagous species. The number of bat samples received and infection rates increased considerably, after a shift from active surveillance (9/355 [2.5%] samples positive), to passive surveillance (90/825 [10.9%] samples positive). Surveillance of rabies virus in bats is fundamental for human and domestic animal health in Ceará State. Bats have to be considered as targets in surveillance and control programmes. Virus lineages should be characterized to increase knowledge on transmission dynamics of sylvatic rabies virus to domestic animals and the human population, and to provide additional evidence for planning and implementation of improved control measures.

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.

[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]. / 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

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%) was positive for DIF reaction and of the 11 CNS samples, three (27.3%) 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.

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.

Rabies transmitted by vampire bats to humans: an emerging zoonotic disease in Latin America?

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.

Potency evaluation of rabies vaccine for human use: the impact of the reduction in the number of animals per dilution.

In order to evaluate the effects of reducing the number of animals used in the NIH mouse protection test for potency determination of inactivated rabies vaccines for human use, a retrospective study of the results obtained in the Brazilian National Control Laboratory, Instituto Nacional de Controle de Qualidade em Saúde (INCQS), was performed, comprising 214 vaccine lots. The INCQS Standard Operating Procedure establishes the use of three vaccine dilutions and 18 animals per dilution, separated into two cages with 9 mice each. The results of the two cages of each dilution were considered as two different groups (C1 and C2), and therefore, for each vaccine lot, three results were obtained: one for the standard test (ST) with 18 mice, one using the C1 cages with 9 mice and another using the C2 cages with 9 mice. The results were evaluated as repeated measures of the same method on the same samples. In this study, the effects of the reduction in: (a) the measurement error and its association with the size of measurement, (b) the agreement between the results using the concordance coefficient of correlation, (c) the agreement of categorized results as "Pass" or "Fail" using the Kappa index, (d) the precision of potency determinations using the 95% confidence interval and (e) the incidence of statistically invalid assays due to non-linearity and non-parallelism were evaluated. It was concluded that the results from the NIH mouse protection test using 9 mice per dilution are in good agreement with the results obtained using 18 mice per dilution. Therefore, nine animals per dilution is a suitable number to meet the statistical requirement for valid assays.

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.

Validation of a virus neutralization potency test in BHK-21 cells for rabies immunoglobulins in a two-center study.

A rabies virus neutralization potency test (VNPT), adapted to microplates from the rapid fluorescent focus inhibition test (RFFIT) for rabies therapeutic immunoglobulin potency evaluation, was standardized and validated in a two-center study in Brazil. The two institutes involved in the study were: Instituto Nacional de Controle de Qualidade em Saúde (Fundação Oswaldo Cruz) and Instituto Butantan. Two equine rabies immunoglobulin samples, all diluted to 1IU/ml, were tested against the WHO 2nd Rabies Human Ig International Standard. Four dilutions of the samples and standards were tested with the VNPT. The potency of the samples was calculated in IU/ml using the probit method; linearity, accuracy, repeatability (intra-assay variation), intermediate precision (inter-assay variation) and reproducibility (inter-laboratory variation) were assessed to evaluate the reliability of the VNPT. Laboratories were arbitrarily coded as Laboratory A and Laboratory B. The following results were obtained with the International Standard: (a) linearity, the overall coefficient of correlation of the dose-response curve was -0.97; (b) accuracy, % error of -0.70 (IU/ml); (c) repeatability, 17.06% (Laboratory A) and 11.61% (Laboratory B); (d) intermediate precision, 16.99% (Laboratory A) and 22.05% (Laboratory B); (e) reproducibility, 14.5%. The final conclusion was that VNPT presents satisfactory linearity, accuracy, repeatability, intermediate precision and reproducibility and is a reliable and suitable method by which to evaluate rabies immunoglobulin potency.

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