Seroprevalence and spatial distribution dynamics of Yersinia pestis antibodies in dogs and cats from plague foci in the State of Ceará, Northeastern Brazil

Abstract INTRODUCTION: In Brazil, the plague is established in several foci located mainly in the northeastern part of the country, where it alternates between active and quiescent periods. These foci in the State of Ceará have high epidemiological importance. In addition to other plague detection activities, plague areas can be monitored through serological surveys of dogs and cats (domestic carnivores), which, following feeding on plague-infected rodents, can develop mild to severe forms of the disease and produce long-lasting antibodies. This study aimed to characterize the circulation dynamics and spatial distribution of Yersinia pestis antibodies in dogs and cats in plague foci areas of Ceará. METHODS: An ecological study was conducted to analyze the temporal series and spatial distribution of secondary data obtained from domestic carnivore serum surveillance in Ceará's plague areas from 1990 to 2014. RESULTS: Joinpoint analysis revealed that the overall trend was a reduction in antibody-positive animals. The mean proportion of antibody-positivity during the whole study period was 1.5% (3,023/203,311) for dogs, and 0.7% (426/61,135) for cats, with more than 4% antibody-positivity in dogs in 1997 and 2002. Antibody titers ranging from 1/16 to 1/64 were frequent. Despite fluctuations and a significant reduction, in recent years, there were antibody-positive animals annually throughout the study period, and the localities containing antibody-positive animals increased in number. CONCLUSION: Yersinia pestis is actively circulating in the study areas, posing a danger to the human population.

rROP2 from Toxoplasma gondii as a potential vaccine against oocyst shedding in domestic cats / rROP2 de Toxoplasma gondii como potencial vacina contra a eliminação de oocistos em gatos domésticos

Abstract The aim of the present study was to evaluate oocyst shedding in cats immunized by nasal route with T. gondii proteins ROP2. Twelve short hair cats (Felis catus) were divided in three groups G1, G2 and G3 (n=4). Animals from G1 received 100 μg of rROP2 proteins plus 20 μg of Quil-A, G2 received 100 μg of BSA plus 20 μg of Quil-A, and the G3 only saline solution (control group). All treatments were done by intranasal route at days 0, 21, 42, and 63. The challenge was performed in all groups on day 70 with ≅ 800 tissue cysts of ME-49 strain by oral route. Animals from G1 shed less oocysts (86.7%) than control groups. ELISA was used to detect anti-rROP2 IgG and IgA, however, there were no correlation between number of oocyst shedding by either IgG or IgA antibody levels. In the present work, in spite of lesser oocysts production in immunized group than control groups, it was not possible to associate the use of rROP2 via nostrils with protection against oocyst shedding. For the future, the use of either other recombinant proteins or DNA vaccine, in combination with rROP2 could be tested to try improving the efficacy of this kind of vaccine.

Resumo O objetivo do presente estudo foi avaliar a eliminação de oocistos de Toxoplasma gondii em gatos imunizados pela via nasal com proteínas ROP2 de T. gondii. Doze gatos sem raça definida (Felis catus) foram divididos em três grupos experimentais G1, G2 e G3 (n = 4). Os animais do G1 receberam 100 μg de proteínas de rROP2 mais 20 μg de Quil-A, G2 recebeu 100 μg de albumina de soro bovino (BSA) junto com 20 μg de Quil-A, e o G3 recebeu apenas solução salina (grupo de controle). Todos os tratamentos foram realizados pela via intranasal nos dias 0, 21, 42 e 63. O desafio foi realizado em todos os grupos no dia 70 com aproximadamente 800 cistos de tecido da cepa ME-49 por via oral. Os animais de todos os grupos tiveram as suas fezes examinadas e o número de oocistos foi determinado durante 20 dias após o desafio. Os animais de G1 eliminaram menos oocistos (86,7%) do que os grupos controles. O ELISA foi utilizado para detectar IgG e IgA anti-rROP2, no entanto, não houve correlação entre o número de eliminhação de oocistos com os níveis de anticorpos IgG ou IgA. No presente trabalho, apesar da menor produção de oocistos no grupo imunizado (G1) em relação aos grupos controles (G2 e G3), não foi possível associar o uso de rROP2 pela via nasal com proteção contra eliminação de oocistos de T. gondii. Para o futuro, a utilização de outras proteínas recombinantes, ou mesmo vacina de DNA, em combinação com rROP2 poderia ser utilizada para tentar melhorar a eficácia deste tipo de vacina.

Urticaria papular y sus agentes causales en Colombia / Papular urticaria: A review of causal agents in Colombia

Resumen La urticaria papular es una enfermedad alérgica causada por la picadura de insectos, la cual predomina en el trópico. El objetivo de esta revisión fue profundizar en sus aspectos epidemiológicos e inmunológicos, particularmente con base en datos publicados en Latinoamérica. Se hizo una revisión no sistemática mediante la búsqueda electrónica de artículos sobre la epidemiología de la urticaria papular, las características entomológicas de los agentes causales y los mecanismos inmunológicos asociados. Según los diversos reportes de centros médicos de Latinoamérica la urticaria papular es frecuente; el único estudio de prevalencia publicado indica que afecta a una cuarta parte de los niños escolares de Bogotá. Hay información sobre la relación causal entre la exposición domiciliaria a la pulga, la pobreza y la urticaria papular en Bogotá, una ciudad representativa de las altitudes andinas. No hay estudios que indaguen directamente sobre los insectos causales en zonas cálidas, aunque se sospecha clínicamente de los mosquitos Aedes aegypti y Culex quinquefasciatus. En cuanto a su patogenia, se destaca la participación de mecanismos celulares que involucran las células colaboradoras Th2, lo cual explica que sea una condición de hipersensibilidad retardada. El papel de la inmunoglobulina E (IgE) en la urticaria papular no está tan claro. Se desconocen los antígenos derivados de los insectos que causan la enfermedad, aunque se plantea que existen moléculas comunes de reacción cruzada entre los insectos, tales como el alérgeno Cte f 2 en la pulga, y sus homólogos en los mosquitos. La urticaria papular es una condición frecuente en Latinoamérica que debe investigarse en profundidad. La caracterización inmunológica de los componentes moleculares que causan esta condición puede resolver interrogantes sobre su etiología y su patogenia.

Abstract Papular urticaria is a chronic allergic reaction induced by insect bites, which is common in the tropics. The objective of this review was to deepen on epidemiological and immunological aspects of this disease, focused on data published in Latin American countries. We conducted a non-systematic review of the literature through electronic search on the epidemiology of papular urticaria, the entomological characteristics of the causative agents and associated immunological mechanisms. Several reports from medical centers suggest that papular urticaria is common in Latin America. Only one epidemiological survey designed to estimate prevalence of papular urticaria has been published, reporting that about a quarter of children under six years of age is affected by this condition in Bogotá. There is evidence on the causal relationship among exposure to indoor fleas, poverty and papular urticaria in Bogotá, a representative city of the Andean altitudes. Information about causal insects in tropical warmer areas is scarce, although from clinical reports Aedes aegypti and Culex quienquefasciatus appear to be the most common. Th2 cellular-mediated mechanisms are involved in its pathogenesis, which explains its delayed hypersensitivity. The role of immunoglobulin E is not clear in this disease. Insect-derived antigens directly involved in papular urticaria etiology are unknown. However, it is possible that common molecules among causal insects mediate cross-reactive reactions, such as Cte f 2 allergen, found in cat fleas, and its counterparts in mosquitoes. Papular urticaria is a frequent disease in Latin America that should be further investigated. Immunological characterization of the molecular components that cause this condition may solve questions about its pathogenesis.

Antibodies to Leishmania spp. in domestic felines / Anticorpos anti-Leishmania spp. em felinos domésticos

Abstract Leishmaniasis is a vector-borne zoonotic disease caused by protozoa in the genus Leishmania, typical of rural and peri-urban environments. The causative agent of American visceral leishmaniasis is Leishmania (Leishmania) infantum chagasi and the main insect vector in Brazil is Lutzomyia longipalpis. Dogs (Canis familiaris) are important in the transmission of the disease, as a reservoir closely related to humans and an infection source for phlebotomine vectors. Since 1990, an increasing number of feline leishmaniasis cases have been reported, suggesting that domestic cats (Felis catus) might be involved in the epidemiology of the disease. The present study analyzed the prevalence of anti-Leishmania spp. antibodies in naturally infected domestic cats from various neighborhoods in the municipality of Belém, Pará, Brazil, using the indirect immunofluorescence assay (IFA) and the direct agglutination test (DAT). Among the 443 samples tested, 18 (4.06%) presented positive reactions in the IFA. The observed titers were 40 IU in 4.97% of the samples and 80 IU in 0.90%. In the DAT test, positive results were found in 25 (5.64%) of the samples. The observed titers were also 40 IU (4.97%) and 80 IU (0.68%). The agreement rate between the two tests was considered low (Kappa coefficient = 0.10).

Resumo As leishmanioses são zoonoses vetoriais causadas por protozoários do gênero Leishmania, características de ambientes rurais e periurbanos. A leishmaniose visceral americana (LVA) é causada pela Leishmania (Leishmania) infantum chagasi, cujo principal vetor no Brasil é Lutzomyia longipalpis. O cão (Canis familiaris) possui papel ativo na transmissão da doença, pois é um reservatório muito próximo do humano e uma fonte de infecção para o flebotomíneo. O aumento do número de casos de leishmaniose felina, descritos na literatura a partir de 1990, sugere que gatos também podem atuar na epidemiologia dessa enfermidade. O presente estudo avaliou a prevalência de anticorpos anti-Leishmania spp. em gatos domésticos (Felis catus) de diferentes bairros do Município de Belém, Pará (PA), pela Reação de Imunofluorescência Indireta (RIFI) e pelo Teste de Aglutinação Direta (TAD), utilizando-se como ponto de corte o título de 40 UI. Entre os 443 gatos estudados, 18 (4,06%) apresentaram reação sorológica positiva na RIFI. Os títulos observados foram de 40 UI em 0,90%. No TAD, foi encontrada positividade em 25 (5,64%) animais. Os títulos observados foram de 40 UI, em 4,97% dos gatos, e 80 UI, em 0,68%. A concordância entre os testes foi considerada baixa (coeficiente Kappa: 0,10).

Detection of antibodies against Leishmania infantum in cats (Felis catus) from the State of Pernambuco, Brazil

Introduction: Little information is available concerning infection by Leishmania infantum in cats. Therefore, the aim of this study was to perform a serological study in domestic cats. Methods: Serum samples (n=153) obtained from animals living in the Cities of Recife and Petrolina, State of Pernambuco, Brazil, were tested by ELISA/S7® (Biogene). Results: Anti-L. infantum antibodies were detected in 3.9% (6/153) of the cats. All seroreagent animals were from Petrolina. Conclusions: These results serve as an important alert, and future studies are needed to better understand the possible role of cats in the epidemiology of visceral leishmaniasis (VL) in this area. .

Prevalência de anticorpos contra Yersinia pestis em carnívoros domésticos nos focos pestosos, do Estado do Ceará / Prevalence of antibodies against Yersinia pestis in domestic carnivores, in plague foci in the State of Ceará

Analisou-se a prevalência de anticorpos contra Yersinia pestis em carnívoros domésticos (cães e gatos) nas áreas pestígenas do Estado do Ceará, visando estabelecer a importância do monitoramento desses animais na rotina do Programa de Controle da Peste. No decênio 1997-2006, analisaram-se 146.732 amostras de soros (95.883 cães e 50.849 gatos), das quais 2.629 (2.234 cães e 395 gatos) revelaram-se positivas. A prevalência entre os cães (85 por cento) foi superior a dos gatos (15 por cento) em todo o decênio e locais, exceto em Ibiapina, em 1998. O significado desses achados ainda não foi determinado. Os estudos sobre a zoonose no Brasil pautaram-se por paradigmas que não contemplavam todos os elementos envolvidos na zoonose, impossibilitando a devida elucidação do papel desses carnívoros. O monitoramento da atividade pestosa, realizado exclusivamente por inquéritos caninos, pode redundar no desconhecimento progressivo da situação epidemiológica da peste, caso não sejam desenvolvidas pesquisas interinstitucionais suplementares.

The prevalence of antibodies against Yersinia pestis in domestic carnivores (dogs and cats), in plague areas in the State of Ceará, was analyzed to establish the importance of monitoring these animals within the routine practice of the plague control program. Over the decade 1997-2006, 146,732 serum samples were examined (95,883 from dogs and 50,849 from cats), of which 2,629 (2,234 from dogs and 395 from cats) proved to be positive. The prevalence among dogs (85 percent) was higher than among cats (15 percent) throughout the decade and in all places, except in Ibiapina in 1998. The significance of these findings has not yet been determined. Studies on this zoonosis in Brazil have been based on paradigms that did not cover all the elements involved in the zoonosis, thus making it impossible to properly understand the role of these carnivores. Monitoring of plague foci conducted exclusively by means of dog surveys may result in progressive lack of knowledge of the epidemiological situation of plague, if supplementary inter-institutional research is not developed.

Comportamento imunológico e antigênico de cinco amostras de Toxoplasma gondii inoculadas em gatos / Immunogenic and antigenic aspects from five Toxoplasma gondii strains inoculated in cats

A biologia do Toxoplasma gondii demonstra que o gato é o hospedeiro completo, responsável pela disseminaçäo do parasito. Assim, dois gatos domésticos foram imunizados com cada uma das amostras, VPS (humano), LIV-IV e LIV-V (suíno), CPL (caprino) e CN (felino) de T. gondii. Foram utilizados taquizoítas vivos em inóculos endovenosos de 2x10 elevado a 6 (1§ inóculo) e 4x10 elevado a 7 (2§ inóculo - 35 dias após), exceto a amostra VPS, onde um gato morreu no 10§ dia com sinais clínicos agudos da doença, nas outras amostras, nenhum sinal clínico foi constatado durante os 6 meses de observaçäo. O nível de anticorpos na imunizaçäo foi acompanhado através da reaçäo de imunofluorescência indireta (IFI) com conjugado anti-IgG de felino. Os títulos de anticorpos obtidos no 20§ dia variaram de 1:1.024 a 1:4.096 e de 1:1.024 a 1:8.000 no 40§ dia. Somente a amostra VPS expressou títulos de 1:16.000 no 30§ dia da imunizaçäo. Títulos homólogos e heterólogos foram equivalentes sem nenhuma diferença entre as amostras. Quando soros imunes foram adsorvidos com taquisoítas vivos de cada amostra, a reduçäo nos títulos de anticorpos foi demonstrada em ambos homólogos e heterólogos. Esses resultados sugerem que, embora diferente em virulência para gatos, a superfície antigênica é comum entre as amostras do T. gondii, com base no nível de anticorpo demonstrado pela IFI. Esses resultados também demonstram que, aparentemente, näo há correlaçäo entre virulência e as características sorológicas das amostras estudadas no T. gondii. Entretanto, a importância do teste IFI em diagnóstico laboratorial é reforçada.

Esporotricosis felina: aspectos clínicos e zoonóticos / Feline sporotrichosis: clinical and zoonotic aspects

La esporotricosis consiste en micosis profunda, de evolución subaguda o crónica decurrente de infección por el hongo dimorfico Sporothrix. Consiste en dermatopatia nmucho frecuente en nuestro medio, resultante de la penetración de abrojos e de arañazos por espinos de plantas. El S. schenkii ha sido descrito, en S. Paulo, en perros, gatos, aseninos, bovinos, equinos y ratones. Todavía, el carácter de antropozoonosis de la enfermedad pocas veces ha sido descrito tanto en la literatura internacional como en la nacional, existiendo apenas una citación en lo Brasil, de probable transmissión gato/hombre. Se descrebió, en lo presente relato, caso clínico de esporotricosis felina con transmisión através de arañadura en propietario, tratador y médico veterinário. Un gato, sin raza definida, macho, con 3 años, mucho agresivo, con grave cuadro cutaneo (cefálico, torácico y de miembros torácico) manifestado por lesiones ulceradas, exudativas de alopecia, deposición de crostas hemorrágicas, agraviado por síntomas de lo complejo respiratório felino, donde por su temperamento agresivo habia areñado en corto espacio de tiempo 5 individuos, donde 3 de los individuos manifestaron sintomas de evolución y gravedad distintas. El diagnóstico clínico presuntivo fue confirmado per lo examen histopatológico (H.E.,PAS) de fragmentos de piel, linfonodos y amígdalas cogidos, "intra-vitam" y/o "post-morten", per lo aislamiento de lo agente, per la inoculación en testículos de ratas adultas y posterior nuevo aislamiento. Se confirmó la patologia por pruebas suerológicas (F.C., anticuerpos precipitantes) y prueba de intradermoreación (esporotriquina) en los pacientes acometido

Detection of antibodies in cats infected with filarial parasites by the indirect immunofluorescence technique.

The indirect immunofluorescence technique in cats infected with filarial parasites, Brugia malayi, B. pahangi and D. repens were studied. The antibody level in infected microfilaraemic cats was higher than that in infected amicrofilaraemic cats and uninfected cats. Papain-treated whole microfilariae appeared to be more sensitive than the sonicated antigen. The comparative IFA titres using papain-treated and sonicated microfilarial antigen, in the serodiagnosis of filariasis is presented.

Humoral immune response of cats to Paragonimus infection.

The time course of humoral immune response to Paragonimus siamensis was studied in 10 cats experimentally infected with either 30 or 60 matacercariae and the antibody produced was detected by enzyme linked immunosorbent assay (ELISA), complement fixation test (CFT), and immunoelectrophoresis (IEP) test. With ELISA and CFT, antibodies was detected as early as 2nd week after infection and the cats remained positive throughout the 12 week period of observation. In contrast, the IEP test was persistently negative. With respect to sensitivity, both ELISA and CFT are equally sensitive but the mean ELISA titer was consistently higher than that of CFT. THe magnitude of the antibody response appeared to be related to duration of the infection but not to the infective dose and the number of worms recovered. There was variability in titers among cats infected with equal numbers of metacercariae. The tests can not be used for differential diagnosis of infections by P. siamensis and P. heterotremus because of the cross-reaction. Such cross-reaction did not not occur against unrelated parasites including hookworm. Toxocara cati and Spirometra mansoni.