Microfilaremia by Cercopithifilaria bainae in a dog from the central western region of Brazil: case report / Microfilaremia por Cercopithifilaria bainae em um cão da região Centro-Oeste do Brasil: relato de caso

Cercopithifilaria bainae is a nematode belonging to the family Onchocercidae that parasitizes the subcutaneous tissue of dogs. Its transmission occurs through the tick Rhipicephalus sanguineus and its geographical distribution overlaps that of this vector. The present study reports the detection of microfilaremia by C. bainae in an eight-year-old male dog that presented anorexia, hyperthermia, motor incoordination, mydriasis, a nodule in the left testicle and concomitant infection by Ehrlichia sp. Blood samples were analyzed using microscopy, PCR and DNA sequencing. Microfilariae measuring 150±5.5µm in length and 7±1.8µm in width were retrieved. The DNA sequence exhibited 98% identity with C. bainae sequences available in Genbank. This is the first report of microfilaremia by C. bainae in a dog in the central western region of Brazil.(AU)

Cercopithifilaria bainae é um nematoide pertencente à família Onchocercidae, que parasita o tecido subcutâneo de cães. Sua transmissão ocorre pelo carrapato Rhipicephalus sanguineus, e sua distribuição geográfica se sobrepõe ao espalhamento desse vetor. O presente estudo relata a detecção de microfilaremia por C. bainae em um cão macho de oito anos que apresentava anorexia, hipertermia, incoordenação motora, midríase e nódulo no testículo esquerdo e infecção concomitante por Ehrlichia sp. A coleta de sangue foi realizada, e o material analisado por meio dos exames de microscopia, PCR e sequenciamento de DNA. Microfilárias medindo 150±5,5µm de comprimento e 7±1,8µm de largura foram recuperadas. A sequência de DNA obtida mostrou 98% de identidade com sequências de C. bainae disponíveis no Genbank. Este é o primeiro relato de microfilaremia de C. bainae em um cão na região Centro-Oeste do Brasil.(AU)

Litomosoides silvai (Nematoda: Onchocercidae) parasitizing Akodon montensis (Rodentia: Cricetidae) in the southern region of Brazil / Litomosoides silvai (Nematoda: Onchocercidae) parasitando Akodon montensis (Rodentia: Cricetidae) na região Sul do Brasil

Abstract In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, "s" shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.

Resumo No presente estudo é relatado pela primeira vez Litomosoides silvai parasitando Akodon montensis coletados na região Sul do Brasil. Foram fornecidas novas informações morfológicas para algumas estruturas desta espécie de nematódeo, tais como extremidade cefálica achatada, a presença de duas papilas cefálicas dorsais, cauda das fêmeas com uma constrição na ponta da cauda, vagina em forma de "s", espículas de característica do grupo de espécies de carinii e cauda da microfilária com constrição na ponta. Este nematódeo parasitava a cavidade torácica com uma prevalência de 10% (2/20), intensidade média de 4 (8/2) e abundância média de 0,4 (8/20), e intervalo de infecção de 2-6 espécimes por hospedeiro no Sul do Brasil. A ocorrência de L. silvai em A. montensis é um novo registro geográfico, no sul do Brasil, a noroeste do estado do Rio Grande do Sul, na ecorregião da Mata Atlântica do Alto Paraná, parte do bioma da Mata Atlântica.

New record of Pelecitus sp. (Nematoda, Onchocercidae) as a parasite of Athene cunicularia (Strigiformes, Strigidae) in southeastern Brazil / Novo registro de Pelecitus sp. (Nematoda, Onchocercidae) como parasita de Athene cunicularia (Strigiformes, Strigidae) no Sudeste do Brasil

The aim of this study was to report the burrowing owl Athene cunicularia as a new host for the filarid nematode Pelecitus sp. in southeastern Brazil for the first time, as well as reporting the occurrence of this nematode species in the body cavity, near the cervical air sac and lung region. This study contributes towards knowledge of parasitism in Brazilian wild birds and an anatomical region of the host as an infection site for Pelecitus sp.

O objetivo do estudo foi relatar, pela primeira vez, a coruja buraqueira Athene cunicularia como um novo hospedeiro para o nematóide filarídeo Pelecitus sp. do Sudeste do Brasil, bem como a ocorrência desta espécie de nematóides na cavidade corporal, próximos à região dos sacos aéreos cervicais e pulmões. Este estudo contribui para o conhecimento do parasitismo em aves silvestres brasileiras e uma região anatômica do hospedeiro como sítio de infecção para Pelecitus sp.

Anatomopatologia de bursite cervical (oncocercose) encontrada em bovinos abatidos sob inspeção estadual no estado do Rio de Janeiro / Anatomopathology of onchocerciases (cervical bursitis) in slaughtered bovine in the north of Rio de Janeiro state

A patologia descritiva das lesões em animais domésticos de açougue permite enriquecer a literatura médica veterinária especializada em inspeção sanitária de carnes, assim como subsidiar tecnicamente os profissionais inspetores. A oncocercose é uma parasitose causada pelo nematódeo Onchocerca sp,, sendo que a espécie O. gutturosa é a que mais acomete bovinos na América do Sul. Foram avaliados, pelo exame anatomopatológico, dois casos de lesões localizadas no ligamento nucal de bovinos abatidos para o consumo. A macroscopia de um caso revelou bursite crônica, representada por grande quantidade de líquido citrino e viscoso e, ainda, muitos corpúsculos livres, elípticos e achatados desprovidos de raiz (arrizo). A microscopia dessas estruturas evidenciou moldes de fibrinas amorfos e eosinofílicos. O segundo caso foi caracterizado por bursite aguda, e a microscopia das lesões ligamentar e periligamentar revelou granulomas epitelioides com reação gigantocitária, centralizados por formações semelhantes ao Onchocerca sp...

The descriptive pathology of lesions in butcher's domestic animals contribute to enrich literature specialized in veterinary sanitary inspection of meat as well as to guide professional meat inspectors. Oncorcecose is a parasitic disease caused by the nematode Onchocerca sp, and the O. gutturosa species affects cattle in South America. Two cases of lesions located in the nuchal ligament of cattle slaughtered for consumption were evaluated by pathological examination. Macroscopic analysis revealed a case of chronic bursitis represented by a large amount of clear and viscous liquid, and also many free, elliptical and flat corpuscles. Microscopy showed arrizoides molds fibrin, amorphous, and eosinophilic structures. The second case was characterized by acute bursitis and microscopic lesions and ligament periligamentous revealed multiple epithelioid granulomas and giant cells centered on formations similar to Onchocerca sp...

Effects of Medication with Ivermectin; Chloroquine and Artemether on Plasma Nitrate / nitrite Levels in Calves Naturally Infected with Onchocerca Gutturosa

In a comparative study involving the use of Ivermectin; Chloroquine and Artemether against Onchocerca gutturosa in calves; the plasma nitrate /nitrite concentration was measured. Following treatment and clearance of skin mf of O. gutturosa; the plasma nitrate/ nitrite concentrations; nor the stable end product of Nitric Oxide (NO) breakdown; rise significantly although it showed short peaks following reduction in dermal mf counts but no clear correlation was detected

Eye lesions and onchocerciasis in a rural farm settlement in Delta State, Nigeria.

Between December 1999 and September 2000, an investigation on 326 inhabitants who voluntarily participated in screening for eye lesions and onchocerciasis in a rural farm settlement in Aniocha North local government area of Delta State, Nigeria was carried out. Microfilariae were reported in the skin tissues of 134 (41.1%) inhabitants. Of these, males had more microfiladermia (49.9%) than their female counterparts (33.3%). The percentage prevalence of the clinical signs of onchocerciasis in the farm settlement was hanging groin 14.1%, onchocercal nodules 25.1%, onchocercal dermatitis 27.6% and scrotal enlargement 3.7%. The percentage prevalence of the eye lesions among the onchocerciasis infected inhabitants was cataract 7.4%, glaucoma 3.7%, optic atrophy 0.6% and uveitis 18 (5.5%). Impaired vision occurred among 80 (24.5%) inhabitants and blindness was reported among 2 (0.6%) inhabitants.

Organization and structure of an Onchocerca ß-tubulin gene

In filarial worms, as in other eukaryotes, microtubules are essential multifunctional components. The major protein of microtubules is tubulin, a heterodimer of two distinct polypeptides, Ó e ß.Tubulin is particulary important in helminthic parasites as a target for anthelminthic benzimidazoles, wich bind to it and inhibit microtubule assembly. Two genomic Onchocerca gibsoni libraries were constructed in NM1149(EcoRi and HindIII). Three clones accounted for the entire gene: one from the EcoRi library (using a Plasmodium falciparum probe) containing the central part of the gene, and two from the HindIII library (using as probes PCR amplified fragments from the ends of the EcoRI clone) which, respectively, contained the 5'- and 3' -ends of the gene. The sequencing procedure for the EcoRI clone relied on the construction of a double-digested DraI/HindIII shotgun library. A number of recombinants were sequenced and aligned with each other for comparison. The sequencing of the overlapping 5' - and 3'-end clones was done by ...

Recent advances in the application of molecular biology in filariasis.

Monitoring of filarial parasites in the host and vector has traditionally depended on morphological identification. Recently, species-specific DNA probes have been developed for Brugia malayi, Brugia pahangi and Wuchereria bancrofti. Repeated DNA sequences are useful in developing DNA probes because they evolve more rapidly then coding sequences and their high copy number increases the sensitivity of detection. The Hhal repeated DNA family represents 12% of the total B. malayi DNA. This DNA family is present in species of Brugia (B. malayi, B. timori and B. pahangi) but not W. bancrofti. Sequence analysis of the repeated DNA in B. malayi and B. pahangi has allowed construction of two species-specific DNA probes. These probes were used in a double blind field study in Indonesia. Microfilariae (mf) from infected cats and humans were identified by classical morphological methods and DNA probes. Agreement was found in 98.6% of the 642 samples tested by the two different techniques. Besides mf identification DNA probes can be used to determine the species of infective larvae (L3s) in infected mosquitos. This is useful because the L3s have similar morphology. DNA probes for the identification of W. bancrofti have recently been developed and are in the initial stages of testing in China (Piessens, personal communication) and Egypt (Williams, personal communication). An alternative approach for identification of infected individuals is to detect specific parasite antigens in circulation. A WHO initiative to use either an antigen or antibody assay to replace night blood is presently underway. This approach, if successful would not require the presence of microfilariae, but could detect occult infections.

Vectores de la onchocera volvulus en Guatemala

La transmisión de la Onchocerca volvulus está restringida a las moscas negras de la familia Simuliidae de las cuales hay en el mundo aproximadamente 1270 especies que pasan su etapa inmadura en corrientes de agua. En Guatemala han sido tradicionalmente conocidos 3 vectores y 1 más que fue agregado recientemente el S. horacioi. El vector es el S. ochracem s.l. Las otras dos especies S. metallicum s.l. y S. callidum al igual que el S. horacioi están calificados como vectores secundarios y juegan un papel sin importancia epidemiológica en el país. En Guatemala hai descritas 52 especies de simúlidos; una mas pendiente de publicación que lleva el nombre de Maya Cnephia isaotadai determinada por Ochoa A. De las 53 especies, 8 son antropofílicas que generalmente se encuentran en las zonas endêmicas de oncocercosis. El S. ochraceum s.l. de mayor importancia epidemiológica se encuentra en 19 departamentos del país y su población en mayor o menor grado se presenta entre los 600 y 1300 mts. de altura sobre el nivel del mar, com poblaciones de adultos y etapas inmaduras mucho más marcadas en una faja longitudinal entre los 900 y 1300 msnm, en el cual se encuentra tambien las localidades con mayor incidencia y prevalencia oncocercósica. La transmisión de la Onchocerca volvulus en Guatemala ocurre en la época seca entre los meses de enero a mayo presentando un pico en el mes de marzo que puede variar al final o principio de los meses vecinos. El S. onchraceum s.l., es un transmisor pobre en eficiencia y debido a la ineficiencia se hace necesaria una alta población de esta especie para mantener el nivel de transmisión. Generalmente el umbral de transmisión en el país es de aproximadamente 8000 picaduras en el sitio de captura. Los simúlidos o moscas negras como se ha mencionado se crían en corrientes de agua pero cada especie tiene su criadero preferencial que muchas vezes varía en volumen y tamño. El ochraceum S.I., se desarrollan en pequeños riachuelos que van desde 0.1 a 10 litros/segundo de descarga con un rango óptimo comprendido entre 0.1 a 5.0 litros por segundo, correspondiendo el 98% de estos riachuelos al último rango mencionado

Onchocerciasis in Ecuador: the situation in 1989

Details are given of the prevalence rates of onchocerciasis from the most recent surveys (1989) conducted in northern Ecuador. The disease has intensified and dispersed considerably due to migration of infected individuals and the presence of a highly efficient vector. Comparison of these data with those from two previous surveys carried out in 1982/83 and 1986 and correlated with entomological findings highly the danger of the formation of new foci of onchocerciasis in areas currently free of the disease. Recommendations are made for further entomological studies in areas either recently or likely to be affected by the disease where potential vectors are unknown or different to those registred in the Santiago focus. Invermectin treatment with local vector control in specific areas is advocated to reduce the disease to a low level of public health importance

Algunos problemas en la investigación para el control de la transmisión de Ochocerca volvulus en México / Research for the control of the transmission of Onchocerca volvulus in Mexico

El tratamiento y control de la oncocercosis en México ha sustentado desde su inicio en la eliminación de las microfilarias con el uso de la dietilcarbamazina y la extirpación quirúrgica de los oncocercomas que arrojan los gusanos adultos. Estas medidas al parecer han disminuido la prevalencia e incidencia de la ceguera en aquellos individuos afectados por esa parasitosis. Sin embargo, no se ha logrado un impacto importante sobre la transmisión de la oncocercosis en México el control químico del vector ha tenido buenos resultados en otras regiones del mundo; en México, sin embargo no ha sido plenamente aceptado como parte integral del control de la oncocercosis por diversas causas. Más aún, pocas investigaciones se han realizado en relación a la búsqueda de nuevas alternativas para el control del vector. Recientemente, el resultado de investigaciones sobre la invermectina (agente microfilaricida) mostraron que esta droga es eficaz y segura para el tratamiento de la oncocercosis. En otros reportes se ha señalado tambien que la ivermectina tiene un efecto sobre la transmisión de esta filaria. No obstante, existen algunas interrogantes acerca de su capacidad para suspender la transmisión de la oncocercosis, discutiendo los problemas para su diagnóstico, tratamiento y control. Además se propone el empleo de parámetros para la evaluación correcta de las medidas de control, con énfasis en las determinaciones entomológicas

The treatment and control of onchocerciasis in Mexico has been supported only on the administration of diethy carbamazine and the removal of adult worms, which are in the onchocercomata. These actions seems to have diminished the prevalence and incidence of blindness in those individuals who are affected by this parasitosis. However, there has not been an important impact on onchocerciasis transmission. The objective of this paper is to critically analyze and discuss subjects related to diagnosis, treatment and control of onchocerciasis transmission in Mexico. Chemical vector control has been successfully archieved in other world regions; however, in Mexico, it has not been fully acepted as part of the integral onchocerciasis control due to several causes. Moreover, there has been few scientific research activties toward the search of new options for vector control. Recently, results of research on ivermectin (a microfilaricide agent) have indicated that this drug is effective and safe for the treatment of onchocerciasis. Additionally, it has been reported that ivermectin has an effect on the onchocerciasis transmission. However, there are several unanswered questions about the efficacy of ivermectin in toping onchocerciasis transmission. In this report, the ain efforts carried out in Mexico against onchocerciasis are analysed and problems related with diagnosis, treatment and control are also discussed Some parameters for the correct evaluation of onchocerciasis control, with entomological emphasis, are proposed.

Detección y descripción de la onchocerca volvulus

La diagnósis de la Onchocerca volvulus en el Ecuador se basa en la detección de la microfilaria en la piel, en la cual, para realizar la biopsia se usa un punch córneoescleral. Después de la incubación, las microfilarias que emergen son enumeradas y los resultados estandarizados. Otros métodos invasivos no son recomendados para la diagnósis. Un nódulo palpable o la presencia de microfilarias en el ojo, en ausencia de una biopsia positiva en la piel, tienen que ser consideradas en la pauta a seguir para la diagnósis. Futuros descubrimientos son necesarios para hacer de las pruebas serológicas un diagnsotico válido. La prueba de la reacción Mazzotti tiene que estar limitada únicamente a áreas en las cuales la biopsia de la piel es negativa y no hay evidencia de microfilaria en el tejido ocular. El gusano filaria extirpado de pacientes con oncocercosis tiene características de Onchocerca vaolvulus