Chemoprophylaxis ofTrypanosoma evansi infections in ponies

Summary An investigation on the protection afforded to ponies, by quinapyramine suraminate and its constituents used singly, againstTrypanosoma evansi infections of low and high intensity was conducted. It was observed that full protection with the suraminate lasted for 61/2 to 231/2 months depending upon the dose of the drug and intensity of the test infection employed. Considerable partial protection was evident up to 38 months. Prophylaxis with suramin and quinapyramine extended up to 1 month and 11/2 months, respectively. The protection period was observed to be directly related to the dose of the suraminate employed and inversely with the intensity of the test infection. Infections breaking through prophylaxis were characterized by sub-microscopic and low-grade parasitaemia which was mostly detected by the rat-inoculation test only.

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Sumario Se ha hecho una investigación sobre la protección conferida por varias dosis de suramina, sales de quinapiramina y MSb en ponis contra infecciones simples deTrypanosoma evansi y suraminato de quinapiramina contra infecciones repetidas. La protección completa con suramina, quinapiramina y su prosal y MSb se extendía hasta 1, 11/2, 2 y 3 meses, respectivamente. La protección con suraminato de quinapiramina variaba de 61/2 a 261/2 meses contra el desafío ‘suave’ y 61/2 a 231/2 meses contra el desafío ‘fuerte’. La protección parcial, sin embargo, era aparente por periodos de hasta 38 meses. La profilaxis con suraminato de quinapiramina era directamente proporcional a la dosisintervalo de la droga usada y usualmente inversamente proporcional a la cantidad del desafío empleado. Las infecciones recurrentes fueron caracterizadas por por una parasitemia rara ó muy escasa. Algunas vecez las infecciones no eran detectadas por la prueba microscópica. Esta conducta atípica de las infecciones fue demostrada no ser debida a una disminuida virulencia de le parásito.

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Résumé Une étude à été faite sur la protection donnée aux chevaux par des doses variables de suramine, sels de quinapyramine et de MSb contre une infection unique parTrypanosoma evansi et par le suraminate de quinapyramine contre les infections répétées. Une protection complète par la suramine, la quinapyramine et son ‘prosalt’ et le MSb durait respectivement jusqu’ à 1, 11/2, 2 et 3 mois. La protection par le suraminate de quinapyramine contre l’épreuve légère variait de 6 mois et demi à 26 mois et demi et, contre l’épreuve sévère, de 6 mois et demi à 23 mois et demi. Une protection partielle a néanmoins été observée pendant des périodes allant jusqu’à 38 mois. La durée de la prophylaxie par le suraminate de quinapyramine était directement proportionnelle à la dose du médicament utilisée, habituellement inversement proportionnelle à la quantité des organismes utilisés pour l’épreuve. Les infections résultantes étaient caractérisées par un type de parasitémie rare et faible. Elles n’ont parfois pas du tout été révélées par l’examen microscopique. Il a été démontré que ce comportement atypique des infections n’était pas d? à une virulence diminuée du parasite.

     

The prevalence and diagnosis ofTrypanosoma evansi infection in camels in southern Ethiopia

Summary An investigation of trypanosomiasis in camels indicated a high prevalence of infection in southern Ethiopia. Various direct and indirect laboratory methods for the diagnosis of infection withTrypanosoma evansi were compared and evaluated. At the present time inoculation of camel blood into laboratory rodents appears to be the best direct diagnostic method. The formol-gel test and the Takata test appear to be the most sensitive and accurate of the biochemical methods available. However, there still remains a need for an accurate diagnostic test for individual cases.

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Resumen Una investigación de Tripanosomiasis en camellos en el sur de Etiopía dio como resultado una prevalencia alta de la infección. Se compararon y evaluaron varios métodos directos e indirectos de laboratorio para el diagnóstico de la enfermedad. Actualmente el mejor método diagnóstico es la inoculación de reodores de laboratorio. Las pruebas químicas del formol gel y la takata parecen ser las más sensitivas y seguras. Sin embargo todavía hace falta una prueba diagnóstica segura para casos individuales.

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Résumé L'étude des trypanosomiases du chameau a montré une grande prédominance de cette infection en Ethiopie du Sud. Diverses méthodes de laboratoire, directes et indirectes, pour le diagnostic de l'infection àT. evansi sont comparées et évaluées. A l'heure actuelle, l'inoculation de sang de chameau à des rongeurs de laboratoire para?t être la meilleure méthode de diagnostic direct. Le test au gel de formol et le test de Takata semblent les méthodes biochimiques les plus sensibles et les plus précises. Cependant un test de diagnostic précis pour les cas individuels reste à trouver.

     

Serodiagnosis of infection withTrypanosoma evansi in camels in the Sudan

Summary Five diagnostic tests for infection withTrypanosoma evansi have been compared in groups of camels experimentally infected or exposed to natural infection in the Sudan. The correlation of positive results obtained by assays of IgM levels, the mercuric chloride test and the formol gel test with the presence of active infection was unsatisfactory, but there was a good correlation between results obtained using IFAT and ELISA and proven infection. Sera from a high proportion of apparently uninfected camels from endemic areas gave positive reactions with all 5 tests, possibly indicating inadequate parasitological diagnosis or persistence of antibody after unsatisfactory chemotherapy. It was concluded that serological tests using trypanosomal antigens to detect antibodies were more sensitive for diagnosis than indirect tests based on raised euglobulin levels. Serodiagnostic tests may therefore have a place in future programmes for surveillance and control ofT. evansi infections in camels.

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Serodiagnostico De La Infeccion PorTrypanosoma Evansi En Camellos En Sudan

Resumen Se compararon cinco pruebas diagnósticas para infecciones porTrypanosoma evansi en grupos de camellos infectados experimentalmente o expuestos a la infección natural. La correlación de los resultados positivos utilizando pruebas de difusión radial aisladas, le niveles de IgM, la prueba de cloruro de mercúrio, y la prueba de agar formol con la presencia de infección activa, fue insatisfactória. Hubo buena correlación entre los resultados obtenidos con IFAT y ELISA con infección comprobada. El suero de una proporción alta de camellos aparentemente sanos, provenientes de áreas endémicas, presentaron reacciones positivas con las cinco pruebas, indicando posiblemente un diagnóstico parasitológico inadecuado, o la persistencia de anticuerpos despues de una quimioterápia inadecuada. Se concluyó, que las pruebas serológicas usando antígenos preparados de tripanosomas para detectar anticuerpos, fueron más sensitovos que las pruebas indirectas basadas en el aumento de euglobulinas. Las pruebas serodiagnósticas posiblemente tendran un lugar en programas futuros de reconocimiento y control deT. evansi en camellos.

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Serodiagnostic De La Trypanosomose AT. Evansi Chez Le Chameau Du Soudan

Résumé Cinq méthodes de diagnostic de la trypanosomose àT. evansi chez le chameau ont été comparées en utilisant des chameaux expérimentalement et naturellement infectés, au Soudan. La corrélation des résultats positifs obtenus par utilisation de la diffusion radiale des Igm, par le test au chlorure mercurique et par le test de la formol gélification à l'occasion des infections en évolution, n'a pas été satisfaisante alors qu'il y a eu bonne corrélation entre les résultats obtenus par IFAT et ELISA et des infections véritables.Les sérums d'une importante proportion de chameaux apparemment non infectés, en provenance de régions à maladie endémique, ont donné des réactions positives aux cinq tests, ce qui peut indiquer soit une insuffisance dans le diagnostic parasitologique soit la persistance d'anticorps résultant d'une chimiothérapie insuffisánte.Les auteurs concluent que les tests sérologiques utilisant des trypanosomes comme antigènes pour mettre les anticorps en évidence sont plus sensibles, en matière de diagnostic, que les tests indirects basés sur la détection des niveaux des IgM. C'est pourquoi les tests faisant appel aux méthodes de sérodiagnostic doivent avoir leur place dans les programmes à venir concernant tant la surveillance que la lutte contre les infections du chameau àT. evansi.

     

伊氏锥虫苏拉灭抗药性的稳定性和对其他抗锥虫药敏感性的影响

将实验室培育的分别源于伊氏锥虫克隆ＪＧｃ１和ＪＸ１ｃ１的抗苏拉灭伊氏锥虫亚克隆ＪＧＳＲ和ＪＸＳＲ以小鼠连续传代，每３个月用体内药物敏感性试验测定１次苏拉灭的ＩＤ１００和ＣＤ１００；另于传代初和传代１２个月后测定它们和它们各自对苏拉灭敏感的亲本克隆对硫胂聚氰胺、喹嘧胺硫酸盐和贝尼尔的敏感性。传代初，ＪＧＳＲ和ＪＸＳＲ的苏拉灭ＩＤ１００均为１００ｍｇ／ｋｇ，ＣＤ１００分别为４００ｍｇ／ｋｇ和＞４００ｍｇ／ｋｇ。连续传代２１个月，ＪＧＳＲ的苏拉灭抗药性仍保持原水平；ＪＸＳＲ于头１５个月保持原水平，传代１８个月，ＩＤ１００降至５０ｍｇ／ｋｇ，２１个月ＩＤ１００进一步降至２５ｍｇ／ｋｇ，ＣＤ１００降至１００ｍｇ／ｋｇ。ＪＧＳＲ和ＪＸＳＲ对喹嘧胺硫酸盐的敏感性比各自的亲本克隆提高了３倍，而对硫胂聚氰胺的敏感性则与亲本克隆相同或相近。ＪＧＳＲ和ＪＸＳＲ仍保持各自亲本克隆的贝尼尔抗药性，传代１２个月也无改变。这些受试伊氏锥虫的贝尼尔抗药性是单一抗药性，对硫胂聚氰胺无显著交叉抗药性。     

Efficacy of RM110, a novel trypanocide,in the treatment ofTrypanosoma evansi infections in camels

Camels artificially infected with a field stock of Trypanosoma evansi isolated from a camel near Gewane, Ethiopia were cured by treatment with RM110, administered by subcutaneous injection at 0.3 or 0.6 mg/kg body weight. Local reactions were mild and transient. Further evaluation of RM110 is indicated, in particular the determination of minimum curative doses for this and other T. evansi stocks in camels.     

Prevalence and infection pattern of Trypanosoma evansi in camels in mid-eastern Sudan

The antigen detection enzyme immunoassay (AgELISA) in conjunction with parasitological examination of blood were used to study the enzootic situation of cameline trypanosomiasis in mid-Eastern Sudan. A one year survey showed that the infection is endemic among pastoral camels with a prevalence of 5.4% based on parasitological examination and 31.3% based on AgELISA. The infection rate was higher during the dry period (November to May) than the wet season. Young camels had a much lower infection rate as detected by parasitological techniques, but not with AgELISA. A lower prevalence of infection was detected by buffy coat technique (BCT) in herds of camels raised by nomads compared with those kept by agropastoralists and in camels located in the southern districts of mid-Eastern Sudan.     

Isoenzyme analysis of stocks of trypanosomes isolated from cattle in Indonesia

Three trypanosome stocks isolated from cattle in Indonesia were shown to differ markedly from an Indonesian stock of Trypanosoma evansi on the basis of the isoenzyme banding patterns of 12 soluble enzymes. The results obtained for these stocks were not consistent with those reported for typical forms of T evansi but were very similar to enzyme patterns obtained for rodent adapted stocks of T vivax.     

The serological reactions of Mycoplasma isolated from pneumonic sheep lungs in the Sudan.

Seven mycoplasma isolated from pneumonic sheep lungs were found to belong to two serologically unrelated groups. Isolates in one group reacted strongly with antisera to M arginini in the metabolic inhibition and growth inhibition tests. All isolates except one failed to react with antisera to M mycoides var capri or M mycoides var mycoides. The results of the present work support the previously reported division of the isolates into two groups on the basis of their biological properties.     

Biochemical and serological studies on Pasteurella multocida isolated from cattle in the Sudan.

Of 42 strains of Pasteurella meltocida isolated from different outbreaks of hemorrhagic septicaemia and from healthy cattle in various parts of the Suden, 38 belonged to Carters' type B and four to type E. The strain used for vaccine production was type E. With respect to somatic antigen determination, there was some correlation between the results of the gel diffusion and the agglutination tests as most strains reacted with 0 groups 6 antisera in both tests. However, some antigens cross-reacted with antisera of different 0 groups in the gel diffusion test. No correlation was observed between the pattern of biochemical reactions and the serological types.     

Susceptibility of Sudanese sheep to a bluetongue virus isolated from apparently healthy cattle in the Sudan

This study intends to clarify the role of apparently healthy cattle as a reservoir of bluetongue (BT) virus to sheep in the Sudan. It confirms earlier work and establishes that cattle can harbour bluetongue virus to which sheep are susceptible in the country. Experimental transmission of BT virus between the two species suggests that the best indicator to determine viraemia in apparently healthy cattle is to inoculate susceptible sheep with suspected cattle virus. The condition of the viraemia and the virus survival in the field are discussed.     

Detection of Trypanosoma evansi in camels using PCR and CATT/T. evansi tests in Kenya

Camel trypanosomosis (Surra) causes high morbidity and is an impediment to the camel husbandry in Kenya. The lack of a sensitive diagnostic test has hindered the collection of accurate epidemiological data and institution of control programmes. A cross-sectional study was conducted in three districts of Kenya to estimate the prevalence of Trypanosoma evansi (T. evansi) and to compare four diagnostic tests: polymerase chain reaction (PCR), card agglutination test (CATT/T. evansi), microhaematocrit centrifugation technique (MHCT) and mouse inoculation (MI). A total of 549 camels were randomly sampled. The overall prevalence of Surra was 5.3% using MHCT, 26.6% using PCR and 45.9% using CATT/T.evansi. There was a significant difference (P < 0.001) between PCR and CATT/T.evansi test, MHCT and MI in detection of T. evansi. The prevalence of T. evansi was 39.8% in Samburu, 24.7% in Nanyuki and 14.4% in Isiolo districts using PCR. A male camel was 2.6 times more likely to be infected with T. evansi compared to a female camel (OR = 3.0% CI: 1.6, 4.1), while an adult camel was 2.2 times more likely to be infected compared to non-adults (OR = 2.2; 95% CI: 1.2, 5.0). There was a poor association between the presence of the published clinical signs and seropositivity (kappa = 0.12), PCR (kappa = 0.11) and MHCT (kappa = 0.05). However, there was a higher agreement between farmers' classification of disease with the PCR test (kappa = 0.5, n = 61). The mean PCV varied with age, presence of infection, locality and gender, with the lowest mean PCV being recorded in MHCT-positive animals (20.97 +/- 0.5) and from infected calves (19.5 +/- 1.2). This study shows that PCR was more sensitive in detecting T. evansi than other tests used. Further, the prevalence of T. evansi in the camel herds sampled is higher than that previously reported in Kenya, and that the judgment by camel keepers may be a reliable "pen-side" diagnostic test for Surra. Considering the low sensitivity of parasitological techniques in detection of chronic T. evansi infection and high cost of PCR, development of a sensitive pen side diagnostic test, with a low cost is still a priority.     

Goat pox in the Sudan

Summary An outbreak of goat pox occurred among 60 adult and young goats in the Sudan. Among the findings of special interest was the extensive and wide distribution of pox lesions on the bodies of the animals. The severe involvement of the mucous membranes of the muzzle, eyes and nostrils gave rise to acute respiratory distress and systemic reaction. The suppression of secondary bacterial infection with local and systemic terramycin in addition to supportive therapy of affected animals alleviated the condition and none of the animals died. Typical pox lesions were produced experimentally on goats and sheep using infected material from goats. Human infections were not encountered.

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Viruela En Cabras En Sudan

Resumen Ocurrió un brote de viruela en un rebaño de 60 cabras adultas y jóvenes en Sudan. De interés fue la extensión y localización de las lesiones en todo el cuerpo de los animales afectados. El compromiso severo de las membranas mucosas de las narices, ojos y hocico originó síntomas respiratorios agudos y reacción sistémica. El tratamiento oportuno con terramicina local y parenteral alivió la condición evitando muertes. Se reprodujeron lesiones tipicas de viruela en cabras y ovejas inoculadas experimentalmente utilizando material de animales enfermos. No se encontraron infecciones humanas.

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Variole Des Chevres Au Soudan

Résumé Une épidémie de variole caprine est apparue sur 60 chèvres adultes et jeunes au Soudan. Parmi les observations intéressantes faites, on peut citer l'extension et la large distribution des lésions de variole sur le corps des animaux. Leur grave développement sur les membranes muqueuses du museau, des yeux et des narines a provoqué une détresse respiratoire aiguë et des réactions systémiques. La suppression des infections bactériennes secondaires par traitement local des lésions à la terramycine à l'appui d'une thérapeutique de soutien des animaux atteints a fait qu'aucun d'eux n'est mort. Des lésions typiques de la variole ont été expérimentalement obtenues sur des chèvres et des moutons, en utilisant du matériel infecté de chèvres. Aucun cas de variole humaine n'a été constaté.