RESUMEN
Trypanosoma evansi (T. evansi) causes a wasting disease in almost all mammals. Trypanosoma evansi infection gives rise to the inflammatory responses that contribute to the development of inflammation-associated tissue injury. To determine what kinds of inflammatory molecules play roles in the pathogenicity of T. evansi infection, polymerase chain reaction array analysis was performed on samples from the infected and uninfected mice. The inflammatory cytokine and chemokine storm, caused mainly by macrophages, was observed. On the other hand, the expression levels of Ccl8 and Il10 in splenocytes were also markedly increased. These results suggested an augmentation in the number and activity of regulatory dendritic cells (DCs). Therefore, the kinetics of regulatory DCs in T. evansi-infected mice were investigated. During T. evansi infection, the regulatory DCs became prevalent, with reducing the amount of inflammatory DCs. Interestingly, when the regulatory DCs were implanted into T. evansi-infected mice, the survival was prolonged, and the expression levels of inflammatory molecules were suppressed. Taken together, these results showed that a subset of regulatory DCs acted as a potential regulator of the inflammatory responses.
Asunto(s)
Células Dendríticas/inmunología , Trypanosoma/inmunología , Trypanosoma/patogenicidad , Tripanosomiasis/inmunología , Animales , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Inflamación/inmunología , Inflamación/parasitología , Inflamación/patología , Leucocitos Mononucleares/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Análisis por MicromatricesRESUMEN
Trypanosoma evansi, a blood-borne protozoan parasite with an extensive geographical range is the causative agent of the livestock disease known as surra. A total of 140 out of 179 T. evansi isolates collected between 2006 and 2007 from 44 villages (comprising of 16 reported surra outbreaks) in 3 provinces (Agusan del Sur (ADS), Surigao del Sur (SDS) and Agusan del Norte (ADN)) in Mindanao, Philippines were each successfully genotyped using a suite of 7 polymorphic microsatellites. The study identified 16 multi locus genotypes (MLG) within the T. evansi isolates and evidence of the spread of surra outbreaks from one village to another, most likely due to the movement of infected animals. Genotyping provided evidence of population sub-structuring with 3 populations (I, II and III (only 1 isolate)) identified. The most abundant population was II, which was the predominant population in ADS and SDS (p=0.022). In addition, buffalo mortality was statistically higher in outbreak areas associated with isolates from population I (13.6%) than with isolates from population II (6.9%) (p=0.047). The present study has highlighted the utility of microsatellite loci to improve understanding of the epidemiology of T. evansi and in tracking surra outbreaks.
Asunto(s)
Trypanosoma/clasificación , Trypanosoma/genética , Tripanosomiasis Bovina/parasitología , Tripanosomiasis/veterinaria , Animales , Búfalos , Bovinos , ADN Protozoario/genética , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/parasitología , Cabras , Enfermedades de los Caballos/epidemiología , Enfermedades de los Caballos/parasitología , Caballos , Ratones , Repeticiones de Microsatélite , Filipinas/epidemiología , Filogenia , Tripanosomiasis/epidemiología , Tripanosomiasis/parasitología , Tripanosomiasis Bovina/epidemiologíaRESUMEN
Simple demographic and infectious disease models of buffaloes and other domestic hosts for animal trypanosomosis (surra) caused by Trypanosoma evansi were developed. The animal models contained deterministic and stochastic elements and were linked to simulate the benefit of control regimes for surra in village domestic animal populations in Mindanao, Philippines. The impact of the disease on host fertility and mortality were key factors in determining the economic losses and net-benefit from the control regimes. If using a high (99%) efficacy drug in surra-moderate to high risk areas, then treating all animals twice each year yielded low prevalence in 2 years; targeted treatment of clinically sick animals, constantly monitored (monthly), required 75% fewer treatments but took longer to reach a low prevalence than treating all animals twice each year. At high drug efficacy both of these treatment strategies increased the benefit over untreated animals by 81%. If drug efficacy declined then the benefit obtained from twice yearly treatment of all animals declined rapidly compared with regular monitoring and targeting treatment to clinically sick animals. The current control regimen applied in the Philippines of annual sero-testing for surra and only treating sero-positive animals provided the lowest net-benefit of all the control options simulated and would not be regarded as effective control. The total net-benefit from effective surra control for a typical village in a moderate/high risk area was 7.9 million pesos per annum (US $158,000). The value added to buffaloes, cattle, horses, goats/sheep and pigs as a result of this control was US $88, $84, $151, $7, $114 per animal/year, respectively.
Asunto(s)
Búfalos/parasitología , Pruebas Diagnósticas de Rutina/veterinaria , Modelos Animales , Tripanosomiasis/veterinaria , Animales , Bovinos , Pruebas Diagnósticas de Rutina/economía , Fertilidad , Modelos Económicos , Filipinas/epidemiología , Prevalencia , Trypanosoma/patogenicidad , Tripanosomiasis/tratamiento farmacológico , Tripanosomiasis/economía , Tripanosomiasis/epidemiologíaRESUMEN
Despite the widespread problem with surra (Trypanosoma evansi) in livestock, there are no published studies on its impact on host populations, probably because of the large financial and time cost involved in performing longitudinal studies. During 2002-6, a cross-sectional survey for T. evansi infection involving 1732 buffaloes from 71 villages in southern Philippines was carried out. Other livestock animals (horses, cattle and goats) in every surveyed village were also tested for infection with T. evansi but domestic buffaloes were the primary survey target. Seroprevalence ranged from 6% to 21% and 13% to 100% for buffaloes in low and high risk areas, respectively. Key demographic parameters were estimated from the age structured distributions of the sampled buffalo population for each sex. All areas were dominated by females (69%) and the annual calving rate for areas of 100% and low seroprevalence was 15% and 47%, respectively. Males were removed at a relatively high annual rate of 27% in all areas. In the main reproductive years (4-10) female removal/mortality was <1% and 10% for low and high risk areas, respectively. Older females were removed/died at a rate similar to males regardless of area. In high risk areas there were consistently more 2-year than 1-year old females and the reverse was true for the low risk areas. This implies that females were imported to the high risk areas for breeding. By assuming a stable age structure and similar size populations in each area, it was estimated that 28% of female calves need to be moved from low to high risk areas to maintain the observed age structure. In high risk areas, surra imposes significant financial losses due to reduced fertility, high mortality/removal rate and the necessity to import replacement buffaloes.
Asunto(s)
Búfalos/parasitología , Tripanosomiasis Bovina/epidemiología , Animales , Anticuerpos Antiprotozoarios/sangre , Bovinos , Estudios Transversales , Femenino , Masculino , Filipinas/epidemiología , Dinámica Poblacional , Prevalencia , Estudios Seroepidemiológicos , Tripanosomiasis/epidemiología , Tripanosomiasis/veterinaria , Tripanosomiasis Bovina/economía , Tripanosomiasis Bovina/mortalidadRESUMEN
A strain of Trypanosoma evansi isolated from an equine case of surra in Mindanao, Philippines was used to infect intravenously two groups (A and B) of five male goats aged 8-10 months. Animals of groups A and B received 5000 and 50 000 trypanosomes, respectively, and five further animals (group C) served as uninfected controls. Four of the 10 infected goats died 8-78 days after inoculation. Group C goats gained weight (mean 22.8 g/day) while infected goats in groups A and B lost weight (means of 21.4 and 45.0 g/day, respectively). Parasitaemia fluctuated regularly between peaks and troughs, with repeated periods of about 6 days during which no trypanosomes were detected in the blood. Clinical signs and clinico-pathological changes in infected goats were not pathognomonic in the absence of parasites in the blood, and leucocytosis was not a reliable indicator of infection. It was concluded that in endemic areas fluctuating fever, progressive emaciation, anaemia, coughing, testicular enlargement and diarrhoea are suggestive of surra; confirmation, however, may necessitate examination of blood every few days for trypanosomes, and possibly other diagnostic tests.
Asunto(s)
Enfermedades de las Cabras , Trypanosoma , Tripanosomiasis/veterinaria , Anemia/diagnóstico , Anemia/veterinaria , Animales , Diarrea/fisiopatología , Diarrea/veterinaria , Emaciación/fisiopatología , Emaciación/veterinaria , Recuento de Eritrocitos , Fiebre/fisiopatología , Fiebre/veterinaria , Enfermedades de las Cabras/diagnóstico , Enfermedades de las Cabras/parasitología , Enfermedades de las Cabras/fisiopatología , Cabras , Hemoglobinas/análisis , Leucocitosis/diagnóstico , Leucocitosis/patología , Leucocitosis/veterinaria , Recuento de Linfocitos , Masculino , Testículo/patología , Trypanosoma/aislamiento & purificación , Tripanosomiasis/parasitología , Tripanosomiasis/fisiopatologíaRESUMEN
Infection of male goats aged 8-10 months with 5000 or 50 000 organisms of a Mindanao strain of Trypanosoma evansi was observed over a period of 90 days. The infection induced clinical disease which was lethal, especially at the higher dose rate. Lesions were more acute in goats that received the higher dose. Gross and microscopical changes were not pathognomonic, except in the presence of demonstrable trypanosomes. At necropsy, a combination of lymphadenopathy, splenomegaly, hepatomegaly, testicular enlargement, anaemic signs and consolidation of the anterior lobes of the lungs was suggestive of surra. Testicular changes, especially aspermia, indicated probable infertility. The cytopathology of the lungs, liver, intestine, kidneys, testes, bone marrow, brain and other organs was immunological in nature, characterized by mononuclear infiltration of interstitial tissues, with minor cellular damage and the presence of trypanosomes. B- and T- cell responses were observed in the lymphatic system, but the findings indicated immunosuppression in the lymph nodes, spleen and bone marrow during the third month after infection. Exudative inflammatory changes were mild. It is suggested that the cytopathology of most haemophilic trypanosomal infections is predominantly an immunological process.
Asunto(s)
Enfermedades de las Cabras/patología , Tripanosomiasis/veterinaria , Animales , Médula Ósea/inmunología , Médula Ósea/patología , Encéfalo/patología , Enfermedades de las Cabras/inmunología , Enfermedades de las Cabras/parasitología , Cabras , Tolerancia Inmunológica , Intestinos/patología , Riñón/patología , Hígado/patología , Pulmón/patología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Masculino , Músculos/patología , Piel/patología , Bazo/inmunología , Bazo/patología , Testículo/patología , Tripanosomiasis/patologíaRESUMEN
Three groups of four calves were experimentally infected with infectious larvae of Mecistocirrus digitatus. One group received a trickle infection of 5000 L3 per day for 8 days, the other two groups received a single infection of 5000 and 40,000 L3, respectively. All animals were necropsied 120 days after infection. Prepatent periods varied between 61 and 79 days, and maximal faecal egg output was reached between 80 and 100 days after infection. Repeated infections were not additive and worm counts at 120 days after infection varied between 100 and 440 in the first two groups and between 120 and 1700 in the last group. There was no significant difference in worm counts between the different infection regimes. However, there was a significant positive relationship between worm burden and faecal egg counts. In addition, there were significant negative relationships between worm burden and packed cell volume, and weight gain. The relative decreases in packed cell volume and weight gain emerged 70-80 days after infection. Serum pepsinogen levels were significantly elevated by the end of the trial, but the observed positive relationship between worm burden and pepsinogen was not significant. An enzyme immunoassay based on crude adult antigen was able to detect M. digitatus infection at 90 and 100 days after infection, but again there was no significant association between worm burden and antibody levels. Therefore, anaemia and a reduction in weight gain caused by the haematophagous activity of adult stages seem to be the most important pathogenic effects of M. digitatus infection in calves.
Asunto(s)
Enfermedades de los Bovinos/fisiopatología , Tricostrongiloidiasis/veterinaria , Animales , Anticuerpos Antihelmínticos/aislamiento & purificación , Bovinos , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/parasitología , Femenino , Masculino , Recuento de Huevos de Parásitos , Pepsinógenos/sangre , Trichostrongyloidea/inmunología , Tricostrongiloidiasis/inmunología , Tricostrongiloidiasis/parasitología , Tricostrongiloidiasis/fisiopatología , Aumento de PesoRESUMEN
Thelazia rhodesii was found in the eyes of 149 of 643 bovine heads (23%) that were examined at the abattoir of Cagayan de Oro City, Philippines, during the period February 1994 to February 1995. In nearly half of the animals both eyes were infected and an average of 4.1 worms per infected animal was recovered. Of the 1286 eyes examined, 17% were infected; worm burdens ranged from one to 36 (average 2.9) worms per infected eye. Monthly prevalence of infection ranged from 13% to 36%. T. rhodesii infection was significantly more common in cattle of more than 3 years of age (25%) than in younger animals (15%). Ocular lesions were observed in 73 (11%) cattle; 22% of these were infected with T. rhodesii. There was no relationship between presence of T. rhodesii and ocular lesions.
Asunto(s)
Enfermedades de los Bovinos/epidemiología , Infecciones Parasitarias del Ojo/veterinaria , Infecciones por Spirurida/veterinaria , Thelazioidea/aislamiento & purificación , Mataderos , Animales , Bovinos , Conjuntivitis/epidemiología , Conjuntivitis/veterinaria , Opacidad de la Córnea/epidemiología , Opacidad de la Córnea/veterinaria , Úlcera de la Córnea/epidemiología , Úlcera de la Córnea/veterinaria , Infecciones Parasitarias del Ojo/epidemiología , Femenino , Incidencia , Queratitis/epidemiología , Queratitis/veterinaria , Masculino , Filipinas/epidemiología , Prevalencia , Infecciones por Spirurida/epidemiologíaRESUMEN
During one year, 597 cattle were examined for Mammomonogamus laryngeus infections in the abattoir of Cagayan de Oro, Philippines. The overall prevalence was 23% with no obvious seasonal variations. The infection rate was 19% in animals up to 4 years old and 24% in animals 4-12 years old. In infected animals up to 8 years old an average of eight parasite pairs was found; infected animals of 8-12 years old had 5.2 parasite pairs on average. All worms were located on the posterior side of the epiglottis. Field observations on cattle in Mindanao revealed that adult M. laryngeus had developed on the epiglottis of a tracer calf that had been on pasture for 30 days and then kept away from possible nematode infection for 28 days.