Casos de anaplasmosis, babesiosis y tripanosomiasis bovina registradas en el INTA Rafaela (2012-2019)

Bovine anaplasmosis, babesiosis and trypanosomiasis are diseases of economic importance caused by Anaplasma marginale, Babesia bovis and/or Babesia bigemina, and Trypanosoma vivax, respectively. In this work, protocols received during 2012-2019 in the laboratory of hemoparasites of the EEA Rafaela with a presumptive diagnosis of one of these three diseases were analyzed. The confirmatory diagnosis was made by microscopic observation of the causal agent. Clinical signs and results of serological and molecular tests were used as complementary information. Association between cases of anaplasmosis (dependent variable), the season of the year and area with or without the presence of Rhipicephalus microplus (independent variables) was analyzed with a generalized linear model using a binomial distribution. 50% of the protocols came from Santa Fe. Confirmatory diagnosis was achieved in 48% (213/441) of the protocols, of which 73% were positive for anaplasmosis, 16% for babesiosis and 11% for trypanosomiasis. In the R. microplus free area, 55 cases of anaplasmosis were recorded. The proportion of anaplasmosis cases was significantly higher in autumn compared to summer (p<0.05). No significant differences were observed when anaplasmosis cases, the season of the year and area were analyzed together. The occurrence of anaplasmosis cases in areas considered naturally free of the disease confirms its expansion. Outbreaks of bovine babesiosis occurred in areas with R. microplus. Bovine trypanosomiasis is also an expanding disease and should be considered in the differential diagnosis of hemoparasitic diseases.Anaplasmosis, babesiosis y tripanosomiasis de los bovinos son enfermedades de importancia económica provocadas por Anaplasma marginale, Babesia bovis y/o Babesia bigemina, y Trypanosoma vivax, respectivamente. En este trabajo se analizaron los protocolos recibidos durante 2012-2019 en el laboratorio de hemoparásitos de la EEA Rafaela con diagnóstico presuntivo de alguna de estas tres enfermedades. Se realizó diagnóstico etiológico de los casos mediante la observación microscópica del agente causal. Signos clínicos y resultados de pruebas serológicas y moleculares se consideraron como información complementaria. Se analizó la relación entre casos de anaplasmosis (variable dependiente), estación del año y zona con o sin presencia de Rhipicephalus microplus (variables independientes) mediante modelo lineal generalizado utilizando distribución binomial. El 50% de los protocolos provino de la Provincia de Santa Fe. Se arribó a un diagnóstico etiológico en el 48% (213/441) de los protocolos, de los cuales un 73% resultó positivo a anaplasmosis, 16% a babesiosis y 11% a tripanosomiasis. En zona libre de R. microplus se registraron 55 casos de anaplasmosis. La proporción de casos de anaplasmosis resultó significativamente mayor en otoño respecto a verano (p<0,05). El análisis conjunto de casos de anaplasmosis, estación del año y zona, no resultó significativo. La ocurrencia de casos de anaplasmosis en zonas consideradas naturalmente libres de la enfermedad confirma su estatus en expansión. Los brotes de babesiosis bovina continúan circunscriptos a las regiones con R. microplus. La tripanosomiasis bovina también es una enfermedad en expansión y debe ser considerada en el diagnóstico diferencial de enfermedades anemizantes

Neosporosis in Argentina: Past, present and future perspectives.

Neosporosis, caused by the protozoan Neospora caninum, was first diagnosed in Argentinean cattle in the 90's. With a national bovine stock of approximately 53 million head, the cattle industry is socially and economically relevant. Severe economic losses have been estimated at US$ 33 and 12 million annually in dairy and beef cattle, respectively. Approximately 9% of bovine abortions in the Buenos Aires province are caused by N. caninum. In 2001, the first isolation of N. caninum oocysts from feces of a naturally infected dog was performed in Argentina and named as NC-6 Argentina. Further strains were isolated from cattle (NC-Argentina LP1, NC-Argentina LP2) and axis deer (Axis axis, NC-Axis). Epidemiological studies revealed a high distribution of Neospora-infections not only in dairy but also in beef cattle, with seroprevalence rates of 16.6-88.8% and 0-73%, respectively. Several experimental infection studies in cattle have been carried out, as well as attempts to develop effective vaccines to avoid Neospora-abortions and transmission. However, no vaccine has proven successful for its use in daily practice. Reduction of seroprevalence, vertical transmission and Neospora-related abortions have been achieved in dairy farms by the use of selective breeding strategies and embryo transfer. Neospora-infections have been also detected in goats, sheep, deer, water buffaloes (Bubalus bubalis) and gray foxes (Lycalopex griseus). Moreover, Neospora-related reproductive losses were reported in small ruminants and deer species and could be more frequent than previously thought. Even though diagnostic methods have been improved during the last decades, control of neosporosis is still not optimal. The development of new strategies including new antiprotozoal drugs and vaccines is highly needed. This paper reviews the information from the previous 28 years of research of N. caninum in Argentina, including seroprevalence and epidemiological studies, available diagnostic techniques, experimental reproduction, immunization strategies, isolations and control measures in domestic and non-domestic animals from Argentina

Evidence for Extensive Genetic Diversity and Substructuring of the Babesia bovis Metapopulation

Babesia bovis is a tick-transmitted haemoprotozoan and a causative agent of bovine babesiosis, a cattle disease that causes significant economic loss in tropical and subtropical regions. A panel of nineteen micro- and minisatellite markers was used to estimate population genetic parameters of eighteen parasite isolates originating from different continents, countries and geographic regions including North America (Mexico, USA), South America (Argentina, Brazil), the Middle East (Israel) and Australia. For eleven of the eighteen isolates, a unique haplotype was inferred suggesting selection of a single genotype by either in vitro cultivation or amplification in splenectomized calves. Furthermore, a high genetic diversity (H = 0.780) over all marker loci was estimated. Linkage disequilibrium was observed in the total study group but also in sample subgroups from the Americas, Brazil, and Israel and Australia. In contrast, corresponding to their more confined geographic origin, samples from Israel and Argentina were each found to be in equilibrium suggestive of random mating and frequent genetic exchange. The genetic differentiation (FST) of the total study group over all nineteen loci was estimated by analysis of variance (Θ) and Nei's estimation of heterozygosity (GST') as 0.296 and 0.312, respectively. Thus, about 30% of the genetic diversity of the parasite population is associated with genetic differences between parasite isolates sampled from the different geographic regions. The pairwise similarity of multilocus genotypes (MLGs) was assessed and a neighbour-joining dendrogram generated. MLGs were found to cluster according to the country/continent of origin of isolates, but did not distinguish the attenuated from the pathogenic parasite state. The distant geographic origin of the isolates studied allows an initial glimpse into the large extent of genetic diversity and differentiation of the B. bovis population on a global scale.Fil: Flores, Daniela Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Minichiello, Y.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Araujo, F. R.. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; BrasilFil: Shkap, V.. Kimron Veterinary Institute Israel; IsraelFil: Benítez, D.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Corrientes. Estación Experimental Agropecuaria Mercedes; ArgentinaFil: Echaide, Ignacio Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Rolls, P.. Tick Fever Centre; AustraliaFil: Mosqueda, J.. Universidad Autónoma de Querétaro; MéxicoFil: Pacheco, G. M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Petterson, M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Jacobsen, Monica Ofelia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Schnittger, Leonhard. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentin