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Anaplasma marginale is the most prevalent vector-borne pathogen in the livestock industry in Colombia, causing economic losses of approximately USD 4.2 million per year. The present study reports the seasonal transmission patterns, genetic diversity and phylogeographic traits of A. marginale strains in cattle and buffaloes from Colombian livestock areas. A three-point longitudinal survey was designed to evaluate the above characteristics of farms in the Caribbean and Orinoquía regions. The A. marginale prevalence was evaluated in 1432 cattle blood samples, 152 buffalo blood samples and the hemolymph of 439 ticks using semi-nested PCR (sn-PCR) targeting the msp5 gene. The molecular prevalence in cattle and buffaloes was 54.8% and 13.1%, respectively, with higher values during the wet and late wet seasons. Factors such as age and production system were significantly associated with the infection. Rhipicephalus microplus was the only carrier of A. marginale DNA, with an infection rate of 17.2%. On the other hand, the tandem repeat and microsatellite analyses of the msp1α gene showed high genetic diversity and new tandem repeats that suggested strain adaptation to different transmission modes. Phylogeographic analysis using the msp4 gene showed a relationship between Colombian isolates and Mexican, Brazilian, Venezuelan, European and Asian isolates, as well as two worldwide haplogroups that were associated with the geographical origin of each isolate. In conclusion, this study shows that A. marginale occurs under enzootic stability in both hosts, with a high prevalence of infection during wet months and in animals dedicated to beef production. The genetic variability analyses suggest that a high strain diversity is associated with multiple selective pressures in the study area, while phylogeographic traits suggest a high genetic similarity between Mexican and South American strains. [ABSTRACT FROM AUTHOR]

In Colombia, vector-borne diseases are one of the most important problems in the livestock industry. The present study reports parasitological and molecular surveys of vector-borne pathogens in cattle from two high-value livestock areas in Colombia. A total of 464 samples (226 from Antioquia and 238 from Arauca) were analyzed. While the blood smear analysis identified 98 (21.1%), 14 (3.0%) and 30 (6.5%) positive samples for Anaplasma spp. , Babesia spp. and Trypanosoma spp., respectively, the molecular methods indicated that 275 (59.3%), 146 (31.5%), 64 (13.8%), 236 (50.9%) and 43 (9.3%) of the samples were positive for Anaplasma marginale , Babesia bigemina , Babesia bovis , Trypanosoma theileri and T. evansi , respectively. Mixed infections were detected in 250 (53.9%) samples. Interestingly, animals aged ≤1 year had higher probabilities of being infected with A. marginale and Babesia spp., and lower probabilities of being infected with Trypanosoma spp., while the animals raised under intensive system breeding had higher probabilities of being infected with all pathogens. Additionally, T. theileri infection was found in higher prevalence in anemic animals than animals with normal packed cell volume (PCV). This is the first molecular report that evaluated the infection with three genders of vector-borne pathogens in cattle in Colombia and provides useful information for a better understanding of the epidemiologic aspects, as well as for the management and control, of these diseases. [ABSTRACT FROM AUTHOR]

Surra disease is a zoonosis caused by Trypanosoma (Trypanozoon) evansi, a salivary trypanosome, originally from Africa, which affects a wide range of mammalian worldwide. Dogs are highly susceptible to T. evansi infection and they often exhibit strong clinical signs than can lead to death, even within weeks in untreated acute cases. The present survey is the first report through clinical, parasitological and molecular approaches, of two fatal cases of T. evansi in Colombian dogs. After analysing two presumptive cases of infection with Trypanosoma spp., in dogs by parasitological methods, we confirmed by molecular techniques the presence of T. evansi, finding clinical signs such as anaemia, thrombocytopenia and hepatosplenomegaly, with fatal outcomes within a week even after the treatment. A phylogenetic and phylogeographic analysis of both isolates from T. evansi, suggest a complex evolutionary relationship with species of Trypanozoon subgenus. Moreover, the haplotype H2 was observed for the first time in Colombia, in common areas where human cases of T. evansi infection has been reported. These findings imply a relevant problem for animal health in the country, and highlight the importance of this infection in domestic animals and the possibility of human cases. [ABSTRACT FROM AUTHOR]

Surra is a zoonotic disease caused by Trypanosoma evansi , affecting the health and production of the livestock significantly. There are several methods to diagnose this disease, which have different principles, sensitivity, and specificity. Among them, the serological techniques using T. evansi as antigen are powerful tools for its epidemiological surveillance. However, they are poorly used due to inefficient in vitro propagation of T. evansi , which requires the use of laboratory animals for antigen production. In the present study, whole cell lysate of T. brucei brucei propagated in vitro was used as an antigen for the detection of anti- T. evansi immunoglobulin G in cattle through an indirect-ELISA. Based on a total of 45 samples from non-infected and 45 samples from T. evansi infected cattle, the sensitivity and specificity were estimated as 100% and 97.7%, respectively. After the validation, serological and molecular surveys were carried out in 710 cattle samples from two endemic Colombian regions (Antioquia and Arauca departments) for T. evansi where molecular prevalences of ˜7.0% were detected through the year and sporadic outbreaks of T. vivax infections have been associated to low prevalence of this species (<1%). A total of 424 (59.7%) samples were positive by indirect-ELISA T. b. brucei , while PCR test for T. evansi and T. vivax , showed 49 (6.9%) and no positive samples, respectively. Interestingly, categories of animals aged>1 year, Bos taurus breed, and those raised under intensive farming system exhibited a higher seroprevalence to T. evansi (P < 0.05). The results displayed a new alternative for antibody detection anti- T. evansi in livestock, using parasites propagated in vitro as antigen, which presents the advantage of higher standardization potential, and avoid the use of live animal for antigen production. A larger availability of this ELISA will generate useful information for a better understanding of the epidemiologic aspects, as well as for the management and control of these diseases in Colombia. However, the ability of the test to detect and/or cross react with T. vivax infections remains to be investigated. [ABSTRACT FROM AUTHOR]