Methods Applied to the Diagnosis of Cattle Trypanosoma vivax Infection: An Overview of the Current State of the Art

Abstract

Trypanosoma vivax bovine trypanosomiasis is a relevant disease in domestic ungulates in Latin America, causing different types of livestock losses, particularly in African and South American countries, leading to loss of millions of dollars/year related to dairy and meat production. In addition, T. vivax trypanosomiasis requires intensive veterinary care. While vector control is a feasible measure to manage disease spreading, the search for accurate diagnostic tools still represents a gap in routine veterinary practices and a challenge for the scientific community. The parasite is mechanically transmitted by fomites or by the saliva of haematophagous, such as Stomoxys sp. and Tabanus sp., infecting cattle as well as a number of animal hosts. The main symptoms of T. vivax bovine trypanosomiasis are apathy, fever, restricted growth, miscarriage, progressive weakness, neurological signs, pale mucous, loss of appetite, lethargy, and substantial weight loss.In most cases, the presence of animals with subclinical infections, nonspecific symptoms and without apparent parasitaemia presents a challenge when making a diagnosis, which requires accurate methods. Herein, we review state of the art concerning current methods available for the diagnosis of T. vivax bovine trypanosomiasis, focusing on clinical, parasitological, immunological and molecular approaches, highlighting the main features of each method, including “pros and cons”. Overall, combining several diagnostic techniques is a better choice since it leads to fewer false negative results and contributes to better disease control.

Improved Serodiagnosis ofTrypanosoma vivaxInfections in Cattle Reveals Higher Infection Rates in the Livestock Regions of Argentina

“…Although T. vivax was initially documented in Argentina in 2006 (15), it was not until the summers of 2016 and 2017 that the first outbreaks were recorded in dairy farms (48). It is important to note that the clinical signs of bovine trypanosomiasis caused by T. vivax are non-specific, rendering clinical diagnosis challenging and imprecise, particularly in the presence of other cattle diseases such as anaplasmosis, babesiosis, bovine leptospirosis, leukemia, neosporosis, and viral infections (14,37,49). The lack of awareness of the disease, the large number of registered dairy farms in the dairy area (50), the sale of infected animals, and the use of the same syringes for vaccination have contributed to its rapid spread between the provinces of Córdoba and Santa Fe.…”

“…Bovine trypanosomiasis caused by T. vivax is currently diagnosed using a combination of clinical, parasitological, molecular, and serological techniques (36)(37)(38). Parasitological diagnosis is the most commonly applied method for identifying T. vivax in the field, although its low sensitivity is only suitable for diagnosis during a short period of high parasitemia (39).…”

“…Argentina has thousands of dairy establishments, with nearly 95% of Argentine milk production coming from the provinces of Córdoba (37%), Santa Fe (32%), and Buenos Aires (25%), followed by Entre Ríos (50) (14,37,49). The lack of awareness of the disease, the large number of registered dairy farms in the dairy area (50), the sale of infected animals, and the use of the same syringes for vaccination have contributed to its rapid spread between the provinces of Córdoba and Santa Fe.…”

Improved serodiagnosis of Trypanosoma vivax infections in cattle reveals high infection rates in the livestock regions of Argentina

“…Bovine trypanosomosis caused by T. vivax is currently diagnosed by a combination of clinical, parasitological, molecular, and serological techniques [36][37][38]. Parasitological diagnosis is the PLOS NEGLECTED TROPICAL DISEASES most commonly used method to identify T. vivax in the field, although its low sensitivity is only suitable for diagnosis during a short period of high parasitemia [39].…”

Development of a Test System Based on Recombinant GM6 Antigen from Trypanosoma evansi for the Determination of Surra in Horses

“…T. equiperdum is transmitted through sexual contact and causes Dourine disease in horses, while T. evansi causes Surra and is mechanically transmitted by blood-sucking insects like Tabanus spp. According to Ferreira et al (2023) and Desquesnes et al (2013), there is an urgent requirement for diagnostic tools and mass screenings in the field due to the high prevalence of these diseases. Gizaw et al (2021) have pointed out that recent outbreaks of trypanosome infections highlight the genuine risk of equine trypanosomosis spreading globally.…”