Serological and molecular detection of Babesia caballi and Theileria equi in Mexico: A prospective study

Prevalence of Theileria Equi and Babesia Caballi and Associated Hemato-Biochemical Changes in Racing Horses in Erbil Province, Iraq

PURPOSES

This study aimed to determine the prevalence of Theileria equi (T. equi) and Babesia caballi (B. caballi) in racing horses in Erbil Province, Iraq, and to assess the associated hemato-biochemical changes in infected animals.

METHODS

A total of 196 horses, including 155 clinically healthy and 41 clinically suspected infected animals, were examined using Giemsa-stained blood films and PCR to determine the prevalence rates. Additionally, the hemato-biochemical parameters of infected horses were compared to a non-infected control group (n = 10).

RESULTS

The prevalence of T. equi and B. caballi was determined using two diagnostic methods. Giemsa-stained blood smear analysis revealed prevalence rates of 15.8% (31/196) for T. equi and 5.1% (10/196) for B. caballi. In comparison, conventional PCR targeting the 18 S rRNA gene detected higher prevalence rates of 22.44% (44/196) for T. equi and 8.2% (16/196) for B. caballi. The prevalence of T. equi was significantly higher than that of B. caballi (P < 0.001). Infected horses exhibited significant hematological alterations, including microcytic anemia, with notable reductions in RBCs, Hb, and PCV, along with increased WBCs, lymphocytes and basophils compared to the healthy control group. Biochemical analysis revealed significant increases in AST, ALT, ALP, and total serum bilirubin, and decreases in total serum protein, albumin, calcium, and glucose in infected horses.

CONCLUSION

These findings highlight the urgent need for heightened awareness, effective diagnostic methods, and targeted treatment strategies to combat equine piroplasmosis among racing horses in Erbil Province, Iraq.

Molecular Investigations of Babesia caballi from Clinically Healthy Horses in Southwestern Romania

Babesia caballi is a tick-borne hemoparasite that causes equine piroplasmosis. It has a significant economic impact, decreasing performance and affecting animal welfare. This study aimed to identify B. caballi DNA in the blood of horses from households in the southwestern and western regions of Romania. We included 310 animals, from which blood was collected via EDTA. To test the samples for the B. caballi parasite genome, we used real-time PCR and conventional PCR. The prevalence of B. caballi was 5.81% (18/310) in apparently healthy horses, suggesting that this parasite is enzootic in the regions studied, although veterinarians did not indicate any symptoms resembling clinical babesiosis. In Romania, there are insufficient epidemiologic data on equine babesiosis, and the results of the present study suggest the need for further investigations into the dynamics of transmission and to identify potential prevention and control strategies.

Prevalence of gastrointestinal and blood parasites in horses of Nakhon Si Thammarat province, Thailand

Background and Aim

The global prevalence of gastrointestinal (GI) and blood parasite infections in horses is a significant concern due to their substantial impact on morbidity, mortality, and economic losses in the horse industry. In Thailand, limited research has been conducted on these parasites in horse populations, and data from southern Thailand are lacking. Consequently, this study aimed to estimate the prevalence of GI and blood parasites in horses in Nakhon Si Thammarat province, Thailand.

Materials and Methods

In total, 79 fecal and blood samples were collected from horses across 11 farms in Nakhon Si Thammarat province. The fecal examination was conducted using simple flotation, formalin-ethyl acetate sedimentation, and a modified McMaster technique. Conventional polymerase chain reaction (PCR) was used to identify blood and strongyle parasites. The influence of sex, age, and body condition score on the prevalence of GI parasites was also analyzed.

Results

Six GI parasites were detected: four nematodes (Oxyuris equi, Parascaris equorum, strongyles, and Strongyloides westeri), one trematode (Gastrodiscus aegyptiacus), and one protozoan (Eimeria leuckarti). The overall prevalence of GI parasites was 74.7%, with single strongyle infections accounting for the highest proportion at 50.6%, followed by co-infections of strongyles and G. aegyptiacus at 10.1%. All 11 pooled strongyle samples were positive for cyathostomins and Strongylus vulgaris using conventional PCR with specific primers. Sex was significantly associated with the overall prevalence of GI parasites, whereas both sex and age were significant risk factors for infection by strongyle parasites. Theileria equi was the only blood parasite species detected in the surveyed horses, with a prevalence of 1.3% (n = 1/79).

Conclusion

This study is the first to estimate the prevalence of GI and blood parasites in horses from Nakhon Si Thammarat province, Thailand. These findings highlight the importance of implementing control measures against GI parasites and are pivotal for developing effective infection prevention strategies.

Molecular detection of Theileria cervi in equids from México

Equine piroplasmosis is a parasitic illness caused by various protozoa of the Babesia and Theileria genera, which parasitize within red blood cells. The transmission of these pathogens occurs through certain genus of ticks, including Amblyomma, Haemaphysalis, Hyalomma, and Rhipicephalus. In recent times, an increase in the identification of new Theileria species and genotypes has been observed. This is further complicated by the presence of mixed Theileria infections in both mammals and tick vectors, particularly in regions where wildlife and livestock share habitats and vectors. Therefore, the objective of this study is to document the occurrence of Theileria cervi in a non-typical host. A total of 88 horses (Equus caballus) and 10 donkeys (Equus asinus) were sampled in three municipalities in Veracruz, Mexico. Molecular techniques were employed to identify Babesia/Theileria through the amplification of a segment of the 18S-rDNA and hsp70 genes. The phylogenetic reconstruction grouped the obtained sequences into a monophyletic cluster alongside sequences of T. cervi. This work represents the first documented occurrence of T. cervi in equids. These findings have significant implications from an epidemiological point of view. In addition, further studies are needed to determine the distribution and pathogenicity of this species for domestic animals and to develop effective control strategies.

Comparison of Seroprevalence and Identification of Risk Factors for Theileria equi in Horses From Vector-Free and Infested Areas in Southern Brazil

The apicomplexan hemoprotozoan Theileria equi is a tick-borne pathogen that causes disease in equids, and together with Babesia caballi, causes equine piroplasmosis (EP). Many ticks are associated with EP around the world, and in South America three species may be related: Dermacentor nitens, Amblyomma sculptum, and Rhipicephalus microplus, as they are commonly found in horses. Among the species cited above, only R. microplus is found in Rio Grande do Sul state, Southern Brazil. In addition, this state has the only area legally free of R. microplus in Brazil. This study aimed to compare the seroprevalence for T. equi on farms located in a tick-free area (23 farms, 215 horses) and a tick-infested (25 farms, 141 horses) adjacent areas, as well as to identify potential risk factors for exposure to T. equi. Blood was collected from 356 horses from both areas, and later an indirect enzyme-linked immunosorbent assay was performed to detect anti-T. equi antibodies. Besides the blood collection, questionnaires and interviews were conducted in an attempt to identify potential risk factors. The R. microplus-free zone had 6% seropositive horses against 70% in the tick-infested zone. Previous observation of ticks on horses of the herd increased four times the odds of a horse to be seropositive for T. equi, and by three times if ticks were observed on cattle which share paddocks with horses on the farm. The results showed a large difference in T. equi seroprevalence between tick-infested and free areas, and also emphasized the relevance of R. microplus in the epidemiology of T. equi. The study also reveals the potential of the establishment of a T. equi-free zone for horse breeding in Southern Brazil.

Seroprevalence of Anti-Theileria equi Antibodies in Horses from Three Geographically Distinct Areas of Romania

Equine piroplasmosis (EP) is an endemic tick-borne disease found in most countries around the world. It affects all species of Equidae, and it is caused by Theileria equi, Babesia caballi and T. haneyi. The research herein is the second study on the prevalence of piroplasms in Romania conducted in the past two decades. The aim of this study was to assess the seroprevalence of anti-Theileria equi antibodies and the geographical distribution of this disease in the southwest, west, and northwest regions of Romania in order to obtain a more thorough understanding of the parasitological status of horses in this country. This study included 522 apparently healthy, mixed-breed horses from three different counties. The serum samples were analysed using the cELISA Theileria equi Antibody Test Kit. The overall seroprevalence rate was 12.84%. From the total number of positive horses, 13.96% were females and 11.21% were males. Based on the distribution of positive cases into age groups, the following values were obtained: 0−60 months: 16.26%, 60−180 months: 10.03%, and >180 months: 15.83%. There was no statistically significant difference between samples, based on age or gender. The positivity percentage in the localities included in the study ranged from 8.33 to 100%. In the population under study, the seroprevalence rate was high, indicating a possible exposure risk in this area of Romania, which could have severe effects on equids in the case of clinical manifestations of the disease. EP represents a serious threat for equine health in Romania; therefore, close and continuous monitoring of the situation is required.