Serosurveillance for equine infectious anaemia in the Ardahan province of Turkey

Equine infectious anaemia is a retroviral infection of horses. All infected horses, including those that are asymptomatic, become carriers and are infectious for life. In this study, blood samples of all equines in the province of Ardahan were collected. The material consisted of 8,947 equines, including 8,769 horses and 178 donkeys, from Ardahan province in northeastern Turkey. Blood was collected from all horses and donkeys and the sera were analysed for the presence of antibodies to equine infectious anaemia virus (EIAV) using an enzyme-linked immunosorbent assay. The results revealed that none of the horses and donkeys were positive for antibodies to EIAV.     

Diagnosis of equine infectious anaemia during the 2006 outbreak in Ireland

In 2006 there was an outbreak of equine infectious anaemia (EIA) in Ireland. This paper describes the use of the diagnosis of clinical and subclinical cases of the disease. In acute cases the ELISAs and the immunoblot were more sensitive than the AGID. In one mare, fluctuating antibody levels were observed in all the serological assays before it seroconverted by AGID. Viral RNA and DNA were detected by RT-PCR and PCR in all the tissues from the infected animals examined postmortem. The PCR detected viral DNA in plasma regardless of the stage of the disease. In contrast, the RT-PCR detected RNA in only 52 per cent of the seropositive animals tested and appeared to be most sensitive for the detection of virus early in infection. Both PCR and RT-PCR demonstrated potential to detect acutely infected horses earlier than some of the official tests. The serological data suggest that the usual incubation/seroconversion period for this strain of the virus was approximately 37 days but may be more than 60 days in a few cases.     

Oxidant-antioxidant imbalance in horses infected with equine infectious anaemia virus

This study assesses the impact of equine infectious anaemia virus (EIAV) infection on the oxidant/antioxidant equilibrium of horses. Blood samples from 96 Romanian horses aged 1-25 years, were divided into different groups according to their EIAV-infection status, age, and time post-seroconversion. The effect of infection on oxidative stress was estimated by measuring enzymatic antioxidants (superoxide dismutase [SOD], glutathione peroxidase [GPx] and catalase), non-enzymatic antioxidants (uric acid and carotenoids), and lipid peroxidation (malondialdehyde [MDA]). Infection modified the oxidant/antioxidant equilibrium in the horses, influencing GPx and uric acid levels (P<0.05). Time post-seroconversion also contributed to oxidative stress imbalance, exhibiting a significant influence on both SOD and MDA concentrations in the blood (P<0.05). Animal age did not have a significant influence on oxidative stress. Recently infected horses (<1 year following seroconversion), and horses >5 years old, represented the most vulnerable category in terms of oxidative stress, followed by recently infected animals <5 years old. The results of this study are novel in implicating EIAV infection in the development of oxidative stress in horses.     

Use of an ELISA test in the eradication of an equine infectious anaemia focus

Summary An enzyme linked immunosorbent assay (ELISA) test and the classic agar gel immunodiffusion (AGID) test were used as diagnostic methods in the eradication of a focus of equine infectious anaemia from a herd of 86 horses. The ELISA test proved to be more sensitive, detecting positive animals earlier than the AGID test. A group of 16 animals positive only by ELISA also became positive to the AGID when retested one month later, except for 2 animals which showed clinical signs of the disease and died before retesting.

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El Uso De Una Prueba Elisa En La Erradicacion De Un Foco De Anemia Infecciosa Equina

Resumen La prubla ELISA (Enzyme Linked Immunosorbent Assay) y la pruebla clásico de imunodifusión en gel agar (IDGA) fueron utilizados como métodos de diagnóstico para eliminar un foco de Anemia Infecciosa Equina. La pruebla de ELISA fue más sensible, detectando los animales positivos antes que la pruebla de IDGA. Un grupo de animales positivos, que fueron detectados solamente por la pruebla de ELISA, fueron también detectados por la pruebla de IDGA en el reteste después de treinta dias. De los 16 animales de ese grupo, solamente 2 mostrarom signos clinicos de la enfermedad y murieron antes de la realización del reteste.

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L'utilisation Du Test Elisa Dans L'eradication D'un Foyer D'anemie Infectieuse Equine

Résumé Un test d'ELISA (Enzyme Linked Immunosorbent Assay) et un test cassique d'immunodiffusion en gel d'agar (IDGA) ont été utilisés comme méthodes de diagnostic de l'erradication d'un foyer d'Anémie Infectiuse Equine. Le test d'ELISA a été le plus sensible detectant animaux positifs plus tot que le test d'IDGA. Un groupe d'animaux positifs qui ont été detectés seulement par le test d'ELISA ont aussi été detectés par le test d'IDGA lors d'un nouveau test après trente jours. De ce groupe constituté par seize animaux, seulement deux ont montré des signes cliniques de la maladie et sort morts avant la réalisation du nouveau test.

     

T and B lymphocytes in horses persistently infected with equine infectious anaemia virus

The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fc positive cells was assayed by the EA rosette test.The majority of peripheral blood lymphocytes (PBL) from both uninfected and EIA-infected horses formed rosettes of each kind with only three erythrocytes indicating a low density of the corresponding receptors on the cell membrane under the condition of the assays used. The percentage of T lymphocytes in the peripheral blood of diseased horses (52.4±1.6%), as detected by E rosettes, was significantly (p<0.01) higher than in control animals (42.4±3.5%). In clinically healthy horses 8.9±1.1% of PBL were identified by A rosettes as active T cells, whereas animals with a chronic form of EIA had a much lower (p<0.001) percentage of these cells (4.7±0.7%). In the B lymphocyte subpopulations the percentages of cells bearing Fc and C3b receptors were markedly elevated (p<0.001) in EIA-infected horses (24.7±0.8% and 42.8±2.2% respectively) as compared to uninfected animals (15.1±1.4% and 29.6±1.2% respectively). Receptors for mouse erythrocytes, as yet undescribed on equine PBL, were demonstrated in approximately equal proportions on lymphocytes from EIA-infected (24.8±1.5%) and uninfected horses (24.3±2.1%).