Transmission of equine infectious anemia virus from horses without clinical signs of disease.
Abstract: Twenty seven adult horses positive to the agar gel immunodiffusion (AGID) test for equine infectious anemia (EIA), but with no history of clinical EIA, were used in transfusion studies to determine whether infectious EIA virus was present in 1 to 5 ml of their blood. Of 27 recipients, 21 (78%) became AGID test-positive at an average of 24 days after inoculation. Two horses that were initially negative when screened were retested and found to carry infectious virus in 5-300 ml of whole blood; the other 4 horses were not retested. Horse flies (Tabanus fuscicostatus Hine) were unable to transmit EIA virus from 10 AGID test-positive donors with no history of clinical EIA, but virus was transmitted from a pony with artificially induced acute EIA and from a horse that had recovered from a clinical attack of EIA 9 months earlier. Histopathologic changes indicative of EIA were noted in all test-positive recipients. The most consistent lesion was paracortical lymphoid hyperplasia in the splenic lymph node.
Publication Date: 1982-02-01 PubMed ID: 6276353
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- Journal Article
Summary
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This research article investigates whether the Equine Infectious Anemia (EIA) virus can be transmitted from horses without any visible signs of the disease. The study showed that nearly 78% of recipient horses became test-positive for EIA after inoculation, indicating that the virus is infectious even from asymptomatic horses.
Research Methodology
- The study involved 27 adult horses that tested positive for Equine Infectious Anemia (EIA) through the agar gel immunodiffusion (AGID) test, but none of them had shown any clinical signs of the disease.
- These horses were used in blood transfusion studies to establish if their blood contained the infectious EIA virus. Specifically, between 1 and 5 ml of blood from each horse was used in these tests.
- The researchers also used horse flies to study transmission from 10 AGID test-positive horses with no history of clinical EIA. This group also included a pony with artificially induced acute EIA and a horse that had recovered from a clinical attack of EIA 9 months earlier.
Findings
- Out of 27 recipient horses, 21 (or roughly 78%) became AGID test-positive for EIA, an average of 24 days after inoculation.
- Two initially negative horses were subsequently found to carry infectious EIA virus in larger volumes (5-300 ml) of whole blood upon retesting; but the remaining four horses were not retested.
- Horse flies could not transmit the EIA virus from asymptomatic horses, but they managed to do so from the pony with induced acute EIA and the previously infected horse.
- All test-positive recipient horses showed histopathologic changes indicative of EIA, with the most consistent lesion being paracortical lymphoid hyperplasia in the splenic lymph node.
Conclusion
- The findings of this study revealed that horses without any manifest signs of the disease can carry and transmit the EIA virus, which is vital information for understanding and controlling the disease’s spread.
- However, the method of transmission seems to be contingent on the clinical status of the donor horse, as the flies were unable to transmit the disease from asymptomatic horses.
Cite This Article
APA
Issel CJ, Adams WV, Meek L, Ochoa R.
(1982).
Transmission of equine infectious anemia virus from horses without clinical signs of disease.
J Am Vet Med Assoc, 180(3), 272-275.
Publication
Researcher Affiliations
MeSH Terms
- Animals
- Blood Transfusion
- Diptera / microbiology
- Equine Infectious Anemia / transmission
- Horses
- Hyperplasia
- Infectious Anemia Virus, Equine / isolation & purification
- Insect Vectors
- Lymph Nodes / microbiology
- Lymph Nodes / pathology
Citations
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