scholarly journals Low Transmission Rates of Equine Infectious Anemia Virus (EIAV) in Foals Born To Seropositive Feral Mares Inhabiting the Amazon Delta Region Despite Climatic Conditions Supporting High Insect Vector Populations

2021 ◽  
Author(s):  
Cláudia Fideles Resende ◽  
Alison Miranda Santos ◽  
Richard Frank Cook ◽  
Raphael Mattoso Victor ◽  
Rebeca Jéssica Falcão Câmara ◽  
...  
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Post Partum ◽  
Climatic Conditions ◽  
Birth Date ◽  
Insect Vector ◽  
Transmission Rates ◽  
Serological Status ◽  
Equine Infectious Anemia ◽  
Marajó Island ◽  
Anemia Virus

Abstract Background Marajó Island within in the Amazon River Delta supports numerous bands of feral equids including the genetically distinct Marajoara horses. Roughly 40% of the equids on the island are infected with the Equine infectious anemia virus (EIAV). In the absence of iatrogenic transmission, spread of this lentivirus is mediated mainly by hematophagous insects whose year-round prevalence on the island is supported by favorable climatic conditions. The euthanasia of all infected equids within the population is not a feasible strategy when the prevalence of the disease is high or in highly specialized or rare breeds of equid such as the Marajoara horse. Preservation of these animals is complicated by high rates of seropositivity with the potential for vertical transmission or insect mediated transmission following parturition of foal. Therefore, the aim of this study was to evaluate EIAV vertical and post-partum insect-mediated transmission rates among foals born to seropositive feral mares until natural weaning. Serum samples of foals born to seropositive feral mares from Soure municipality, within Marajó Island, were collected to investigate their serological status, using an indirect ELISApgp45 with positive samples being tested in the classical agar gel immunodiffusion (AGID) assay to confirm the results. Results Twenty-eight foals were sampled and their serological status was monitored over a 2-year period. Depending on the birth date, some of them were sampled up to six times. All foals remained with their respective mares until fully weaned, approximately 10 months of age, and just 2 of 28 foals (7.14%) in the study group became seropositive against EIAV. Conclusion The results showed that in most cases it is possible to obtain negative foals born to and eventually weaned by EIA positive mares, even in equatorial regions where substantial rainfall and high temperatures favor the proliferation of insect vectors.

scholarly journals Equine infectious anemia on Marajo Island at the mouth of the Amazon river

2015 ◽  
Vol 35 (12) ◽  
pp. 947-950 ◽  
Author(s):  
Nayra F.Q.R. Freitas ◽  
Carlos M.C. Oliveira ◽  
Rômulo C. Leite ◽  
Jenner K.P. Reis ◽  
Fernanda G. Oliveira ◽  
...  
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Serological Survey ◽  
Santa Cruz ◽  
Agar Gel ◽  
Incurable Disease ◽  
Island State ◽  
Equine Infectious Anemia ◽  
Marajó Island ◽  
Males And Females ◽  
Anemia Virus

Abstract: Equine infectious anemia (EIA) is a transmissible and incurable disease caused by a lentivirus, the equine infectious anemia virus (EIAV). There are no reports in the literature of this infection in Equidae on Marajo Island. The objective of this study was to diagnose the disease in the municipalities of Cachoeira do Arari, Salvaterra, Santa Cruz do Arari and Soure, on Marajó Island, state of Pará, Brazil. For serological survey samples were collected from 294 horses, over 5-month-old, males and females of puruca and marajoara breeds and from some half-breeds, which were tested by immunodiffusion in Agar gel (AGID). A prevalence of 46.26% (136/294) positive cases was found. EIA is considered endemic in the municipalities studied, due to the ecology of the region with a high numbered population of bloodsucking insect vectors and the absence of official measures for the control of the disease.

scholarly journals Evaluation of equine infectious anemia virus by the indirect ELISA EIA-LAB as screening tools in Mexico

2021 ◽  
pp. 103372
Author(s):  
Maria Carla Rodríguez Domínguez ◽  
Roberto Montes-de-Oca-Jiménez ◽  
Juan Carlos Vázquez Chagoyan ◽  
Alberto Barbabosa Pliego ◽  
Jorge Antonio Varela Guerrero ◽  
...  
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Indirect Elisa ◽  
Screening Tools ◽  
Equine Infectious Anemia ◽  
Anemia Virus

scholarly journals Mapping of Equine Lentivirus Receptor 1 Residues Critical for Equine Infectious Anemia Virus Envelope Binding

2007 ◽  
Vol 82 (3) ◽  
pp. 1204-1213 ◽  
Author(s):  
Baoshan Zhang ◽  
Chengqun Sun ◽  
Sha Jin ◽  
Michael Cascio ◽  
Ronald C. Montelaro
Keyword(s):  
Equine Infectious Anemia Virus ◽  
Tumor Necrosis Factor Receptor ◽  
Binding Domain ◽  
Virus Envelope ◽  
Immunodeficiency Virus ◽  
Equine Infectious Anemia ◽  
Anemia Virus ◽  
Functional Receptor ◽  
Herpesvirus Entry Mediator ◽  
Necrosis Factor

ABSTRACT The equine lentivirus receptor 1 (ELR1), a member of the tumor necrosis factor receptor (TNFR) protein family, has been identified as a functional receptor for equine infectious anemia virus (EIAV). Toward defining the functional interactions between the EIAV SU protein (gp90) and its ELR1 receptor, we mapped the gp90 binding domain of ELR1 by a combination of binding and functional assays using the EIAV SU gp90 protein and various chimeric receptor proteins derived from exchanges between the functional ELR1 and the nonbinding homolog, mouse herpesvirus entry mediator (murine HveA). Complementary exchanges of the respective cysteine-rich domains (CRD) between the ELR1 and murine HveA proteins revealed CRD1 as the predominant determinant of functional gp90 binding to ELR1 and also to a chimeric murine HveA protein expressed on the surface of transfected Cf2Th cells. Mutations of individual amino acids in the CRD1 segment of ELR1 and murine HveA indicated the Leu70 in CRD1 as essential for functional binding of EIAV gp90 and for virus infection of transduced Cf2Th cells. The specificity of the EIAV SU binding domain identified for the ELR1 receptor is fundamentally identical to that reported previously for functional binding of feline immunodeficiency virus SU to its coreceptor CD134, another TNFR protein. These results indicate unexpected common features of the specific mechanisms by which diverse lentiviruses can employ TNFR proteins as functional receptors.

Molecular detection of equine infectious anemia virus in clinically normal, seronegative horses in an endemic area of Mexico

2021 ◽  
pp. 104063872110061
Author(s):  
César I. Romo-Sáenz ◽  
Patricia Tamez-Guerra ◽  
Aymee Olivas-Holguin ◽  
Yareellys Ramos-Zayas ◽  
Nelson Obregón-Macías ◽  
...  
Keyword(s):  
Nested Pcr ◽  
Equine Infectious Anemia Virus ◽  
Antibody Detection ◽  
Economic Losses ◽  
Clinically Normal ◽  
Pcr Product ◽  
Surveillance Programs ◽  
Equine Infectious Anemia ◽  
Anemia Virus ◽  
Equine Industry

Equine infectious anemia (EIA) is a highly infectious disease in members of the Equidae family, caused by equine infectious anemia virus (EIAV). The disease severity ranges from subclinical to acute or chronic, and causes significant economic losses in the equine industry worldwide. Serologic tests for detection of EIAV infection have some concerns given the prolonged seroconversion time. Therefore, molecular methods are needed to improve surveillance programs for this disease. We attempted detection of EIAV in 6 clinical and 42 non-clinical horses in Nuevo Leon State, Mexico, using the agar gel immunodiffusion (AGID) test for antibody detection, and nested and hemi-nested PCR for detection of proviral DNA. We found that 6 of 6, 5 of 6, and 6 of 6 clinical horses were positive by AGID, nested PCR, and hemi-nested PCR, respectively, whereas 0 of 42, 1 of 42, and 9 of 42 non-clinical horses were positive by these tests, respectively. BLAST analysis of the 203-bp 5′-LTR/ tat segment of PCR product revealed 83–93% identity with EIAV isolates in GenBank and reference strains from other countries. By phylogenetic analysis, our Mexican samples were grouped in a different clade than other sequences reported worldwide, indicating that the LRT/ tat region represents an important target for the detection of non-clinical horses.

scholarly journals Functional Replacement and Positional Dependence of Homologous and Heterologous L Domains in Equine Infectious Anemia Virus Replication

2002 ◽  
Vol 76 (4) ◽  
pp. 1569-1577 ◽  
Author(s):  
Feng Li ◽  
Chaoping Chen ◽  
Bridget A. Puffer ◽  
Ronald C. Montelaro
Keyword(s):  
Life Cycle ◽  
Virus Particle ◽  
Matrix Protein ◽  
Particle Production ◽  
Equine Infectious Anemia Virus ◽  
Virus Infectivity ◽  
Gag Protein ◽  
Equine Infectious Anemia ◽  
Anemia Virus ◽  
Hiv 1

ABSTRACT We have previously demonstrated by Gag polyprotein budding assays that the Gag p9 protein of equine infectious anemia virus (EIAV) utilizes a unique YPDL motif as a late assembly domain (L domain) to facilitate release of the budding virus particle from the host cell plasma membrane (B. A. Puffer, L. J. Parent, J. W. Wills, and R. C. Montelaro, J. Virol. 71:6541-6546, 1997). To characterize in more detail the role of the YPDL L domain in the EIAV life cycle, we have examined the replication properties of a series of EIAV proviral mutants in which the parental YPDL L domain was replaced by a human immunodeficiency virus type 1 (HIV-1) PTAP or Rous sarcoma virus (RSV) PPPY L domain in the p9 protein or by proviruses in which the parental YPDL or HIV-1 PTAP L domain was inserted in the viral matrix protein. The replication properties of these L-domain variants were examined with respect to Gag protein expression and processing, virus particle production, and virus infectivity. The data from these experiments indicate that (i) the YPDL L domain of p9 is required for replication competence (assembly and infectivity) in equine cell cultures, including the natural target equine macrophages; (ii) all of the functions of the YPDL L domain in the EIAV life cycle can be replaced by replacement of the parental YPDL sequence in p9 with the PTAP L-domain segment of HIV-1 p6 or the PPPY L domain of RSV p2b; and (iii) the assembly, but not infectivity, functions of the EIAV proviral YPDL substitution mutants can be partially rescued by inclusions of YPDL and PTAP L-domain sequences in the C-terminal region of the EIAV MA protein. Taken together, these data demonstrate that the EIAV YPDL L domain mediates distinct functions in viral budding and infectivity and that the HIV-1 PTAP and RSV PPPY L domains can effectively facilitate these dual replication functions in the context of the p9 protein. In light of the fact that YPDL, PTAP, and PPPY domains evidently have distinct characteristic binding specificities, these observations may indicate different portals into common cellular processes that mediate EIAV budding and infectivity, respectively.

scholarly journals Specificity of serum neutralizing antibodies induced by transient immune suppression of inapparent carrier ponies infected with a neutralization-resistant equine infectious anemia virus envelope strain

2005 ◽  
Vol 86 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Laryssa Howe ◽  
Jodi K. Craigo ◽  
Charles J. Issel ◽  
Ronald C. Montelaro
Keyword(s):  
Immune Suppression ◽  
Neutralizing Antibodies ◽  
Equine Infectious Anemia Virus ◽  
Antibody Responses ◽  
Serum Antibodies ◽  
Virus Envelope ◽  
Specific Serum ◽  
Surface Envelope ◽  
Equine Infectious Anemia ◽  
Anemia Virus

It has been previously reported that transient corticosteroid immune suppression of ponies experimentally infected with a highly neutralization resistant envelope variant of equine infectious anemia virus (EIAV), designated EIAVΔPND, resulted in the appearance of type-specific serum antibodies to the infecting EIAVΔPND virus. The current study was designed to determine if this induction of serum neutralizing antibodies was associated with changes in the specificity of envelope determinants targeted by serum antibodies or caused by changes in the nature of the antibodies targeted to previously defined surface envelope gp90 V3 and V4 neutralization determinants. To address this question, the envelope determinants of neutralization by post-immune suppression serum were mapped. The results demonstrated that the neutralization sensitivity to post-immune suppression serum antibodies mapped specifically to the surface envelope gp90 V3 and V4 domains, individually or in combination. Thus, these data indicate that the development of serum neutralizing antibodies to the resistant EIAVΔPND was due to an enhancement of host antibody responses caused by transient immune suppression and the associated increase in virus replication.

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