Transfusion of hyperimmune plasma for protecting foals against Rhodococcus equi pneumonia.

The bacterium Rhodococcus equi causes pneumonia in foals that is prevalent at breeding farms worldwide. In the absence of an effective vaccine, transfusion of commercial plasma from donor horses hyperimmunised against R. equi is used by many farms to reduce the incidence of pneumonia among foals at farms where the disease is endemic. The effectiveness of hyperimmune plasma for controlling R. equi pneumonia in foals has varied considerably among reports. The purposes of this narrative review are: (1) to review early studies that provided a foundational basis for the practice of transfusion of hyperimmune plasma that is widespread in the United States and in many other countries; (2) to summarise current knowledge of hyperimmune plasma for preventing R. equi pneumonia; (3) to provide an interpretive summary of probable explanations for the variable results among studies evaluating the effectiveness of transfusion of hyperimmune plasma for reducing the incidence of R. equi pneumonia; (4) to review mechanisms by which hyperimmune plasma might mediate protection; and (5) to consider risks of transfusing foals with hyperimmune plasma. Although the weight of evidence supports the practice of transfusing foals with hyperimmune plasma to prevent R. equi pneumonia, many important gaps in our knowledge of this topic remain including the volume/dose of hyperimmune plasma to be transfused, the timing(s) of transfusion, and the mechanism(s) by which hyperimmune plasma mediates protection. Transfusing foals with hyperimmune plasma is expensive, labour-intensive, and carries risks for foals; therefore, alternative approaches for passive and active immunisation to prevent R. equi pneumonia are greatly needed.

Development, application, and validation of a survey for infectious disease control practices at equine boarding facilities.

OBJECTIVE: To develop a questionnaire for self-assessment of biosecurity practices at equine boarding facilities and to evaluate infectious disease control practices in these facilities in Colorado. DESIGN: Cross-sectional study. SAMPLE POPULATION: 64 equine boarding facilities in Colorado. PROCEDURES: Survey questions were rated according to importance for prevention and containment of equine infectious diseases. Point values (range, 0 to 20) were assigned for possible responses, with greater values given for optimal infection control methods. Questionnaires were mailed to equine boarding facilities in Colorado advertised on the World Wide Web. Survey responses were compared with assessments made by a member of the research team during visits to 30 randomly selected facilities. Agreement among results was analyzed via a kappa test and rated as poor, fair, moderate, substantial, or nearly perfect. RESULTS: Survey responses were received for 64 of 163 (39%) equine boarding facilities. Scores ranged from 106 to 402 points (maximum possible score, 418). Most facilities received better scores for movement and housing of equids than for other sections of the survey. Respondents at 24 of 48 (50%) facilities that routinely received new equids reported isolation of new arrivals. Agreement between self-assessment by survey respondents and evaluation by a member of the research team was determined to be fair to substantial. CONCLUSIONS AND CLINICAL RELEVANCE: Most equine boarding facilities have opportunities to improve measures for prevention or containment of contagious diseases (eg, isolation of newly arrived equids and use of written health management protocols). Most self-assessments of infection control practices were accurate.