New approaches for post-vaccination surveillance of foot-and-mouth disease.

Foot-and-mouth disease (FMD) is a contagious and important transboundary disease of cloven-hoofed animals and ruminants. In ruminants, an animal is considered as a foot-and-mouth disease virus (FMDV) carrier if a live FMDV/FMDV RNA is obtained from the oro-pharyngeal fluid (OPF) beyond 28 days after infection. These carrier animals may pose a risk for causing outbreaks in healthy animals. Moreover, it is important to conduct serosurveillance to know the virus circulation. In the present study, an ELISA was developed using field samples to detect FMDV specific secretory IgA antibodies. These samples were also tested for the presence of FMDV RNA using quantitative real-time PCR (qRT-PCR). It was found that more carrier animals were detected by IgA ELISA in comparison to qRT-PCR. Thus, IgA ELISA is an important tool to detect FMD carriers. An ELISA based on detection of antibodies against FMDV 2B non-structural protein (NSP) was also used to confirm the results obtained from screening of 3AB3 NSP ELISA. These two new approaches (IgA ELISA and 2B ELISA) form important tools for detection of carriers and virus circulation, respectively, during FMD eradication program. Keywords: foot-and-mouth disease virus; carriers; IgA; 2B non-structural protein; 3AB3 non-structural protein.

A Web-based approach to blood donor preparation.

BACKGROUND: Written and video approaches to donor education have been shown to enhance donation attitudes and intentions to give blood, particularly when the information provides specific coping suggestions for donation-related concerns. This study extends this work by comparing Web-based approaches to donor preparation among donors and nondonors. STUDY DESIGN AND METHODS: Young adults (62% female; mean [±SD] age, 19.3 [±1.5] years; mean [range] number of prior blood donations, 1.1 [0-26]; 60% nondonors) were randomly assigned to view 1) a study Web site designed to address common blood donor concerns and suggest specific coping strategies (n = 238), 2) a standard blood center Web site (n = 233), or 3) a control Web site where participants viewed videos of their choice (n = 202). Measures of donation attitude, anxiety, confidence, intention, anticipated regret, and moral norm were completed before and after the intervention. RESULTS: Among nondonors, the study Web site produced greater changes in donation attitude, confidence, intention, and anticipated regret relative to both the standard and the control Web sites, but only differed significantly from the control Web site for moral norm and anxiety. Among donors, the study Web site produced greater changes in donation confidence and anticipated regret relative to both the standard and the control Web sites, but only differed significantly from the control Web site for donation attitude, anxiety, intention, and moral norm. CONCLUSION: Web-based donor preparation materials may provide a cost-effective way to enhance donation intentions and encourage donation behavior.

An adapted postdonation motivational interview enhances blood donor retention.

BACKGROUND: Blood donors may hold conflicting thoughts about future donation. While they may perceive the direct benefit to themselves and others, they often report compelling reasons not to give again. As a result the standard encouragements to return may not be sufficient to motivate some donors. This study examined the effects of a postdonation adapted motivational interview (AMI) on blood donor attitudes and repeat donation behavior. STUDY DESIGN AND METHODS: Donors (n = 215) were randomly assigned to either an AMI or a no-interview control group. Approximately 1 month after their index donation, donors in the AMI group completed a brief telephone interview to clarify individual-specific motivations and values concerning blood donation and address potential barriers. They were then asked to complete questionnaires regarding donation attitudes, anxiety, self-efficacy, and intention to donate. Donors in the control group were also contacted 1 month after donation and asked to complete the same series of questionnaires. RESULTS: Donors in the AMI group reported greater intention to provide a future donation (F = 8.13, p < 0.05), more positive donation attitudes (F = 4.59, p < 0.05), and greater confidence in their ability to avoid adverse reactions (F = 10.26, p < 0.01). Further, AMI was associated with higher rates of attempted donation at 12 months (odds ratio, 2.48; 95% confidence interval, 1.27-4.87). CONCLUSION: Application of an AMI may be an effective strategy to increase the donor pool by enhancing retention of existing donors.

Evaluation of immune response to bovine rotavirus following oral and intraperitoneal inoculation in mice.

With a view to use mice as an experimental model for studying immune response to bovine rotavirus (BRV), the kinetics of humoral and cellular immune responses to BRV in mice were evaluated by immunizing through intraperitoneal and oral route with UK strain of BRV. Following immunization with BRV, anti-rotavirus antibodies was developed in mice. The mean log antibody titres as measured by ELISA in mice immunized by intraperitoneal route were significantly higher than those immunized by oral route. Significant cellular immune response was observed in BRV-immunized mice on stimulation with BRV antigen, as measured by lymphocyte proliferation assay. The thymidine uptake by splenic and mesenteric lymph-node cells of intraperitoneally immunized mice on stimulation with BRV was 21328 +/- 1225 and 739 +/- 55 CPM, respectively. The splenic cells showed significantly higher stimulation (stimulation index 12.98) as compared to those of mesenteric cells (stimulation index 1.57). Foot pad inoculation test showed maximum virus-specific delayed type hypersensitivity reaction at 24 hr post-challenge following primary immunization and at 18 hr post-challenge following secondary immunization. The results indicate that BRV immunization by intraperitoneal route generates more efficient immune response in mice than by oral route and this route may be used for immune response studies involving BRV infection.

Kinetics of humoral immune response in pigs vaccinated against foot and mouth disease.

The present investigation was conducted to study the foot and mouth disease virus (FMDV)-specific humoral immune response (HIR) in pigs, following vaccination with oil adjuvanted foot and mouth disease (FMD) vaccine, upto 90 days post vaccination (dpv). For this, 40 Large White Yorkshire (LWY) pigs (20; one-year old female (gilts) and 20; three-month old piglets) were vaccinated @ 2 ml/animal, subcutaneously. Sera samples were collected at fortnight interval from all the animals. The log10 SN50 antibody titres against all the serotypes (Type O, A and Asia-1) were detected in both gilts and piglets from day 7 to 90 dpv indicating the persistence of HIR up to the last day of sampling. The maximum antibody titres were observed on 28 dpv, thereafter, titres started declining, but were present till 90 dpv against all the three FMDV serotypes. HIR was more pronounced in piglets in comparison to gilts, as group mean SN antibody titres against all the three FMDV serotypes were found to be more maintained and significantly higher in piglets.

Macrophage modifying factor secreted by the tetrathyridia of Mesocestoides corti (Cestoda): monoclonal antibody to the modifying factor antagonizes its immunological activity.

Immunomodulation of macrophage activity by in vitro secretions of Mesocestoides corti has been previously demonstrated. The modifying activity secreted by M. corti had the effect of reducing the normal accessory function of macrophages in a Con-A-activated lymphocyte proliferation assay. This paper describes the purification of the modifying activity by FPLC techniques and the generation of a monoclonal antibody (MoAb) to this molecule in mice. The MoAb bound immunomodulatory FPLC fractions of M. corti in an ELISA. When MoAb was applied in conjunction with immunomodulatory parasite secretions to macrophages in vivo or in vitro, the modifying effect of the secretions was abolished. This profound effect of the MoAb should help to elucidate the mechanisms by which metacestode parasites avoid host immune responses and may enable therapeutic intervention.

Modification of macrophage -T cell interaction during infection of mice with Mesocestoides corti (Cestoda).

Peritoneal macrophages from Mesocestoides corti-infected mice showed a marked and progressive loss of ability to act as accessory cells for syngeneic Con A-stimulated mesenteric lymph node lymphocytes. The same effect on the macrophages could be induced by intraperitoneal injection of M. corti culture supernatant, despite a concurrent increase in numbers of peritoneal adhesive macrophages. The findings are used to compare and contrast the known immunomodulatory effects of M. corti and taeniid metacestodes, the latter differing chiefly in their potential for modifying T-cell as well as macrophage behaviour.

Effect of aflatoxin B1 on the delayed type hypersensitivity and phagocytic activity of reticuloendothelial system in chickens.

Efforts were made to see the effect of feeding aflatoxin B1 at 0.3 ppm level on various aspects of the immune system in chickens. The birds were fed aflatoxin B1 (AFB1) mixed ration from 0 to 6 weeks of age and thereafter normal feed was given up to 12 weeks of age. The delayed type hypersensitivity reaction of these birds was assessed by contact sensitivity to Dinitrofluorobenzene. The dietary AFB1 significantly suppressed the cell mediated immune response at all the three periods tested (30, 45 and 60 days of age). The toxin showed residual effect on immunity as the suppression of cell mediated immunity was maximum three days after the withdrawal of toxin from the feed. The effect of AFB1 on the phagocytic status of reticulo endothelial system (RES) was assessed by colloidal carbon clearance test at various intervals. The residual effect of toxin was observed on RES too as phagocytic index of AFB1 fed birds was significantly lowered up to 45 days of age.