Differences in capabilities of different enzyme immunoassays to detect anti-hepatitis E virus immunoglobulin G in pigs infected experimentally with hepatitis E virus genotype 3 or 4 and in pigs with unknown exposure.

Hepatitis E virus (HEV), a major cause of acute viral hepatitis in humans in many developing countries, is highly prevalent in the pig population worldwide. The objective of this study was to assess the capability of three porcine prototypes of a human enzyme-linked immunosorbent assay (ELISA), an in-house ELISA and a line-immunoassay (LIA) to detect anti-HEV antibodies in pigs infected experimentally with HEV (n = 57), known to be negative for HEV infection (n = 27), or with unknown exposure to HEV infection (field samples, n = 90). All 27 samples from non-infected pigs were negative with all five assays. The earliest detection of anti-HEV antibodies occurred at 14 days post-inoculation (dpi) with four of five assays. From 42 dpi, all samples from infected pigs were detected correctly as anti-HEV positive. Kappa analysis demonstrated substantial agreement among tests (0.62-1.00) at 14 dpi and complete agreement (1.00) at 56 dpi. The overall area under the curve for all quantitative tests as determined by receiver operator characteristic analysis ranged from 0.794 to 0.831 indicating moderate accuracy. The results showed that all five assays can detect anti-HEV IgG antibodies accurately in pigs infected experimentally with HEV. In field samples, a higher prevalence of anti-HEV IgG was found in breeding herds than in growing pigs (100% versus 66.7-93.9%). These serological assays should be very useful in veterinary diagnostic labs for HEV diagnosis in swine.

Comparison of biofeedback and relaxation in the treatment of pediatric headache and the influence of parent involvement on outcome.

The relative efficacy of EMG-frontalis feedback and progressive relaxation was examined in children with tension-type or combined headaches (8-14 yrs. old). Furthermore, the influence of parent involvement, in the form of a three-session educational approach, on training outcome was systematically explored (2 x 2 factor design). Fifty children took part in the study, 40 were randomly assigned to the four different treatment conditions, 10 children participated in the self-monitoring control group. The training comprised 6 sessions of 1 hr each in the relaxation treatment and 12 sessions of 1/2 hr duration in the biofeedback group. Headache diaries were kept by children and parents for 4-week period prior to therapy, and for a similar length of time at post-treatment and follow-up (6 months). Multivariate analyses of variance on the headache diary data yield no significant main or interaction effects of treatment format or of parent involvement, but only a main effect of period, indicating a general efficacy of the four treatment conditions. At follow-up the reduction of headache activity is even more prominent. A different evaluative approach points to the superiority of biofeedback revealing a mean effect size for biofeedback training that reflects a good to excellent improvement rate. Correlations between headache data from children and parents are high.