FIG. 1.

OD/CO ratios of each serum or DSS sample are plotted, according to storage condition. The mean value of OD/CO ratios is shown for each condition. (a) The protocol used for detection of HAVM from DSS did not modify the input of serum in ELISA plates for this capture immunoassay; thus, mean OD/CO ratios of DSS and matched sera are not significantly different, whatever the storage condition. (b) The modified protocol used for HAVT detection from DSS samples implied the addition of a lower volume of neutralizing solution in this competitive ELISA (negative samples have OD values greater than the CO). This adaptation resulted in the OD/CO ratios for negative DSS being significantly lower than those for negative sera. However, OD values for positive and negative DSS samples are clearly separated from the CO, as further assessed by calculation of the delta values. Abbreviations: D, day; M, month; RT, room temperature.