Figure 2. Interval between consecutive DENV infections according to inapparent or symptomatic outcome as determined by total antibody titer.

The mean interval was calculated for all consecutive DENV infections (A) and stratified considering infection number into first-to-second sequences (B) and other (not first-to-second) infection (C). The inapparent-to-inapparent interval is shorter than inapparent-to-symptomatic (A) but only for first-to-second sequences (B). Error bars represent the standard error of the mean. * Mann–Whitney U test, p<0.05.