Flowchart of recruitment of study participants and sample testing.

<p>Study participants were split into two groups, those who returned to the convalescent visit (left side of the flowchart) and those who were lost at follow-up (right side of the flow chart). The left side of the flow chart demonstrates that out of 400 recruited patients, 209 returned for the follow-up visit and their convalescent samples were initially screened for anti-CHIKV IgG. Out of 208 tested samples, 55 (26.4%) were positive and 153 (75.6%) were negative. Further, the corresponding 55 acute samples of the positive samples were screened for anti-CHIKV IgG. A total of 44 (21.2%) were positive with stationary titers, 3 (1.4%) were positive with four fold titer rise and 6 (2.9%) seroconverted. The right side of the flow chart demonstrates that 191 individuals did not return for their follow-up; 156 acute samples were available for testing and of these 38 (24.4%) and 118 (75.6%) were positive and negative, respectively. * Percentage against the total number of patients who returned to convalescent visit. ** Samples not tested because of insufficient volume