Figure 4. Correlations in serum responses between rK28 and the individual component proteins rK39, rK26 and rK9 on testing with Sudanese VL patient sera.

Correlation coefficients were calculated using ELISA results of sera from 62 individuals with confirmed VL. A: Comparison of antibody levels (OD) against rK28 and rK39, B: Comparison of antibody levels (OD) against rK28 and rK26, C: Comparison of antibody levels (OD) against rK28 and rK9. Sudanese VL patients with extremely low rK39 antibody titers demonstrate much higher titers against rK28 as demonstrated by a strong and statistically significant positive correlation on the Spearman test (r = 0.8383, p<.0001).