Table 4. Proportion of suspected patients tested with evidence of IgM antibodies against Chikungunya virus in serum by days since illness onset, Char Kushai, Bangladesh 2011, N = 245.

Days since illness onset	No. and proportion positive
<7	1 (9)
7–15	16 (64)
15–30	33 (72)
30–60	63 (93)
>60	83 (87)
Total	196 (80)