Fig. 1.

Prospective study. ELISA IgM results in acute and convalescent sampling for Puumala virus (PUUV) in eight cases of seroconfirmed (ELISA IgM positive) leptospirosis; and one leptospirosis-negative case (case 7). Results are expressed as Q values (observed OD/control cut-off OD), where Q values ⩾2 (- - - -) are considered as positives. Case 1 (red line) remained just under the positivity level, whereas case 2 (■) and case 5 (*) remained PUUV-negative. Five other cases are clearly PUUV-positive in at least one sampling.