Of the 37 confirmed cases of LF infection by RT-PCR; 21 (57) were IgM positive. Amongst the 35 confirmed negative cases (control group); eight were IgM positive. The diagnostic sensitivity and specificity of the IgM assay were 57 and 77 respectively. The negative and positive predictive values of the IgM serological assay were 63 and 72 ; respectively; while the efficiency of the test was 67.
Conclusion:
The specificity and sensitivity of IgM as a screening tool for early detection of LF appear weak and; hence; the need for a reliable LF ""rapid screening kit"" since RT-PCR is unavailable in most centers. In the interim; ""high clinical index of suspicion;"" irrespective of IgM status; requires urgent referral to confirmatory centers."