MI044 - WIDAL SLIDE AGGLUTINATION, SERUM Detail

The Widal Slide Agglutination Test is a rapid serological test used for the qualitative detection of antibodies against Salmonella Typhi and Salmonella Paratyphi in human serum for the diagnosis of enteric (typhoid) fever. The test is based on the antigen–antibody reaction in which a drop of patient serum is mixed with standardized O and H antigen suspensions on a glass slide; if specific antibodies are present, visible agglutination (clumping) occurs within a short time. The antigens commonly tested include S. Typhi O (TO), S. Typhi H (TH), S. Paratyphi A (AH), and S. Paratyphi B (BH). A positive slide test indicates the presence of corresponding antibodies, and significant results should be confirmed by the tube agglutination method for titre determination. Interpretation must be correlated with clinical findings and local baseline titres, especially in endemic areas.