Determination of baseline Widal titre in healthy individuals in Karbala city, South of Iraq

Abstract

Objective To determine the cutoff of antibodies directed against Salmonella enterica subspecies enterica serotype typhi, paratyphi A, and
paratyphi B in normal population in Karbala city, south Iraq.
Methods Widal test was performed for 90 serially diluted serum samples collected from apparently healthy volunteers. A commercial Widal
test kit was used. Agglutination results were observed within 1 minute.
Results In the current study, 23.33%, 22.22%, 6.6%, 4.4%, 38.88% and 5.55% of individuals had antibody titre ≥1:20 for S. enterica subspecies
enterica serotype typhi O, H, S. enterica serotype paratyphi AO, AH, S. enterica serotype paratyphi BO and BH, respectively.
Conclusion Based on these results, antibody titres of 1:160 for O and H, 1:40 for AO, 1:80 for AH and BH and 1:320 for BO antigens were
considered as baseline titre in Karbala.