The Journal of Medical Microbiology, Vol 29, Issue 3 195-198, Copyright © 1989 by Society for General Microbiology
A simple adherence test for detection of IgM antibodies in typhoid
L. Y. Ong, T. Pang, S. H. Lim, E. L. Tan and S. D. Puthucheary
Department of Genetics and Cellular Biology, University of Malaya, Kuala Lumpur.
A simple adherence test to detect IgM antibodies in patients with typhoid
is described. The test utilises the IgM-"capture" approach, in which the
test serum is applied to microtitration plate wells previously coated with
anti-human IgM, followed by application of a stained Salmonella typhi
antigen suspension which shows adherence in positive cases. By this test,
58 (95%) of 61 sera from confirmed cases of typhoid possessed IgM
antibodies to the H or O or both antigens of S. typhi. In patients for whom
a diagnosis of typhoid was based only on a significant Widal-test titre, 31
(41%) of 76 sera had IgM antibodies to the H or O or both antigens of S.
typhi. Some cross-reactivity of the IgM antibodies was detected, especially
with the O antigens of S. paratyphi A and B. A total of 82 sera from
non-typhoidal fevers (leptospirosis, typhus, dengue fever) showed no
reactivity in this test. In normal sera there was no detectable IgM to the
O antigen of S. typhi and only a small number (3.9%) had low levels of IgM
to the H antigen. The significance and potential importance of this simple,
sensitive, specific and economical test is discussed.
