Low risk of invasive amebiasis in cyst carriers. A longitudinal molecular seroepidemiological study
Ruiz-Palacios, G.M.; Castañon, G.; Bojalil, R.; Tercero, E.; Rausser, S.; Herbert, L.; Agabian, N.; Martínez-Palomo, A.
Archives of Medical Research 23(2): 289-291
1992
ISSN/ISBN: 0188-4409 PMID: 1340317 Document Number: 391212
The risk of chronic asymptomatic cyst carriers of Entamoeba histolytica developing the invasive disease was investigated. Zymodeme patterns of strains, isolated from these patients, were correlated both with clinical disease and the serological response to the M-17 amoeba antigen. Of 48 chronic cyst carriers studied, antibodies to crude E. histolytica antigen were detected by ELISA in 16 (31%) and antibodies to the M-17 fusion protein were found in 8 (16%) and 2 (4%) by ELISA and Western blot, respectively. In contrast, all 16 patients with amoebic liver abscess had high antibody levels to the M-17 fusion protein. Asymptomatic carriers appear to be infected with non-virulent strains of E. histolytica, and none developed illness or an immune response to epitopes of a surface antigen of E. histolytica.