A study on parasites in Mexican rheumatic disease patients.

Blastocystis hominis is a common human parasite with infection rates up to 50% in developing countries, and giardiasis is the commonest intestinal one in Mexico. No doubt, various parasites as Giardia lamblia and Entamoeba histolytica can cause rheumatic diseases. This study coproparasitoscopic analysis evaluated the cysts by B. hominis, G. lamblia, E. hartmani, E. coli and E. histolytica in Mexican rheumatic disease patients. Also, ELISA was used to detect E. histolytica, Ascaris lumbricoides, Toxocara canis, and Trichinella spiralis in Mexican patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Thirty-six patients (24 with AS and 12 with RA) and 77 healthy control individuals were enrolled in this study. The frequencies of protozoan cysts were comparable in rheumatic disease patients (AS and RA) and healthy control donors (33 and 25 vs. 26%, respectively; p > 0.05). The frequency of antibodies to T. canis was significantly higher in AS patients than in healthy control donors (16 vs. 2.6%, respectively; p = 0.027), whereas no differences were observed for the prevalence of antibodies for the other parasites (E. histolytica, A. lumbricoides and T. spiralis) (p > 0.05). This information indicates the need to intensify educational efforts for the prevention of parasite infections associated with AS disease that cannot be controlled only by drugs.