The seroepidemiology of Cryptosporidium species in different population groups in Spain

Abstract Cryptosporidium species induce an immune response in the host despite the fact that the life cycle of the parasite occurs within an extracytoplasmic vacuole of the enterocyte. Antibodies against Cryptosporidium species were determined by indirect immunofluorescence in 116 randomly chosen healthy children and adults, 12 patients with cryptosporidiosis and 75 parenteral drug abusers with antibodies against human immunodeficiency virus (HIV). The prevalence of IgG in the randomly chosen population was 6.9%. This seropositivity was higher in subjects from rural settings and in children. IgM were detected in a healthy child from a rural area and in four patients, also IgG-positive, with cryptosporidiosis. No specific antibodies were detected in six patients parasitized with a low excretion of oocysts in faeces, nor in the anti-HIV positive parenteral drug abuser group.