RESUMO
Since 1975, increasing numbers of patients with inflammatory, migrant, recidivant nodules were observed in the towns of Temazcal, state of Oaxaca, Tierra Blanca, Veracruz and others along the Papaloapan river. Larvae of Gnathostoma sp. have been obtained from some of them. The local species, although not completely identified, must be very close to G. spinigerum. Infection is related to ingestion of "ceviche", a very popular mexican delicacy made with raw Cyclid fishes of the Miguel Aleman dam. Ecological and social changes provoked by the construction of the dam and hypotheticaly related to the dissemination of the parasite are described. As the Temazcal Fish Culture Center has delivered tilapia fishes to many secondary culture centers, it is feared that the infection could spread through the country, so signs and symptoms of the disease are described in order to help Mexican doctors make the diagnosis if they were to encounter the disease.
