A study of 94 slugs, collected from urban and rural areas in and around Léon, Nicaragua, was carried out in order to confirm the role of Vaginulus plebeius as an intermediate host of Angios trongylus costaricensis. Third-stage larvae of A . costaricensis were obtained from these molluscs. Some of these larvae were then orally inoculated into two laboratory-bred rats Sigmodon hispidus and adult worms of A . costaricensis were recovered two months later. The infection rate of these slugs ranged from 4 % in urban areas to 85 % in rural areas. These data suggest that contamina tion to man is a major risk especially in rural areas and that abdominal angiostrongyliasis could be a health problem in Nica ragua. Résumé : Infection naturelle par Angiostrongylus costaricensis chezQuatre-vingt-quatorze limaces collectées dans des zones urbaines et rurales de la province de Léon, ont été soumises à un processus de digestion artificielle. Des larves du troisième stade ont été iso lées. Des rats du coton, Sigmodon hispidus, élevés au laboratoire, ont été infestés par voie orale à l'aide de ces larves. Les rongeurs ont été autopsiés deux mois après l'infestation et de nombreux vers adultes ont été retrouvés dans les artères mésentériques. LesVaginulus plebeius au Nicaragua.parasites ont été identifiés à Angiostrongylus costaricensis. Le taux d 'infestation chez les limaces était de 4 % en zone urbaine à 85 % en zone rurale. Cette prévalence montre que la population rurale est très exposée à la contamination, ce qui permet de penser que l'angiostrongylose abdominale peut constituer un problème méconnu de santé publique au Nicaragua.

A retrospective study was done to determine the presence of abdominal angiostrongyliasis in Nicaragua. Twelve cases of this parasitic disease were found among 48 visceral specimens: small intestine, liver and testes. The patients with intestinal lesions pre sented symptoms of an acute abdomen, and in some instances, a tumor-like mass was palpated in the lower right quadrant. A thickening of the intestinal wall accompanied by necrosis and per foration were the most important macroscopic findings. One patient with hepatic localisation of Angiostrongylus costaricencis displayed a clinical picture of visceral larva migrans-like syndrome. The chief laboratory findings were leukocytosis and eosinophilia. The histopathological examination showed granulomas and heavy eosino philic infiltration around the eggs and larvae of A. costaricencis. Also, an adult worm was seen in one biopsy.