SHORT COMMUNICATION A rat model of intragastric infection with Anisakis spp. live larvae: histopathological study Jaime Zuloaga & Cruz Rodríguez-Bobada & María Teresa Corcuera & Fernando Gómez-Aguado & Pablo González & Rosa Rodríguez-Perez & Javier Arias-Díaz & María Luisa Caballero Received: 17 January 2013 / Accepted: 15 February 2013 / Published online: 23 February 2013 # Springer-Verlag Berlin Heidelberg 2013 Abstract Anisakiasis is a fish-borne parasitic disease caused by consumption of raw or undercooked fish or cephalopods parasited by Anisakis spp. third stage larvae. The pathological effects of the infection are the combined result of the mechanical action of the larva during tissue invasion, the direct tissue effects of the excretory/secretory products released by the parasite, and the complex interac- tion between the host immune system and the Anisakis antigens. The aim of this study was to develop an experi- mental model of infection with Anisakis spp. live larvae in rats, useful to study the acute and chronic histopathological effects of the Anisakis infection. Sprague–Dawley rats were subjected to esophageal catheterization to place larvae di- rectly into the stomach. Reinfections at different intervals after the first infection were preformed. Live larvae were found anchored to the mucosa and passing through the wall of the stomach and showed a strong resistance being able to stay alive at different sites and at the different pH. Migration of larvae from the stomach to other organs out of the gastrointestinal tract was also observed. The histopatholog- ical study showed the acute inflammatory reaction, with predominance of polymorphonuclear eosinophils and a mild fibrotic reaction. The model of infection described is valid to study the behavior of the larvae inside the host body, the histopathological changes at the invasion site, and the ef- fects of the repeated infections by ingestion of live larvae. Anisakiasis is a fish-borne parasitic disease caused by con- sumption of raw or undercooked fish or cephalopods parasited by Anisakis spp. third stage larvae (Klimpel et al. 2004). Symptoms of acute gastric infection include sudden epigastric pain, nausea, and vomiting, and can occur 1–12 h after the infected meal. Anisakiasis is often associated with a strong allergic response, with clinical symptoms ranging from isolated swellings to urticaria, angioedema, and life- threating anaphylactic shock (Audicana et al. 1996; Del Pozo et al. 1997). Anisakiasis is classified into three categories according to the location of the lesions: gastric, intestinal, and heterolo- gous or ectopic (extragastrointestinal location of larvae) (Ishikura et al. 1993). The pathological changes occurring during infection with Anisakis simplex are the combined result of the mechanical action of the larva during tissue invasion, the direct tissue effects of the excretory/secretory products released by the parasite, and the complex interac- tion between the host immune system and the Anisakis antigens (Audicana and Kennedy 2008). A technique for induction of an oral infection with Anisakis spp. larvae in mice was previously described (Figueiredo et al. 2012), and studies of experimental anisakiasis have been reported based on describing the serological response of the host (Campos et al. 2004; Cho J. Zuloaga : J. Arias-Díaz Department of Surgery, Universidad Complutense - Hospital Clínico San Carlos, Madrid, Spain C. Rodríguez-Bobada : P. González Experimental Medicine and Department of Surgery, Hospital Clínico San Carlos, Madrid, Spain M. T. Corcuera : F. Gómez-Aguado Department of Pathology, Hospital Carlos III, Madrid, Spain R. Rodríguez-Perez : M. L. Caballero (*) Department of Immunology, Hospital Carlos III, Sinesio Delgado, 10, 28029 Madrid, Spain e-mail: mlcsoto@hotmail.com Parasitol Res (2013) 112:2409–2411 DOI 10.1007/s00436-013-3359-6