Anisakidae: two different findings in a tertiary-care hospital in Italy during 2013

Objectives. The aim of this study wasto describe the detection of the larval stage of Anisakidae, rarely encountered in our setting.Human anisakiasis caused by nematodes of the species Anisakis simplex and Pseudoterranova decipiens is due to thepresence of larvae in advanced stage of maturation in the wall of the stomachor intestine and occasionally in the abdominal cavity or the extraintestinal sites.The transmission to humans is mediated by the recruitment of marine fish (salmon,cod, herring, and mackerel for Anisakis spp., and cod, haddock, pollock, andhalibut for Pseudoterranova) orcephalopods uncooked or undercooked containing the third-stage larvae (L3) ofthe parasite. In Italy the reported cases are rare,mainly concerning immigrants; the small number of cases is the result of the effectivepublic health control of fish and the not widespread habit of consumption of uncookedfish in our country. In this study we report 2 cases of finding of larvae of Anisakidae, observed both in2013, ina tertiary-care hospital in which laboratoryof clinical parasitology is included since 1992 neverreporting such observation. Methods. In the first case, a nematode was foundin a fish ready to eat subjected first to freezing and then cooked. In thesecond case the viable larva was found in the oral cavity of a patient whoreported a recent meal with uncooked fish. Results. The larva of the first case was of a reddishcolor, with a size of 35 mmlong by 1.5 mmin width. The larva of the second case appeared pink -white, with a size ofabout 18 mmx 1.5 mm.For each larva three prominent lips at the proximal end and an outer cuticlewith a streak were observed. These features allowed to identify in the first casea nematode L3 larva of Pseudoterranovadecipiens and in the second one as a L3 larva of Anisakis simplex. Conclusions. These dataare of interest because the finding of larval stages of Anisakidae in our country is a relatively recent phenomenon and itassumes a particular importance being the habit of eating uncooked marine fish,previously widespread in other countries, increasedalso in Italy. These findings also suggest the thatphysicians and parasitologists should be prepared to face such a diagnosticchallenge in order to detect such parasites.