Echinococcus muftilocularis infection in red foxes in Italy

M. T. Manfredi, DVM, C. Genchi, DVM, Dipartimento di Patologia Animale, Igiene e Sanita Pubblica Veterinaria, Sezione di Patologia Generale e Parassitologia, Universita degli Studi di Milano, Facolta di Medicina Veterinaria, via Celoria 10, 20133 Milan, Italy P. Deplazes, DVM, Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057 Zurich, Switzerland K. Trevisiol, DVM, Istituto Zooprofilattico Sperimentale, via Bisio 59, 39100 Bolzano, Italy C. Fraquelli, DVM, Istituto Zooprofilattico Sperimentale, via Lavisotto 129, 38100 Trento, Italy Echinococcus multilocularis is a cestode of the red fox (Vulpes vulpes) which involves rodents as its intermediate hosts. Human beings can acquire infection orally, for example, by eating food contaminated with infective eggs, or via contaminated hands. The larvae (metacestodes) then proliferate in a tumour-like manner, mostly in the liver. Alveolar echinococcosis is rare, but is considered to be one of the most lethal helminthic zoonoses if not treated adequately (Auer and Aspock 1990, Lucius and Bilger 1995). Central Europe has been known as an endemic area of alveolar echinococcosis for many years, with the highest incidence rates being reported in Switzerland, Germany and some areas of France (Eckert 1997, Eckert and Deplazes 1999). The prevalence of infection in foxes shows a wide variability between countries and in endemic areas, ranging from below 1 per cent to more than 60 per cent (Eckert and Deplazes 1999). A high prevalence and abundance were also found in foxes sampled in the rural area of the municipality of Zurich (Hofer and others 2000). Recent European surveys have shown that E multilocularis is far more widespread than previously thought, but these data are not necessarily proof of an increased spread of the parasite (Romig and others 1999). People are at risk of infection in all areas where the cestode occurs in foxes, as they are responsible for contaminating the environment with infective eggs. Cats and dogs are also considered to be a possible source of infection for human beings, although the prevalence in these hosts is lower than in foxes (Lucius and Bilger 1995, Eckert 1997, Eckert and Deplazes 1999, Petavy and others 2000). Although Italian alpine regions border European countries where E multilocularis is widespread (that is, lower Austria, Switzerland and eastern France), the parasite has not been found in previous surveys of gastrointestinal parasites in foxes sampled from Italy (Rossi and others 1983, Iori and others 1990, Manfredi and others 1998, Stancampiano and others 1998). Over the past 10 years, however, there has been an increase in the fox population, possibly due to the success of rabies control programmes in Europe (Schott and Muller 1989). This may have facilitated the movement of a larger number of foxes from the north of the alpine regions towards the south. This short communication describes the first report of E multilocularis in Italy. In a recent survey, 360 foxes from the provinces of Trento and Bozen in Trentino-Alto Adige, north-east Italy, were examined for E multilocularis from September 1997 to September 2000. Most of the foxes were shot as part of the official local population control programme. A faecal sample was collected from each fox and analysed by ELISA (CHEKITEchinotest; Bommeli Diagnostic) to detect tapeworm coproantigens. Positive or ambiguous ELISA results were confirmed by parasitological examination of the intestine using the sedimentation technique (Deplazes and Eckert 1996, Deplazes and others 1999). Of the 360 faecal samples taken, 23 were coproantigen positive and 13 had an ambiguous ELISA result. E multilocularis specimens (>100 worms) were found in the intestine of two foxes which were positive by coproantigen assay. E multilocularis was identified by analysis of the morphological and morphometric features (Petavy and others 1997). It is a small cestode, ranging in length from 1-3 to 2-5 mm, and possesses up to five proglottids. There are 23 to 28 rostellar hooks and the gravid proglottid has the genital pore anterior to the midline. The uterus is saclike without lateral branches, with cestode eggs concentrated behind the cirrus pouch. Tapeworm infections, for example with Taenia species, dipylidids or Mesocestoides species, were found in 14 ELISA-positive foxes. The infected foxes were from two localities ofVal Pusteria: Kohler Pichl, Gsies, 1250 m above sea level, and Golsev, Prags, 1300 m above sea level, in the province of Bozen close to southern Austria, where the highest prevalence of human alveolar echinococcosis has been recorded (Auer and Aspock 1990). It is possible that the cestode has been introduced into Italy as a consequence of foxes moving between bordering countries. Furthermore, the increase in the fox population is likely to be responsible for the extension of the parasite further south. In the study area, an increase in the fox population has been confirmed by the number of foxes shot during population control schemes. For instance, in the province of Bozen, nearly 2000 foxes are regularly shot in the annual population control programme. Moreover, it is likely that this area of Italy represents part of the central European range of E multilocularis because of the climate, the geological characteristics and the availability of the intermediate hosts that support the parasite life cycle (Lucius and Bilger 1995, Veit and others 1995). To the authors' knowledge, this is the first report of E multilocularis in Italy.