title: Evidence for an increasing presence of Echinococcus multilocularis in foxes in The Netherlands.
abstract: Echinococcus multilocularis, a tapeworm causing alveolar echinococcosis which is considered a serious zoonosis known to affect humans, appears to be expanding its geographical range in Europe. We studied the emergence of the parasite in the European westernmost edge of its geographical distribution, based on two consecutive parasitological examinations of red foxes (Vulpes vulpes) sampled between 1996 and 2003 in The Netherlands. The average worm count increased from 2.6 worms per fox in the first surveillance to 16.6 worms per fox in the second. Using a mathematical model for a spatially spreading parasite, we found a strong indication that the parasite population is increasing in number and is spreading northward at the speed of 2.7 km per year. The reproduction number (R0), reflecting the parasite's transmission process, is estimated from the surveillance data and it is likely to be more than 1 but not exceeding a value of 4. We analysed a parasite control strategy by estimating the critical fox density for parasite elimination. We conclude that E. multilocularis is an emerging parasite in The Netherlands and thus in the western part of Europe. Control will be very difficult given the current high fox population density.
authors.affiliation: Laboratory for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control, National Institute for Public Health and Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3720 BA, Bilthoven, The Netherlands. Katsuhisa.Takumi@rivm.nl
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Takumi
authors.forename: Ankje
authors.initials: A
authors.lastname: de Vries
authors.forename: Mei Ling
authors.initials: ML
authors.lastname: Chu
authors.forename: Jaap
authors.initials: J
authors.lastname: Mulder
authors.forename: Peter
authors.initials: P
authors.lastname: Teunis
authors.forename: Joke
authors.initials: J
authors.lastname: van der Giessen
mesh_terms: D000818:Animals; D003710:Demography; D004443:Echinococcosis / Q000453:epidemiology* / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D048210:Echinococcus multilocularis / Q000254:growth & development / Q000302:isolation & purification*; D005589:Foxes / Q000469:parasitology*; D007422:Intestines / Q000469:parasitology; D008954:Models, Biological; D009426:Netherlands / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence