چکیده (انگلیسی):

Fish-borne cestodes capable of infecting humans are represented almost exclusively by so called
broad tapeworms, i.e. members of the order Diphyllobothriidea. These large-sized human tapeworms
have three host life-cycles, in which teleost fishes (except in the case of Spirometra) play a
role of the second intermediate hosts and represent a source of human infection. Although the
broad fish tapeworms (genera Adenocephalus, Diphyllobothrium and Diplogonoporus) have been recognized
as human parasites for a long time,many aspects of their biology and epidemiology, including
species composition of individual genera, their clinical relevance and geographical distribution
have been noticeably understudied. The overriding obstacle preventing clarification of the diversity,
origin and host-associations of diphyllobothriids is the poor state of systematics of the group. Even
though diphyllobothriosis itself is not a life-threatening disease, it is considered the most important
fish-borne zoonosis caused by a cestodewith up to 20 million people estimated to be infectedworldwide,
with an affinity to colder climates including subarctic and arctic areas of the North and partly
South Hemisphere. Moreover, several species seemto (re)-emerge in themost developed countries.
Current (re)-emergence of diphyllobothriosis and the introduction of its agents into new geographical
regions aremainly fuelled by: (i) increased preference of human societies to consume raw food,
(ii) globalized trade with fish products, (iii) humanmigration. Dozens of nominal species have been
described so far, but only 15 species currently recognized as valid have been reported to infect
humans. Moreover, the validity of species described from Alaska, which have been reported from
man (Diphyllobothrium alascense, D. dalliae, D. ursi) should be confirmed using molecular data. Yet,
we still lack information about the intraspecific variability and species boundaries of themost important
broad tapeworm species including those occurring in cold climates, such as Diphyllobothrium
latum, D. dendriticum and D. nihonkaiense. Moreover, molecular data indicate paraphyly of the
genus Diphyllobothrium, which may explain different host associations and morphology of species
in distantly related lineages. For the first time in the literature, data on all human-infecting broad
fish tapeworms, most ofwhich occur in cold climates, are summarized, with focus on rare or uncommon
species that were largely neglected in the literature or appeared in hardly accessible papers.
© 2016 The Authors. Published by Elsevier Inc. on behalf of International Association of Food
and Waterborne Parasitology. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/).