Pseudoterranova decipiens (Nematoda, Anisakidae) larvae reported from humans in Iceland after consumption of insufficiently cooked fish

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenRecently, two human cases of Pseudoterranova decipiens nematode larvae were confirmed in Iceland. In each case a larva was found in the throat five and six days after the consumption of insufficiently cooked filets of the common catfish Anarhicas lupus that were bought fresh in a fish store. In both cases the larva had already developed from 3rd to the 4th stage during the time of infection. In the former case a young male woke up in the morning as he noticed a larva crawling around in his throat. In the latter case a young woman coughed up the larva after intense itching in her throat. Anisakid larva of Pseudoterranova decipiens and Anisakis simplex are common in fish around Iceland. Both are known as human pathogens but usually Anisakis simplex causes more severe symptoms and is more commonly found in human cases than Pseudoterranova decipiens. Traditional cooking of fish in Iceland by boiling or thorough frying before consumption is believed to prevent human anisakidosis in Iceland. However, increased consumption of fresh or poorly heated fish and fish products might result in increased anisakidosis cases in Iceland.Greint er frá tveimur tilfellum hringormasmits í fólki hér á landi. Tegundin Pseudoterranova decipiens fannst í koki tveggja einstaklinga sem neytt höfðu illa hitaðra rétta úr ferskum steinbít fimm og sex dögum áður. Þriðja stigs lirfur upprunnar úr fiskholdinu höfðu í báðum tilvikum þroskast upp á 4. stig á þeim tíma sem liðinn var frá smitun. Í fyrra tilvikinu vaknaði ungur karlmaður við að ormur var að hreyfa sig í koki og í hinu fann ung kona fyrir ertingu í hálsi. Þegar hún hóstaði barst lirfan upp í kok. Lirfur hringormanna Pseudoterranova decipiens og Anisakis simplex eru algengar í fiskum við Íslandsstrendur. Menn eru ekki náttúrulegir lokahýslar en hringormar sem koma úr fiski geta lifað í fólki og valdið sjúkdómi. Erlendis er Anisakis simplex mun algengari sjúkdómsvaldur og oftast heldur illskeyttari en Pseudoterranova decipiens. Hefðbundnar matreiðsluaðferðir hér á landi sem fela í sér suðu eða eldun á ferskum fiski upp fyrir 70°C hafa að líkindum að mestu komið í veg smitun manna. Hætta er þó á að tilfellum geti fjölgað hér á landi aukist neysla á hráum fiski og hráum hrognum eða fiskréttum sem ekki hafa verið hitaðir eða frystir nægjanlega lengi til að drepa í þeim hringorma

The tropical rat mite Ornithonyssus bacoti attacks humans in Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenIn the summer of 2001 the obligate, intermittent tropical rat mite Ornithonyssus bacoti attacked humans in an Icelandic household where infected Mongolian gerbils (Meriones unguiculatus), bought in a local pet shop, had been kept for few months. After a rapid proliferation the mite started attacking the humans living in the house. A boy sharing room with the pets suffered from extensive dermatitis. Optimal conditions for O. bacoti are at 24-26 degrees C and a relative humidity of 47%. Similar conditions frequently occur indoors in Icelandic premises. Therefore, if O. bacoti has been noticed indoors, necessary measures should be undertaken to immediately eliminate the pest.Áttfætlumaurinn Ornithonyssus bacoti er blóðsjúgandi sníkjudýr sem lifir oftast á nagdýrum en leitar einnig á fólk. Þegar maurinn sýgur blóð úr mönnum myndast oftast kláðabólur á stungustaðnum. Sumarið 2001 varð þess vart að O. bacoti var að sjúga blóð úr fólki á heimili á Reykjavíkursvæðinu. Barst óværan þangað með stökkmúsum (Meriones unguiculatus) sem keyptar höfðu verið nokkrum mánuðum áður í gæludýraverslun. Eftir öra tímgun maursins á stökkmúsunum tók hann að leggjast á heimilisfólkið og olli verulegum óþægindum. Kjöraðstæður virðast vera fyrir maurinn til að fjölga sér í húsum hér á landi því tegundin þrífst best við 24-26° hita og 47% raka. Í greininni er líffræði maursins reifuð og varað við þessum nýja landnema

Are nasal Trichobilharzia cercariae potential threath to human health?

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenDuring late summer in 1995 to 1997, repeated outbreaks of maculopapular skin eruptions were observed on legs of children after wading in the pond of the Family Park in Reykjavík, Iceland. Investigation, starting in autumn 1997, revealed that the causative agent was a previously undescribed schistosome cercaria of the genus Trichobilharzia, shed by Radix peregra, the only snail occurring in the pond. This was the first report of swimmer's itch in Iceland. Infection experiments with cercariae from the pond have revealed adult worms and eggs of a Trichobilharzia in the nasal area of ducklings (Anas platyrhynchos f.dom.) 18-23 days p.i., and schistosomula in the spinal cord of BALB/c mice 3, 6 and 10 days p.i. Moreover, a mouse killed 3 days p.i. also had schistosomula in the lungs. During the prepatent period the infected ducklings had neuromotoric symptoms and gross pathology revealed petechiae in the nasal cavity. The results indicate that the cercaria responsible for swimmer's itch in Iceland is a nasal schistosome. Furthermore, adults of two visceral Trichobilharzia species have been found in Icelandic whooper swans Cygnus cygnus. As schistosomula of both nasal and visceral Trichobilharzia species are able to develop and migrate for several days in a non-specific mammalian host, humans are warned to expose themselves to Trichobilharzia cercariae in Iceland.Síðsumars árin 1995 til 1997 fundust þráfaldlega kláðabólur á fótum barna eftir að þau höfðu verið að vaða í tjörn í Fjölskyldugarðinum í Laugardal í Reykjavík. Rannsóknir sem hófust haustið 1997 leiddu í ljós að útbrotin voru eftir sundlirfur áður óþekktrar tegundar fuglablóðögðu af ættkvíslinni Trichobilharzia. Kláðabóla myndast eftir hverja lirfu sem nær að smjúga í gegnum húðina. Sundlirfurnar fjölga sér kynlaust í vatnasniglinum Radix peregra sem er algengur í tjörninni. Á ensku eru útbrot sem þessi nefnd sundmannakláði (swimmer's itch) en sjúkdómurinn gengur undir nafninu cercarial dermatitis. Í sýkingartilraunum hefur þessum sundlirfum verið gefinn kostur á því að smjúga í gegnum húð fugla, einkum andfugla. Nýverið báru tilraunirnar árangur því fullorðnar blóðögður og egg fundust í slímhimnu í nefholi andarunga (Anas platyrhynchos f. dom.). Endurteknar smittilraunir hafa leitt til sömu niðurstöðu. Ormar nasablóðagða ferðast upp í nefhol á um þremur vikum eftir að sundlirfurnar hafa borað sig inn í gegnum húðina á fótum. Ferðalagið þangað er sérstakt því ormarnir fikra sig eftir úttaugum upp í mænu, eftir mænunni upp í heila og í gegnum hann á áfangastaðinn í nefholi. Á leiðinni stækka ormarnir og þroskast en þeir lifa á taugavef hýsilsins. Taugaskemmdir virðast standa í réttu hlutfalli við fjölda lirfa sem smita fuglinn. Tilraunamýs hafa einnig verið smitaðar með sundlirfunni úr vaðtjörn Fjölskyldugarðsins og hefur komið í ljós að hluti þeirra lifir og þroskast að ákveðnu marki í þeim í að minnsta kosti tíu daga. Þegar eftir þrjá daga eru ormarnir komnir upp í mænu. Einnig hafa lirfur fundist í lungum þremur dögum eftir sýkingu. Þar sem sundlirfur fuglablóðagða virðast í einhverjum tilfellum geta náð þroska í spendýrum, þótt aldrei hafi verið sýnt fram á að þær nái fullum þroska í þeim, er fólki ráðlagt að forðast Trichobilharzia sundlirfur á Íslandi

Swimmer's itch in Landmannalaugar, Iceland

Hægt er að lesa greinina í heild sinni með því að smella á hlekkinn View/OpenSwimmer's itch (SI) or human cercarial dermatitis is caused by free-swimming larvae of bird parasites of the family Schistosomatidae (Trematoda) which have penetrated thorough the skin. Sometimes, mainly during first infections, the larvae do not cause any symptoms but if trapped by the immune system of the host each larva causes a maculopapular eruption. So far, five bird schistosome species have been reported in Iceland. Cercariae are shed by the freshwater snail Radix peregra but adults live in anseriform birds; one nasal Trichobilharzia species occurs in the nasal cavity of mallards, two visceral species have been found in veins of whooper swans and a visceral species has been found in greylag goose and in mallards, respectively. Experiments have shown that developing schistosomulae are able to survive for days or even weeks in mammals. Long term pathologic effects on the host are unknown. During the second half of August 2003 thousands of bathers got SI in a slowly streaming brook with geothermally heated groundwater in Landmannalaugar, the most frequently visited area in the interior of Iceland. The number of cercariae in the water and SI cases decreased until October but still in December and in late winter 2004 SI cases were reported. In August 2004 SI again started in the area but the density of cercariae in the water seemed to be less than in the previous year. The prevalence of snails shedding Trichobilharzia cercariae on the bathing site never exceeded 1%. The rapid increase of cercariae in the water by the middle of August in 2003 and 2004 were caused by a breeding mallard female and its ducklings which were raised on the bathing site during summer. All the ducklings had nasal- and visceral Trichobilharzia infections which they must have acquired soon after hatching. Three weeks later the adult worms could have started egg-laying. Consequently, emerging miracidia infected the snails which finally started shedding the cercariae by middle of August in 2003 and 2004. In future years this rapid increase of cercariae could be avoided if ducklings are not allowed to have access to the bathing site and the adjacent brook. Retrospective enquiries suggest that some visitors have occasionally got SI after bathing in the brook in preceding decades. Low number of papules, however, indicates a low density of cercariae in the water

Eimeria rangiferis (Protozoa: Eimeriidae) reported from caribou in Ameralik, West Greenland

In recent decades the native Barren-ground caribou (Rangifer tarandus groenlandicus) south of the Godthaabs fjord (Nuup Kangerlua fjord) in West Greenland have mixed with semi-domesticated Norwegian reindeer (R. t. tarandus) imported in 1952 from Finnmark Norway and released onto the range of the Ameralik caribou population. Fecal samples from three calves of the Ameralik caribou population were examined for the presence of nematode eggs and eimerid oocysts. Two distinct nematode egg types were observed: the first, Nematodirella longissimespiculata, was found in all calves, while the second, a strongylid nematode, was detected in one calf. The coccidian eimerid Eimeria rangiferis was identified in all calves. This host-specific eimerid is found in Icelandic feral reindeer, which were also imported from Finnmark Norway. We suggest that Finnmark reindeer were the source of Eimeria rangiferis observed in Ameralik caribou today. There are three possible origins for the presence of N. longissimespiculata in Ameralik, 1) arrival with colonizing caribou from North America within the past 4000 years, 2) the 1952 introduction of semi-domesticated Norwegian reindeer, or 3) the current immigration of muskoxen

Post-Translational Protein Deimination Signatures in Plasma and Plasma EVs of Reindeer (Rangifer tarandus)

The reindeer (caribou) Rangifer tarandus is a Cervidae in the order Artiodactyla. Reindeer are sedentary and migratory populations with circumpolar distribution in the Arctic, Northern Europe, Siberia and North America. Reindeer are an important wild and domesticated species, and have developed various adaptive strategies to extreme environments. Importantly, deer have also been identified to be putative zoonotic carriers, including for parasites, prions and coronavirus. Therefore, novel insights into immune-related markers are of considerable interest. Peptidylarginine deiminases (PADs) are a phylogenetically conserved enzyme family which causes post-translational protein deimination by converting arginine into citrulline in target proteins. This affects protein function in health and disease. Extracellular vesicles (EVs) participate in cellular communication, in physiological and pathological processes, via transfer of cargo material, and their release is partly regulated by PADs. This study assessed deiminated protein and EV profile signatures in plasma from sixteen healthy wild female reindeer, collected in Iceland during screening for parasites and chronic wasting disease. Reindeer plasma EV profiles showed a poly-dispersed distribution from 30 to 400 nm and were positive for phylogenetically conserved EV-specific markers. Deiminated proteins were isolated from whole plasma and plasma EVs, identified by proteomic analysis and protein interaction networks assessed by KEGG and GO analysis. This revealed a large number of deimination-enriched pathways for immunity and metabolism, with some differences between whole plasma and EVs. While shared KEGG pathways for whole plasma and plasma EVs included complement and coagulation pathways, KEGG pathways specific for EVs were for protein digestion and absorption, platelet activation, amoebiasis, the AGE–RAGE signaling pathway in diabetic complications, ECM receptor interaction, the relaxin signaling pathway and the estrogen signaling pathway. KEGG pathways specific for whole plasma were pertussis, ferroptosis, SLE, thyroid hormone synthesis, phagosome, Staphylococcus aureus infection, vitamin digestion and absorption, and prion disease. Further differences were also found between molecular function and biological processes GO pathways when comparing functional STRING networks for deiminated proteins in EVs, compared with deiminated proteins in whole plasma. This study highlights deiminated proteins and EVs as candidate biomarkers for reindeer health and may provide information on regulation of immune pathways in physiological and pathological processes, including neurodegenerative (prion) disease and zoonosis

New cryptic species of the ‘revolutum’ group of Echinostoma (Digenea: Echinostomatidae) revealed by molecular and morphological data

BACKGROUND: The digenean species of Echinostoma (Echinostomatidae) with 37 collar spines that comprise the so-called ‘revolutum’ species complex, qualify as cryptic due to the interspecific homogeneity of characters used to differentiate species. Only five species were considered valid in the most recent revision of the group but recent molecular studies have demonstrated a higher diversity within the group. In a study of the digeneans parasitising molluscs in central and northern Europe we found that Radix auricularia, R. peregra and Stagnicola palustris were infected with larval stages of two cryptic species of the ‘revolutum’ complex, one resembling E. revolutum and one undescribed species, Echinostoma sp. IG. This paper provides morphological and molecular evidence for their delimitation. METHODS: Totals of 2,030 R. auricularia, 357 R. peregra and 577 S. palustris were collected in seven reservoirs of the River Ruhr catchment area in Germany and a total of 573 R. peregra was collected in five lakes in Iceland. Cercariae were examined and identified live and fixed in molecular grade ethanol for DNA isolation and in hot/cold 4% formaldehyde solution for obtaining measurements from fixed materials. Partial fragments of the mitochondrial gene nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) were amplified for 14 isolates. RESULTS: Detailed examination of cercarial morphology allowed us to differentiate the cercariae of the two Echinostoma spp. of the ‘revolutum’ species complex. A total of 14 partial nad1 sequences was generated and aligned with selected published sequences for eight species of the ‘revolutum’ species complex. Both NJ and BI analyses resulted in consensus trees with similar topologies in which the isolates from Europe formed strongly supported reciprocally monophyletic lineages. The analyses also provided evidence that North American isolates identified as E. revolutum represent another cryptic species of the ‘revolutum’ species complex. CONCLUSION: Our findings highlight the need for further analyses of patterns of interspecific variation based on molecular and morphological evidence to enhance the re-evaluation of the species and advance our understanding of the relationships within the ‘revolutum’ group of Echinostoma

Development of 14 microsatellite markers for zoonotic tapeworm dibothriocephalus dendriticus (Cestoda: Diphyllobothriidea)

Dibothriocephalus dendriticus is one of the causative agents of the fish-borne zoonosis diphyllobothriosis. Polymorphic microsatellite markers were originally developed for future genetic studies using microsatellite library screening and next-generation sequencing (NGS). Out of 128 microsatellite candidates selected after NGS analysis, 126 yielded PCR products of the expected size. A declared repetitive motif was confirmed in 92 loci by Sanger sequencing. The level of polymorphism was tested by fragment analysis. Statistical tests for observed and expected heterozygosities and deviations from Hardy–Weinberg equilibrium revealed 14 polymorphic microsatellite loci suitable for studies on the finer genetic structure of global populations of D. dendriticus

Echinococcus across the north : Current knowledge, future challenges

Foodborne Parasites in Cold ClimatesAbstract Zoonotic Echinococcus spp. cestodes are present in almost all circumpolar nations, and have historically posed a risk to health of indigenous as well as other northern residents. However, surveillance data on both alveolar (AE) and cystic (CE) echinococcosis remains incomplete throughout the circumpolar region: Russia, Fennoscandia, Iceland, Greenland, Canada and Alaska (USA). Prevalence of Echinococcus spp. varies considerably in definitive canid hosts, animal intermediate hosts and accidental hosts like humans. Yet despite the high prevalence reported in canids in some geographic locations, human AE and CE are much less common than in endemic Asian and central European countries. This paper explores knowledge gaps and future challenges posed by Echinococcus spp. in eight circumpolar countries, a region where rapid environmental and social change are rewriting the boundaries, transmission, and impact of many pathogens, including zoonotic Echinococcus spp. Genotypes G6, G8 and G10 of Echinococcus canadensis are causative agents of human CE and have been identified in sylvatic (wild animal) and synanthropic (ecological association with humans) cervid-canine life cycles in the following northern regions: Alaska and northern Canada - G8 and G10; northern Russia - G6, G8, G10; and Fennoscandia - G10 in Finland - with no recent reports from Norway or Sweden. Echinococcus multilocularis, which causes AE, has been identified in a sylvatic arvicoline rodent-canine lifecycle in Alaska, Canada, Russia, Sweden and Svalbard (Norway). Asian, Mongolian, European and North American strains of E. multilocularis are found in Russia, with the North American N1 strain predominating in the north. The N1 strain is also found in Alaska, as well as Svalbard, whilst Asian strains have been identified in western Alaska. Central North American (N2) strain and European-type strains of E. multilocularis are present in Canada. Typing of the strain in Sweden is still pending. Individual human cases of AE with N2 and European-type strains are reported in North America, as well as multiple cases with Asian strains in Russia and historically on St Lawrence Island, Alaska (although genotyping of human cases was not available at the time). Echinococcus spp. have not been detected in Greenland and have been eliminated from Iceland. The predominance of E. multilocularis N1 strain and E. canadensis genotypes, in regions with high prevalence in definitive hosts yet low incidence of human AE and CE, suggests that these genotypes have lower zoonotic potential and pathogenicity than European and Asian strains of E. multilocularis and livestock genotypes of E granulosus sensu stricto. The continued monitoring of the emergence of Echinococcus genotypes within definitive and intermediate hosts, as well as people, is needed to assess the impact on public health risk, since the introduction of other genotypes could have serious repercussions. Lastly, determining risk factors and source attribution for human cases, including the possibility of food and waterborne transmission and the likelihood of autochthonous transmission, remain challenges.Peer reviewe

Human Pseudoterranova and Anisakis cases in Iceland 2004-2020

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadÁ árabilinu 2004-2020 voru 18 hringormslirfur (Nematoda) sendar til rannsókna og tegundagreiningar á sníkjudýradeild Tilraunastöðvarinnar að Keldum. Fjórtán lirfanna höfðu lifað tímabundið í fólki og voru lifandi þegar þær fundust, þrjár fundust lifandi í fiski sem fólk var að borða, ein fannst dauð. Pseudoterranova decipiens fannst í 16 tilvikum (89%), Anisakis simplex í tveimur (11%). Annað Anisakis-tilfellið var lirfa sem fannst spriklandi í bleyju barns sem talið var að hefði fengið lirfuna úr vanelduðum fiski á barnaheimili. Í hinu tilvikinu fannst dauð lirfa í soðinni ýsutuggu, sem barn, sem verið var að mata, spýtti út úr sér. Pseudoterranova-lirfur sem lifað höfðu í fólki (n=13) fundust oftast í munni (11 tilvik), í einu tilfelli fann móðir spriklandi lirfu í ælu barns, í öðru fannst hringormur hreyfa sig við endaþarmsop við þrif eftir salernisferð. Lengd lirfanna var 30 mm til 47 mm og voru þær taldar hafa lifað allt frá einum upp í 9 daga í fólkinu. Níu lirfanna höfðu þegar náð að þroskast upp á fjórða stig (L4), fjórar voru enn á þriðja stigi (L3). Þorskur var oftast nefndur sem uppspretta lirfanna (5 tilfelli af 14), tvær manneskjur töldu lirfurnar komnar úr steinbít, einn nefndi báðar þessar tegundir. Sushi eða skarkoli voru álitin uppsprettan í einu tilviki, einn smitaðist í sushi-veislu. Uppruninn var óþekktur í fjórum tilvikum. Oftast töldu menn sig hafa smitast í heimahúsi, þrír álitu sig hafa smitast á veitingastað, sama barn smitaðist tvisvar á barnaheimili og hafnarstarfsmaður smitaðist við að borða hráan fisk.During 2004-2020 in total 18 anisakid larvae (Nematoda) were sent in to the Laboratory of Parasitology at Keldur for investigation and species identification. Fourteen had temporarily lived within the human body and were alive when detected, three were noticed alive in food just before being consumed, one larva was found dead. Pseudoterranova decipiens was found í 16 instances (89%), Anisakis simplex in two (11%). The one Anisakis case was a wriggling larva detected in the diaper of a baby that was believed to have ingested the larva with undercooked fish three days earlier in the kindergarten. In the other case a dead larva was found entangled in fish chew, spit out by a baby being fed with boiled haddock. Pseudoterranova larvae in humans (n=13) were most frequently detected in the mouth (11 persons). In one instance winding movements of larva in vomit of a baby attracted the attention of the mother, in another case a person detected tickling movements of a larva when cleaning the anal area after defecation. Length of the 13 Pseudoterranova larvae varied between 30 and 47 mm. They were believed to have lived in their hosts from one up to nine days. Nine larvae had already developed to the L4, stage, four were still in the L3 stage. Cod was the most frequently mentioned source of infection (5 of 14 cases), two persons regarded catfish to be the culprit, one named both fish species. In one case either sushi or plaice was believed to be the infection source, one person presumably got the larva participating in a sushi feast. In four cases the fish source remained unknown. Most often the larva was consumed in private homes, three persons believed to have gotten the larva when dining in a restaurant, a harbour worker got the worm when eating raw fish and the same baby got a larva on two different occasions in the kindergarten