Nasal localization of a Pseudoterranova decipiens larva in a Danish patient with suspected allergic rhinitis.

Pseudoterranoviasis is a zoonotic disease caused by nematode larvae of species within the genus Pseudoterranova (seal worm, cod worm). Most infections are gastrointestinal, oesophageal or pharyngeal, but here we report a nasal infection. A 33-year-old patient suffering from rhinitis for 1.5 years recovered a worm larva from the nose. Diagnosis was performed by morphological and molecular characterization, showing the causative agent to be a third-stage larva of Pseudoterranova decipiens (sensu stricto). Various infection routes are discussed.

Urticaria and silent parasitism by Ascaridoidea: Component-resolved diagnosis reinforces the significance of this association.

Urticaria remains a major problem in terms of aetiology, investigation, and management, and although parasitic diseases are considered potential causes, the absence of a consistent link between parasitic infections and skin allergy symptoms leads to the need for a deeper study of parameters that support this association. The objectives of this study were to analyse a possible relationship between parasitism by Ascarididae (Toxocara canis and Anisakis simplex) and the clinical expression of urticaria and to identify possible parasitic molecular markers for improving the diagnosis of unknown urticaria aetiology. The prevalence of Toxocara and Anisakis infestations was evaluated by measuring the levels of specific IgG (sIgG) and IgE (sIgE) antibodies against crude extracts and isolated components from whole larvae of Anisakis simplex (Ani s 1, Ani s 3 and Ani s 7) and Toxocara canis (TES-120, TES-70, TES-32 and TES-26) using immunologic and molecular diagnostic methods. A cross-sectional study was performed in a group of 400 individuals. The study group consisted of 95 patients diagnosed with urticaria (55 with chronic urticaria and 40 with acute urticaria). A control group consisted of 305 subjects without urticaria (182 diagnosed with respiratory allergy and 123 without allergy). Statistically significant differences were demonstrated in the seroprevalence of specific IgG and IgE antibodies between the urticaria patients and the healthy general population when isolated ascarid antigens were evaluated. The prevalence of IgG antibodies against Ani s 1, IgE antibodies against TES-120 and IgE antibodies against TES-70 were significantly different between the control individuals (healthy general population) and patients with urticaria. Moreover, the urticaria patient group demonstrated a higher seroprevalence of antibodies (sIgE and sIgG) against Anisakis simplex larva whole extract than the control group but just with statistically diferences when sIgE was evaluated. The presence of IgE and/or IgG antibodies against Ani s 3 (tropomyosin) can help to discriminate between patients with and without urticaria. Both ascarids seem to be associated with urticaria, although in our region, Anisakis seems to have greater involvement than Toxocara in this relationship. Molecular diagnostics can be used to associate urticaria with parasite infestations. Tropomyosin and Ani s 1 were the most relevant markers to demonstrate the association between urticaria and the most relevant Ascarididae parasites in our region.

Functional Ultrastructure of the Excretory Gland Cell in Zoonotic Anisakids (Anisakidae, Nematoda).

Excretory and secretory products are crucial for parasite infectivity and host immunomodulation, but the functioning and ultrastructure of the excretory gland cell (EC) that produces these products are still scarcely understood and described. In light of growing reports on anisakiasis cases in Europe, we aimed to characterise the EC of larval Anisakispegreffii and adult Pseudoterranovaazarasi. In the latter, EC starts 0.85 mm from the head tip, measuring 1.936 × 0.564 mm. Larval EC shows a long nucleus with thorn-like extravaginations toward the cytoplasm, numerous electron-dense and -lucent secretory granules spanning from the perinuclear to subplasmalemmal space, an elevated number of free ribosomes, small, spherical mitochondria with few cristae and a laminated matrix, small and few Golgi apparatuses, and few endoplasmic reticula, with wide cisternae complexes. Ultrastructure suggests that anaerobic glycolysis is the main metabolic pathway, obtained through nutrient endocytosis across the pseudocoelomic surface of the EC plasmalemma and its endocytic canaliculi. Thorn-like extravaginations of EC karyotheca likely mediate specific processes (Ca2+ signaling, gene expression, transport, nuclear lipid metabolism) into the extremely wide EC cytosol, enabling focal delivery of a signal to specific sites in a short time. These functional annotations of parasitic EC should help to clarify anisakiasis pathogenesis.

Characteristics of parasitic egg shedding over a 1-year period in foals and their dams in 2 farms in central Saskatchewan.

The goals of this study were to report the seasonal shedding patterns of strongyle and Parascaris spp. eggs in repeated fecal samples for mares (n = 38) and foals (n = 39), and to evaluate the efficacy of ivermectin treatment in mares from 2 selected horse breeding farms in central Saskatchewan. Median strongyle fecal egg counts (FEC) peaked in July and August in adult horses. The farms differed significantly (P = 0.0005) in regard to strongyle shedding categories (< 200; 200 to 500; and > 500 eggs/g) over time, but for each individual horse (both farms combined) these categories did not differ over time (P = 0.13) on samples collected in grazing season. When evaluating 3 samples collected fall, summer and fall in 2 consecutive grazing seasons, 94% of horses that shed < 200 eggs/g on 2 initial samples, remained in the same category on the third sample. Mares on each farm didn't differ statistically in shedding categories when comparing September samples from 2 consecutive years (Farm A: P = 0.56, Farm B: P = 0.06). Peak strongyle shedding occurred late fall in the first year of life for foals on Farm A, and in July in the second year of life for foals on Farm B. Parascaris spp. FEC were greatest in foals ≤ 6 months of age, with peak observed when foals were 5 to 6 months old. Ivermectin was 100% effective at reducing strongyle FEC 2 weeks after treatment in adult horses. Horses in Saskatchewan had relatively high strongyle shedding levels, which were significantly different between the farms, and high prevalence of Oxyuris equi. Strongyle shedding consistency was observed for FECs collected from mares in grazing season (July to September).

Caractéristiques de l'excrétion des oeufs de parasites pendant une période de 1 an chez les poulains et leurs mères dans deux fermes du centre de la Saskatchewan. Cette étude avait pour but de dresser un rapport sur les tendances d'excrétion saisonnière des oeufs des strongyles et de Parascaris spp. dans des prélèvements fécaux répétés pour les juments (n = 38) et les poulains (n = 39) et d'évaluer l'efficacité du traitement à l'ivermectine chez deux juments provenant de deux fermes d'élevage de chevaux dans le centre de la Saskatchewan. Les comptes médians d'oeufs fécaux des strongyles ont culminé en juillet et en août chez les chevaux adultes. Les fermes présentaient des différences significatives (P = 0,0005) à l'égard des catégories d'excrétion des strongyles (< 200; de 200 à 500; et > 500 oeufs/g) dans le temps, mais, pour chaque cheval individuel (les deux fermes combinées), ces catégories ne présentaient pas de différences à la longue (P = 0,13) pour les échantillons prélevés durant la saison de pâturage. Lors de l'évaluation des reois échantillons prélevés à l'automne, à l'été et à l'automne pendant deux saisons de pâturage consécutives, 94 % des chevaux qui avaient excrété < 200 oeufs/g pour deux prélèvements initiaux, sont demeurés dans la même catégorie pour le troisième échantillon. Les juments de chaque ferme ne présentaient pas de différences statistiques pour les catégories d'excrétion lorsque l'on comparait les échantillons de septembre provenant de deux années consécutives (Ferme A : P = 0,56, Ferme B : P = 0,06). L'excrétion des strongyles a culminé à la fin de l'automne pendant la première année de vie pour les poulains de la Ferme A et en juillet de la deuxième année de vie pour les poulains de la Ferme B. Les comptes d'oeufs fécaux de Parascaris spp. étaient les plus importants chez les poulains âgés de ≤ 6 mois et le point culminant était observé lorsque les poulains étaient âgés de 5 ou 6 mois. L'ivermectine était efficace à 100 % pour réduire les comptes d'oeufs fécaux 2 semaines après le traitement chez les chevaux adultes. Les chevaux de la Saskatchewan ont présenté des taux d'excrétion relativement élevés de strongyles, qui étaient significativement différents entre les fermes, et une forte prévalence d'Oxyuris equi. La constance de l'excrétion des strongyles a été observée pour les comptes d'oeufs fécaux obtenus auprès des juments pendant la saison de pâturage (de juillet à septembre).(Traduit par Isabelle Vallières).

Molecular diagnosis of Pseudoterranova decipiens s.s in human, France.

BACKGROUND: Anisakis and Pseudoterranova are the main genera involved in human infections caused by nematodes of the Anisakidae family. Species identification is complicated due to the lack of differential morphological characteristics at the larval stage, thus requiring molecular differentiation. Pseudoterranova larvae ingested through raw fish are spontaneously eliminated in most cases, but mechanical removal by means of endoscopy might be required. To date, only very few cases of Pseudoterranova infection have been reported in France. CASE PRESENTATION: A 19-year-old woman from Northeastern France detected, while brushing her teeth, a larva exiting through her mouth. The patient who presented with headache, diarrhea, and abdominal cramps reported having eaten baked cod. The worm was a fourth-stage larva with a size of 22 × 0.9 mm, and molecular biology identified it as Pseudoterranova decipiens sensu stricto (s. s.). In a second P. decipiens infection case, occurring a few months later, a worm exited through the patient's nose after she had eaten raw sea bream. CONCLUSION: These two cases demonstrate that Pseudoterranova infection is not uncommon among French patients. Therefore, molecular techniques should be more widely applied for a better characterization of anisakidosis epidemiology in France.

Larva migrans in squirrel monkeys experimentally infected with Baylisascaris potosis.

Roundworms of the genus Baylisascaris are natural parasites primarily of wild carnivores, and they can occasionally cause infection in humans and animals. Infection results in visceral larva migrans and/or neural larva migrans, which can be severe or fatal in some animals. Recently, Baylisascaris nematodes isolated from kinkajous (Potos flavus) and previously referred to as Baylisascaris procyonis were renamed as Baylisascaris potosis; however, data regarding the pathogenicity of B. potosis towards animals and humans are lacking. In the present study, we experimentally infected squirrel monkeys (Saimiri sciureus) with B. potosis to determine the suitability of the monkey as a primate model. We used embryonated eggs of B. potosis at two different doses (10,000 eggs and 100,000 eggs) and examined the animals at 30 days post-infection. Histopathological examination showed the presence of B. potosis larvae and infiltration of inflammatory cells around a central B. potosis larvae in the brain, intestines, and liver. Nevertheless, the monkeys showed no clinical signs associated with infection. Parasitological examination revealed the presence of B. potosis larvae in the intestines, liver, lung, muscles, brain, kidney, and diaphragm. Our findings extend the range of species that are susceptible to B. potosis and provide evidence for the zoonotic potential of larva migrans in high dose infections.

Experimental infection of Mongolian gerbils with Baylisascaris potosis.

The present study evaluated the pathogenicity of Baylisascaris potosis, a newly described ascarid nematode, in Mongolian gerbils. Gerbils were infected with varying doses of either B. potosis or Baylisascaris transfuga embryonated eggs (100, 1,000, and 4,000) for 30 days postinfection (pi). Baylisascaris potosis-infected gerbils showed no clinical signs of disease; however, gerbils exposed to 1,000 and 4,000 B. transfuga eggs showed severe neurologic signs at 22-29 days and 14-15 days pi, respectively. Histopathologic examination revealed larvae and lesions in the intestine, lung, liver, and muscles of B. potosis-infected gerbils, but not in the brain, whereas B. transfuga larvae were found only in the brain and muscle. These results indicate that B. potosis larvae migrate through numerous organs and are associated with visceral larva migrans in gerbils, but less frequently migrate to the nervous system in gerbils than does B. transfuga .

Baylisascaris larva migrans.

Baylisascaris procyonis is a roundworm of the raccoon found primarily in North America but also known to occur in other parts of the world including South America, Europe, and Japan. Migration of the larvae of this parasite is recognized as a cause of clinical neural larva migrans (NLM) in humans, primarily children. It is manifested as meningoencephalitis associated with marked eosinophilia of the cerebrospinal fluid and peripheral blood. Diagnosis is made by recovering and identifying larvae in or from the tissues, epidemiological history, serology, and imaging of the central nervous system. Treatment is with albendazole and steroids, although the prognosis is generally poor. This parasite can also cause ocular larva migrans (OLM) which usually presents as diffuse unilateral subacute neuroretinitis (DUSN). The ocular diagnosis can be made by visualizing the larva in the eye and by serology. Intraocular larvae can be destroyed by photocoagulation although albendazole and steroids may also be used. However, once visual disturbance is established the prognosis for improved vision is poor. Related Baylisascaris species occur in skunks, badgers, and certain other carnivores, although most cases of NLM are caused by B. procyonis. Baylisascaris procyonis has also been found in kinkajous in the USA and South America and may also occur in related procyonids (coatis, olingos, etc.).

Baylisascariosis--infections of animals and humans with 'unusual' roundworms.

The nematode genus Baylisascaris (order Ascaridida, superfamily Ascaridoidea) contains nine relatively host-specific, parasite species of carnivores, omnivores, herbivores, carnivorous marsupials or rodents. They have a facultative heteroxenous life cycle, at least under experimental conditions. Eggs passed in faeces embryonate in the environment and the second-stage larva infective for both definitive and intermediate hosts develops. In intermediate hosts larvae migrate extensively through tissues, where they grow and moult to the third-stage, causing extensive damage. All Baylisascaris spp. are considered a potential cause of visceral, ocular and/or neural larval migrans in mammals including humans and in birds. This paper summarises our current knowledge on the prevalence, biology, pathogenicity and zoonotic significance of three Baylisascaris species: B. transfuga, B. schroederi and B. procyonis which have as definitive hosts bears, giant pandas and raccoons (occasionally dogs), respectively.

Sequence analysis of the Bs-Ag1 gene of Baylisascaris schroederi from the giant panda and an evaluation of the efficacy of a recombinant Baylisascaris schroederi Bs-Ag1 antigen in mice.

The Baylisascaris schroederi infection rate among wild giant pandas may reach over 50% or even 100%, making it one of the leading causes of death from primary or secondary infection in wild populations. Until now, little was known about how protective immunity to B. schroederi infection could be achieved. The present study was conducted to evaluate the immunogenicity and protective efficacy of recombinant Bs-Ag1 from B. schroederi, by cloning the full-length Bs-Ag1 gene of B. schroederi and expressing it in a heterologous host, Escherichia coli BL21. In mice vaccinated with rBs-Ag1 coupled with Freund's complete adjuvant (FCA), there was a significant reduction (69.2%) in the recovery of challenged B. schroederi L3 compared with either nonvaccinated controls or mice vaccinated with FCA alone. Our study supports the use of Bs-Ag1 as a potential candidate for vaccination against B. schroederi infection and provides basic data for further vaccination trials with mixtures of antigens (with Bs-Ag2 and Bs-Ag3) to B. schroederi.

Two new species of Contracaecum Railliet & Henry, 1912 (Nematoda: Anisakidae), C. fagerholmi n. sp. and C. rudolphii F from the brown pelican Pelecanus occidentalis in the northern Gulf of Mexico.

DNA sequencing of the nuclear ribosomal DNA internal transcribed spacers (ITS) and mitochondrial rrnS and cox2 genes, and analysis of polymorphisms in restriction profiles in the ITS and rrnS, were used to characterise anisakid nematodes belonging to Contracaecum Railliet & Henry, 1912 infecting the brown pelican Pelecanus occidentalis (L.) in Galveston Bay, Texas and Sarasota Bay, Florida. Molecular data led to the detection of two new species: Contracaecum fagerholmi n. sp., which was also supported by clear morphological evidence, and Contracaecum rudolphii F, a new cryptic species within the Contracaecum rudolphii Hartwich, 1964 complex. Bayesian phylogenetic analysis demonstrated that C. fagerholmi and C. rudolphii F form two well-separated clusters, with C. fagerholmi being closely related to Contracaecum bioccai Mattiucci et al., 2008 and C. rudolphii F being included in the C. rudolphii complex. C. fagerholmi can be readily differentiated morphologically from all of its congeners, other than C. microcephalum (Rudolphii 1809) and the five currently recognised members of the C. rudolphii complex (C. rudolphii A, B, C, D and E). C. fagerholmi differs from C. microcephalum in the length of the spicules and the shape of the distal tip of the spicules, and from C. rudolphii (sensu lato) in the shape and size of the ventro-lateral and dorsal lips and by having interlabia which are not distally bifurcate. Further studies are needed to determine which morphological characteristics can be used to distinguish the cryptic species of the C. rudolphii complex in order to assign them with formal names. The recovery of a third species, C. bioccai, from the brown pelican confirms its occurrence in this host and extends its known geographical distribution.

Raccoon roundworms in pet kinkajous--three states, 1999 and 2010.

Baylisascaris procyonis (BP) is the common roundworm of raccoons (Procyon lotor). Adult BP live in the small intestine of this host, where they produce eggs that are passed in the feces. BP eggs ingested by nondefinitive host species hatch in the intestine, producing larvae that can migrate widely, causing visceral, ocular, or neural larva migrans. Cases of neural larva migrans in humans caused by BP likely acquired from raccoons have resulted in severe encephalitis with permanent deficits and in death. Although raccoons are the most common definitive host of BP in North America, some other carnivores, including domestic dogs, can serve as definitive hosts, making them a potential source of human disease. Less well-documented is infection in procyonids other than raccoons (e.g., kinkajous [Potos flavus], coatis [Nasua spp.], olingos [Bassaricyon spp.], and ringtails [Bassariscus astutus]) and the potential for transmission from these species to humans. This report describes cases of BP infection in pet kinkajous that placed humans at risk for infection. Avoiding contact with feces from potentially infected animals and routine deworming of pets, including dogs and exotic species that might host this parasite, will prevent infection with BP.

Anisakidae nematodes and Trypanorhyncha cestodes of hygienic importance infecting the king mackerel Scomberomorus cavalla (Osteichthyes: Scombridae) in Brazil.

From February to October 2007, thirty specimens of the king mackerel, Scomberomorus cavalla (Cuvier, 1829) were purchased from markets in the municipalities of Niterói and Rio de Janeiro. The fishes were measured, filleted and further had their organs investigated for helminths. Ten out of the thirty fish specimens were parasitized with anisakid nematodes represented by Anisakis sp. and Contracaecum sp. with prevalence of 1% and 16%, mean intensity of 2 and 3.31 and mean abundance of 0.02 and 0.53, respectively. The infection range with Contracaecum sp. was 1-9. The sites of infection were the stomach serosa and mesentery. Seventeen fish specimens (53%) out of the 30 investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus gracilis, Pterobothrium crassicole, Callitetrarhynchus speciosus and Tentacularia coryphaenae in the mesentery, with prevalence of 26, 20, 6, 3%, intensity and mean intensity of 3.25, 3.5, 1, 2 and mean abundance of 0.86, 0.7, 0.06 and 0.06, respectively. The infection range due to C. gracilis and P. crassicole were of 1-5 and 1-20, respectively. Anisakis sp., C. speciosus and P. crassicole are reported in S. cavalla for the first time. Considerations on the zoonotic potential of the parasites and their rules in sanitary inspection are presented.

Mercury in parasitic nematodes and trematodes and their double-crested cormorant hosts: bioaccumulation in the face of sequestration by nematodes.

Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values (δ(15)N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. δ(13)C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.

Cold tolerance in sealworm ( Pseudoterranova decipiens) due to heat-shock adaptations.

Third-stage larvae of Pseudoterranova decipiens commonly infect whitefish such as cod, and the parasite can be transferred to humans through lightly prepared (sushi) meals. Because little is known about the nematode's cold tolerance capacity, we examined the nematode's ability to supercool, and whether or not cold acclimation could induce physiological changes that might increase its ability to tolerate freezing conditions. Even if third-stage Pseudoterranova decipiens larvae have some supercooling ability, they show no potential for freezing avoidance because they are not able to withstand inoculative freezing. Still, they have the ability to survive freezing at high subzero temperatures, something which suggests that these nematodes have a moderate freeze tolerance. We also show that acclimation to high temperatures triggers trehalose accumulation to an even greater extent than cold acclimation. Trehalose is a potential cryoprotectant which has been shown to play a vital role in the freeze tolerance of nematodes. We suggest that the trehalose accumulation observed for the cold acclimation is a general response to thermal stress, and that the nematode's moderate freeze tolerance may be acquired through adaptation to heat rather than coldness.

Baylisascaris procyonis encephalitis in Patagonian conures (Cyanoliseus patagonus), crested screamers (Chauna torquata), and a western Canadian porcupine (Erethizon dorsatum epixanthus) in a Manitoba zoo.

Neurological disease occurred in 4 Patagonian conures (Cyanoliseus patagonus), 2 crested screamer chicks (Chauna torquata), and 1 western Canadian porcupine (Erethizon dorsatum epixanthus) at a Manitoba zoo. Baylisascaris procyonis, the common raccoon roundworm, not previously identified in Manitoba, is considered the likely cause of neural larval migrans in these cases.

Full recovery from Baylisascaris procyonis eosinophilic meningitis.

Infection by Baylisascaris procyonis is an uncommon but devastating cause of eosinophilic meningitis. We report the first case-patient, to our knowledge, who recovered from B. procyonis eosinophilic meningitis without any recognizable neurologic deficits. The spectrum of illness for this organism may be wider than previously recognized.

Human pseudoterranovosis, an emerging infection in Chile.

Fifteen cases of human pseudoterranovosis are reported for Chile, representing an emerging parasitic infection in this country caused by larvae of the nematode Pseudoterranova sp. Our observations also included an outbreak of pseudoterranovosis in 3 of 4 individuals who shared the same raw fish dish (cebiche). Most of the cases occurred in adult patients. The main source of infection was from consumption raw or fried marine fish, including hakes (Merluccius australis or Merlucciuts gayi), pomfret (Brama australis), Inca scad (Trachurus murphvi), and corvina (Cilus gilberti). Seasonal distribution showed most of the cases to occur in fall and spring. Parasite larvae were isolated from the mouths of most of the patients after they reported a pharyngeal tickling sensation, coughing, vomiting, or a foreign body in the mouth or throat.

Effects of low and high temperatures on viability of Parascaris equorum eggs suspended in water.

Microcentrifuge tubes containing 5000 eggs of Parascaris equorum suspended in water were frozen at -5, -10, -15, -20, and -80 degrees C for 1-168 h and then thawed at a room temperature. Other samples of P. equorum eggs suspended in water were inserted into wells in the heated metal block of a thermal DNA cycler. Block temperatures were set at 5 degrees C incremental temperatures from 40 to 100 degrees C. At each temperature setting microcentrifuge tubes containing P. equorum eggs were removed 1 and 5 min later. Both, frozen and heated egg suspensions as well as untreated control suspensions were then incubated to test of viability based on the development of infective larvae inside viable eggs. We found out that eggs of P. equorum in water can retain viability and infectivity after freezing and that eggs survive longer at higher freezing temperatures. Our results also indicated that when water containing P. equorum eggs reached temperatures of 60 degrees C or higher within 1 min, the viability of eggs was lost.