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.

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.

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.

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.

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.

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.

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.

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.

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 .

Diffuse retinochoroiditis due to Baylisascaris procyonis in Monglian gerbils.

Baylisascaris procyonis, raccoon roundworm, causes a severe retinal lesion in humans. The lesion is termed as diffuse unilateral subacute neuroretinitis (DUSN). To understand the pathogenesis of B. procyonis in gerbils, we inoculated 17 embryonated eggs/g body weight of B. procyonis into 15 male Mongolian gerbils, Merionis ungiculatus, and monitored their fundi with an ophthalmoscope. Six of 15 gerbils (40%) showed severe retinitis with a sinuous track due to larval movement. The lesions extended across nearly half of the affected fundi. Histopathological examination revealed perivasculitis in the optic disk region, inflammatory proliferation of the pigment cells, and vitreitis in most cases. These findings were similar to those in human cases of DUSN, suggesting that gerbils might be a useful model for understanding the pathogenesis of B. procyonis infection in humans.

Larva migrans by Baylisascaris transfuga: fatal neurological diseases in Mongolian jirds, but not in mice.

Raccoon roundworms (Baylisascaris procyonis) and other Baylisascaris species cause patent or latent larva migrans (LM) in a variety of mammals and birds, including humans. It is not clear whether LM by Baylisascaris transfuga, roundworms of bears, is associated with clinical neurological disorders. To clarify this issue, ICR and BALB/c mice as well as Mongolian jirds (Meriones unguiculatus) were orally inoculated with 2,000-5,000 embryonated eggs of B. transfuga. In mice, the ascarid caused symptomatic LM of limited extent and duration, whereas the infection was fatal in jirds; i.e., they exhibited general signs such as severe depression and emaciation on days 8-11 postinfection (PI) and died, or they developed progressive and fatal neurological disorders after day 14 PI. Histological examination showed B. transfuga larvae in the brain of all mice and jirds examined, and the larvae collected from them developed to a size comparable with that of B. procyonis. There existed, however, critical differences in host reactions against larvae localized in the brain of mice and jirds; B. transfuga larvae found in mice were surrounded by granulomatous reactions and immobilized, whereas larvae found in jirds were free from any host reaction and mobile, causing extensive malacia.

Experimental infection in chickens with larvae of Baylisascaris transfuga (Nematoda: Ascaridoidea).

The larvae of Baylisascaris transfuga (Rudolphi, 1819) were able to penetrate the liver, lungs, carcass and brain of infected chickens, but a great number of larvae accumulated in the liver. No clinical signs were seen. Birds may serve as paratenic hosts of the parasite, but B. transfuga seems not to be a possible agent of avian cerebrospinal nematodosis.

Parenteral infection in mice with Baylisascaris transfuga (Nematoda: Ascaridae) infective eggs.

In order to investigate the ability of infective larvae of the nematode Baylisascaris transfuga (Rudolphi, 1819) Sprent, 1968 to hatch from the egg-shells and then to migrate in tissues, parenteral infections of mice with embryonated eggs were performed. Two groups of outbred albino mice were infected with approximately 3500 B. transfuga infective eggs subcutaneously (s.c.) or intraperitoneally (i.p.). B. transfuga larvae in the i.p. group rapidly hatched and migrated to the intestine, liver, lungs, brain and carcass. Subcutaneous inoculation of eggs was followed also by migration of hatched larvae in the examined organs. In the s.c. mice, extensive encapsulating reactions involving the subcutaneous tissues and carcass, and containing large numbers of hatched eggs and free motile larvae, were found at the sites of inoculation. Some differences in the migratory behaviour were observed between the two groups. It is shown that B. transfuga infective larvae are able to hatch and migrate in tissues of mice, and tend to settle and/or to be trapped in the intestinal wall and muscles, even after parenteral inoculations of embryonated eggs. These results could provide basic data for further investigations on the migratory pathways of B. transfuga larvae or to perform immunological and therapeutical studies.

Evaluation in white mice of the infectivity of eggs of Lagochilascaris minor (Nematoda: Ascarididae), incubated by decortication with sodium hypochlorite (NaOCl).

White mice were used to study the infectivity of the eggs of Lagochilascaris minor Leiper, 1909 after incubation in liquid media, with or without preservative substances. Potassium bichromate (K2Cr2O7) at 1% restrict hatching, while 1% formalin gave a greater larval yield. Incubation of eggs in distilled water, in Roux or Falcon flasks gave a good yield, whether the eggs were obtained from human feces or from experimentally infected cats. Treatment of eggs with Sodium hypochlorite (NaOCl) at 5.25% for 2 min prior to inoculation, produced a notable increment of the larval yield in the infections.

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.).