Camallanus carangis Olsen, 1954 (Nematoda: Camallanidae) reported from French Polynesia and Hawai'i with a redescription of the species.

The marine fish parasite Camallanus carangis Olsen, 1954 (Nematoda: Camallanidae) is redescribed from the honeycomb grouper Epinephelus merra (Serranidae) in the Tuamotu Islands of French Polynesia and the glasseye Heteropriacanthus cruentatus (Priacanthidae) in Hawai'i, both coral reef fishes. Camallanus carangis is reported for the first time from French Polynesia and Hawai'i. Camallanus marinus Schmidt and Kuntz, 1969 is designated a synonym of C. carangis and Camallanus paracarangis Velasquez, 1980 is regarded as a species inquirenda. Additionally, the genus Oncophora may need to be redefined to accommodate Camallanus aotea Slankis and Korotaeva, 1974, which bears more resemblance to Oncophora than Camallanus.

Redescription of Camallanus cotti Fujita, 1927 (Nematoda: Camallanidae) from Hawai'i.

The freshwater fish parasite Camallanus cotti Fujita, 1927 (Nematoda: Camallanidae) is redescribed from the guppy Poecilia reticulata (Poeciliidae). We confirm previous reports of its occurrence in other introduced poeciliids in Hawai'i, in 4 species of native Hawaiian gobioid stream fishes, and in an elasmobranch, an aquarium-reared stingray Potamotrygon sp. (Dasyatididae) from Hawai'i. Because the source localities of introduced freshwater fish parasites may be far removed geographically from communities that they have invaded, especially oceanic archipelagos (such as Hawai'i), we believe that research on these exotic parasites must be based upon critical taxonomic evaluations. Our redescription of C. cotti serves as a foundation upon which ecological studies of this parasite, performed in conjunction with conservation efforts for native Hawai'ian stream fishes, will be based.

Evaluation of bleached kraft mill process water using Microtox(R), Ceriodaphnia dubia, and Menidia beryllina toxicity tests.

To determine whether a 7- to 10-d embryo toxicity/teratogenicity test with the inland silverside fish, Menidia beryllina, is a sensitive indicator for evaluation of bleached kraft mill effluents, we compared this test with the Microtox(R) 15-min acute toxicity test and the Ceriodaphnia dubia 7-d chronic toxicity test. Water samples used in each test were collected from three areas in a bleached kraft pulp and paper mill using a 100% chlorine dioxide bleaching process: 1) river water prior to use in the mill; 2) the combined acid/base waste stream from the pulping process prior to biological treatment in the aerated stabilization basin (ASB); and 3) the effluent from the ASB with a retention time of approximately 11 d. Relative toxicity determined by the three tests for each water sampling location was compared. All three toxicity tests were predictive indicators of toxicity; however, the C. dubia and M. beryllina tests were the more similar and sensitive indicators of toxicity. Process water (ASB influent) prior to biological treatment in the ASB was toxic at all concentrations using the Microtox(R) and C. dubia tests. The fish embryo test showed no toxicity at 1% concentrations, slight toxicity at 10%, and acute toxicity at the 100% ASB influent concentration. Tests with biologically-treated ASB effluent indicated a substantial reduction in observed toxicity to Microtox(R) bacteria, C. dubia, and M. beryllina. No toxic responses were observed in any test at a 1% ASB effluent concentration which was the approximate effluent concentration in the receiving river following mixing. No relationship was found among any toxicological response and effluent levels of adsorbable organic halides, polychlorinated phenolic compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran, total suspended solids, color, chemical oxygen demand, or total organic carbon.

Epidemiology of marine fish-borne parasitic zoonoses.

Most parasites of marine animals are of little public health concern; however, some helminths are capable of infecting humans. Marine zoonotic infections in humans result from consumption of contaminated edible tissues or products of seafood or, to a lesser extent, from physical contact with contaminated seafood. Worldwide, over 50 species of helminth parasites from fishes, crabs, crayfishes, snails, and bivalves are known to produce human infections. Most helminth zoonoses are rare and invoke only slight to moderate injury; however, some are more prevalent and pose serious potential health hazards. Worldwide, the majority of seafood zoonoses occur along coastal regions where seafood products are commonly consumed. Continuing improvements in transportation, technology, and food handling, however, allow fresh seafood to be shipped throughout the world; thus, the potential for acquisition of parasitic infections from marine products is not limited to coastal populations. Although the number of documented cases continue to increase, the overall risk of human infection is slight. The increasing exploitation of the marine environment by humans, changing dietary habits incorporating "natural" seafood dishes (eg, sushi and sashimi), and tendency to reduce cooking times when preparing seafood products, all increase the chances of becoming infected with these parasites.

Human anisakiasis transmitted by marine food products.

Seafood-transmitted parasitic diseases represent an emerging area of interest to the U.S. Food and Drug Administration. Human infections with marine parasites are generally the result of ingesting uncooked seafood products. Over 50 species of helminthic parasites are known to infect humans worldwide. Recently, the number of infections with one of these helminths, the juvenile stage of the marine nematode, Anisakis simplex, has increased in the United States. Raw fish dishes such as lomi lomi salmon and sashimi are known to transmit the parasite to unsuspecting citizens and the most frequently implicated fish in the transmission of this zoonotic disease is the Pacific salmon (Oncorhynchus spp.). The risk of infection from fishes caught in Hawaiian waters is slight; however, a juvenile Anisakis simplex infected one patient from either locally caught aku or ahi. We report 4 new cases, which brings the total number of known cases in Hawaii to 7. Five of the 7 cases were diagnosed and treated by means of an endoscope and biopsy forceps. Serological profiles are presented in several of these cases. One case represents the first known instance of reinfection; the initial infection occurred 2 years prior. The second infection gave an opportunity to compare the human response to a challenge infection and to investigate the validity of the "double hit" theory. Increased awareness by physicians to the clinical features of this disease is warranted. The zoonotic disease, anisakiasis, should be considered in patients presenting with intense abdominal pain, if these patients admit they have recently eaten raw or undercooked seafoods.

Anisakis simplex: histopathological changes in experimentally infected CBA/J mice.

Third-stage juveniles (L3) of Anisakis simplex, surgically implanted into the abdominal cavity of CBA/J mice and necropsied at 7, 14, or 21 days postinfection (PI), embedded in the gut mesentery and only rarely invaded viscera. Histologically, intense aggregations of neutrophils adjacent to the parasites were noted at Day 7 PI. At Day 14 PI, mature granulomata consisting mostly of eosinophils and large numbers of fibroblasts and associated collagen were observed. Granulocytes and occasionally multinucleate giant cells occupied the host-parasite interface. At 21 day PI, lesions displayed the predominance of connective tissue. Multinucleate giant cells were found adjacent to the L3 with eosinophils adjacent to parasite remnants or scattered within the walls of the granulomata. Most L3 were viable at Days 7 and 14 PI; however, at Day 21 PI the L3 were dead and invaded by inflammatory cells. Hematological findings indicated that infected mice had a neutrophilia of varying magnitude regardless of the number of worms implanted. Eosinophil levels as a percentage of the total leukocyte pool in peripheral blood always remained at or below normal limits. On Days 7 and 14 PI, the peripheral blood showed an increase in neutrophils that began to return to normal values at 21 day PI. Conversely, peripheral blood eosinophils decreased on Days 7 and 14 PI and returned to normal values on Day 21 PI. Surgical implantation of A. simplex L3 into mice produced both a hematological and histological picture consistent with that seen in human anisakiasis.

Human nanophyetiasis: transmission by handling naturally infected coho salmon (Oncorhynchus kisutch).

The first US case of human nanophyetiasis that does not involve ingestion of raw or undercooked salmonid fishes is reported. The patient worked with highly infected fish. Hand contamination with the infectious metacercariae of the digenetic trematode Nanophyetus salmincola (family Troglotrematidae) occurred during the handling of fresh-killed, juvenile coho salmon, Oncorhynchus kisutch. Diagnosis of nanophyetiasis was based on the clinical findings of chronic diarrhea, nausea, abdominal discomfort, and a peripheral blood eosinophilia of 43% and was confirmed on finding characteristic bipolar eggs in a stool specimen. The patient rarely ate seafood products and never ate raw or cold smoked fish. He responded favorably to praziquantel and was asymptomatic after therapy.

Prevalence of larval Anisakis simplex in pen-reared and wild-caught salmon (Salmonidae) from Puget Sound, Washington.

The abundance of parasites of public health significance in pen-reared salmon and wild-caught salmon was compared. Two hundred eighty-seven salmon from Puget Sound, Washington, were examined for third-stage larvae of Anisakis simplex. Of these fish, 237 Atlantic salmon (Salmo salar), coho salmon (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) were reared in commercial salmon pens and 50 sockeye salmon (O. nerka) were caught during their spawning migration. All wild-caught salmon were found to be infected with larval A. simplex; conversely, all pen-reared fishes lacked such infections. Edible musculature of wild salmon were infected with 581 (87%) nematode larvae. Of other salmon parasites known to infect humans, one Diphyllobothrium sp. plerocercoid was collected from each of three of the 50 wild-caught salmon. The study showed that farmed salmon may increase the margin of safety for consumers of raw seafood.

Commercial blast-freezing of third-stage Anisakis simplex larvae encapsulated in salmon and rockfish.

Sixty-four fish were blast-frozen to -35 C for 15 hr to determine the effects of commercial blast-freezing on the viability of third-stage larvae of Anisakis simplex encapsulated in the muscle and viscera of sockeye salmon (Oncorhynchus nerka) and canary rockfish (Sebastes pinniger). Parallel tests were conducted on larval nematodes in 16 whole (round) salmon, 16 dressed salmon (heads and viscera removed), and 32 whole (round) rockfish. After blast-freezing, 4 in-the-round salmon, 4 dressed salmon, and 8 in-the-round rockfish were examined at 1, 24, 48, and 72 hr. A total of 3,539 dead and 6 live larvae were collected from the fish tissues after standard enzymatic digestion. Salmon were infected with 1,245 of these larvae, and rockfish with 2,300. The 6 live worms, 2 from salmon and 4 from rockfish rounds, were recovered from muscle 1 hr after freezing; they were slightly motile and showed severe internal damage. No viable worms were found at or after 24 hr. The commercial blast-freezing process effectively killed larval nematodes in whole or dressed fish. Market-ready samples of previously blast-frozen silver salmon (O. kisutch) and chum salmon (O. keta) fillets and chum salmon steaks yielded no live worms, thereby confirming the efficacy of this process.

Intestinal anisakiasis. A case diagnosed by morphologic and immunologic methods.

The diagnosis of the fourth reported case of intestinal anisakiasis in the United States was based on the morphologic characteristics of the worm in histologic sections of resected ileum. Detection of antibodies to the worm by a radioallergosorbent test (RAST), enzyme-linked immunosorbent assay (ELISA), and an immunofluorescent antibody assay (IFA) support the diagnosis. IgE antibodies in patient serum reacted specifically to larval Anisakis antigens but not to larval Ascaris antigens in the RAST. IgG and IgM antibodies to larval Anisakis antigen could be detected by ELISA up to six months after infection. IFA findings demonstrated that patient serum recognized the excretory-secretory products produced by the worm and showed their presence in vivo. These products appear to originate from the excretory pore and dorsal esophageal gland of the larval parasite.

Rhinebothrium devaneyi n. sp. (Eucestoda: Tetraphyllidea) and Echinocephalus overstreeti Deardorff and Ko, 1983 (Nematoda: Gnathostomatidae) in a thorny back ray, Urogymnus asperrimus, from Enewetak Atoll, with phylogenetic analysis of both species groups.

The new species is a member of an apparently monophyletic group within the genus that includes R. flexile, R. walga, R. himanturi, R. burgeri, R. euzeti, R. hawaiiensis, R. urobatidium, R. paratrygoni, R. ditesticulum, R. tetralobatum, R. margaritense, R. biorchidum, and R. spinicephalum. All of these species have bothridia with medial longitudinal septa, a constriction at mid-bothridium, and, primitively, at least 42 loculi per bothridium and 17-22 testes per proglottid. Of the above, the new species is apparently most closely related to R. burgeri, with which it shares an increased number of testes (30-43) per proglottid, a V-shaped ovary, and a muscular genital pore. The new species is distinct by virtue of possessing 94-152 loculi per bothridium--no other known species has more than 78. This is the second report of Echinocephalus overstreeti from a stingray. It represents a new host, U. asperrimus, and a new location, Enewetak Atoll. Phylogenetic and biogeographic analysis of each species group suggests an ancient Tethys Sea-circum-Pacific origin and evolution. This supports the hypothesis of ancient Pacific origins for potamotrygonid stingrays.

Anisakis simplex: larval excretory secretory protein production and cytostatic action in mammalian cell cultures.

Excretory secretory proteins produced in vitro by Anisakis simplex larvae incubated in Medium 199 or phosphate buffered saline with dextrose are similar with respect to protein content and biological activity. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggested that the molecular weight of the component(s) responsible for inhibition of mitogen induced lymphocyte blastogenesis is between 66,000 and 95,000. In vitro production of excretory secretory protein, approximately 1 microgram/24 hr by a single larva, was sufficient to inhibit lymphocyte blastogenesis. Serum from a human anisakiasis patient reacted with these proteins in immunoblots, indicating that, during invasion of the gastric mucosa, enough of them are produced in vivo to induce an immune response. The excretory secretory proteins significantly inhibited proliferation of transformed mammalian cell lines of lymphoid (P3/X63-Ag8) and epithelioid (HeLa) origin. As in mitogen stimulated lymphocytes, the inhibitory effect was cytostatic rather than cytotoxic. These findings suggest that, in addition to being potent immunogens, larval excretory secretory proteins are produced in sufficient quantity to modulate the host response in anisakiasis.

Piscine adult nematode invading an open lesion in a human hand.

The first case of an adult, parasitic nematode entering an open lesion is reported. A female dracunculoid, Philometra sp., invaded a puncture wound in a fisherman's hand while he was filleting an infected carangidae fish, Caranx melampygus, in Hawaii. This accidental infection represents a previously unrecognized risk in handling uncooked, infected fish.

Invasive anisakiasis. A case report from Hawaii.

A confirmed case of penetration into the stomach wall by an anisakine nematode, to our knowledge the first in the United States, is reported. A viable third-stage larva of Anisakis simplex was removed from a woman in Hawaii who had eaten fresh, raw salmon. A serodiagnostic test showed the serum of the patient to be positive for A. simplex-specific IgE at days 11 and 60 postinfection. Our results indicate that eating fresh, raw salmon exposes consumers to a significant health risk.

Anisakis simplex and Terranova sp.: inhibition by larval excretory-secretory products of mitogen-induced rodent lymphoblast proliferation.

Excretory-secretory products were collected from supernatants of in vitro cultures of larval nematodes, Anisakis simplex (type I) and Terranova sp. (Hawaii type A). These materials were found to be more potent inhibitors of rodent lymphocyte blast transformation induced by concanavalin A and bacterial lipopolysaccaride than whole worm extracts of the same parasites. Inhibition of blast transformation was a result of cytostatic rather than toxic effects on proliferating lymphoid cells. The material(s) responsible for suppression are greater than 10,000 MW and are heat labile.

Histopathology induced by larval Terranova (Type HA) (Nematoda: anisakinae) in experimentally infected rats.

Terranova Type Hawaii A larvae, gavaged into the stomach of Wistar rats, demonstrated the ability to invade the stomach and intestinal tissues of the rat without penetrating the serosa. Lesions induced by these third-stage larvae were present in 25 of 37 (68%) inoculated rats. Larvae adhered to the mucosa of the stomach within 1 hr PI. Mucosal ulceration and acute, focal, hemorrhagic areas in the mucosa and submucosa were associated with most worm-penetrations. Reactions of inflammatory tissue occurred from 4 hr to 6 days PI and granulomas occurred by day 7 PI. Indurated craterlike lesions were noted 10 to 15 days PI. Resolving granulomas were present by day 30 PI. Chronic gastric ulcers were observed at day 30 PI.

Thynnascaris rhacodes sp. n. (Nematoda: Ascaridoidea) in fishes from the Israeli Mediterranean coast.

Thynnascaris rhacodes sp. n. infects Pelates quadrilineatus, Solea vulgaris, Boops boops, Lithognathus mormyrus, Obleida melanura, Diplodus vulgaris, D. sargus, and Sparus auratus from the eastern Mediterranean Sea. Unique in that the cuticle on the female tail is wrinkled, the ascaridoid is further characterized by possessing 27 to 35 precloacal papillae, a body length of 11 to 85 mm, similar spicules 3 to 6% of body length, a length-ratio of intestinal cecum to ventricular appendage of 1 : 1 to 5, and lips longer than wide.