Locally acquired infection with Dibothriocephalus nihonkaiense (=Diphyllobothrium nihonkaiense) in France: the importance of molecular diagnosis.

Diphyllobothriasis is a parasitic fish-borne disease caused by tapeworms of the genus Dibothriocephalus (=Diphyllobothrium). The majority of reported cases are attributed to D. latum, based on morphological identification of eggs or proglottids. However, numerous reports in recent years suggested that other Dibothriocephalus species could be involved in human infections, mainly after consumption of salmonid fish. Among these, D. nihonkaiense has been predominantly reported from Eastern Asia and probably underestimated in the rest of the world. We report here a clinical case of D. nihonkaiense in a French patient (without history of travel abroad) after consumption of salmon. Suspected on morphological characteristics, the final identification of D. nihonkaiense was performed using molecular methods by sequencing nad1, cox1, and 5.8S rRNA (containing ITS1 and 2) genes sequences. The patient was successfully treated by a single dose of praziquantel. Reports of diphyllobothriasis due to D. nihonkaiense are rare outside Asia, but worldwide demand of seafood could lead to the globalization of cases and reflect the need to monitor the distribution of Dibothriocephalus species. Thus, clinical parasitologists should be aware of this risk and able to raise the possibility of infections by non-endemic Dibothriocephalus species in order to use the proper molecular tools.

Molecular Identification of Diphyllobothrium latum from a Pediatric Case in Taiwan.

Human diphyllobothriasis is a parasitic disease caused by ingestion of larvae (plerocercoids) in raw or undercooked fish and commonly found in temperate areas. Rare cases were reported in tropical or subtropical areas especially in children. The first documented case of pediatric diphyllobothriasis in Taiwan had been reported 11 years ago. Here, we report another 8-year-old girl case who presented with a live noodle-like worm hanging down from her anus, with no other detectable symptoms. We pulled the worm out and found the strobila being 260 cm in length. Examination of gravid proglottids showed that they were wider than their lengths, containing an ovoid cirrus sac in the anterior side and the rosette-shaped uterus. Eggs extracted from the uterus were ovoid and operculated. Diphyllobothrium latum was confirmed by molecular analysis of the mitochondrial DNA cytochrome c oxidase subunit 1 (cox1) gene. The girl was treated with a single oral dose of praziquantel, and no eggs or proglottids were observed from her stool in the subsequent 3 months. The reemergence of human diphyllobothriasis in non-endemic countries is probably due to prevalent habit of eating imported raw fish from endemic areas. This pediatric case raised our concern that human diphyllobothriasis is likely underestimated because of unremarkable symptoms.

Human Diphyllobothrium nihonkaiense infection in Washington State.

A patient in Washington State harbored a fish tapeworm most likely acquired from eating raw salmon. Diphyllobothrium nihonkaiense was identified by cox1 sequence analysis. Although this is the first documented human D. nihonkaiense infection in the United States, the parasite may have been present earlier but misidentified as Diphyllobothrium latum.

Diphyllobothrium nihonkaiense infections in a family.

Diphyllobothrium latum and Diphyllobothrium nihonkaiense are morphologically similar to each other, and only genetic method can differentiate clearly between the 2 species. A strobila of diphyllobothriid tapeworm discharged from a 7-year-old boy was analyzed to identify the species by mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequencing. He and his family (total 4 persons) ate slices of 3 kinds of raw fish 16 days before visiting our outpatient clinic. All family members complained of abdominal pain and watery diarrhea. They all expelled tapeworm strobilae in their stools. They were treated with a single oral dose of praziquantel and then complained of no more symptoms. The cox1 gene sequencing of the strobila from the boy revealed 99.9% (687/688 bp) similarity with D. nihonkaiense and only 93.2% (641/688 bp) similarity with D. latum. Thus, we assigned this tapeworm as D. nihonkaiense. This is the first report of D. nihonkaiense infection in a family in Korea, and this report includes the 8th pediatric case in Korea. The current report is meaningful because D. nihonkaiense infection within a family is rare.

Extracorporeal worm extraction of Diphyllobothrium nihonkaiense with amidotrizoic acid in a child.

Infection cases of diphyllobothriid tapeworms are not much in the below teen-age group. We report a case of Diphyllobothrium nihonkaiense infection in a 13-year-old boy. He presented with severe fatigue, occasional abdominal pain at night time. He also had several episodes of tapeworm segment discharge in his stools. By his past history, he had frequently eaten raw fish including salmon and trout with his families. Numerous eggs of diphyllobothriid tapeworm were detected in the fecal examination. We introduced amidotrizoic acid as a cathartic agent through nasogastroduodenal tube and let nearly whole length (4.75 m) of D. nihonkaiense be excreted through his anus. After a single dose of praziquantel, the child's stool showed no further eggs, and his symptoms disappeared. The evacuated worm was identified as D. nihonkaiense by mitochondrial cox1 gene analysis. Here we report a successful extracorporeal worm extraction from an infection case of D. nihonkaiense by the injection of amidotrizoic acid.

Two human cases of Diphyllobothrium nihonkaiense infection in Korea.

Diphyllobothrium latum and Diphyllobothrium nihonkaiense are the 2 reported main causes of human diphyllobothriasis in the Republic of Korea. However, the differentiation of these 2 species based on morphologic features alone is difficult. The authors used nucleotide sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene to diagnose Diphyllobothrium spp. Two patients visited the emergency room at Kyungpook National University Hospital on 3 April and 12 April 2013, respectively, with fragments of parasites found while defecating. The parasites were identified as Diphyllobothrium spp. based on morphologic characteristics, and subsequent cox1 gene sequencing showed 99.9% similarity (1,478/1,480 bp) with D. nihonkaiense. Our findings support the hypothesis that D. nihonkaiense is a dominant species in Korea.

Four human cases of Diphyllobothrium latum infection.

Diphyllobothrium latum infections in 4 young Korean men detected from 2008 to 2012 are presented. Three were diagnosed based on spontaneously discharged strobila of the adult worm in their feces, and 1 case was diagnosed by finding the worm at colonoscopy examination in a local clinic. The morphologic characteristics of the gravid proglottid and eggs were consistent with D. latum. All patients were treated with praziquantel 15 mg/kg, and follow-up stool examinations were done at 2 months after the medication. The main clinical complaints were intermittent gastrointestinal troubles such as indigestion, abdominal distension, and spontaneous discharge of tapeworm's segments in their feces. The most probable source of infection was the flesh of salmon or trout according to a patient's past history. These are the 45th to 48th recorded cases diagnosed by the adult worm in the Republic of Korea since 1971.

[Implementation of a network drug strategy: the case of praziquantel]. / Implementación de una estrategia de medicamentos en red: el caso de praziquantel.

Parasitic infections cause a huge burden of disease and are a current public health problem. The category of emerging or re-emerging disease is influenced by phenomena that occur in today's interconnected world because of globalization, the displacement of people, trade, uncoordinated urbanization and climate change, they have a very important influence on transmission of these diseases. In 2021 there was an increase in the number of patients who have required treatment for diphyllobothriasis in the Los Ríos Region. This article reviews aspects related to integrated Health Service networks to provide access to pharmacological treatments to patients diagnosed with diphyllobothriasis (tapeworm infection), implemented by the Valdivia Health Service Department, in collaboration with the San José de Osorno hospital, primary care centers and private centers in the Los Ríos Region.

The DL1 repeats in the genome of Diphyllobothrium latum.

Diphyllobothrium latum is a widespread intestinal parasite, which has a great clinical relevance, but there are no sequences of its nuclear genome. In this paper, a repetitive element in the D. latum genome is firstly described. The adult D. latum was obtained in the result of expulsion from intestinum of a patient suffering from diphyllobothriasis. Genomic DNA was isolated from several proglottids of this individual. PstI restriction products of D. latum genomic DNA were sequenced. Polymerase chain reaction (PCR) amplification of these products using genomic DNA and selected primers was carried out. Thereby a cluster of a repetitive element, called DL1, was discovered. For precise identification of a beginning and an end of the repeat, a product of PCR amplification of D. latum genomic DNA with one specific primer was sequenced. In discussion, several evidences that DL1 repeat is a member of the SINE family of retroposons were adduced.

[Molecular identification of human Diphyllobothrium nihonkaiense using mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequence].

Identification of Diphyllobothrium species has been carried out based on their morphology, especially sexual organs. In addition to these criteria, PCR-based identification methods have been developed recently. A 20 year-old Japanese living in Kochi Prefecture passed tapeworm. He was successfully treated with single dose of gastrografin. We examined the morphologic features of the proglottids and eggs using histology and scanning electron microscope. We also analyzed mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of the proglottids. The causative tapeworm species was identified as D. nihonkaiense based on the results of morphologic features and genetic analysis. We discussed the advantage of PCR-based identification methods of Diphyllobothrium species using cox1 sequence in the clinical laboratory.

The Things They Carry: Diphyllobothriasis at Sea, a Case Report.

Diphyllobothrium, also known as the "Broad Tapeworm" or "Fish Tapeworm," is a genus of Cestoda acquired through the consumption of undercooked fish. Although infection by a Diphyllobothrium spp. in the United States is rare, it remains an important global zoonosis, with an estimated burden of approximately 20 million people worldwide. A seldom on the Primary Care Physician's differential diagnosis in the United States, Diphyllobothrium spp. should be considered more readily when treating operational service members as they are exposed to endemic regions more frequently than the civilian population. This case presents one such service member diagnosed with Diphyllobothrium while aboard a U.S. naval vessel at sea, illustrating the importance of military medical providers considering Tapeworm infection even when risk factors seem remote. Diagnostic considerations, practical limitations of the Ova and Parasite (O&P) exam, particulars of specimen collection and handling, and recommendations for empiric treatment in the operational setting will be reviewed.

Dibothriocephalus nihonkaiensis: an emerging foodborne parasite in Brittany (France)?

BACKGROUND: Diphyllobothriosis is an intestinal cestodosis caused by tapeworms of the family Diphyllobothriidae. In France, endemic cases are limited to south-east and due to Dibothriocephalus latus. In this paper, we investigate a series of seven cases of diphyllobothriosis in the non-endemic French region of Brittany. All have been diagnosed between 2016 and 2018 at the University Hospital of Rennes. METHODS: Parasites were identified by their morphological features and by phylogenetic analysis of the cox1 gene. Phylogenetic tree was built using maximum likelihood criterion under the GTR+G+I model and 2000 bootstrap replicates. A form was sent to all patients to collect data concerning clinical signs and possible sources of infection. RESULTS: All cases were due to Dibothriocephalus nihonkaiensis, a species strictly distributed in the North Pacific. Epidemiological investigation showed that the parasite was probably acquired in France, after consumption of Japanese food containing raw salmon. All patients presented with at least abdominal pain and fatigue except for one patient who had no symptoms. CONCLUSIONS: To our knowledge, this case series is the most important cohort of allochthonous diphyllobothriosis described in Europe. This sudden emergence raises concern about foodborne infections, highlighting (i) risky food habits in absence of adequate sanitary control; and (ii) the breaking of the rule of geographical restriction due to globalization and worldwide trades.

Case Report: Acute Generalized Exanthematous Pustulosis Caused by Praziquantel.

Praziquantel is widely used for treating parasitic infections globally, especially in countries with endemic schistosomiasis. However, severe hypersensitivity to praziquantel has rarely been reported. We report the case of a 30-year-old Japanese man who developed acute generalized exanthematous pustulosis (AGEP), which is a rare and severe cutaneous reaction usually triggered by drugs, after taking praziquantel. During medical examination, eggs of Diphyllobothrium nihonkaiense were found in his stool. He took praziquantel 600 mg for 1 day and developed skin rashes and fever the next day. Pruritic generalized maculopapular erythematous eruptions were observed over the entire body. He had elevated white blood cell count, liver enzymes, and C-reactive protein level. We prescribed acetaminophen, fexofenadine hydrochloride, loxoprofen sodium, and topical ointments including difluprednate and hydrocortisone. Over the next 3 days, he developed pinhead-sized, non-follicular pustules on his diffusely erythematous skin. Histological findings of the pustular lesion showed spongiform subcorneal pustules with perivascular inflammatory cells. Approximately 8 days after taking praziquantel, the pustules resolved with desquamation. He became afebrile on day 9 and his laboratory parameters returned to normal levels on day 16. He was diagnosed with AGEP caused by praziquantel. Physicians need to be aware that praziquantel could cause AGEP, although it is generally considered a safe drug.

A 2-year-old girl with Diphyllobothrium nihonkaiense infection treated with oral praziquantel and a laxative.

We report a case of Diphyllobothrium nihonkaiense infection in a 2-year-old Japanese girl. When infection occurs in early childhood, it is necessary to offer supportive care in addition to standard treatment with oral praziquantel or with of a duodenal tube using a radiopaque contrast medium. We treated D. nihonkaiense infection in a 2-year-old girl successfully treated with oral praziquantel and a laxative.

Diphyllobothrium latum infection in a non-endemic country: case report.

Diphyllobothriasis, which is rarely described in Brazil, was reported initially as a travelers disease and as an accidental infection in individuals who ate raw freshwater fish. This report aims to present the case of a 20-year-old patient with confirmed Diphyllobothrium latum infection.

Diphyllobothriasis in a U.S. Military Aviator.

BACKGROUND: Diphyllobothriasis is estimated to afflict 10-20 million people worldwide; however, this is the first case reported in a United States military aviator. Among the largest parasites of humans, the "fish tapeworm" grows from 2-15 m in length, can live >20 yr in the intestines, and is contracted through consumption of uncooked, unfrozen freshwater or anadromous fish species. CASE REPORT: A 32-yr-old male F-22 pilot presented with mild stomach cramping, bloating, nausea, and intermittent loose stools. Symptoms were relieved with bismuth subsalicylate until several days later when the patient, during otherwise normal bowel movements, extracted multiple broken segments of tapeworm. Although physically asymptomatic, he was psychologically disturbed. Based on the large number of ova with characteristic shape, size, color, and operculum, coupled with the flattened body, yellowish coloration, and rectangular proglottids with centrally located "rosette" uteri, he was diagnosed with diphyllobothriasis (likely D. latum or D. nihonkaiense). Successful treatment with a single oral dose of praziquantel (>10 mg · kg-1) was confirmed by negative stool examination over 60 d posttreatment. He likely contracted the parasite from ingesting salmon sushi or sashimi while previously stationed in Japan. DISCUSSION: Despite only mild physical symptoms, the pilot's psychological distress and distraction from knowing about the meters-long tapeworm was significant. Prompt treatment was paramount to resumption of military operations. Aviators should be educated and encouraged to eat only well-cooked or previously frozen fish, especially when indulging in cultural cuisine.Kasteler SD. Diphyllobothriasis in a U.S. military aviator. Aerosp Med Hum Perform. 2018; 89(5):473-477.

A case of human diphyllobothriasis in northern Taiwan after eating raw fish fillets.

The consumption of raw fish fillets is increasing in Taiwan. A male Taiwanese aged 30 years presented after passing a flat, white noodle-like worm. Strobila examination showed that most proglottids were wider than they were long, with the genital pore located at the posterior edge of the cirrus. Histological and coprological findings confirmed the diagnosis of Diphyllobothrium latum; ova were ellipsoidal with operculate characteristics, and had a small knob in the anti-operculum side. Hematological data, including vitamin B12 levels, were normal, except for a low folate level. The patient was treated with a single dose of praziquantel 600 mg and 196 cm of proglottids were expelled during the 3 days following treatment. Further follow-up was declined. Consumption of raw and undercooked fish (especially salmon) poses a risk of D. latum infection.