Local outbreak of spontaneous pneumothorax secondary to paragonimosis in southwestern Ontario dogs.

Three dogs were diagnosed with spontaneous pneumothorax and referred to the Ontario Veterinary College Health Sciences Centre for management. The 3 dogs were diagnosed with secondary spontaneous pneumothorax due to paragonimosis. The diagnosis was made by visualization of adult trematodes during surgical exploration with histopathological confirmation in 1 dog, and detection of trematode eggs via fecal sedimentation in the other 2 dogs. Two of the dogs developed unusual additional lesions, including hemoabdomen, muscle abscess, and abdominal adhesions. These were suspected to be secondary to aberrant fluke larval migration. All 3 dogs lived within a relatively small geographical area of Ontario and were hospitalized between December 2021 and March 2022. Each dog survived to discharge with surgical or medical management of the pneumothorax and treatment with a prolonged course of fenbendazole. Key clinical message: Paragonimosis should be considered as a differential diagnosis for canine spontaneous pneumothorax in areas where Paragonimus kellicotti is, or may be, endemic, or in dogs that have travelled to endemic areas - particularly if the patient has a history of cough or potential exposure to freshwater crayfish. Routine anthelmintic treatment does not prevent infection and standard fecal floatation methods may not detect the eggs. Therefore, diagnostic testing should include a fecal sedimentation test and thoracic radiographs to screen for P. kellicotti.

Éclosion locale de pneumothorax spontané secondaire à la paragonimose chez des chiens du sud-ouest de l'Ontario. Trois chiens ont reçu un diagnostic de pneumothorax spontané et ont été référés au Ontario Veterinary College Health Sciences Centre pour prise en charge. Les 3 chiens ont été diagnostiqués avec un pneumothorax spontané secondaire dû à la paragonimose. Le diagnostic a été posé par la visualisation des trématodes adultes lors de l'exploration chirurgicale avec confirmation histopathologique chez 1 chien, et la détection des oeufs de trématodes par sédimentation fécale chez les 2 autres chiens. Deux des chiens ont développé des lésions supplémentaires inhabituelles, notamment un hémoabdomen, un abcès musculaire et des adhérences abdominales. Ces lésions étaient soupçonnées d'être secondaires à une migration larvaire aberrante de la douve. Les 3 chiens vivaient dans une zone géographique relativement restreinte de l'Ontario et ont été hospitalisés entre décembre 2021 et mars 2022. Chaque chien a survécu jusqu'à sa sortie avec une prise en charge chirurgicale ou médicale du pneumothorax et un traitement avec un traitement prolongé au fenbendazole.Message clinique clé :La paragonimose doit être considérée comme un diagnostic différentiel du pneumothorax spontané canin dans les zones où Paragonimus kellicotti est, ou peut être, endémique, ou chez les chiens qui ont voyagé dans des zones endémiques ­ en particulier si le patient a des antécédents de toux ou une exposition potentielle aux écrevisses d'eau douce. Le traitement vermifuge de routine n'empêche pas l'infection et les méthodes de flottaison fécale standard peuvent ne pas détecter les oeufs. Par conséquent, les tests de diagnostic doivent inclure un test de sédimentation fécale et des radiographies thoraciques pour dépister P. kellicotti.(Traduit par Dr Serge Messier).

A case of cerebral paragonimiasis misdiagnosed as eosinophilic granulomatosis with polyangiitis.

Paragonimiasis is a parasitic disease caused by Paragonimus westermani infection, and migration to the brain results in cerebral paragonimiasis. Cerebral paragonimiasis is now extremely rare, but a few cases are still reported. A 48-year-old Japanese woman presented with right-hand convulsion, right-hand numbness, sputum, and fatigue. Chest computed tomography demonstrated multiple nodular lesions, and head computed tomography revealed a hemorrhagic lesion in the left motor cortex. Magnetic resonance imaging revealed multiple small ring-shaped lesions with surrounding edema. Laboratory evaluation demonstrated peripheral eosinophilia. We considered eosinophilic granulomatosis with polyangiitis and started steroid treatment as a diagnostic therapy since we wanted to avoid cerebral lesion biopsy if possible. However, the patient underwent craniotomy surgery after steroid treatment for four months because a new intracerebral mass lesion had appeared. Trematode eggs were detected in the sample, and the final diagnosis was cerebral paragonimiasis. The patient was successfully treated with praziquantel. Cerebral paragonimiasis is extremely rare but should be considered in the differential diagnosis if atypical intracranial hemorrhage and peripheral eosinophilia are observed.

Dynamic transcriptome landscape of Paragonimus proliferus developmental stages in the rat lungs.

Paragonimus proliferus, a lung fluke of the genus Paragonimus, was first reported in Yunnan province, China. P. proliferus can infect Sprague-Dawley (SD) rats and cause lung damage, but there is still no direct evidence of human infection. Until now, there has been a lack of studies on P. proliferus parasitism and development in mammalian lung tissue. The aim of this study was to perform transcriptomic profiling of P. proliferus at different developmental stages. SD rats were infected with P. proliferus metacercariae obtained from crabs; worms isolated from the lungs at different time points as well as metacercariae were subjected to whole transcriptome sequencing. Overall, 34,403 transcripts with the total length of 33,223,828 bp, average length of 965 bp, and N50 of 1833 bp were assembled. Comparative analysis indicated that P. proliferus, similar to other Paragonimus spp., expressed genes related to catabolism, whereas P. proliferus-specific transcripts were related to the maintenance of cellular redox homeostasis, sensitivity to bacteria, and immune response. Transcriptional dynamics analysis revealed that genes involved in the regulation of catabolism and apoptosis had stable expression over the P. proliferus life cycle, whereas those involved in development and immune response showed time-dependent changes. High expression of genes associated with immune response corresponded to that of genes regulating the sensitivity to bacteria and immune protection. We constructed a P. proliferus developmental model, including the development of the body, suckers, blood cells, reproductive and tracheal systems, lymph, skin, cartilage, and other tissues and organs, and an immune response model, which mainly involved T cells and macrophages. Our study provides a foundation for further research into the molecular biology and infection mechanism of P. proliferus.

An outbreak of Paragonimus westermani infection among Cambodian technical intern trainees in Japan, exhibiting various extrapulmonary lesions.

We encountered an outbreak of paragonimiasis among Cambodian technical intern trainees (TITs) at a food-processing factory in Fukuoka, Japan. The patients were 20-28 years old, seven females and two males, who had been in Japan for one to four years. All of them had consumed raw or undercooked Japanese mitten crab they purchased at a local grocery store near their training place. CT images showed multiple lesions not only in the lungs but in the extrapulmonary organs as well, such as subcutaneous tissues, abdominal muscles, and mesentery, in most of the patients. Their medical records indicated that all of them acquired infection in Japan, not in Cambodia. Diagnosis was made serologically and the patients were treated with praziquantel successfully. Foreign workers and TITs are increasing in Japan so rapidly, that food borne-infections, including paragonimiasis, should be considered in people from developing countries who have exotic dietary habits.

Paragonimus heterotremus Chen et Hsia, 1964 (Digenea: Paragonimidae): species identification based on the biological and genetic criteria, and pathology of infection.

As a result of the experimental infection of rats with metacercariae of Paragonimus heterotremus Chen et Hsia, 1964 from crabs (Potamiscus tannanti) caught in Yen Bai province, Vietnam, it was found that worms migrated into the lungs, to the liver and less frequently to the tissue that lines body cavities of the hosts, where they reached the adult stage, but in the muscles, worms stayed at the larval stage. Studies have shown that for P. heterotremus, rats can simultaneously play the role of the final and paratenic host; herewith, an infection with the trematode of this species can lead to the development of three forms of paragonimiasis: pulmonary, hepatic and muscular. Eggs from the adult worms localised in the liver, unlike eggs from the adult worms localised in the lungs, were not excreted into the external environment, but accumulated inside the organ. Histology and description of changes, which take place on the external surface of organs affected with P. heterotremus, are given in this study. Based on the behavioural characteristics of worms during rat infection and molecular genetic data, we established that worms from Vietnam and India should be assigned to different species of Paragonimus. P. heterotremus distribution is limited to the territory of the Southeast China, Northern Vietnam, Laos and Thailand.

Pleuropulmonary Paragonimiasis with Multiple Nodules in the Pleura.

An asymptomatic 47-year-old woman was admitted with pleural effusion and pulmonary infiltrates 1 month after ingesting raw wild boar and deer meat. Both her blood and pleural fluid were eosinophilic. Thoracoscopy revealed multiple nodules of the pleura, and biopsy samples of the nodules showed necrosis with epithelioid cell granulomas. An enzyme-linked immunosorbent assay was positive for antibodies against Paragonimus westermani, and the patient was successfully treated with praziquantel. This is the first reported case of pulmonary or pleuropulmonary paragonimiasis where several pleural nodules were observed. The detection of pleural nodules on thoracoscopy can contribute to the prompt and accurate diagnosis of paragonimiasis.

Intraspinal Paragonimiasis in Children: MRI Findings and Suggestions for Pathogenesis.

BACKGROUND AND PURPOSE: Intraspinal paragonimiasis is a rare entity for which imaging findings have seldom been described. The present study investigated the MR imaging features of spinal paragonimiasis, thus providing diagnostic imaging evidence and exploring the possible pathogenesis of intraspinal paragonimiasis. MATERIALS AND METHODS: The clinical and imaging findings of spinal paragonimiasis in 6 children were analyzed retrospectively. Spinal MR imaging was performed in all patients, 5 of whom also underwent enhanced MR imaging. The diagnosis was confirmed by enzyme-linked immunosorbent assay in all cases and postoperative pathology in 4 cases. RESULTS: All cases manifested as fusiform-shaped or beanlike masses in the extradural space in the thoracic spine. The extradural masses were connected with pleural lesions through the intervertebral foramen. The plain MR imaging scan showed mixed signals with predominant isointensity on T1WI and hyperintensity on T2WI, among which 5 (5/6) masses presented as patchy hemorrhage with hyperintensity on T1WI. On enhanced scans, all masses (5/5) showed heterogeneous marked enhancement, with thickening and enhancement in the adjacent spinal meninges (5/5). Various degrees of spinal cord compression and edema were found in 5 cases (5/6). CONCLUSIONS: MR imaging is sensitive for detecting and characterizing spinal paragonimiasis. The MR imaging features of intraspinal granulomas included localization to the extradural space and thoracic segment, connections between intraspinal lesions and pleural lesions through the intervertebral foramen, and hemorrhagic foci within the mass. These findings support an intraspinal mode of paragonimiasis pathogenesis: The Paragonimus larvae migrate from the chest into the extradural space through the intervertebral foramen.

[Clinical and imaging features of thirty cases of paragonimiasis westermani].

OBJECTIVE: To analyze the clinical manifestations and imaging characteristics of pulmonary and extra pulmonary paragonimiasis westermani. METHODS: A retrospective analysis was performed of 30 patients diagnosed by clinical features, laboratory serological tests and surgical pathology. RESULTS: The symptoms of the lung included mainly chest distress, fever, chest pain, cough and expectoration, and dyspnea. The extra pulmonary symptoms included abdominal pain, vomiting, diarrhea, poor appetite, emaciation, both lower extremities asthenia, headache, dizziness, epileptic seizures, and subcutaneous migratory masses. The laboratory examination showed that the eosinophil numbers of serum and pleural effusion of all the thirty patients were increased, and the eggs of Paragonimus westermani were found by the stool tests in four cases. The chest CT tests found abnormal nodules, ground glass changes, insect damages, pleural effusion, "tunnel" signs, and "halo" signs. Cranial CT and MRI showed intracranial hemorrhage foci, and extensive "finger-like" edema. Abdominal CT showed serpentine deformation and "tunnel" signs in the hepatic and spleen capsules. CONCLUSIONS: Paragonimiasis westermani is a multiple organ system involved infection, and it has complex and varied clinical manifestations. The "tunnel" sign and serpentine deformations in the intracranial part, lung, liver and spleen are important imaging manifestations of the disease.

[Clinical analysis of 50 cases of serous cavity effusion related with paragonimiasis].

OBJECTIVE: To analyze the clinical characteristics of serous cavity effusion related with paragonimiasis, so as to improve the physician's ability of the clinical diagnosis and treatment. METHODS: The clinical data of 50 cases of serous cavity effusion related with paragonimiasis diagnosed in a hospital in recent 3 years were collected and retrospectively analyzed. RESULTS: Among the 50 patients, there were 35 males and 15 females, and 35 children and 15 adults. Eighteen patients had a clear history of exposure to the foci. Among the children, the respiratory symptoms accounted for 68.6% (24/35), gastrointestinal symptoms for 22.9% (8/35), and no apparent symptoms for 8.6% (3/35); among the adults, the respiratory symptoms accounted for 93.3% (14/15) and the abdominal distention for 6.7% (1/15). The paragonimus antibody was positive in all the patients. The chest radiography or CT showed pulmonary inflammatory exudation and serous cavity effusion. Eosinophilia in blood was found in 25 cases, a large number of eosinophils in serous cavity effusion were found under microscopy in 12 cases, and eosinophil infiltration of pleura was found in 7 cases. All were cured after the patients received chemotherapy (praziquantel) and drainage fluid. CONCLUSIONS: The clinical manifestations of paragonimiasis are not very specific and paragonimiasis is often accompanied with serous cavity effusions. Clinically, paragonimiasis is easily misdiagnosed as tuberculosis or cancer. We should consider about the possibility of paragonimiasis when eosinophil is high in blood, serous cavity effusion and pleura.

Morphological and molecular characterization of Paragonimus caliensis Little, 1968 (Trematoda: Paragonimidae) from Medellin and Pichinde, Colombia.

Paragonimiasis is a subacute to chronic inflammatory granulomatous lung disease caused by the genus Paragonimus. In Latin America Paragonimus mexicanus Miyazaki & Ishii, 1968 is the only confirmed species to cause human infections. Paragonimus caliensis Little, 1968 is an uncommon species often regarded as a synonym of P. mexicanus. Recently, the study of two types of Paragonimus metacercariae from Costa Rica has provided new molecular and morphological evidence that P. caliensis is a separate species from P. mexicanus. In the present study, molecular, morphological and phylogenetic tools have been used to characterize two populations of Paragonimus located at west of Medellin, Antioquia and at Pichinde, Valle del Cauca (type locality of P. caliensis), Colombia. Adults and metacercariae obtained from Medellin, and metacercariae from Pichinde were analyzed. For morphological observations we used light microscopy and scanning electron microscopy (SEM). Morphology of metacercariae and adults matched with the holotype of P. caliensis. The number and arrangement of sensory papillae in the acetabulum region differs from the morphotypes reported for P. caliensis in Costa Rica. Two morphotypes in branching patterns of ovary and two morphotypes in branching patterns of testes were identified. The main morphological differences between P. caliensis and P. mexicanus corresponded to the size of gonads and their relative positions in the body, and the occasional presence of a cyst wall in P. caliensis metacercariae. The molecular and phylogenetic analyses (using nuclear ribosomal ITS2 and partial cytochrome c oxidase subunit 1 CO1 sequences) confirmed that P. caliensis from the type locality is the same species from Medellin and Costa Rica. Furthermore, these analyses also suggest genetic as well as geographical separation of P. caliensis populations between Colombia and Costa Rica. Currently, P. mexicanus and P. caliensis are sympatric in the Colombian Pacific bioregion, and specific diagnosis based on their egg size is not possible. Therefore, it is necessary to determine the biogeographic distribution ranges of both species and to implement molecular techniques to establish the role of P. caliensis in human paragonimiasis in Colombia.

Takotsubo cardiomyopathy associated with Paragonimiasis westermani.

An 11-year-old boy collapsed during morning assembly at his junior high school. The automated external defibrillator detected ventricular fibrillation and provided shock delivery. He was successfully resuscitated and reverted to sinus rhythm. Electrocardiography showed ST-T elevation in the precordial leads. Echocardiography and angiography demonstrated akinesia of the apex and mid-wall of the left ventricle with preserved contraction of the basal segments, which suggested Takotsubo cardiomyopathy. The patient and his family had often eaten uncooked crab, and his father had a past history of infection with Paragonimiasis westermani. The patient had had a persistent cough and chest pain for several weeks. Chest radiograph showed cystic cavities in the left upper lung. Microbiological examination of the sputum demonstrated an egg of P. westermani and immunological assay showed a raised antibody titre to P. westermani. On the12th day of admission, he developed seizures, and magnetic resonance imaging demonstrated cerebral involvement. After the administration of praziquantel for 3 days, the clinical manifestations improved immediately, and echocardiography normalised within 3 weeks. The patient was discharged on the 32nd day + and follow-up was normal. Takotsubo cardiomyopathy following a potentially fatal arrhythmia is a rare cardiac complication associated with pulmonary and central nervous system infection by P. westermani.

A Case of Ectopic Paragonimiasis in a 17th Century Korean Mummy.

Archaeoparasitological studies on fossilized feces obtained from Joseon Dynasty (1392-1910 CE) mummies have provided invaluable data on the patterns of parasitic infection in pre-modern Korean societies. In our recent radiological investigation of a 17th century Joseon mummy discovered in Cheongdo (South Korea), we located a liver mass just below the diaphragm. Anatomical dissection confirmed the presence of a mass of unknown etiology. A subsequent parasitological examination of a sample of the mass revealed a large number of ancient Paragonimus sp. eggs, making the current report the first archaeoparasitological case of liver abscess caused by ectopic paragonimiasis.

Eosinophilic Meningitis Due to Infection With Paragonimus kellicotti.

Paragonimus kellicotti is an emerging pathogen in the United States with 19 previously reported cases, most in Missouri. Pulmonary symptoms with eosinophilia are most common, though 1 case did involve the central nervous system with few symptoms. We describe the first 2 cases of eosinophilic meningitis due to Paragonimus kellicotti.

[Clinical, pathologic and radiologic analysis of paragonimiasis in children].

Objective: To analyze the clinical, pathological and radiological characteristics of paragonimiasis in children for accurate diagnosis and therapy. Methods: A total of 31 patients with paragonimiasis treated from 2002 to 2016 were selected, including 17 cases from migrant areas and 14 cases from Wenzhou area. Results: In migrant children group, the serum IgE was significantly higher than that in Wenzhou area group [(2 379±944) IU/mL∶(1 552±1 121) IU/mL, t=-2.23, P<0.05], and the duration of therapy was remarkable longer [(13.8±6.5) days∶(9.9±3.4) days, t=-2.15, P<0.05]. Among all cases, 10 showed polyserositis including pleural effusion, ascites and pericardial effusion at different degrees on chest CT scans. Five cases with cerebral paragonimiasis were confirmed by MR imaging. Most of the lesions were located in the parietal lobe with slight low signal on T1WI but high signal on T2WI surrounded by disproportionate edema. Annular enhancement was prominent by Gd-DTPA. Paragonimiasis serum antibody was positive in all cases by ELISA. Pathologic features included formation of irregular lacunae or sinus tracts, presence of paragonimus bodies, and eosinophilic infiltration in the adjacent tissues. Conclusions: Clinical manifestations of paragonimiasis are complex and non-specific in children.In migrant children group, clinical manifestations are diverse, more serious with more complications and difficulties in treatment, while patients in Wenzhou area group have favorable prognosis and less complicated treatment. The early diagnosis and timely treatment should be determined by patient's detailed history, eosinophilic count, radiologic findings and immunological test to avoid serious complications.

Electromagnetic Navigational Bronchoscopy Spares a Drunken Crab From the Surgeon's Knife.

Surgical resection is traditionally the preferred treatment for fluorodeoxyglucose-avid peripheral pulmonary nodules that grow over time. However, new technologies, including electromagnetic navigational bronchoscopy (ENB), provide an opportunity to confirm or possibly exclude a cytologic cancer diagnosis, before resection. We present a case of a 56-year-old North American man who presented with a fluorodeoxyglucose-avid pulmonary nodule and sought a second opinion after being recommended thoracotomy with lobectomy. The peripheral nodule was biopsied using ENB and pathologic evaluation of the lesion demonstrated parasitic eggs with features of Paragonimus westermani. No evidence of malignancy was found. The radiographic abnormalities resolved after treatment with praziquantel. Using a minimally invasive procedure with ENB, we successfully diagnosed pulmonary infection with P. westermani, a rare infectious cause of peripheral pulmonary lesions in a patient without travel to an endemic area. Furthermore, an alternative diagnosis to cancer was established, sparing this patient an unnecessary thoracotomy with right middle lobectomy.

Severe Pleuropulmonary Paragonimiasis Caused by Paragonimus mexicanus Treated as Tuberculosis in Ecuador.

A 30-year-old male, from a subtropical region of Ecuador, was hospitalized with a 5-year history of persistent cough with rusty brown sputum, chest pain, and progressive dyspnea. The patient underwent thoracic surgery 3 years ago for pleural effusion and subsequently received a 9-month regimen treatment of tuberculosis. However, there was no clinical resolution and symptoms became progressively worse. A chest radiograph and computerized tomography scan showed several small nodules in both lungs. Eggs of Paragonimus spp. were observed in sputum smears, but the smears were negative for acid-fast bacilli. Molecular characterization of eggs by the internal transcribed spacer-2 regions identified them as Paragonimus mexicanus The patient was treated with praziquantel and tested negative parasitologically for 12 months. There was clinical resolution of the cough and expectoration, but dyspnea and chest pain persisted.

Cerebral Paragonimiasis Presenting with Sudden Death.

A 58-year-old Korean-born woman with a history of seizures and psychiatric issues was found dead at home. Autopsy was notable for large, calcified nodules that had nearly replaced her right temporal lobe. Histologic examination revealed the presence of Paragonimus eggs. This case demonstrates a rare manifestation of an aberrantly migrated lung fluke that resulted in epilepsy and sudden death years after the initial infection.