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.

DNA detection of Paragonimus westermani: Diagnostic validity of a new assay based on loop-mediated isothermal amplification (LAMP) combined with a lateral flow dipstick.

Paragonimus westermani (P. westermani) is widely spread in Asian countries and is one of the most important causative agents for lung fluke diseases. The prevention and control of Paragonimiaisis mainly depends on the accurate diagnosis and effective treatment. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay targeted to a portion of the Ty3/gypsy-like LTR retrotransposon (Rn1) sequence coupled with a lateral flow dipstick (LFD) for the rapid detection of P. westermani-specific amplicons. The positive LAMP products were biotin-labeled and hybridized with a fluorescein isothiocyanate-labeled probe which could be visually detected by LFD. No cross-reaction were observed with other parasitic pathogens including Trichinella spiralis, Anisakis simplex, Schistosoma japonicum and Gnathostoma spinigerum, but this LAMP assay could not distinguish P. westermani with Paragonimus skrjabini and Paragonimus heterotremus. The detection limit of the LAMP assay for P. westermani was 2.7 fg/µL, while that of PCR method was 27 fg/µL. LAMP method was applied to detect P. westermani genomic DNA in blood samples form experimental infected dogs, and results showed the parasite was detectable as early as week 2. LAMP-LFD assay applicability was successfully tested in dog blood samples collected from five cities (Wenzhou, Hangzhou, Huzhou, Jiaxing and Shaoxing) in Zhejiang province. In summary, the established LAMP-LFD assay targeted to the Rn1 sequence is a rapid and convenient method for specific detection of P. westermani.

Analysis of COI and ITS2 regions of DNA obtained from Paragonimus westermani eggs in ancient coprolites on Joseon dynasty mummies.

The genetic information of ancient Paragonimus westermani, the oriental lung fluke infecting over 20 million people worldwide, has not been thoroughly investigated thus far. We analysed genetic markers (COI and ITS2) of P. westermani from coprolite specimens (n = 6) obtained from 15th to 18th century Korean mummies. Our results indicated that all P. westermani sequences were generally distinct from the other species of the genus Paragonimus. The sequences were clustered into three groups: Group I for East Asia; Group II for South and Southeast Asia; and Group III for India and Sri Lanka. In this study, we found that ancient P. westermani sequences in Korea belong to Group I, adding invaluable information to the existing knowledge of Paragonimus paleogenetics.

Analysis of COI and ITS2 regions of DNA obtained from Paragonimus westermani eggs in ancient coprolites on Joseon dynasty mummies

The genetic information of ancient Paragonimus westermani, the oriental lung fluke infecting over 20 million people worldwide, has not been thoroughly investigated thus far. We analysed genetic markers (COI and ITS2) of P. westermani from coprolite specimens (n = 6) obtained from 15th to 18th century Korean mummies. Our results indicated that all P. westermani sequences were generally distinct from the other species of the genus Paragonimus. The sequences were clustered into three groups: Group I for East Asia; Group II for South and Southeast Asia; and Group III for India and Sri Lanka. In this study, we found that ancient P. westermani sequences in Korea belong to Group I, adding invaluable information to the existing knowledge of Paragonimus paleogenetics.

Cerebral Paragonimiasis With Hemorrhagic Stroke in a Developed Country.

Paragonimiasis is a food-borne parasitic disease caused by Paragonimus lung flukes, which are epidemic in Asia. Cerebral paragonimiasis accounts for <1% of symptomatic paragonimiasis but is the most common extrapulmonary infection. Cerebral paragonimiasis often mimics stroke and sometimes causes severe neurological sequelae. A 61-year-old woman was admitted to the hospital for severe headache. A head computed tomography scan revealed intracerebral hemorrhage with subarachnoid hemorrhage. The patient also had lesions in the lungs. She frequently ate Japanese mitten crab. Peripheral blood examination results of increased eosinophilia and immunological testing results confirmed the diagnosis of Paragonimus westermani infection. The patient was successfully treated with praziquantel as the first-line agent. Cerebral paragonimiasis is currently rare in developed countries; however, it is an important disease to consider.

Unresolving Pneumonia with Pleural effusion: Pulmonary Paragonimiasis.

Paragonimiasis is a zoonosis caused by many species of Paragonimus commonly P. westermani. Human get infected by eating raw, salted, pickled, smoked, partially cooked crustaceans (crayfish or crabs). Clinical manifestations ranges from non-specific symptoms like pain abdomen, diarrhea, urticarial rashes, fever to pleuropulmonary symptoms like cough, hemoptysis, chest pain and dyspnea. A 48 years, female presented at TUTH emergency with fever on and off for nine months, cough and shortness of breath for three months, lethargy, malaise and urticaria with history of raw crab intake one month prior to the onset of symptoms. Blood and pleural fluid analysis revealed raised total counts with eosinophilia and x-ray showed bilateral infiltration of lower lobes with pleural effusion. Diagnosis was confirmed by microscopic examination of sputum for Paragonimus. She responded well to Praziquantel. Pulmonary paragonimiasis must be considered in the differential diagnosis of unresolving pneumonia and unexplained hypereosinophilia.

A Case of Ectopic Peritoneal Paragonimiasis Mimicking Diverticulitis or Abdominal Abscess.

Paragonimiasis is a parasitic disease caused by Paragnonimus species. The primary site of infection is the lung, and extrapulmonary involvement is also reported. When infected with Paragonimus westermani, which is the dominant species in Korea, the central nervous system is frequently involved along with the liver, intestine, peritoneal cavity, retroperitoneum, and abdominal wall. Ectopic paragonimiasis raises diagnostic challenge since it is uncommon and may be confused with malignancy or other inflammatory diseases. Here, we report an ectopic paragonimiasis case initially presented with recurrent abdominal pain. The patient developed abdominal pain 3 times for the previous 3 years and the computed tomography (CT) of the abdomen revealed fluid collection with wall enhancement. Recurrent diverticulitis was initially suspected and part of the ascending colon was resected. However, the specimen showed intact colon wall without evidence of diverticulitis and multiple parasite eggs and granulomas were found instead. The size of about 70 µm, the presence of an operculum and relatively thick egg shell suggested eggs of Paragonimus species. With appropriate exposure history and a positive antibody test, the definitive diagnosis was made as peritoneal paragonimiasis.

Recent Incidence of Paragonimus westermani Metacercariae in Freshwater Crayfish, Cambaroides similis, from Two Enzootic Sites in Jeollanam-do, Korea.

An epidemiological study was performed to know the recent infection status of Paragonimus westermani metacercariae (PwMc) in freshwater crayfish, Cambaroides similis, from 2 streams in Jeollanam-do, Republic of Korea. Crayfish were collected from creeks in Bogil-do (Island), Wando-gun, and in a creek near Daeheung Temple in Haenam-gun. The infection rate of crayfish with PwMc in Bogil-do was 89.8%, and the metacercarial burden was 37 PwMc per the infected crayfish. Crayfish in a creek near Daeheung Temple were larger and twice heavier than those in Bogil-do. Of them, 96.5% were infected with PwMc. An average of 140 metacercariae was found in the infected crayfish, almost quadruple to those of Bogil-do. There was a strong correlation between the number of PwMc and body weight of the crayfish. These results suggest that P. westermani metacercariae are still prevalent in crayfish of the 2 regions in Jeollanam-do, Korea.

Inactivation of Paragonimus westermani metacercariae in soy sauce-marinated and frozen freshwater crabs.

Soy sauce-marinated freshwater crabs (Eriocheir japonicus) are a source of human paragonimiasis. The viability of Paragonimus westermani metacercariae (PwMc) in marinated crabs was investigated in an experimental setting. The PwMc collected from freshwater crayfish were inoculated into freshwater crabs, which were then frozen or marinated in soy sauce. All PwMc in the freshwater crabs were inactivated after freezing for 48 h at -20 °C and after freezing for 12 h at -40 °C. After marinating for 32 days, the survival rate of PwMc in 5% NaCl soy sauce was 50%, in 7.5% NaCl soy sauce it was 33.3%, and in 10.0% NaCl soy sauce it was 31.3%. When marinated for 64 days, all PwMc were inactivated in all experimental groups. These results revealed that freezing and soy sauce marination were detrimental to the survival of PwMc in freshwater crabs. Specifically, freezing crabs for more than 48 h or soaking them in soy sauce containing at least 5.0% NaCl for 64 days can inactivate PwMc. These results can inform the production of the traditional Korean soy sauce-marinated freshwater crabs known as gejang.

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.

Venison, another source of Paragonimus westermani infection.

Paragonimiasis is a typical food-borne parasitic disease, endemic in most parts of Asia, with sporadic case reports from American and African countries. The major source of infection is undercooked freshwater crab or crayfish, though consumption of wild boar meat is also responsible for the infection in Japan, because wild boar is a paratenic host for Paragonimus westermani. Recently, living juveniles of P. westermani were isolated from muscle of a sika deer, Cervus nippon, in Japan, raising the possibility that venison has been another source of infection. In order to clarify the potential contribution of venison consumption to the occurrence of paragonimiasis, we analysed dietary histories of those paragonimiasis patients in whose diagnoses we were involved between 2001 and 2015. Among 380 patients, freshwater crab had been consumed by 208 patients, wild boar meat by 190, and wild deer meat by 76 patients before the onset of the disease. Overall contribution of wild deer meat was estimated to be 6.8% to 20.0%, although in Oita and Gifu Prefectures, where a substantial proportion of patients had consumed raw venison, the contribution of venison consumption was much higher (27.5 to 62.1% and 42.1 to 78.9% in Oita and Gifu Prefectures, respectively). We demonstrated P. westermani-specific antibodies in the sera of 4 out of 160 sika deer from Gifu Prefecture, strongly suggesting that these deer were infected with P. westermani.

Paragonimus westermani infection mimicking recurrent lung cancer: A case report.

Herein, we report a case of Paragonimus westermani infection, which required differentiation from recurrent lung cancer. A 66-year old Japanese man with a history of lung cancer who had undergone a lobectomy was referred to our clinic for treatment of cough, sputum, dyspnea, and a right pulmonary nodule. He had previously eaten seafood he visited China. P. westermani infection was confirmed by the presence of antibody against P. westermani antigen in the patient's serum and eggs in his sputum. Eventually, molecular identification by PCR-restriction fragment length polymorphism analysis and sequencing confirmed that the patient was infected with triploid forms of P. westermani.

Molecular and morphological variation of Paragonimus westermani in Vietnam with records of new second intermediate crab hosts and a new locality in a northern province.

Paragonimus westermani is one of the most medically important lung flukes and is widely distributed in Asia. It exhibits considerable variation in morphological, genetic and biological features. In central provinces of Vietnam, a high prevalence of metacercariae of this species has been reported from the crab intermediate host, Vietopotamon aluoiense. In this study, we detected P. westermani metacercariae in two additional crab hosts, Donopotamon haii in Quang Tri Province, central Vietnam and Indochinamon tannanti in Yen Bai Province in the north. The latter is a new locality for P. westermani in a northern region of Vietnam where P. heterotremus is the only species currently known to cause human paragonimiasis. Paragonimus westermani metacercariae found in Vietnam showed considerable morphological variation but slight genetic variation based on DNA sequences from the nuclear ribosomal ITS2 region and the mitochondrial 16S gene. Co-infection of the same individual crabs with P. westermani and P. heterotremus and/or some other Paragonimus species was found frequently, suggesting potential for co-infection in humans. The findings of the present study emphasize the need for highly specific molecular and immunodiagnostic methods to differentially diagnose between P. westermani and P. heterotremus infections.

Pulmonary Paragonimiasis: The Detection of a Worm Migration Track as a Diagnostic Clue for Uncertain Eosinophilic Pleural Effusion.

A 38-year-old woman with sustained right chest pain was referred to our hospital. She showed pleural effusion and peripheral blood eosinophilia. Thoracentesis revealed eosinophilic pleural effusion in which the smear, culture and cytological examinations were all negative. Although she had no notable dietary history, chest CT revealed linear opacities, which suggested the migration tracks of paragonimiasis. The diagnosis was confirmed using enzyme-linked immunosorbent assays, which showed elevated Paragonimus westermani and Paragonimus miyazakii antibody levels. After the initiation of praziquantel therapy, all clinical findings were promptly improved. The detection of a migration track may therefore be useful in the diagnosis of paragonimiasis.

Evaluation of the MGL method to detect Paragonimus eggs and its improvement.

Dog feces containing 500 Paragonimus westermani eggs per gram were examined by the Medical General Laboratory (MGL), the simple sedimentation (SS), and the Army Medical School III (AMS III) methods. The number of eggs per gram of feces (EPG) obtained by the MGL method was 17.2 and was significantly lower than those obtained by the SS method (324.0) and the AMS III method (505.6). When isolated P. westermani eggs were processed by the MGL method and four layers (ether, ether-fecal, formalin layers, and sediment) of the final centrifugation product were separately examined, almost 100% of eggs were found at the ether-fecal layer. Similarly, when fecal samples containing P. westermani, Paragonimus skrjabini miyazakii, Paragonimus ohirai, or Paragonimus harinasutai eggs were processed by the MGL method, more than 95% of the eggs were found in the supernatant layers. The formalin-ethyl acetate (FEA) method showed a similar tendency as the MGL method and over 90% of eggs remained in the supernatant layers. Contrary to Paragonimus eggs, 63 and 96% of Clonorchis and Metagonimus eggs were found in the sediment in the MGL method, respectively. When surfactant (Tween 80) was added to fecal solution, most of Paragonimus eggs spun down in the sediment in the MGL and FEA methods, suggesting that Paragonimus eggs have hydrophobic components on their surface. It is suggested that surfactant addition to the fecal solution should be considered when the MGL method is used for detection of Paragonimus eggs.

First case of Paragonimus westermani infection in a female patient in India.

Paragonimiasis is a foodborne parasitic zoonosis caused by lung fluke species of the genus Paragonimus. The Paragonimus westermani is the most common human pathogen in Asian countries. In northeast India, Paragonimus heterotremus has been documented as the only human pathogen in the earlier literature. In India, P. westermani infection in humans remained undetermined. Herein, we report a case of pulmonary paragonimiasis due to P. westermani in an adult female in Manipur. The diagnosis was made by morphological and molecular characterisation of the eggs in the sputum. This is the first confirmed case of paragonimiasis due to P. westermani in India.