Lung Fluke Paragonimus Westermani Research Articles

Demographic characteristic and analysis of pulmonary paragonimiasis in patients attending RIMS, Manipur.

Background:Human infection by the lung fluke Paragonimus westermani is widely distributed in Africa, Asia, and South America. Transmission of the parasite to humans primarily occurs through the consumption of raw or undercooked crabs. Clinical features of recently diagnosed pulmonary Paragonimiasis show that patients present with a variety of clinical and radiological findings, frequently mimics tuberculosis and lung cancer.Methods:Here in this study, we report a cross-sectional study of pulmonary paragonimiasis in our institute over a period of two year.Results:it was observed that out of eleven cases, prevalence of paragonimiasis was almost equal among both the genders, with a mean age of 38.1 ± 16.96, affecting people from hills. Three patients were erroneously treated with antitubercular drugs without any relief. The association with eosinophilia in the peripheral blood and tissue[16] was seen in all the study subjects and majority patients had pleural fluid eosinophilia. Patients were diagnosed by serological test, Paragonimus ova in Sputum smear and Pleural fluid. All study subjects had excellent clinical responses to praziquantel given at dose of 25 mg/kg given orally 3 times daily for 3 consecutive days.Conclusions:There is a need to generate awareness among the clinicians and public regarding Paragonimiasis and to consider it in differential diagnosis of TB and carcinoma lung. Physicians should consider the possibility of paragonimiasis among patients who present with chest complaints with eosinophilia from the endemic regions.

Paragonimus kellicotti: A Lung Infection in Our Own Backyard

Paragonimiasis is an infection caused by the lung fluke of the genus Paragonimus. Within the United States, paragonimiasis has been commonly diagnosed in Southeast Asian immigrants infected with the Asian lung fluke Paragonimus westermani. Infections from the North American lung fluke, Paragonimus kellicotti, have been rare, although more infections have been seen in people in the Midwestern United States. A 29-year-old male with a history of pleomorphic xanthoastrocytoma presented with hemoptysis. A CT scan showed a mass in the left upper lung lobe. A biopsy showed eosinophils and parasite eggs, some with a recognizable operculum. Further investigation revealed that he takes canoe trips on rivers within Missouri and would eat crayfish caught from these rivers. A blood sample was confirmed positive for Paragonimiasis serologically at the Center for Disease Control. Paragonimus kellicotti is found in rivers within the Mississippi basin. Infection occurs by consuming uncooked or undercooked crawfish. Microscopic identification of parasite eggs has been the gold standard. Serologic tests have been developed to aid in the diagnosis. Patients typically present with fever and hemoptysis. Common CT findings include pleural effusion, a mass, and lymphadenopathy. Awareness of P. kellicotti is important to guide appropriate diagnostic testing and ensuring proper treatment.

Gene structure of the two-domain taurocyamine kinase from Paragonimus westermani: Evidence for a distinct lineage of trematode phosphagen kinases

Taurocyamine kinase (TK) is an enzyme that catalyzes the reversible transfer of a phosphate between ATP and taurocyamine. Annelid TKs were suggested to have evolved from a CK ancestor. However, TKs from the lung fluke Paragonimus westermani comprised another lineage. Construction of phylogenetic tree and comparison of exon/intron organization showed that P. westermani TK and other trematode TKs evolved from a molluscan arginine kinase (AK) gene. Exon shuffling probably caused the changes in amino acid sequence thereby changing the affinity from AK to TK. The present study provides new insights on the evolution of phosphagen kinases found in trematodes.

PREVALENCE OF <i>PARAGONIMUS</i> INFECTION

Paragonimiasis (human infections with the lung fluke Paragonimus westermani) is an important public health problem in parts of Africa. This study was aimed at assessing the prevalence of Paragonimus infection in Ebonyi State. Deep sputum samples from 3600 individuals and stool samples from 900 individuals in nine Local Government Areas in Ebonyi State, Nigeria were examined for Paragonimus ova using concentration technique. The overall prevalence of pulmonary Paragonimus infection in the area was 16.30%. Six foci of the infection were identified in Ebonyi North and Ebonyi Central but none in Ebonyi South. The intensity of the infection was generally moderate. Of the 720 individuals examined, 16 (12.12%) had less than 40 ova of Paragonimus in 5 mL sputum and 114 (86.36%) had between 40 and 79 ova of Paragonimus in 5 mL sputum. While 2 individuals (1.52%) had over 79 ova of Paragonimus in 5 mL Sputum. Furthermore, there was higher prevalence of paragonimiasis in rainy season than in dry season. The results of this study indicated the growing public health threat posed by paragonimiasis in Ebonyi North and Ebonyi Central. A combination of chemotherapy, to bring relief to persons already infected by the disease and public health education related to paragonimiasis transmission to increase awareness of the infection in the areas is recommended.

Human Paragonimiasis in North America following Ingestion of Raw Crayfish

Paragonimiasis (human infections with the lung fluke Paragonimus westermani) is an important public health problem in parts of Southeast Asia and China. Paragonamiasis has rarely been reported from North America as a zoonosis caused by Paragonimus kellicotti. Paragonimus species have complex life cycles that require 2 intermediate hosts, namely, snails and crustaceans (ie, crabs or crayfish). Humans acquire P. kellicotti when they consume infected raw crayfish. Humans with paragonimiasis usually present with fever and cough, which, together with the presentation of hemoptysis, can be misdiagnosed as tuberculosis. Only 7 autochthonous cases of paragonimiasis have been previously reported from North America. Our study describes 3 patients with proven or probable paragonimiasis with unusual clinical features who were seen at a single medical center during an 18-month period. These patients acquired their infections after consuming raw crayfish from rivers in Missouri. It is likely that other patients with paragonimiasis have been misdiagnosed and improperly treated. Physicians should consider the possibility that patients who present with cough, fever, hemoptysis, and eosinophilia may have paragonimiasis.

Molecular characterization and kinetic properties of a novel two-domain taurocyamine kinase from the lung fluke Paragonimus westermani

Taurocyamine kinase (TK) was previously reported to be restricted to certain marine annelids; however, the present study has proven otherwise. The lung fluke Paragonimus westermani has a contiguous two-domain TK with a mass of 80 216 Da consisting of 713 amino acid residues sharing higher sequence identity with molluscan arginine kinase (AK). Both domains of P. westermani TK have significant activity for the substrate taurocyamine and exhibited synergism during substrate binding. Since TK plays a key role in energy metabolism and is not present in mammals, inhibitors against P. westermani TK could be effective novel chemotherapeutic agents and could be utilized for the development of specific diagnostic tools for the detection of paragonimiasis.

Infection of a group of boar-hunting dogs with Paragonimus westermani in Miyazaki Prefecture, Japan

A 5-year-old male mixed-bred boar-hunting dog with a Plott hound background weighing 23 kg was brought to the Veterinary Teaching Hospital, University of Miyazaki, in October 2002. The dog was diagnosed with active infection with the lung fluke Paragonimus westermani by serological testing and also by detection of parasite eggs in his feces. Subsequent examination of four other dogs working with this dog as a boar-hunting team revealed that all five dogs were infected with P. westermani.

Artemether and tribendimidine lack activity in experimental treatment of Paragonimus westermani in the dog

Artemether and tribendimidine are active against several trematode species, but no data are available regarding the lung fluke Paragonimus westermani. We infected six dogs with 100 P. westermani metacercariae each. At day 103 post-infection, four dogs were treated orally for 3 days with either artemether (total dose, 66.7 and 75 mg/kg) or tribendimidine (total dose, 100 mg/kg). The remaining dogs were left untreated and served as control. Sixteen days after the final dosing, dogs were killed, and P. westermani flukes were recovered from the lungs and counted. Neither artemether nor tribendimidine showed activity against P. westermani at this dose regimen in dogs.

Caspase-3-Mediated Apoptosis of Human Eosinophils by the Tissue-Invading Helminth Paragonimus westermani

Background: Eosinophils are important cells in host immunity to infections by parasitic worms. Tissue-invasive helminthic parasites have been known to induce apoptosis of immune cells for their successful establishment in vivo. We have previously found that high doses of excretory-secreted products (ESP) secreted by lung fluke Paragonimus westermani newly excysted metacercariae (PwNEM), which cause pulmonary or extrapulmonary paragonimiasis in human beings, accelerate eosinophil cell death. However, little is known about the mechanism of eosinophil apoptosis induced by the Paragonimus-derived products. Objective: We examined involvement of caspase 3 activation in eosinophil cell death induced by ESP produced by PwNEM. Methods: Eosinophils were isolated from the peripheral blood of healthy donors by CD16-negative immunomagnetic selection. We examined the inhibitory effect of pan-caspase inhibitor on ESP-triggered phosphatidylserine (PS) externalization on the outer surface of eosinophils and intracellular activation of caspase 3 in cell lysates treated with the ESP. Results: When ESP secreted by PwNEM were incubated for up to 3 h with eosinophils, they increased surface exposure of PS on eosinophils in a time- and dose-dependent manner. This proapoptotic effect of the ESP on eosinophils was significantly inhibited by pretreatment of cells with pan-caspase inhibitor z-VAD-fmk, and was completely abolished by heat inactivation of ESP at 56°C. The activated forms of caspase 3 were also clearly detected in eosinophils incubated with ESP. Moreover, ESP potently inhibited prolonged survival of eosinophils induced by cytokines such as IL-5, IL-3, and GM-CSF. Conclusion: These results suggest that ESP secreted by PwNEM contain biological active factors causing caspase-3-mediated apoptosis of human eosinophils, thereby enabling the larvae to evade and to subvert the tackle by eosinophils during the early phase of the infection.

Occurrence of a Diploid Type and a New First Intermediate Host of a Human Lung Fluke, Paragonimus westermani, in Korea

Park, G. M., Lee, K. J., Im, K. I., Park, H., and Yong, T. S. 2001. Occurrence of a diploid type and a new first intermediate host of a human lung fluke Paragonimus westermani, in Korea. Experimental Parasitology99, 206–212. The biology, chromosome number, and karyotype of a lung fluke, Paragonimus westermani (Kerbert, 1878) collected in Haenam, Haenam-gun Chollanam-do, Korea were analyzed. We compared the size of metacercariae from Haenam with those taken from a crayfish collected at Youngam, Youngam-gun, Chollanam-do, Korea. The mean length of P. westermani metacercariae from Haenam was 300.3 μm and that from Youngam was 362.0 μm. Adult worms were recovered from the lungs of experimentally infected dogs. The mean egg sizes obtained from adult flukes were 72.1 × 46.8 μm from Haenam and 93.5 × 54.2 μm from Youngam. Semisulcospira tegulata collected in the Youngam area were found to be infected with cercariae of P. westermani, one of the snail-borne human lung fluke trematodes in Korea. Of 4218 snails studied, 5 (0.12%) harbored P. westrermani larvae. This is the first report of S. tegulata serving as the initial intermediate host of P. westermani. The chromosome numbers of P. westermani from Haenam and Youngam were 2n = 22 and 3n = 33. The diploid type of P. westermani has not been previously reported in Korea.

The Localization of Allergens of Paragonimus westermani by Pleural Exudates from Patients

The allergens of the lung fluke Paragonimus westermani were localized by indirect immunostaining in adult fluke sections using pleural exudates from 3 patients with P. westermani. Immunostaining performed by using pleural exudate with the highest level of specific IgE revealed that the P. westermani major allergen (or allergens) was located in the gut epithelium and luminal contents and that minor allergens were in the tegument and parenchyma. The antigens recognized by specific IgG were located at various sites including those recognized by specific IgE. Paragonimus westermani-specific IgE cross-reacted with only the gut of 2 other Paragonimus species, Paragonimus miyazakii and Paragonimus ohirai. The major allergen in the gut also was recognized by the other 2 pleural exudates. These results indicate that the substance present in and secreted from the gut is not only a major allergen but is also a common allergen among Paragonimus species.

Cerebral paragonimiasis. A report of forty-seven cases.

<h3>Introduction</h3> In Far Eastern countries, particularly Japan, Korea, China and Taiwan (Formosa), and the Philippines, the habit of eating raw crabs and other crustaceans is responsible for an endemic infection with the lung fluke Paragonimus westermani. The fluke, after leaving the cyst, pierces the intestinal wall to enter the abdominal cavity, whence it may perforate the diaphragm and penetrate the lung, either becoming encysted there or being carried to other organs. As a result of the pulmonary infection, the commonest symptom is hemoptysis. This is so common in these eastern countries that it is considered lightly. The diagnosis may be made in patients with a chronic cough and rusty-brown expectoration by a demonstration of the ova in the sputum. Paragonimus infection of the brain, first reported by Otani,¹⁰of Japan, in 1887, is a frequent manifestation of the disease. Of 201 cases exhibiting extrapulmonary involvement, 93 had signs