[Investigation of the population diversity of intermediate host snails and crabs of Paragonimus along Jiulong River, Zhangjiang River and Dongxi River basins in southern Fujian Province].

OBJECTIVE: To investigate the population distribution of intermediate host snails and crabs of Paragonimus along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, so as to provide baseline data for researches on parasitic disease prevention and control and enlargement of samples in the parasitic resource bank. METHODS: A total of 23 villages in 8 counties (districts) along the Jiulong River, Zhangjiang River, and Dongxi River basins in Zhangzhou City, Fujian Province were selected as survey sites during the period from November 2020 through March 2023, and snail and freshwater crabs were sampled from 1 to 3 streams and ditches neighboring residential areas in each village. Morphological identification of snails was performed according to the external morphological characteristics of collected snail shells, and the unidentified snail species sampled from the natural foci of paragonimiasis in Yunxiao County were subjected to se-quence analysis of the mitochondrial cytochrome oxidase 1 (CO1) gene. The crab species was identified by observing the morphological characteristics of the terminal segment of the first pleopod of male crabs, and Paragonimus cercariae and metacercariae were detected in collected snails. RESULTS: The shells of the unidentified snails sampled from the natural foci of paragonimiasis in Yunxiao County were approximately 50 mm in height and 18 mm in width, thick and solid, long tower cone-shaped, and had 8 to 10 whorls. CO1 gene sequence analysis identified the snail species as Sulcospira hainanensis. A total of 6 freshwater snail species belonging to 5 genera within 3 families, identified 23 survey sites, including Semisulcospira libertina, Paludomus zhangchouensis and S. hainanensis that belonged to the Family Pleurceridae, Tricula fujianensis and T. huaanensis that belonged to the subfamily Triculinae, Family Pomatiopsidae, and Melanoides tuberculata (Family Thiaridae), and 11 species of freshwater crabs belonging to 5 genera within 2 families were identified, including Sinopotamon genus of S. jianglense, S. pinheense, and S. zhangzhouense, Huananpotamon genus of H. planopodum and H. zhangzhouense, Nanhaipotamon genus of N. huaanense and N. longhaiense, and Minpotamon genus of M. nasicum and M. auritum that belonged to the Family Potamidae, and Somanniathelphusa genus of S. huaanensis and S. zhangpuensis (Family Parathelphusidae). In addition, the prevalence of P. westermani cercariae infections was 0.08% (2/2 317) in P. zhangchouensis from Danyan Village in Changtai District and 0.09% (1/1 039) in S. hainanensis from Jinkeng Village in Yunxiao County, and the prevalence of P. westermani metacercariae infections was 25.81% (8/31) in S. jianglense from Danyan Village in Changtai District, and 26.31% (5/19) in S. zhangzhouense from Jinkeng Village in Yunxiao County, respectively. CONCLUSIONS: There is a population diversity in the intermediate host snails and crabs along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, and P. zhangzhouensis and S. hainanensis are, for the first time, confirmed as the first intermediate hosts of P. westermani.

Activation of RIG-I signaling in the early stage of Paragonimus proliferus infection causes lung injury via type I immune response in rat.

Paragonimiasis is a common zoonotic parasitic disease. The retinoic acid-inducible gene I (RIG-I) signaling is very important for the host to recognize invading pathogens (especially viruses and bacteria). However, the role of RIG-I signaling in the early stages of P. proliferus infection remains unclear. Therefore, in this study, Sprague-Dawley (SD) rat models with lung damage caused by P. proliferus were established. Experimental methods including Enzyme-linked Immuno Sorbent Assay (ELISA), real-time fluorescent quantitative polymerase chain reaction (PCR), western blotting, and hematoxylin and eosin (HE) staining were used to explore the mechanisms of lung injury caused by P. proliferus. As a result, the expression of the mRNA and proteins of RIG-I signal-related key target molecules, including RIG-I, tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6), interferon regulatory Factor 7 (IRF7), IPS-1, and downstream C-X-C chemokine ligand 10 (CXCL10), were significantly up-regulated immediately after infection, peaked at 3 or 7 days, and showed a downward trend on after 14 days. The levels of pro-inflammatory cytokines interleukin-1 (IL-1), interferon (IFN)-α, -ß, and -γ, which represent type 1 immune response, gradually increased and reached a peak by 14 days, which was consistent with the changes in the degree of inflammatory damage observed under HE staining of lung tissues. In conclusion, RIG-I signaling is activated in the early stage (before 14 days) of P. proliferus infection, it is inferred that the lung injury of the host may be related to the activation of RIG-I like signaling to induce type I immune response.

SARCOCYSTIS AND OTHER PARASITES IN FECES OF BOBCATS (LYNX RUFUS) FROM MISSISSIPPI.

Rectal contents of 56 adult bobcats (Lynx rufus) in 2014 and 2017 from remote areas of Mississippi were examined microscopically for parasite stages after the sugar flotation method. Among the helminths, eggs/larvae found were: Paragonimus sp. in 12, Toxocara cati-like in 16, trichurid-capillarid-like in 3, hookworms in 27, and lungworms in 28. Among the protozoa, oocysts/cysts found were: Cystoisospora felis-like in 2, Cystoisospora rivolta-like in 4, Cryptosporidium sp. in 1, and Giardia sp. in 1. Additionally, numerous Sarcocystis sporocysts were detected in the feces of 12 bobcats; sporocysts were described morphologically. The status of C. felis derived from the bobcat and other wild felids is reviewed and compared with C. felis from the domestic cat. It is the first record of C. rivolta from the bobcat. The presence of eggs of Paragonimus sp. and T. cati in feces of 21.4% and 28.5%, respectively, suggests a role for the bobcat in the dissemination of these zoonotic helminths in the environment in the wild. Taxonomy of coccidia of wild Felidae is discussed and Isospora lyncisLevine and Ivens, 1981 from the Lynx is now regarded as a species inquirenda.

[Sequence analysis of Paragonimus internal transcribed spacer 2 and cyclooxygenase 1 genes in freshwater crabs in Henan Province].

OBJECTIVE: To investigate the sequences of internal transcribed spacer 2 (ITS2) and cyclooxygenase 1 (COX1) genes of Paragonimus metacercariae in freshwater crabs in Henan Province, identify the species of Paragonimus and evaluate its genetic relationships with Paragonimus isolates from other provinces in China. METHODS: Freshwater crabs were collected from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province from 2016 to 2021, and Paragonimus metacercariae were detected in freshwater crabs. Genomic DNA was extracted from Paragonimus metacercariae, and the ITS2 and COX1 genes were amplified using PCR assay, followed by sequencing of PCR amplification products. The gene sequences were spliced and aligned using the software DNASTAR, and aligned with the sequences of Paragonimus genes in the GenBank. Phylogenetic trees were created using the MEGA6 software with the Neighbor-Joining method based on ITS2 and COX1 gene sequences, with Fasciola hepatica as the outgroup. RESULTS: The detection rates of Paragonimus metacercariae were 6.83% (11/161), 50.82% (31/61), 18.52% (5/26), 8.76% (12/137), 14.29% (9/63), 17.76% (19/105), 18.50% (32/173) and 42.71% (41/96) in freshwater crabs from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province, with a mean detection rate of 19.46% (160/822), and a mean infection intensity of 0.57 metacercariae/g. The amplified ITS2 and COX1 gene fragments of Paragonimus were approximately 500 bp and 450 bp in lengths, respectively. The ITS2 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (99.8% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: MW960209.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with P. skrjabini from Sichuan Province (GenBank accession number: AY618747.1), Guangxi Zhuang Autonomous Region (GenBank accession number: AY618729.1) and Hubei Province (GenBank accession number: AY618751.1), and P. miyazaki from Fujian Province (GenBank accession number: AY618741.1) and Japan (GenBank accession number: AB713405.1). The COX1 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (90.0% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: AY618798.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with all P. skrjabini and clustered into the same sub-clade with P. skrjabini from Hubei Province (GenBank accession numbers: AY618782.1 and AY618764.1). CONCLUSIONS: Paragonimus species from freshwater crabs in Henan Province were all characterized as P. skrjabini, and the ITS2 and COX1 gene sequences had the highest homology to those of P. skrjabini from Hubei Province. The results provide insights into study of Paragonimus in Henan Province and China.

Trends in Paragonimiasis Global Research: Bibliometric Analysis of a Neglected Food-Borne Parasite.

Background: Paragonimus is a genus of parasitic flatworms known as lung flukes that cause the parasitic disease paragonimiasis in humans and other mammals. We aimed to use bibliometric analysis to identify the global characteristics and temporal trends of published literature about paragonimiasis. Methods: Using the Web of Science database, we identified all original articles on paragonimiasis 1997 to 2022. After collecting the bibliographic and citation data, keywords, citation networks, and co-citations pertaining to paragonimiasis was carried out using the VOSviewer program. Results: The study identified 563 paragonimiasis articles published in 250 journals. Publications in paragonimiasis research have been cited 6190 times and 2803 times without self-citations. The years with the most publications were 2013, 2016, and 2021. The minimal threshold for analysis was met by 19 of the 52 countries investigated. The study included 19 items, yielding 170 links between countries. The total strength of these links was discovered to be 104772. The journal with the most publications in this category was Parasitology Research (n=31). The most frequently used terms in paragonimiasis study were "paragonimiasis", "Paragonimus westermanii", and "lung-fluke." Conclusion: The study concluded by providing an overview of the paragonimiasis research field, including current trends, development, and researcher collaboration. By addressing gaps in this bibliometric analysis and increasing collaboration, stake-holders could strengthen their strategies to effectively combat paragonimiasis and improve public health outcomes.

Exudative pleural effusion caused by lung fluke infection: A practical diagnostic approach.

OBJECTIVES: Pleural effusion caused by lung fluke is a rare etiology of exudative pleural effusion (EPE), which is often misdiagnosed or delayed. We aim to summarize the diagnosis and treatment course of EPE caused by lung fluke infection and put forward a practical diagnosis approach. METHODS: We retrospectively analyzed the diagnosis and treatment of 14 cases of EPE caused by lung fluke infection diagnosed by enzyme-linked immunosorbent assay of serum antibodies or egg detection. RESULTS: All patients (100%) with an absolute count of eosinophils in peripheral blood exceeded 0.5 × 109/l, and 10 patients (71.4%) had a history of special ingestion. Eosinophilic PE occurred in 11 patients (78.6%), pleural biopsy of medical thoracoscopic demonstrated eosinophils infiltration in nine patients (64.3%), and parasite eggs in one patient. All patients showed positive intradermal tests for Paragonimus-specific antigens and enzyme-linked immunosorbent assay of serum antibodies to Paragonimus. CONCLUSION: For patients with unexplained PE, lung fluke infection should be highly suspected when pleural fluid or pleural biopsy shows eosinophilic PE or eosinophils infiltration, especially for patients with certain diet history.

Pneumothorax with Eosinophilia is an Important Diagnostic Clue for Distinguishing Paragonimiasis from Chronic Eosinophilic Pneumonia: A Case Report.

The Paragonimus westermani infection is a parasitic foodborne infection that induces systemic symptoms with eosinophilia in humans. Here, we described pneumothorax in addition to pulmonary opacities with eosinophilia in a man with a positive P. westermani serology. He was misdiagnosed with chronic eosinophilic pneumonia (CEP) during the initial phase. Paragonimiasis can share similar clinical findings with CEP in cases where the worm is confined to the lungs. The findings of the current study suggest that paragonimiasis and CEP can be distinguished from each other by the presence of various symptoms. Notably, eosinophilia with pneumothorax should be an important diagnostic factor for paragonimiasis.

[High-fat intake alleviates lung injury induced by Paragonimus proliferus infection in rats through up-regulating CYP 4A1 expression in lung tissues].

OBJECTIVE: To explore the improvements of high-fat intake on lung injury induced by Paragonimus proliferus infection in rats, and to preliminarily explore the mechanisms underlying the role of cytochrome P450 4A1 (CYP 4A1) in the improve ments. METHODS: SD rats were randomly assigned into three groups, including the normal control group (n = 10), the infection and normal diet group (n = 12) and the infection and high-fat diet group (n = 12). Rats in the normal control group were fed with normal diet and without any other treatments, and animals in the infection and normal diet group were subcutaneously injected with 8 excysted metacercariae of P. proliferus via the abdominal wall, followed by feeding with normal diet, while rats in the infection and high-fat diet group were subcutaneously injected with 8 excysted metacercariae of P. proliferus via the abdominal wall, followed by feeding with high-fat diet. All rats were sacrificed 28 weeks post-infection, and serum samples and lung specimens were collected. Following hematoxylin-eosin (HE) staining of rat lung specimens, the rat lung injury was observed under an optical microscope, and alveolitis was evaluated using semi-quantitative scoring. Serum interleukin-1ß (IL-1ß) and tumor necrosis factor alpha (TNF-α) levels were measured using enzyme-linked immunosorbent assay (ELISA), and the cytochrome P450 4A1 (CYP 4A1) expression was quantified in rat lung specimens at transcriptional and translational levels using quantitative real-time PCR (qPCR) and Western blotting assays. RESULTS: Alveolar wall thickening, edema and inflammatory cell infiltration were alleviated 28 weeks post-infection with P. proliferus in rats in the infection and high-fat diet group relative to the infection and normal diet group, and no alveolar consolidation was seen in the infection and high-fat diet group. The semi-quantitative score of alveolitis was significantly higher in the infection and normal diet group [(2.200 ± 0.289) points] than in the normal control group [(0.300 ± 0.083) points] and the infection and high-fat diet group [(1.300 ± 0.475) points] (both P values < 0.05), and higher serum IL-1ß [(151.586 ± 20.492)] pg/mL and TNF-α levels [(180.207 ± 23.379) pg/mL] were detected in the infection and normal diet group than in the normal control group [IL-1ß: (103.226 ± 3.366) pg/mL; TNF-α: (144.807 ± 1.348) pg/mL] and the infection and high-fat diet group [IL-1ß: (110.131 ± 12.946) pg/mL; TNF-α: (131.764 ± 27.831) pg/mL] (all P values < 0.05). In addition, lower CYP 4A1 mRNA (3.00 ± 0.81) and protein expression (0.40 ± 0.02) was quantified in lung specimens in the infection and normal diet group than in the normal control group [(5.03 ± 2.05) and (0.84 ± 0.14)] and the infection and high-fat diet group [(11.19 ± 3.51) and (0.68 ± 0.18)] (all P values < 0.05). CONCLUSIONS: High-fat intake may alleviate lung injuries caused by P. proliferus infection in rats through up-regulating CYP 4A1 expression in lung tissues at both translational and transcriptional levels.

Mitogenomic and nuclear ribosomal transcription unit datasets support the synonymy of Paragonimus iloktsuenensis and P. ohirai (Paragonimidae: Platyhelminthes).

The complete mitogenome (mtDNA) of nominal Paragonimus iloktsuenensis (Paragonimidae: Trematoda) and the nuclear ribosomal transcription unit (rTU) coding region (rTU*: from 5'-terminus of 18S to 3'-terminus of 28S rRNA gene, excluding the external spacer region) of this species and of P. ohirai were obtained and used to further support the previously suggested synonymy of these taxa in the P. ohirai complex. The complete mitogenome of P. iloktsuenensis was 14,827 bp long (GenBank: ON961029) and nearly identical to that of P. ohirai (14,818 bp; KX765277), with a 99.12% nucleotide identity. The rTU* was 7543 bp and 6932 bp in these two taxa, respectively. All genes and spacers in the rTU were identical in length, with exception of the first internal transcribed spacer, which contained multiple tandem repeat units (6.7 for P. iloktsuenensis and 5.7 for P. ohirai). There was near 100% identity for the rTU genes. The phylogenetic topology inferred from the mtDNA and from individual gene regions (partial cox1 of 387 bp and the ITS-2 of 282 bp - 285 bp) indicated a very close relationship consistent with synonymy of P. iloktsuenensis and P. ohirai. The datasets provided here will be useful for taxonomic reappraisal as well as studies of evolutionary and population genetics of the genus Paragonimus and family Paragonimidae.

A case of a dog with paragonimiasis after consumption of raw deer meat.

A 6-year-old castrated male Cavalier King Charles Spaniel was referred to the Animal Medical Center, Tokyo University of Agriculture and Technology, for examination and treatment of recurrent pneumothorax. Chest radiography and computed tomography showed multiple cavitary lesions in the caudal right posterior lobe. These lesions were surgically excised via thoracotomy. Subsequent histopathological examination revealed paragonimiasis. In the postoperative review, we found that the owner had fed raw deer meat to the dog four months earlier. Deer meat has attracted attention as a source of Paragonimus in humans. To our knowledge, this is the first report of Paragonimus infection in a dog due to deer meat consumption.

A case of spontaneous pneumothorax due to paragonimiasis in North America with literature review.

The species, Paragonimus kellicotti , causes human paragonimiasis in North America. As a foodborne disease, human infection with P. kellicotti occurs after eating raw or undercooked crayfish containing metacercariae. Many risk factors have been described in the literature, including young adult age, male, alcohol consumption, outdoor activities involving rivers within Missouri, and ingesting raw or partially cooked crayfish. Here, we report a case of a 41-year-old male with a 5-year history of cough who presented with acute shortness of breath. Further workup showed mild eosinophilia and spontaneous pneumothorax. A definitive diagnosis was made with a lung biopsy, which showed P. kellicotti eggs. Further questioning revealed that the patient took a hunting and river rafting trip on a river in Missouri 5 years ago, though the history was negative for any crayfish consumption. Paragonimiasis should be considered in those with associated clinical features, including cough and eosinophilia, with a history of a river raft float trip in Missouri, even if the history is negative for crayfish ingestion or travel.

The first case report of Paragonimus westermani infection diagnosed by transbronchial lung cryobiopsy.

We report a case of pulmonary paragonimiasis diagnosed by transbronchial lung cryobiopsy (TBLC). TBLC is likely to be a superior method to transbronchial forceps biopsy because TBLC can get larger specimens, resulting in a higher chance of containing the eggs. A male patient aged 57 years presented with hemoptysis and dyspnea on exertion. His initial chest computed tomography scans showed a cavitary nodule with a peripheral ground-glass appearance, leading to a prescription of an oral antibiotic, with an initial assumption of pneumonia. A follow-up chest computed tomography, however, revealed an appearance of a new nodule adjacent to the original nodule. TBLC and transbronchial forceps biopsy were done to rule out lung cancer and eventually, the eggs of Paragonimus westermani were found using TBLC. Praziquantel was prescribed, showing improvements in symptoms and chest X-ray findings. TBLC has more potential to be utilized as a diagnostic method than transbronchial forceps biopsy because it has a better chance to confirm pulmonary paragonimiasis, which can be initially suspected as pulmonary tuberculosis or lung cancer.

Endemic Paragonimus kellicotti infections in animals and humans in USA and Canada: Review and personal perspective.

Infections with the lung fluke, Paragonimus kellicotti, have been diagnosed in a variety of domestic and wild animals and humans in USA and Canada. Although there are many species of Paragonimus in other parts of the world; P. kellicotti is the only species definitively diagnosed in USA and Canada. Fresh water snails (several species) and crayfish (mainly Orconectes spp.) are its intermediate hosts. Humans and animals become infected with P. kellicotti only by ingesting metacercariae encysted in the heart of crayfish. After ingestion, the fluke penetrates intestinal wall, enters peritoneal cavity, and reaches pleural cavity by direct penetration of diaphragm, 2-3 weeks post inoculation (p.i.). Young flukes penetrate lungs and become encysted in pulmonary tissue, often in pairs. Time to maturity is around 4-7 weeks p.i. Eggs are coughed up, swallowed, and are excreted in feces. Although the parasite has been known for more than a century, there has been an upsurge of human infections in the USA. Here, I review P. kellicotti infections in naturally infected hosts. Pathogenesis, diagnosis, and treatment in parasite-free cats and dogs experimentally infected P. kellicotti are reviewed to shed light on the pathogenesis of human paragonimiasis. Problems and challenges facing diagnosis of paragonimiasis, especially non-pulmonary infections, are discussed. Fluke stages are deposited in Smithsonian Museum.

A Cluster of Paragonimiasis with Delayed Diagnosis Due to Difficulty Distinguishing Symptoms from Post-COVID-19 Respiratory Symptoms: A Report of Five Cases.

Paragonimiasis caused by trematodes belonging to the genus Paragonimus is often accompanied by chronic respiratory symptoms such as cough, the accumulation of sputum, hemoptysis, and chest pain. Prolonged symptoms, including respiratory symptoms, after coronavirus disease 2019 infection (COVID-19) are collectively called post-COVID-19 conditions. Paragonimiasis and COVID-19 may cause similar respiratory symptoms. We encountered five cases of paragonimiasis in patients in Japan for whom diagnoses were delayed due to the initial characterization of the respiratory symptoms as a post-COVID-19 condition. The patients had consumed homemade drunken freshwater crabs together. One to three weeks after consuming the crabs, four of the five patients were diagnosed with probable COVID-19. The major symptoms reported included cough, dyspnea, and chest pain. The major imaging findings were pleural effusion, pneumothorax, and nodular lesions of the lung. All the patients were diagnosed with paragonimiasis based on a serum antibody test and peripheral blood eosinophilia (560-15,610 cells/µL) and were treated successfully with 75 mg/kg/day praziquantel for 3 days. Before diagnosing a post-COVID-19 condition, it is necessary to consider whether other diseases, including paragonimiasis, may explain the symptoms. Further, chest radiographic or blood tests should be performed in patients with persistent respiratory symptoms after being infected with COVID-19 to avoid overlooking the possibility of infection.

Immunoblotting Identification of Diagnostic Antigens of Paragonimus westermani Type 1 for the Detection of Human Pulmonary Paragonimiasis in North East India.

Human pulmonary paragonimiasis, an emerging concern in North East India, frequently masquerades as pulmonary tuberculosis due to clinical and radiological similarities, leading to diagnostic challenges. This research aimed to harness the immunoblotting technique to discern immunodiagnostic protein antigens from both adult worm and excretory-secretory (ES) extracts of the prevalent Paragonimus westermani type 1 in Arunachal Pradesh, North East India. We studied the time kinetics of immunoreactive patterns in relation to the duration of infection in rodent models. Immunoblot analyses were also conducted using sera from ELISA-positive patients confirmed with paragonimiasis, facilitating the selection of antigenic extracts with diagnostic potential. Further, ES protein antigens were subjected to 2D immunoblot analysis and immunoreactive protein spots identified using MALDI-TOF MS. The immunoreactivity patterns of ES antigens with sera of paragonimiasis-positive patients were detailed, and specific immunoreactive protein antigens were pinpointed using peptide mass fingerprinting (MALDI-TOF). This work underscores the enhanced diagnostic accuracy when combining ELISA with immunoblotting for pulmonary paragonimiasis in regions like North East India, marked by co-existing helminth infections.

High-fat intake alleviates lung injury induced by Paragonimus proliferus infection in rats through up-regulating CYP 4A1 expression in lung tissues / 中国血吸虫病防治杂志

Objective To explore the improvements of high-fat intake on lung injury induced by Paragonimus proliferus infection in rats, and to preliminarily explore the mechanisms underlying the role of cytochrome P450 4A1 (CYP 4A1) in the improve ments. Methods SD rats were randomly assigned into three groups, including the normal control group (n = 10), the infection and normal diet group (n = 12) and the infection and high-fat diet group (n = 12). Rats in the normal control group were fed with normal diet and without any other treatments, and animals in the infection and normal diet group were subcutaneously injected with 8 excysted metacercariae of P. proliferus via the abdominal wall, followed by feeding with normal diet, while rats in the infection and high-fat diet group were subcutaneously injected with 8 excysted metacercariae of P. proliferus via the abdominal wall, followed by feeding with high-fat diet. All rats were sacrificed 28 weeks post-infection, and serum samples and lung specimens were collected. Following hematoxylin-eosin (HE) staining of rat lung specimens, the rat lung injury was observed under an optical microscope, and alveolitis was evaluated using semi-quantitative scoring. Serum interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) levels were measured using enzyme-linked immunosorbent assay (ELISA), and the cytochrome P450 4A1 (CYP 4A1) expression was quantified in rat lung specimens at transcriptional and translational levels using quantitative real-time PCR (qPCR) and Western blotting assays. Results Alveolar wall thickening, edema and inflammatory cell infiltration were alleviated 28 weeks post-infection with P. proliferus in rats in the infection and high-fat diet group relative to the infection and normal diet group, and no alveolar consolidation was seen in the infection and high-fat diet group. The semi-quantitative score of alveolitis was significantly higher in the infection and normal diet group [(2.200 ± 0.289) points] than in the normal control group [(0.300 ± 0.083) points] and the infection and high-fat diet group [(1.300 ± 0.475) points] (both P values < 0.05), and higher serum IL-1β [(151.586 ± 20.492)] pg/mL and TNF-α levels [(180.207 ± 23.379) pg/mL] were detected in the infection and normal diet group than in the normal control group [IL-1β: (103.226 ± 3.366) pg/mL; TNF-α: (144.807 ± 1.348) pg/mL] and the infection and high-fat diet group [IL-1β: (110.131 ± 12.946) pg/mL; TNF-α: (131.764 ± 27.831) pg/mL] (all P values < 0.05). In addition, lower CYP 4A1 mRNA (3.00 ± 0.81) and protein expression (0.40 ± 0.02) was quantified in lung specimens in the infection and normal diet group than in the normal control group [(5.03 ± 2.05) and (0.84 ± 0.14)] and the infection and high-fat diet group [(11.19 ± 3.51) and (0.68 ± 0.18)] (all P values < 0.05). Conclusion High-fat intake may alleviate lung injuries caused by P. proliferus infection in rats through up-regulating CYP 4A1 expression in lung tissues at both translational and transcriptional levels.

Sequence analysis of Paragonimus internal transcribed spacer 2 and cyclooxygenase 1 genes in freshwater crabs in Henan Province / 中国血吸虫病防治杂志

Objective To investigate the sequences of internal transcribed spacer 2 (ITS2) and cyclooxygenase 1 (COX1) genes of Paragonimus metacercariae in freshwater crabs in Henan Province, identify the species of Paragonimus and evaluate its genetic relationships with Paragonimus isolates from other provinces in China. Methods Freshwater crabs were collected from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province from 2016 to 2021, and Paragonimus metacercariae were detected in freshwater crabs. Genomic DNA was extracted from Paragonimus metacercariae, and the ITS2 and COX1 genes were amplified using PCR assay, followed by sequencing of PCR amplification products. The gene sequences were spliced and aligned using the software DNASTAR, and aligned with the sequences of Paragonimus genes in the GenBank. Phylogenetic trees were created using the MEGA6 software with the Neighbor-Joining method based on ITS2 and COX1 gene sequences, with Fasciola hepatica as the outgroup. Results The detection rates of Paragonimus metacercariae were 6.83% (11/161), 50.82% (31/61), 18.52% (5/26), 8.76% (12/137), 14.29% (9/63), 17.76% (19/105), 18.50% (32/173) and 42.71% (41/96) in freshwater crabs from 8 survey sites in Zhengzhou, Luoyang, Pingdingshan, Nanyang and Jiyuan cities of Henan Province, with a mean detection rate of 19.46% (160/822), and a mean infection intensity of 0.57 metacercariae/g. The amplified ITS2 and COX1 gene fragments of Paragonimus were approximately 500 bp and 450 bp in lengths, respectively. The ITS2 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (99.8% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: MW960209.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with P. skrjabini from Sichuan Province (GenBank accession number: AY618747.1), Guangxi Zhuang Autonomous Region (GenBank accession number: AY618729.1) and Hubei Province (GenBank accession number: AY618751.1), and P. miyazaki from Fujian Province (GenBank accession number: AY618741.1) and Japan (GenBank accession number: AB713405.1). The COX1 gene sequences of Paragonimus metacercariae from 8 survey sites of Henan Province showed the highest homology (90.0% to 100.0%) with the gene sequence of P. skrjabini (GenBank accession number: AY618798.1), and phylogenetic analysis showed that the Paragonimus in this study was clustered into the same clade with all P. skrjabini and clustered into the same sub-clade with P. skrjabini from Hubei Province (GenBank accession numbers: AY618782.1 and AY618764.1). Conclusions Paragonimus species from freshwater crabs in Henan Province were all characterized as P. skrjabini, and the ITS2 and COX1 gene sequences had the highest homology to those of P. skrjabini from Hubei Province. The results provide insights into study of Paragonimus in Henan Province and China.

Pulmonary Paragonimiasis in Native Community, Esmeraldas Province, Ecuador, 2022.

Paragonimiasis is a food-borne infection caused by several species of the Paragonimus fluke. Clinical manifestations can mimic tuberculosis and contribute to diagnostic delay. We report a cluster of paragonimiasis in a community in Ecuador, where active surveillance was set up after detection of the first 2 cases.