Paragonimiasis misdiagnosed as liver abscess: A case report.

BACKGROUND: Paragonimiasis is a typical food-borne zoonotic disease. Hosts acquire Paragonimus infection through the ingestion of raw or undercooked crayfish and crab. The clinical manifestations of the disease are varied, and it is often misdiagnosed or missed. The diagnosis of paragonimiasis should be considered comprehensively. Praziquantel is the first choice for treatment, and albendazole can be used in combination with repeated courses in severe cases. CASE SUMMARY: We report a case of liver paragonimiasis that was misdiagnosed as an abscess. The patient presented with fatigue and poor appetite for 2 months, and was diagnosed with liver abscess in the local hospital. After 6 months, the patient visited our hospital because of recurrent abdominal pain and was diagnosed with liver paragonimiasis based on epidemiological history, clinical presentations, and laboratory findings. He was treated with praziquantel (25 mg/kg) three times a day for 3 days; however, the symptoms still presented after treatment. He was treated with oral praziquantel and albendazole for one further course. Follow-up suggested that the treatment was effective and the symptoms improved. CONCLUSION: The combination of albendazole and praziquantel may improve the therapeutic efficacy of paragonimiasis.

A rare occurrence of paragonimiasis accompanied by cryptococcal pneumonia.

Pulmonary paragonimiasis may be accompanied by a rare infectious disease, such as cryptococcal pneumonia. To our knowledge, this is the first case ever reported in the English literature.

Paragonimiasis.

Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species. Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex. Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 6.1).

Peripheral blood eosinophils: an important reference for radiologists to distinguish between pulmonary paragonimiasis and tuberculous pleurisy in children.

OBJECTIVE: In this study, we examined the value of chest CT signs combined with peripheral blood eosinophil percentage in differentiating between pulmonary paragonimiasis and tuberculous pleurisy in children. METHODS: Patients with pulmonary paragonimiasis and tuberculous pleurisy were retrospectively enrolled from January 2019 to April 2023 at the Kunming Third People's Hospital and Lincang People's Hospital. There were 69 patients with pulmonary paragonimiasis (paragonimiasis group) and 89 patients with tuberculous pleurisy (tuberculosis group). Clinical symptoms, chest CT imaging findings, and laboratory test results were analyzed. Using binary logistic regression, an imaging model of CT signs and a combined model of CT signs and eosinophils were developed to calculate and compare the differential diagnostic performance of the two models. RESULTS: CT signs were used to establish the imaging model, and the receiver operating characteristic (ROC) curve was plotted. The area under the curve (AUC) was 0.856 (95% CI: 0.799-0.913), the sensitivity was 66.7%, and the specificity was 88.9%. The combined model was established using the CT signs and eosinophil percentage, and the ROC was plotted. The AUC curve was 0.950 (95% CI: 0.919-0.980), the sensitivity was 89.9%, and the specificity was 90.1%. The differential diagnostic efficiency of the combined model was higher than that of the imaging model, and the difference in AUC was statistically significant. CONCLUSION: The combined model has a higher differential diagnosis efficiency than the imaging model in the differentiation of pulmonary paragonimiasis and tuberculous pleurisy in children. The presence of a tunnel sign on chest CT, the absence of pulmonary nodules, and an elevated percentage of peripheral blood eosinophils are indicative of pulmonary paragonimiasis in children.

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.

Epidemiologic evaluation of pulmonary paragonimiasis in Japan using a Japanese nationwide administrative database.

BACKGROUND: Paragonimiasis is a parasitic disease primarily contracted through consumption of undercooked freshwater crustaceans or wild boar meat. Large-scale nationwide epidemiological data on paragonimiasis are lacking. In this study, we aimed to investigate the nationwide epidemiology of hospitalized patients with paragonimiasis in Japan using a comprehensive nationwide Japanese administrative database. METHODS: We evaluated the Japanese Diagnosis Procedure Combination (DPC) data of patients diagnosed with pulmonary paragonimiasis between April 1, 2012 and March 30, 2020. The patients' address and information, including age, sex, treatment (medication: praziquantel; surgery: open thoracotomy or intracranial mass extirpation), Japan coma scale, comorbidities, and length of hospital stay, were extracted. RESULTS: Of the 49.6 million hospitalized patients, data were extracted on 73 patients with paragonimiasis, of whom 36 were male and 37 were female. The mean age was 49.7 years and the mean length of stay was 12.5 days. The most frequent comorbidity was pleural effusion (31.5 %), followed by pneumothorax (13.7 %). The sites of ectopic paragonimiasis in organs other than the lung included the liver (5.5 %), skin (4.1 %), and brain (2.7 %). Geographically, most patients were from the Kyushu region (54.8 %), followed by the Kanto region (22.0 %). Fukuoka Prefecture had the highest number of patients (22.0 %) by prefecture. During the study period, an average of 9.1 patients/year were hospitalized with lung paragonimiasis in Japan. CONCLUSION: Paragonimiasis has not completely disappeared in Japan; thus, physicians should be aware of paragonimiasis in the Kyushu region, especially in the Fukuoka Prefecture.

[Case of Abdominal Colicky Pain Caused by Hepatic Paragonimiasis].

In Korea, the prevalence of paragonimiasis has decreased markedly since 1970 and is now rarely encountered. Although the lung is the primary site of paragonimiasis, ectopic infestation can occur in other sites. The central nervous system is the most commonly involved ectopic site, accounting for only approximately 1% of all paragonimiasis patients. Therefore, the liver is an extremely rare site of ectopic infestation. The authors experienced the case of a 55-year-old female with hepatic paragonimiasis who presented with abdominal colicky pain.

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.

An unusual presentation of pulmonary nodules.

A pulmonary nodule is a common radiological finding encountered in routine medical practice. It needs to be extensively evaluated as the differential diagnosis can range from sinister malignancies to fully treatable infectious causes. Here, we present a rare case of pulmonary paragonimiasis presenting as pulmonary nodule. This case report aims to sensitise the medical practitioner regarding pulmonary paragonimiasis which is completely treatable but carries a high risk of being under diagnosed.

Pediatric paragonimiasis: a retrospective analysis of cases from a county in south-west China.

Introduction: The clinical manifestations of paragonimiasis are diverse and non-specific, and can easily lead to misdiagnosis. We aimed to analyze the clinical manifestations, laboratory features, treatment, and clinical outcome of children with paragonimiasis in order to improve recognition of this disease and avoid misdiagnosis. Methods: Children diagnosed with paragonimiasis from August 2016 to July 2022 were included in the study. Information on population informatics, medical history, and laboratory features was extracted from case data. The clinical features of paragonimiasis were retrospectively analyzed. Results: A total of 45 children were included in this study. All children had, at least, one risk factor. The clinical features mainly included fever, cough, pleural effusion, peritoneal effusion, and subcutaneous nodules. The main imaging findings were alveolar exudation, peritoneal effusion, pleural thickening, and local nodules. The "tunnel sign" finding on computed tomography (CT)/magnetic resonance imaging (MRI) was helpful in establishing the diagnosis of paragonimiasis. After praziquantel treatment, most of the children improved, and one child with cerebral paragonimiasis experienced sequelae. Conclusion: Most children with paragonimiasis have a good prognosis, but few children can experience sequelae. Avoidance of untreated water and raw food is a simple, feasible, and effective preventive measure.

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.

Thoughts underlying "pneumonia" resulting from eating: A case report.

As a rare zoonotic helminth disease, paragonimiasis is easy to be misdiagnosed. Adequate attention to the medical history of the patient and early detection of serological antibodies can improve the diagnosis rate. Praziquantel and trichlorobendazole are commonly used for treatment, and the prognosis is good. This case report mainly introduces the classification, diagnosis, and treatment of paragonimiasis, with an aim to draw the attention of doctors to the disease.

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.

Massive secretions in paragonimiasis pleural effusion: a new finding concerning clinical recognition and treatment.

Some paragonimiasis patients in Chongqing, southwest China, have recently exhibited pleural effusions (PEs) with massive viscous secretions. This study aimed to investigate their clinical characteristics, thereby promoting effective treatments. A 3-year retrospective review of paragonimiasis patients who were admitted for nonhomogeneous PEs at Chongqing University Three Gorges Hospital was conducted. Epidemiological data, symptoms, laboratory and imaging findings, treatments, and outcomes were analyzed. Twenty-eight patients were identified, of which 22 (78.6%) were males and 22 (78.6%) were rural residents. Respiratory (85.7%) and constitutional (57.1%) symptoms were common. Paragonimus-specific ELISA was positive in all patients. Eosinophilia was detected in all patients in peripheral blood and PEs. Irregular hyperdense signals were observed in PEs by chest CT scans (96.4%) and ultrasonography (100.0%). Thoracic closed drainage failed in 10 patients (conservative group) because of tube blockage and was eventually replaced by video-assisted thoracoscopic surgery (VATS). Eighteen patients (surgery group) initially underwent VATS, or thoracotomy surgery, without complications. Massive secretions, described as "bean-dregs" or "egg-floccule," were detected intraoperatively, which explained the imaging findings and tube blockage. All patients recovered well after 2-3 courses of postoperative praziquantel treatment. Viscous secretions in paragonimiasis patients warrant great concern. Irregular hyperdense signals in effusions are important characteristics in CT scans and ultrasonography. Treatments such as thoracic closed drainage may fail due to viscous secretions blocking the tube; therefore, surgeries should be considered. In-depth multidisciplinary research may help determine the optimal treatment strategy and reveal the origin of these secretions.

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.

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.

Two cases of Lophomonas blattarum infection combined with paragonimiasis and literature review / 中国基层医药

Objective:To investigate the clinical manifestations, diagnosis, and treatment methods of Lophomonas blattarum infection combined with paragonimiasis in children, and improve pediatricians' understanding of the disease. Methods:The clinical data of two children with Lophomonas blattarum infection combined with paragonimiasis who received treatment in the Department of Pediatrics of The First People's Hospital of Yunnan Province were retrospectively analyzed. Children's clinical manifestation and diagnosis and treatment were analyzed. Relative literature was reviewed. Results:Case 1 had the onset of gastrointestinal symptoms. Case 2 had the onset of headache and liver dysfunction. Routine blood tests showed elevated eosinophils two cases and sputum examination results revealed the presence of live eggs of Lophomonas blattarum and paragonimiasis in two cases. Fecal roundworm eggs were also detected in case 1. Follow-up results showed that both cases were cured after treatment with metronidazole injection and praziquantel tablets. Conclusion:Lophomonas blattarum infection is a relatively rare opportunistic infection. Paragonimiasis is a natural parasitic disease that affects both humans and animals. Mixed infection of the two pathogens is rare. We hope that the findings from this paper will broaden clinical physicians' thoughts and guide clinical practice.