Sparganum mansoni parasitic infection in the lung showing a nodule

Low prevalence of spargana infection in farmed frogs in the Yangtze River Delta of China

Frogs are the main source of infection for human sparganosis. In this study, the prevalence and pathogenicity of plerocercoid larvae (sparganum) in frogs collected from the Yangtze River Delta in East China were investigated. A total of 386 frogs belonging to five species were purchased from farmers' markets across all three provincial level areas in the Yangtze River Delta region. The overall prevalence was 4.9% (19/386), and 39 spargana were detected visually, with the intensity ranging from 1 to 11. The spargana infection rate was 7.7% (11/143) in Jiangsu Province and 4.4% (8/181) in Shanghai City, while no spargana infection was detected in Zhejiang Province. In five tested frog species, only Rana nigromaculata and R. limnocharis were found to harbor spargana infection, with a prevalence of 7.7% (13/168) and 6.3% (6/95), respectively. There was no significant difference among the months of the experimental period, July to September. The spargana mostly parasitized the muscle tissues of frogs, especially in the hind legs. All the spargana were identified by molecular analysis based on cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, and all plerocercoids were Spirometra erinaceieuropaei. Nine mice were infected orally with 1 to 3 scoleces, and 77.8% (14/18) of plerocercoids were found in mice at the 30th day post infection. No obvious clinical symptoms were observed in the mice; however, histopathological analysis showed an inflammatory cellular response in all tissues except intestinal tissue. Hematologic analysis showed an increased number of white blood cells (WBCs) at the 18th day post infection. These results indicated that R. nigromaculata and R. limnocharis are a potential source of zoonotic sparganosis in the Yangtze River Delta of China, and farmed frogs may substantially reduce zoonotic risk as compared to eating wild frogs. Our findings will provide data for frog food safety and prevention and control of sparganosis in the region.

Identification of sparganosis based on next-generation sequencing

The incidence of sparganosis, a parasitic disease caused by plerocercoid larvae of the genus Spirometra, has gradually risen worldwide (especially in remote areas) in recent years. Pulmonary and pleural sparganosis, as well as other sites of infestation, including the subcutaneous tissues, the abdominal viscera, brain and eyes, has been reported. In clinical practice, due to the atypical signs and symptoms as well as limited laboratory approaches for the specific detection of sparganum, sparganosis is often misdiagnosed. In the present study, an 11-year-old girl visited the Department of Infectious Diseases in Shanghai Children's Medical Center for recurrent shoulder and chest pain and shortness of breath. Imaging tests demonstrated bilateral pleural and pericardial effusion, enlarged lymph nodes in front of the tracheal carina, and infection of the left lower lobe. Sparganum were not observed in the dissected soft tissue at the root of the right thigh with naked-eye and light microscopy examination. Histologic examination revealed granulomatous inflammation and tunnel-like necrosis with eosinophilic, neutrophilic and lymphocytic infiltration. Although the patient's serum was positive for sparganum antibodies, the diagnosis of sparganosis was not confirmed for more than three months. Ultimately, genomic DNA of Spirometra erinaceieuropaei was detected in the mass at the root of the right thigh using next-generation sequencing (NGS), confirming the diagnosis of sparganosis. The patient was treated with praziquantel (150 mg/kg/day) without recurrence after an eight-month follow-up. We present, for the first time, a study of human sparganosis diagnosed using NGS, which provided a clinically actionable diagnosis of a specific infectious disease from an uncommon pathogen.

Orbital sparganosis in an 8-year boy: a case report

Background

Sparganosis is one of the neglected but important food-borne parasitic zoonoses, with higher prevalence in Asian countries. The infection is commonly located in the subcutaneous tissue, brain, breast, and lung, but fewer reported infections involve the eye. Because the majority of patients with sparganosis are adults, it is likely to be missed in children.

Case presentation

An 8-year-old boy presented to our clinic complaining of a painless ocular mass in his right eye for 1 month. The boy had a history of eating frogs and frog poultice applications to his eyelids. The patient was checked for an elliptical mass near the medial wall of the right eye. Serodiagnosis testing was positive in an enzyme-linked immunosorbent assay. During surgical operation on the patient, calcified parasite eggs and foreign body granulomatous reaction were found using histological examination. Due to early detection and surgery, the patient fully recovered with no damage to his eyesight.

Conclusions

Although rare, ocular sparganosis should be suspected in a mass of the eye when there is a history of eating frogs and frog poultice applications on eyelids. Early surgical resection is important for a good prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0675-8) contains supplementary material, which is available to authorized users.

Clinical Manifestation of a Patient With Forehead Sparganosis

Human sparganosis is a parasite infection caused by the larva of a tapeworm of the genus Spirometra. Ocular, central nervous system, auricular, pulmonary, intraosseous, intraperitoneal, and subcutaneous manifestations of this infection in the neck or inguinal region have been described.The authors report the rare occurrence of cutaneous forehead sparganosis of a 19-year-old male who presented with a soft subcutaneous mass in the forehead, along with a related literature review.

Clinical Features of Pulmonary Sparganosis

BACKGROUND

Sparganosis is an infectious disease caused by the sparganum of Spirometra species, which seldom invades the respiratory system. The aim was to describe the clinical features and outcomes of pulmonary sparganosis.

METHODS

A total of 40 patients with pulmonary sparganosis were reviewed, including 12 cases known from this experience and 28 cases reported in the literature.

RESULTS

Among these 40 patients at an average age of 45.4 ± 11.1 years (men 29), 34 (85%) had a history of ingesting raw or undercooked meat (mainly frogs or snakes). The top 3 symptoms were coughing (60.0%), fever (57.5%) and chest pain (42.5%). Peripheral blood eosinophilia was found in 30 cases (75%). Lesions were located in lung parenchyma, airway, pleura and pulmonary vessels of the patients. Thirty-one patients (77.5%) had pleural effusion. The diagnosis was established by antisparganum antibody test in 30 cases (75%) and by pathology in 9 cases (22.5%); 1 case was not mentioned. Among the 35 cases with follow-up information, 2 treated with complete surgical removal and 31 with oral administration of praziquantel had no recurrence; the remaining 2 died without effective treatments.

CONCLUSIONS

As an extremely rare and life-threatening parasitic zoonosis, pulmonary sparganosis should be diagnosed by combining the epidemiology, patient history, eosinophilia and the positive antisparganum antibody test result together if no worm was detected. Oral praziquantel is considered to be an effective treatment.

Thoracoscopic examination of empyema in a patient with sparganosis mansoni

A 27-year-old man was admitted to our hospital with right pleural effusion. He had suffered from right chest and back pain and a high fever for one week prior to the admission. He had been treated with clarithromycin without improvement. Since thoracoscopy under local anesthesia revealed purulent effusion, synechiae and fibrous septa in the thoracic cavity, synechiotomy was performed and we started antibiotic treatment with the diagnosis of acute bacterial empyema. At the same time, we also suspected parasitic infection because of massive eosinophilic infiltration in pleural effusion and his dietary history of eating raw frogs. During the course of the disease, he had an infiltration in the right lower lobe and pneumothorax. Finally, we diagnosed him with sparganosis mansoni because his serum as well as pleural effusion was positive for the binding to sparganosis mansoni plerocercoid antigen, without any positive findings in bacteriology. His pleural effusion and lung infiltration were resolved after the administration of a high-dose praziquantel. We report this rare parasitic empyema with findings by thoracoscopic examination.

Human sparganosis, a neglected food borne zoonosis

Human sparganosis is a food borne zoonosis caused by the plerocercoid larvae (spargana) of various diphyllobothroid tapeworms of the genus Spirometra. Human infections are acquired by ingesting the raw or undercooked meat of snakes or frogs, drinking untreated water, or using raw flesh in traditional poultices. More than 1600 cases of sparganosis have been documented worldwide, mostly in east and southeast Asia. Sporadic cases have been reported in South America, Europe, and Africa, and several cases have been described in travellers returning from endemic regions. Epidemiological data suggest that the increased effect of sparganosis on human health is because of greater consumption of raw meat of freshwater frogs and snakes. This Review provides information about the Spirometra parasites and their lifecycles, summarises clinical features, diagnosis, and treatment of human sparganosis, and describes geographical distribution and infection characteristics of Spirometra parasites in host animals.

Sparganosis presenting as pericardial effusion and lung lesions

We herein report a rare form of sparganosis in a 29-year-old man presenting with pericardial effusion and lung lesions. The diagnosis was confirmed by the patient's history of eating inadequately cooked snake, significant elevated eosinophils in the peripheral blood and pericardial effusion, and marked positive reactions against Sparganum mansoni antigen in the serum. After two consecutive doses of praziquantel treatment, the patient's symptoms and laboratory and imaging findings were improved. Both specific antibody detection and follow-up of the patient's eosinophils, serum antibody, and imaging changes are important for sparganosis diagnosis, particularly in cases without a subcutaneous lump or mass.

Pulmonary sparganosis mansoni: a case report from a non-endemic region

Sparganosis mansoni is a parasitic disease caused by the larva of Spirometra mansoni. It occurs worldwide, but only a few patients show pulmonary involvement. Here, we present a case of pulmonary sparganosis mansoni in a non-endemic region. A 32-year-old Chinese woman presented with intermittent bloody phlegm, peripheral blood eosinophilia, and migratory patch shadows in both lungs. She had been misdiagnosed with eosinophilic pneumonia. She had a history of eating raw frogs, and the sparganum mansoni antibody was positive in both her blood and bronchoalveolar lavage fluid. Several sparganum mansoni were found in a frog sample that the patient provided. Consequently, she was diagnosed with pulmonary sparganosis mansoni. After two oral courses of praziquantel were administered, her symptoms and radiological lesions improved significantly. To our knowledge, this is the first case of pulmonary sparganosis mansoni occuring in Shanghai. Oral praziquantel is effective for the treatment of sparganosis mansoni, although its course of therapy may need to be repeated.

Two cases of pulmonary and pleural sparganosis confirmed by tissue biopsy and immunoserology

Sparganosis in humans is an incidental infection and is known to be associated with eating insufficiently cooked meat of frogs and snakes or drinking unboiled stream water. Although it can involve various internal organs, pulmonary and pleural involvement due to sparganum is rare. Because we recently experienced two cases involving lung parenchyma and pleura that were misdiagnosed as bacterial pneumonia and lung cancer, we herein intend to present them in detail.

Imaging of Parasitic Diseases of the Thorax

A broad spectrum of parasitic infections frequently affects the lungs, mediastinum, and thoracic wall, manifesting with abnormal imaging findings that often make diagnosis challenging. Although most of these infections result in nonspecific abnormalities, familiarity with their imaging features and the diagnostic pathways help the radiologist to formulate an adequate differential diagnosis and to guide diagnosticians in reaching a definitive diagnosis.