| Abstract|| |
Paragonimiasis is an infectious disease caused by Trematodes of the genus Paragonimus that is endemic in Asia, Africa, and South America. Most patients with paragonimiasis are cured by standard praziquantel treatment. However, several cases have been reported to have unsatisfactory responses to the standard praziquantel treatment. To probe the clinical characteristics, possible cause, and management of the paragonimiasis individuals improved by multiple therapies, we present a 12-year-old Chinese boy, who was infected with Paragonimus accompanied by arachnoid cyst involvement, as not having typical clinical symptoms, but repeatedly presenting with migrated lesions between the lung and pleura. He responded to treatment with 3 cycles of praziquantel and 1 cycle of albendazole.
Keywords: Albendazole, migrated lesions, multiple therapies, paragonimiasis, praziquantel
|How to cite this article:|
Hu Y, Qian J, Yang D, Zheng X. Pleuropulmonary paragonimiasis with migrated lesions cured by multiple therapies. Indian J Pathol Microbiol 2016;59:56-8
|How to cite this URL:|
Hu Y, Qian J, Yang D, Zheng X. Pleuropulmonary paragonimiasis with migrated lesions cured by multiple therapies. Indian J Pathol Microbiol [serial online] 2016 [cited 2019 Jul 20];59:56-8. Available from: http://www.ijpmonline.org/text.asp?2016/59/1/56/174820
| Introduction|| |
Paragonimiasis is an infectious disease caused by lung flukes of the genus Paragonimus and is endemic in Asia, Africa, and South America.  The nationwide prevalence in China is estimated at 1.71%.  In Hubei Province, an epidemiological survey revealed that paragonimiasis is widespread with a mean prevalence of 10-20%.  Transmission to humans occurs by the ingestion of inadequately cooked crabs or crayfish that are infected with Paragonimus. The life cycle of Paragonimus involves crabs or crayfish as intermediate hosts and humans, cats, dogs, or foxes as definitive hosts. The clinical manifestations of paragonimiasis characteristically present in the chest, abdomen, or brain. The pulmonary manifestations are a predominately cough, hemoptysis, chest pain, dyspnea, and eosinophilia.
Praziquantel is the most commonly used the drug for the treatment of human paragonimiasis in China.  About 80-90% of , paragonimiasis cases can be successfully treated with praziquantel. Here, we report a 12-year-old Chinese boy, who was infected with Paragonimus accompanied by arachnoid cyst involvement, as not having typical clinical symptoms, but repeatedly presenting with migrated lesions between the lung and pleura, which was resistant to standard treatment, but improved with 3 cycles of praziquantel treatment and 1 cycle of albendazole treatment.
| Case report|| |
The patient is a 12-year-old boy who resides in Enshi City, China. He was first admitted to a local hospital in September 2012 with a 1-week history of marasmus, fatigue, anorexia, and occasional headache. Blood tests showed that his total white blood cell count (WBC) was 18.38 × 10 9 cells/L with 8.2% eosinophilia. The enzyme-linked immunoabsorbent assay (ELISA) for Paragonimus species was positive. The report of computed tomography (CT) scan of the chest revealed right lung infiltrate with a pleural effusion on the right side (the image was not available). The abdominal sonography indicated a small amount of ascites. Upon further questioning, he had visited his relatives in the mountain area of Enshi, Hubei, China, in July 2012, and consumed two incompletely cooked freshwater crabs. His cousins, who ate more crabs, were asymptomatic. The patient was diagnosed with paragonimiasis and treated with praziquantel (150 mg/kg in 3 divided doses for 3 days). Five days after treatment, the chest CT scan showed significant improvement except for the small residual pleural effusion on the right side. The ascites had disappeared. At discharge, he did not complain of any discomfort. At the follow-up visit in December 2012, his WBC was elevated (17.12 × 10 9 cells/L) and the eosinophil percentage was 54.3%. The chest CT showed a right lung nodule and a pleural effusion on the right side [Figure 1]a. He was readmitted to the local hospital and received an additional cycle of praziquantel treatment (150 mg/kg in 3 divided doses for 3 days). His WBC decreased to 11.77 × 10 9 cells/L and the eosinophil count came down to 13.9%. The chest CT showed the resolution of the right lung nodule, improvement of the right pleural effusion and clearing of the lung fields. At follow-up examination in January 2013, the patient's WBC was elevated to 13.23 × 10 9 cells/L and the eosinophil count was back to 20.9%. The chest CT scan at that time indicated that the lesions had migrated to the left lower lobe.
|Figure 1: The changes of the chest computed tomography scans over time in a 12-year-old boy who had migrated lesions between the lung and pleura. (a) Before the second praziquantel treatment, computed tomography scan of the chest showing a right lung nodule and a pleural effusion on the right side. (b) Before the third praziquantel treatment, computed tomography scan of the chest with intravenous contrast showing multiple lung nodules and a mass of the upper left lung|
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The patient was referred to our hospital for further treatment in February 2013. His initial examination showed normal temperature, blood pressure of 106/66 mm Hg, the pulse of 85 beats/min, and a respiratory rate of 20 breaths/min. No other outward significant signs were found. However, his total WBC count was 13.84 × 10 9 cells/L, with 27.7% eosinophilia, and the erythrocyte sedimentation rate was 29 mm/h. The CT scan of his chest with intravenous contrast showed multiple lung nodules and a mass of the upper left lung [Figure 1]b. The magnetic resonance imaging (MRI) of his brain showed an arachnoid cyst (size 6.2 cm × 5.5 cm × 6.2 cm) of the left temporal lobe. Serum was sent to several different laboratories for a Paragonimus antibody test and the results were positive. Other parasite infections such as Schistosomiasis Japonica, Trichinosis, and Cysticercosis were excluded. The serological tests were negative for Rickettsia, Ehrlichia, and Strongyloides species, Epstein-Barr virus, herpes simplex virus, Cytomegalovirus, and human immunodeficiency virus. Tuberculin skin testing and immunological tests for tuberculosis were negative. The patient's parent refused bronchoscopy. The diagnosis of paragonimiasis was confirmed based on the patient's epidemiology history, eosinophilia, serological results, and chest findings. The brain MRI results were reviewed by a radiologist, a neurosurgeon, and a neurologist, and the arachnoid cyst was diagnosed as a benign cyst and not associated with the paragonimiasis. The patient was treated with a third cycle of praziquantel therapy (150 mg/kg in 3 divided doses for 3 days). The next day after treatment, the chest CT indicated that the nodules in the left lung had disappeared and only a very small pleura effusion was present on the left side. The WBC and eosinophil remained elevated.
In March 2013, the patient's WBC remained elevated (WBC, 15.61 × 10 9 cells/L; eosinophil, 33.2%). The chest CT indicated a large left pleural effusion. Therefore, he was readmitted to our hospital. The pleural fluid was aspirated by thoracentesis and laboratory tests on the pleural fluid showed the following findings: WBC, 11,075 cells/μL (20% neutrophils, 8% lymphocytes, 7% monocytes, and 65% eosinophils); pH, 7.135; proteins, 8.8 g/dl; albumin, 2.5 g/dl; and glucose, 6 mg/dl. The eggs of Paragonimus were not found in the pleural fluid. Triclabendazole is the second line drug that can be used for paragonimiasis treatment; however, it is not available in China. The patient was thus given a cycle of albendazole treatment (8 mg/kg in 2 doses each day for 7 days). Following the albendazole treatment, in over 1-month, the WBC was back to normal and eosinophil gradually went back to normal levels. The chest sonography showed no pleural effusion.
| Discussion|| |
The incidence of paragonimiasis has decreased in many endemic countries. However, paragonimiasis is increasing in some regions. , In our case, the patient had always resided in an urban area that is not considered endemic. He only visited the mountain area in Enshi once and was infected with Paragonimus after only eating two undercooked freshwater crabs. Other members of his family, who also consumed freshwater crabs at the same time, had no symptoms. This may indicate that persons who live in the endemic area may have a protective immunity to Paragonimus. Persons who live in nonendemic areas may be more sensitive to Paragonimus infection.
The typical symptoms of pleuropulmonary paragonimiasis include fever, cough, blood-tinged sputum, dyspnea, abdominal pain, and chest pain.  Our patient did not present with these typical symptoms. He only complained of anorexia, marasmus, fatigue, and occasional headache. It was doubtful that he had a parasite infection due to the marked peripheral blood eosinophilia and dietary history. Further tests showed that only the antibody to Paragonimus was positive and the results were confirmed by several different laboratories, including two reference laboratories. Other parasite infections such as Schistosomiasis japonica, Trichinosis, and Cysticercosis were excluded. The CT image indicated that the patient might have a parasite infection. The patient's mild symptoms did not match with his severe lesions in the lung. The predominant Paragonimus species are Paragonimus westermani and Paragonimus skrjabini in China.  The ELISA kit used for detecting the antibody to Paragonimus cannot differentiate these two species. We tried to get the eggs of Paragonimus from the pleural fluid aspirate and feces, but they could not be detected.
When humans eat parasitized crayfish or crabs, the metacercaria excyst in the duodenum can migrate to the lung and ectopic locations such as brain or subcutaneous tissues. , Most paragonimiasis case reports only present a 1-time CT image, but the dynamic change of these lesions is not known. This patient had dynamic CT images and they clearly showed that the lesions migrated from the upper right lung to the lower left lung and then moved to the upper left lung. When the lesions in the lung disappeared, the pleural effusion appeared. The brain MRI showed an arachnoid cyst, but it was concluded that it was congenital and not associated with paragonimiasis based on the patient's clinical symptoms and the MRI characteristics.
The reasons that patients are resistant to standard praziquantel are not clear. The chronicity of paragonimiasis or the severity of paragonimiasis could be the reason for the requirement of additional doses of treatment.  Although this patient did not present typical clinical symptoms, the lesions were severe and this may be the reason that he did not respond well to standard treatment. Triclabendazole is another WHO-recommended drug for treatment of paragonimiasis; however, this drug cannot be obtained in China. A search of the published literature indicated that albendazole is also useful in the treatment of paragonimiasis. 
Since this patient did not show typical symptoms, it was difficult to conclude whether he was completely cured or not based on the clinical symptoms. The experience obtained from this patient should remind physicians that it is very important to have follow-up examinations after every treatment.
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Department of Infectious Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Avenue 1277, Wuhan 430022
Source of Support: None, Conflict of Interest: None