A Case of Delayed Diagnosis of Pulmonary Paragonimiasis due to Improvement after Anti-tuberculosis Therapy

Paragonimiasis Misdiagnosed as Pulmonary Tuberculosis: A Case Report

Paragonimiasis is a zoonosis caused by the ingestion of raw or undercooked crustaceans parasitized with metacercaria of Paragonimus spp. In Peru, Cajamarca is considered an endemic region for paragonimiasis. A 29-year-old man from the department of San Martín, Peru presented with a three-year history of cough, chest pain, fever, and hemoptysis. Treatment for tuberculosis (TB) was initiated even with negative results for sputum acid-fast bacillus (AFB), due to the patient's clinical characteristics and the high prevalence of the condition in the region. After eight months, due to the lack of any clinical improvement, he was referred to a regional hospital, where Paragonimus eggs were evidenced in direct sputum cytology. The patient received treatment with triclabendazole and showed clinical and radiological improvement. It is important to consider eating habits, even in non-endemic areas, for diagnosing paragonimiasis in patients with TB symptoms who do not respond to a specific treatment.

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.

Pleuropulmonary Paragonimiasis with Multiple Nodules in the Pleura

An asymptomatic 47-year-old woman was admitted with pleural effusion and pulmonary infiltrates 1 month after ingesting raw wild boar and deer meat. Both her blood and pleural fluid were eosinophilic. Thoracoscopy revealed multiple nodules of the pleura, and biopsy samples of the nodules showed necrosis with epithelioid cell granulomas. An enzyme-linked immunosorbent assay was positive for antibodies against Paragonimus westermani, and the patient was successfully treated with praziquantel. This is the first reported case of pulmonary or pleuropulmonary paragonimiasis where several pleural nodules were observed. The detection of pleural nodules on thoracoscopy can contribute to the prompt and accurate diagnosis of paragonimiasis.

A tool for mass-screening of paragonimiasis: an enzyme-linked immunosorbent assay with urine samples

BACKGROUND

Paragonimiasis is one of the foodborn trematodiases and number of the patients was estimated to be about 23 million around the world. To obtain good compliance of people for the surveillance of paragonimiasis, an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of paragonimiasis with unconcentrated urine samples was developed.

RESULTS

Paragonimus westermani antigen specific IgG and IgG4 were detected in urine samples from paragonimiasis patients and the levels correlated well with those detected in the paired serum samples. Cross-reactions observed among other trematodiasis and a tuberculosis patient with the antigen specific IgG were much reduced by detecting the antigen specific IgG4; 9.2 % to 2.3 %.

CONCLUSIONS

The ELISA with urine samples, which are collected safely and easily, will be a useful tool for a mass-screening of paragonimiasis.

North American paragonimiasis: epidemiology and diagnostic strategies

Paragonimiasis is a zoonotic, food-borne trematode infection that affects around 23 million people in Asia, Africa and the Americas. North American paragonimiasis, caused by Paragonimus kellicotti, is a common infection of crustacean-feeding mammals in parts of the USA and Canada. Although infection rates in crayfish are very high in some areas, human infections are rare and depend on the consumption of raw or undercooked crayfish. Human infections can be easily prevented and treated, but proper diagnosis of paragonimiasis is a problem. Paragonimus lung flukes often cause serious disease symptoms before they produce eggs that may be detectable in sputum, bronchoalveolar lavage, stool or histological sections by microscopy or PCR. Antibodies against selected Paragonimus proteins are detectable as early as 2-3 weeks after infection. Therefore, antibody serology is the most promising diagnostic approach for paragonimiasis in North America and elsewhere.