Spectrum of pleuropulmonary paragonimiasis: An analysis of 685 cases diagnosed over 22 years

Paragonimiasis is a global foodborne zoonosis. Overlapping clinical and imaging features with other lung pathologies hamper correct diagnosis and require differential diagnosis.

During 1982-2003, 49,012 samples were referred for immunodiagnosis of helminthiases. We detected paragonimiasis cases by enzyme-linked immunosorbent assay (ELISA). We assessed clinical, radiographical and laboratory characteristics, and diagnostic dilemmas associated with delayed diagnosis.

We analyzed 685 pleuropulmonary paragonimiasis cases. ELISA-positive was 665. Eggs were detected in 50. Symptom duration correlated well with the appearance of chest radiographs; 359 pleural, 33 pleuroparenchymal, and 264 parenchymal lesions (P < 0.001). Twenty-nine had normal chest images. Eosinophilia, seen in 304, was common in pleural and pleuroparenchymal patients (P < 0.05). Chest pain and dyspnea were characteristic for pleurisy patients. Sputum (odds ratios [OR]: 6.79; 95% CI: 4.41-10.47), blood-tinged sputum (OR: 5.62; 95% CI: 3.75-8.42), and foul-odor (OR: 2.70; 95% CI: 1.42-5.16) were significant in parenchymal patients. Delayed diagnosis (119) for ≥ 25 weeks was attributed mainly to misdiagnosis as tuberculosis, malignancy, or chronic obstructive pulmonary disease (COPD) (OR: 111.75; 95% CI: 43.25-288.74).

Variable symptoms and radiographs of pleuropulmonary paragonimiasis depended on the stage of infection. Suspicion of tuberculosis, malignancy, or COPD was major cause of delayed diagnosis.