Current Status of Paragonimus and Paragonimiasis

Abstract

Lung flukes of the genus Paragonimus are widely distributed over the world and are primarily parasitic in the lungs of man and of wild and domestic animals. Until 20 years ago, it was believed that all human paragonimiasis infections were caused by Paragonimus westermani, which originated in the Orient. The generally accepted criteria for differentiating the species of adult Paragonimus are the arrangement of the cuticular spines, shape of the ovary and testes, the shape and the size of the eggs, and the relative size of the oral and ventral suckers. Although the lung is the primary site of infection with P. westermani, the involvement of the brain, spinal cord, subcutaneous tissue, abdomen, eye and genital organs may be found. Seroimmunological tests play an important role in diagnosing pulmonary and extrapulmonary paragonimiasis, in the screening of paragonimiasis cases in the endemic areas, in the speciation of Paragonimus involved, and also in the evaluation of chemotherapeutic results.