One delayed diagnosis of paragonimiasis case and literature review

Human paragonimiasis has been appearing all over the world due to increased human migration, international travel, and worldwide food trading. However, delayed and missed diagnosis rates are also increasing due to atypical clinical manifestations and the lack of disease understanding by clinical workers. We describe the case of a 43-year-old man, who was hospitalized with cough and chest pain for two months. Chest computed tomography (CT) revealed bilateral emphysema, left pleural effusion, and bilateral atelectasis. The hypereosinophilia gave us a clue; ultimately, the diagnosis of paragonimiasis was made through a diet history and a positive result of serum Paragonimus sp. immunoglobulin (Ig) G antibody. Moreover, 27 misdiagnosed paragonimiasis cases in the past decade have been reported. We draw conclusions by summarizing their characteristics for suspicious eosinophilic paragonimiasis patients; we should inquire diet history carefully, test serum IgG antibodies, and try to detect eggs. Once diagnosed, praziquantel is preferred for treatment.

Paragonimus and paragonimiasis in Asia: An update

Paragonimiasis, or lung fluke disease, is a typical food-borne parasitic zoonosis caused by infection with trematodes belonging to the genus Paragonimus. More than 50 species of Paragonimus have been reported throughout the world, of which seven valid species infect humans, an estimated one million people annually worldwide. Among the seven species, P. westermani, P. heterotremus, and P. skrjabini/P. s. miyazakii, distributed in Asia, are the most important species as the cause of paragonimiasis. Humans acquire infection through the ingestion of raw, pickled or undercooked freshwater crustaceans, 2nd intermediate hosts, or consuming raw meat of wild boar or deer, paratenic hosts. Infections often occur clustered in foci where dietary habits allow transmission of the parasites. Paragonimiasis typically causes a subacute to chronic inflammatory disease of the lungs. The symptoms, including chronic cough, chest pain, dyspnea and hemoptysis, mimic those of tuberculosis and lung cancer. Serologic tests are commonly used for the diagnosis of paragonimiasis, and Praziquantel is the treatment of choice. In this review, the current status of Paragonimus and paragonimiasis in Asia is outlined based on the latest information and findings. We also summarize current trends of paragonimiasis in Japan, which is one of the most endemic area of paragonimiasis in the world, for the better understanding and control of paragonimiasis.