The re-emergence of paragonimiasis in Japan

Paragonimiasis is a re-emerging parasitic disease in Japan. The patients nowadays in Japan are mostly middle-age males. There are some cases of foreigners living in Japan. Over 50% of the patients had pleurisy and the egg detection rate in the sputum/bronchoscopic aspirates was <50%. When we examined parasite-specific IgM/IgG antibody titers, IgM antibody titers were higher in the patients having pleurisy than that in the patients having lung parenchymal lesions. The reverse relationship was observed in IgG antibody titers and the disease state. Furthermore, peripheral blood eosinophilia was also prominent in the patients having pleurisy. Although the elevation of total IgE level in serum was observed in >90% of the cases, the level did not correlate with the disease state. Taking all these results together, the paragonimiasis patients in Japan nowadays are mostly right grade infections and/or are diagnosed at the early stage of the disease. Along with the globalization of travelling and food trading, and popularization of ethnic dishes, paragonimiasis can be seen all over the world.