Paragonimus harinasutai metacercariae were found in a species of freshwater crab, Indochinamon ou, collected in a small stream of Namback District, Luang Prabang Province, Lao PDR. Adult flukes were recovered after experimental infection of the metacercariae to dogs. Metacercariae were round or slightly elliptical, 0.666 x 0.626 mm in average size, and had a thin cyst wall of about 20 microm in thickness, a black excretory bladder, convoluted ceca, and some pinkish materials in the body. Adults were somewhat elongated, 95.2 x 36.5 mm in average size, covered with single-tipped tegumental spines, had a smaller oral sucker than the ventral sucker, a moderately branched ovary, and 5-6 lobulated testes. Eggs were ovoid and bilaterally symmetrical in shape, 79 x 45 microm in average size, and had a uniformly thickened shell. By the present study, it has been confirmed that I. ou is a new second intermediate host for P. harinasutai.
Animals ; Crustacea/*parasitology ; Disease Reservoirs/*parasitology ; Dogs ; Female ; *Host-Parasite Interactions ; Humans ; Laos ; Male ; Paragonimiasis/*parasitology ; Paragonimus/anatomy & histology/*isolation & purification/ultrastructure ; Shellfish/*parasitology

Human paragonimiasis was endemic in Korea until the 1960's, and nowadays, the prevalence is decreasing. However, it is still one of the important helminthic diseases. Though it is essentially a pulmonary disorder, it may involve brain, muscle, mesentery, genital tract, pleura, peritoneum, spinal cord, spleen, and liver. We experienced two cases of paragonimiasis in a family who had ingested raw crabs together for 7 months. A 57-year-old female patient was admitted due to abdominal pain, diarrhea and tenesmus for 6 months. And, her 35-year-old son complained of cough, chest discomfort and dyspnea. The definite diagnosis for paragonimiasis could be made by the detection of the egg and adult worm from stool, sputum and involved lesion. Neither an egg or worm was detected. However, they were diagnosed based on the food history, laboratory data including serum eosinophilia, ELISA for specific IgG, pleural and peritoneal fluid examination, radiological findings, and intradermal tests. They were treated with praziquantel and their symptoms improved rapidly over 2 days. Both patients were asympromatic at a follow-up visit 2 months later.
Adult ; Animals ; Crustacea/parasitology ; Family Health ; Humans ; Male ; Paragonimiasis/complications/*diagnosis/transmission ; *Paragonimus westermani ; Peritonitis/*complications/diagnosis/parasitology ; Pleurisy/*complications/diagnosis/parasitology ; Shellfish/parasitology