Studies on Paragonimus and paragonimiasis in the Republic of the Philippines. I. Paragonimus metacercariae infection in Parathelphusa grapsoides
Cabrera, B.D.
Southeast Asian Journal of Tropical Medicine and Public Health 4(1): 55-62
1973
ISSN/ISBN: 0125-1562 PMID: 4718129 Document Number: 62755
Examination of 792 Parathelphusa grapsoides from 4 rivers of barrio Pitogo, barrio Buri and Jaro town in Eastern Leyte, Philippines, revealed rates of infection with Paragonimus westermani metacercariae ranging from zero in the Kabayongan river to 67.4% in the Mainit river; the over-all infection rate was 53.28% (54.24% of males and 52.59% of females). The Mainit river also had the heaviest metacercarial load per crab (53 per male and 98.7 per female; over-all 80.2 per crab). The average metacercarial load in this study was very high at 53 per crab (37.86 per male, 64.51 per female). The organs of preference were the gills (95.97%), followed by the thoracic muscles (55.21%), the heart (50.47%), the viscera (33.41%) and the leg muscles (31.27%). There appeared to be 2 types of metacercarial cyst in the crabs: spherical and thick-walled (cyst wall 15 mu or more in thickness), and spherical and thin-walled (7 to 15 mu ). It is concluded that ingestion of raw or partially-cooked crabs will be a source of human paragonimiasis in the area.