The relation of genders, size sand habitats of rice-field crabs (Esanthelphusa sp.) to the infection of lung fluke metacercariae in rice field of Khamcharoen Village, Detudom District, Ubonratchathani Province

Abstract

The relationship of infection factors of lung fluke in rice field crabs, Esanthelphusa sp. is still not clear. Therefore this study aims to investigate the influence of genders, sizes and habitats on prevalence of fluke metacercaria in rice field crabs which were collected from rice field located at Khamcharoen Village, Detudom District, Ubonratchathani Province. All samples were collected during July 2013 to June 2014. All detected metacercariae were classified as Paragonimus sp. 116 from total 270 crabs were infected with a total prevalence of 42.96% and with an intensity of 4.95. The infection was higher in male than in female with prevalence of 45.26 and 40.60% and with intensity of 4.47 and 5.43, respectively. The infection was associated to crab size, the prevalence of metacercariae in crab size of 2.00-3.00, 3.01-4.00 and 4.01-6.00 cm. were 8.82, 42.86 and 33.6%, respectively, and with intensity of 2.76, 4.53 and 4.97, respectively. The dissimilarity of infection was found in crabs collected from different habitats. The prevalence of metacercariae in crab that collected from habitat with surface water, groundwater but no surface water and no water in both surface and ground were 34.44, 45.56 and 48.89%, with intensity of 7.27, 5.93 and 1.66, respectively. No statically significant difference of finding metacercaria in crabs with different sex, size and habitat by using Chi-square test. The data from this study can be applied to design experiments for studying factors that influence parasite infection in the second intermediate host of lung fluke.