The deposition characteristics of Schistosoma japonicum eggs and its application in hatching method

Abstract

Background Schistosomiasis is an important zoonotic parasitic disease, which remains a major public concern in china. However, the detection of schistosomiasis in the field is still based on the traditional faecal hatching method, which is tedious and time-consuming. Therefore, method for detecting schistosomiasis in the field needs to be improved. Methods New Zealand rabbits artificially infected with S. japonicum cercariae were used as animal models to study the deposition characteristics of Schistosoma japonicum eggs. The distributions of eggs in the intestinal wall at 42 d and 60 d post-infection were compared. The distributions of eggs in rabbit faecal samples were also observed. Goat faeces were used to compare the conventional faecal hatching method and the simplified direct immersion faecal hatching method. Results The distribution of eggs in the intestinal wall in the animal model at 42 d post-infection was as follows: the number of eggs per gram (EPG) was the highest (42780.13 ± 4789.81 eggs/g) in the rectum. The caecum had the largest proportion (42.97%) of eggs deposited. At 60 d post-infection, the rectum still had the highest EPG (117868.20 ± 67232.80 eggs/g). However, instead of the caecum, the lower colon had the largest proportion (64.90%). Moreover, 42.20% of eggs occupied the periphery of rabbit faeces. In the comparison between the conventional faecal hatching method and the simplified direct immersion faecal hatching method, the direct faecal hatching method was simpler, and the results were similar to those of the conventional faecal hatching method. Conclusion The deposition characteristics of eggs and their distributions in faecal samples suggest that the direct faecal hatching method can be used to simplify routine faecal hatching detection.