A comparative study of mud-like and coralliform calcium carbonate gallbladder stones

A systematic study on 33 gallbladder stones resembling adult Clonorchis sinensis worms

Limited studies provide direct evidence of Clonorchis sinensis adults in the early stage of gallbladder stone formation. Our current research systematically studied 33 gallbladder stones resembling adult worms and shed light on the definite connection of C. sinensis infection with concomitant cholelithiasis. A total of 33 gallbladder stones resembling adult C. sinensis worms were systematically analysed. Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray energy spectrometry were used to analyse the composition and microstructure. Meanwhile, a histopathological examination of the stone was carried out. The 33 gallbladder stones resembling adult C. sinensis worms included nine calcium carbonate (CaCO₃) stones, 12 bilirubinate stones and 12 mixed stones. Clonorchis sinensis eggs were found in 30 cases, including all CaCO₃ and mixed stones. Parasite tissues were detected in 12 cases, which were mainly CaCO₃ stones or bilirubinate-CaCO₃ mixed stones. The outer layer of stones was wrapped with 12.88% calcium salt, as revealed by X-ray energy spectrometry, while surprisingly, many C. sinensis eggs were found in the inner part of these stones. Based on our current findings, we concluded that calcification and packaging occurred after C. sinensis adult entrance into the gallbladder, subsequently leading to the early formation of CaCO₃ or bilirubinate-CaCO₃ mixed gallbladder stones. This discovery highlights definite evidence for C. sinensis infection causing gallbladder stones.

Risk Factors for Clonorchis sinensis Infection in Residents of Binyang, Guangxi: A Cross-Sectional and Logistic Analysis Study

Background: Clonorchiasis is a serious food-borne parasitic disease caused by Clonorchis sinensis infection. C. sinensis, a major fish-borne trematode, is a known causative agent of cholangiocarcinoma. The risk factors for C. sinensis infection include individual eating behaviors and environmental factors. In this study, we evaluated the C. sinensis infection rate and the associated risk factors among residents in Binyang County, Guangxi, China.

Methods: In 2016 and 2017, five villages from Binyang, Guangxi were selected by multistage cluster random sampling for a cross-sectional study. A modified Kato-Katz thick smear method was used to examine C. sinensis eggs in fecal samples in triplicate (three smears for each sample). Both uni-variate and multi-variate logistic regression analyses were carried out to identify the risk factors for C. sinensis infection.

Results: A total of 1,977 fecal samples were collected from villagers in the investigated areas. The overall infection rates of C. sinensis in Binyang County was 20.49% (405/1,977). The mean age of participants was 39.42 ± 23.48 (range: 3–89 years old), and the highest infection rate (33.72%) was seen in the age group of 40-49 years old, followed by those aged 50–59 (31.83%). Multi-variate logistic regression analysis showed that higher infection rates were significantly associated with males (aOR = 6.51, 95% CI = 4.67–9.08), Zhuang (aOR = 2.41, 95% CI = 1.62–3.59), ages (aOR = 33.51, 95% CI = 10.13–110.86), frequency of raw fresh fish consumption (aOR = 14.56, 95% CI = 9.80–21.63), and close contact with cats and dogs (aOR = 1.53, 95% CI = 1.02–2.30). Occupations and education levels showed no significant association with C. sinensis infection (P > 0.05).

Conclusions: High levels of C. sinensis infection were observed among residents in Binyang County, Guangxi. Intervention strategies should be strengthened among the investigated population at high risk, such as males, Zhuang and older individuals, especially those who frequently eat raw fresh fish. In addition, the individuals contacting with cats and/or dogs were observed to have significantly higher infection rate of C. sinensis than those having no contact with cats and dogs. The association between contacting with cats and/or dogs and C. sinensis infection needs to be explored and confirmed in the future study by more epidemiological investigations of human C. sinensis infection from different areas.