A cross-sectional analysis of schistosomiasis case detection by rectal mucosal biopsy among patients attending the digestive endoscopy unit of the internal medicine department

Abstract

Introduction: The detection of schistosome eggs in stool or urine specimens is the most used technique in population-based studies, while the rectal mucosal biopsy is the commonly used technique in hospital setting. The aim of this hospital-based study was to describe the epidemiological aspects of schistosomiasis. Methods: A cross-sectional study with retrospective data collection was conducted between January 01, 2011 to December 31, 2017 among patients who have undergone endoscopy and rectal mucosal biopsy at the digestive endoscopy Unit of internal medicine Department at the University Hospital Center Point G. We conducted univariate analysis to obtain mean and standard deviation for quantitative data and numbers and percentages for qualitative data. In the bivariate analysis, the Chi-square and Fisher´s exact tests were used to assess the statistical significance and strength of the associations between the categorical independent variables and the outcome variables. Variables with a Chi-square test with p < 0.2 at bivariate analysis were included in a multivariate logistic regression. Results: 840 rectal mucosal biopsies reports (sex-ratio= 2.4, mean age= 30,99 ± 16, 66 years) were considered for analysis. Clinical indications were dominated by schistosomiasis related symptoms (46.0%), edematous syndrome (10.4%). 306 (36,4%) rectal mucosal biopsies were positive for Schistosoma haematobium (36.4%) and 8 (0.95%) for schistosoma mansoni. The highest positivity rates of Schistosoma haematobium and Schistosoma mansoni were observed in 2015 with 42.67% and in 2016 with 3.77%. The positivity rate of Schistosoma haematobium was 1.44 times more common in males than in females (p=0.030). The highest positivity rate of Schistosoma haematobium (90.24%) and Schistosoma mansoni (71.43%) were observed in patients under 50 years and 24 years, respectively. Factors independently associated with Schistosoma heamatobium infection positivity were: age group of 50 – 74 years (p=0.035), Malinké ethnic group (p=0.031), Soninké ethnic group (p=0.023), Segou residents (p=0.000), Mopti residents (p=0.039), pupil/student (p=0.003), trader (p=0.001) and hematuria (p=0.029). Conclusion: The analysis of rectal mucosal biopsy showed a higher positivity rate of Schistosoma haematobium than of Schistosoma mansoni. The annual realization rate of rectal mucosal biopsy decreased from 2011 to 2017. The annual positivity rate of schistosomiasis is very disparate.

Keywords

• neglected tropical diseases
• schistosomiasis
• parasitic diseases
• epidemiology
• internal medicine