Association between Sanitary toilet coverage rate and intestinal infectious disease in Jiangsu Province, China

Abstract

Intestinal infectious diseases are one of the most common disease group prevalent worldwide. It is also the commonly report acute infectious diseases in Jiangsu Province, China. This problem may result from the use of unhygienic toilet. Chinese government had announced the China's toilet improvement campaign for more than decades. The purpose of this ongoing campaign is to improve the hygiene and promote health. However, there is limited study evaluating the effect of toilet improvement and the incidence of intestinal infectious diseases. This study aims to determine the association of the increasing of sanitary toilets and intestinal infectious diseases in Jiangsu Province, China. The research used ecological study design, taking Jiangsu Province and 13 cities in Jiangsu province as the unit of analysis. The toilet coverage rate and the incidence of intestinal infectious diseases from 2011 to 2019 were obtained through National and Jiangsu Provincial Health Commission with permission of using secondary data. The water quality and other environmental data (i.e. temperature, rainfall) were obtained from Jiangsu Water Resources Bureau and Statistical Bureau, respectively. Descriptive analysis was used to describe the distribution of toilet coverage and the incidence of intestinal infectious diseases. Multiple linear regression analysis was performed to investigate association of toilet coverage rate and intestinal infectious disease. From 2011 to 2019, the total incidence of strictly control type A (cholera) and B (i.e. hepatitis A, E, and untyped viral hepatitis, bacillary and amoebic dysentery, typhoid and paratyphoid) intestinal infectious diseases（IIDs）together in Jiangsu Province showed a downward trend, of which viral hepatitis and dysentery dominated the entire trend. Type C IDD (i.e. other infectious diarrhea and hand-foot-mouth disease) accounted for more than 90% of all IIDs and the incidence of other infectious diarrhea increased year by year, and hand-foot-mouth disease has a high incidence every other year throughout the study period. The accumulative households using various types of sanitary toilets in Jiangsu Province were increased over time. Except for the compliance rate of surface water quality and average temperature showing an upward trend, there are no obvious variation rule in other factors (vector density, environmental factors). Simple linear regression analysis show that the accumulative households using various types of sanitary toilets (i.e. sanitary toilets, harmless sanitary toilets and sanitary public toilets), the compliance rate of surface water quality, and the average temperature are significantly different from intestinal infectious diseases. The total incidence of Type A and B intestinal infectious diseases, incidence of viral infections and dysentery are all negatively correlated with the three types of sanitary toilets. The surface water quality and average temperature are mainly negatively correlated to Type A and B intestinal infectious diseases, while the relationship with other infectious diarrhea of ​​Type C is completely opposite. In the study of various cities, there are inconsistent results. Multiple linear regression analysis results suggested that the incidence of type A and B IDDs together was negatively associated with the accumulative use of sanitary toilet (β = -0.036) and surface water quality (β = -0.135) with p < 0.05. The similar effect on each city was the average temperature, which is negative correlated to the incidence of Type A and B IIDs. This study revealed that the toilet improvement campaign and water quality control can reduce the number of new cases which benefit to the population in the province. However, this study lack of the personal characteristics and behavior of using toilet of each individual. Further study may conduct at the household level and the recommendation for individual can be provided.