Assessment of knowledge, attitude and practices and analysis on risk factor regarding schistosomiasis among fshermen and boatmen in Dongting Lake Basin, P.R. China
Zhou Guan National Institute of parasitic diseases, Chinese Center for Disease Control and Prevention Si-Min Dai National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention Jie Zhou Hunan Institute of Schistosomiasis Control Xiao-Bing Ren Yueyang County Ofce for Preventive and Control on Schistosomiasis Zhi-Qiang Qin National Institute of Parasistic Diseases, Chinese Center for Disease Control and Prevention Yin-Long Li National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention Shan Lv National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention Shi-Zhu Li National Institute of Parasistic Diseases, Chinese Center for Disease Control and Prevention Xiao-Nong Zhou National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention Jing Xu ( [email protected] ) National Institute of parasitic diseases, Chinese Center for Disease Control and Prevention
Research
Keywords: Schistosomiasis, Knowledge, Attitude, Practice, Prevalence, Infuence factors, Logistic regression
Posted Date: December 6th, 2019
DOI: https://doi.org/10.21203/rs.2.18362/v1
Page 1/20 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License
Version of Record: A version of this preprint was published at Parasites & Vectors on June 1st, 2020. See the published version at https://doi.org/10.1186/s13071-020-04157-4.
Page 2/20 Abstract
Background: Fishermen and boatmen are high risk population to get infection by schistosomes due to their high frequency water contact in endemic areas of schistosomiasis in the People’s Republic of China (P. R. China). To develop specifc interventions towards this population, understanding their knowledge, attitude and practices (KAPs) towards schistosomiasis and exploring risk factors for schistosomiasis are necessary. Therefore, our present study was designed to assess the KAPs of fshermen and boatmen and to identify the risk factors associated with schistosome infection based on a cross-sectional survey in selected area.
Methods: A cross section survey was conducted in Dongting Lake Basin of Yueyang County, Hunan Province, P. R. China. A total of 601 fshermen and boatmen were interviewed from October to November in 2017. Information regarding socio-demographic details and knowledge, attitude, and practices toward schistosomiasis were collected through a standardized questionnaire. Meanwhile, fecal samples of participants were collected and detected by Polymerase Chain Reaction (PCR) technique to understand the infection status of schistosomes among fshermen and boatmen.
Results: Of the 601 interviewed participants, more than 90% respondents knew the way of getting infection, intermediate host of schistosomes and preventive methods, while majority of the respondents knew this disease and its cause, clinical manifestations and transmission mode properly. The majority of the respondents had positive attitude towards schistosomiasis prevention. However, only 6.66% respondents had installed latrine on their boats, while 32.61% respondents defecated in the public toilets on shore. In addition, only 4.99% respondents protected themselves while contacting freshwater. The overall positive rate of schistosome nucleic acid among fshermen and boatmen in Yueyang County was 13.81% (83/601). Multivariate logistic regression analysis showed that age, years of doing current job, times receiving treatment and whether treated in last two years were the main infuencing factors of S. japonicum infection among this population.
Conclusions: Fishermen and boatmen are still at high risk of infection in China, and gaps existed between knowledge, attitude and practices toward schistosomiasis in this population group. Chemotherapy, health education encouraging behavior change in combination with other integrated approaches to decrease the transmission risk in environments should be strengthened.
Introduction
Schistosomiasis has been considered to be one of neglected tropical diseases (NTDs) of public health importance in tropical and subtropical areas of the world [1–3]. It is endemic in 78 countries and territories globally with 250 million people infected [4]. People’s Republic of China (P.R. China) used to have the highest disease burden of schistosomiasis japonica caused by infection with Schistosoma japonicum. According to the national survey conducted in 1950s, there were 11.60 million cases
Page 3/20 estimated and 1 million infected cattle. Schistosomiasis japonica is acquired when people or domestic animals contact freshwater contaminated with free-swimming cercariae of schistosomes.
During the past sixty years, great efforts have been made to control schistosomiasis through consecutive and vertical control programs by Chinese government. This is especially obvious in the latest decade when schistosomiasis ranks higher priority among four infectious diseases in alliance with HIV/AIDS, tuberculosis and hepatitis B [5], and integrated control strategy was implemented according to the medium and long term national control plan [6–8]. The prevalence and intensity of infection with Schistosoma japonicum in human reduced substantially and the number of endemic provinces has decreased from 12 to 7 [9, 10]. Currently, schistosomiasis japonica is mainly endemic in areas surrounding Dongting Lake, Poyang Lake and beaches along Yangtze River [11–14], with fshermen, boatmen and farmers being groups at high-risk of infection and suffering the highest disease burden caused by schistosomiasis [15].
In spite of great achievements obtained for schistosomiasis control in P.R. China, there are still enormous difculties and challenges during the process towards transmission interruption and elimination of schistosomiasis [16]. Firstly, potential risk factors for resurgence of schistosomiasis japonica still exists and the prevalence of schistosomiasis japonica is easy to rebound in the lake and marshland region due to its unique environment [17]. Secondly, tools used to determine the infection status or prevalence of schistosomiasis in human beings still heavily rely on traditional methods, such as Kato-Katz, which presents an increasingly obvious disadvantage of poor sensitivity, especially in low endemic situations where patients are just slightly infected [18, 19]. And these false negative and incorrect positive results could eventually contribute to inappropriate decisions made by the government. Thirdly, foating population, especially fshermen and boatmen, is becoming increasingly infuential on schistosomiasis transmission according to the national surveillance data [20]. The re-infection with S. japonicum among fshermen and boatmen is still a key issue impeding the transmission interruption or elimination of schistosomiasis in the lake and marshland regions in China [15].
Adequate knowledge, positive attitudes and correct preventive practices of population towards schistosomiasis prevention and control in endemic regions can provide an effectively supportive environment for the success and sustainability of schistosomiasis control [21–23]. Although health education is an important component for schistosomiasis intervention, information on the current infection status and KAPs on schistosomiasis among fshermen and boatmen still remains unclear. Therefore, we conducted a study aimed to assess the KAPs towards schistosomiasis among fshermen and boatmen in particular areas. Infectious status and its infuential factors were also identifed in this population.
Methods
Study design
Page 4/20 This study was a cross-sectional survey that assessed knowledge, attitude and practices (KAPs) on schistosomiasis, evaluated the prevalence of schistosomiasis and its risk factors among fshermen and boatmen in study area.
Study area and population
The study was carried out from October to November in 2017 in Yueyang county, Hunan province, which is located on the eastern bank of Dongting Lake in southern China (Fig.1). Two villages, Lujiao and Matang, in this county were sampled in random by the stratifed clustered sampling, in which the prevalence and villages are viewed as stratum and clustering, respectively. As a typical lake and marshland endemic area of schistosomiasis, there are numerous fshermen and boatmen who were considered to be the most at-risk group of S. japonicum infection. Fishermen and boatmen in this region commonly live or work on ships for at least four months a year, and their economic incomes mainly comes from fshing, goods transportation. The study population was comprised of either the professional fshermen and boatmen or the sidelines, and all participants involved had not received any anti- schistosome treatment within a period of six months before the study. The interviews were conducted when their ships berthed in docking spots of Lujiao and Matang in Yueyang County, Hunan Province, P. R. China.
Questionnaire survey
A pre-tested semi-structured questionnaire was developed after performing a thorough literature review of comparable studies [21, 24-27], to assess the knowledge, attitude and practices (KAP) of participants towards schistosomiasis prevention. This survey was conducted by well-trained interviewers, and was monitored by quality-control supervisors who were arranged for each group before the interviews. The questionnaire consists of four main sections. The frst part covered socio-demographic information such as age, gender, education, family income, water-contacting frequency, history of receiving examination and treatment. The second chapter examined participants’ knowledge on schistosomiasis, including transmission season, susceptible population, defnitive host, transmission mode, intermediate host, clinical manifestations, impacts on children and female, preventive methods and anti-schistosome drug. The third component assessed participants’ attitudes towards schistosomiasis prevention. The last section interviewed participants’ practices on schistosomiasis prevention. The full questionnaire can be found in online supplementary table S1.
Prevalence survey and laboratory investigations
Page 5/20 At least 30g stool sample from each participant was collected using a specifc container, coded by unique identifers and transferred to a laboratory in local schistosomiasis control institute. Each sample was scraped out 2g with nylon silk and plastic rods to remove the residue from the feces, and then was placed in the cryopreservation tube and kept in the environment of -20℃. After all the samples had been pretreated, DNA of Schistosoma japonicum eggs were extracted from feces specimens according to the steps of the DNA extraction kit (QIAGEN, Germany).
Genomic DNA extracted from fecal samples were subjected to 18S-FW (5′-TTCCG ATAAC GAACG AGAC- 3′) and 18S-RV (5′-AGCGA TAAAG CCACT ACAAC-3′) specifc primers reactions amplifying the gene region of 469bp of S. japonicum 18S-rRNA gene fragment [28]. PCR was carried out in a fnal volume of 50.0μl, containing: 2.0μl of template DNA, 25.0μl of dNTPs Mix (TIANGEN BIOTECH Co., Ltd, BEIJING), 1.0μl of upstream and downstream primers respectively, 21.0μl of sterile double distilled water. The PCR conditions were as follows: 5min at 94 ℃ (initial denaturation), 30 cycles of 20s at 94 ℃, 30s at 56℃, 40s at 72℃, 30 cycles, and fnally 5min at 72℃ (fnal extension). Meanwhile, negative control (sterile double distilled water) and positive control (worm body tissues DNA) were set up in each batch of experiments. The PCR products were separated on 1.50% agarose gel. All the positive PCR amplifcation products encoding 18sRNA were sequenced, and Blast comparison analysis was applied to check the consistency with 18sRNA.
Data management and statistical analysis
Data collected was entered into a database using EpiData Version 3.0. Data analysis was done using SAS Version 9.4 (Statistical Analysis System, RTI, Cary, North Carolina, USA). The analysis consisted of three parts. Firstly, descriptive statistics were used for demographic characteristics of respondents. Secondly, schistosomiasis control knowledge rates, attitude correct rates, and correct behavior rates were calculated in order to inform the KAPs of S. japonicum among study participants. Finally, Schistosoma nucleic acid positive rate was calculated according to results of PCR amplifcation and electrophoresis. Risk factors related to the infection of schistosomiasis were analyzed by univariable logistic analysis followed by stepwise regression and multivariate logistic regression model. P-values less than 0.05 were considered statistically signifcant.
Results
Socio-demographic characteristics
A total of 753 fshermen and boatmen were enrolled in this cross-sectional study. However, 122 people provided none or insufcient amounts of stool to prepare for the detection by PCR technique, and 30 individuals had no or incomplete questionnaire data. Final study population therefore consisted of 601
Page 6/20 individuals who completed the questionnaire and provided qualifed stool samples. The socio- demographic characteristics of the respondents are presented in Table1. The number of males was 345 (57.40%) and females was 256 (42.60%). The mean age of respondents was 50.04 years old (±10.97). 59.90% of respondents (360/601) were sideline fshermen and boatmen while 38.27% (230/601) were professional boatmen. The majority (381/601, 63.39%) have already done current jobs for 10 to 29 years, followed by those who have done this job for more than 30 years (128/601, 21.30%). More than 95% respondents received treatment against schistosomiasis at least once.