Retrospective Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Feb 27, 2024; 16(2): 229-240
Published online Feb 27, 2024. doi: 10.4254/wjh.v16.i2.229
Epidemiological survey of cystic echinococcosis in southwest China: From the Qinghai-Tibet plateau to the area of Yunnan
Jin-Rong Zi, Dan Xiao, Jia Peng, Fang-Wei Wu, Jian-Xiong Li, Xin-Liu Yan, Zheng-Qing Wang, Xuan Cai, Qian Xu, Ben-Fu Li, Ya-Ming Yang
Jin-Rong Zi, Ben-Fu Li, Yunnan Provincial Center of Malaria Research, Yunnan Institute of Parasitic Diseases, Puer 665000, Yunnan Province, China
Jin-Rong Zi, Jia Peng, Fang-Wei Wu, Jian-Xiong Li, Xin-Liu Yan, Zheng-Qing Wang, Xuan Cai, Qian Xu, Yunnan Institute of Parasitic Diseases, Yunnan Institute of Parasitic Diseases, Puer 665000, Yunnan Province, China
Dan Xiao, Tibet Center for Disease Control and Prevention, Tibet Center for Disease Control and Prevention, Lhasa 85000, Tibet Autonomous Region, China
Ya-Ming Yang, Yunnan Provincial Center of Malaria Research, Yunnan Institute of Parasitic Diseases, Puer 655000, Yunnan Province, China
Co-first authors: Jin-Rong Zi and Dan Xiao.
Co-corresponding authors: Ben-Fu Li and Ya-Ming Yang.
Author contributions: Yang YM, Li BF and Wu FW designed the research study; Zi JR and Xiao D contributed equally to this work, analyzed the data and wrote the manuscript; Peng J, Li JX, Yan XL, Wang ZQ, Cai X and Xu Q analyzed and interpreted the data; contributed analytical tools or data; all authors have read and approved the final manuscript. Li BF and Yang YM designed the research study, investigation and analysis. Zi JR and Xiao D analyzed and interpreted the data; contributed analytical tools or data; wrote the paper. Li BF and Yang YM conceived and designed the experiments; analyzed and interpreted the data. Li BF and Yang YM proposed the concept and design of the epidemiological investigation of echinococcosis in Yunnan Province, wrote investigation plans, coordinated with investigated hospitals, guided on-site work, and reviewed investigation data. Co-first authors Zi JR and Xiao D are responsible for specific work, including on-site investigation, data organization, database entry, summarization, analysis, and writing of the manuscript.
Supported by Central Government Transfer Payment of China; Open Project of Key Laboratory of Echinococcosis Control and Research of the National Health Commission of People’s Republic of China, No. 2021WZK1001.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of Yunnan Institute of Parasitic Diseases.
Informed consent statement: All study participants or their legal guardian provided informed written consent in relation to personal and medical data collection prior to study enrollment.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Ben-Fu Li, MMed, Technician, Yunnan Provincial Center of Malaria Research, Yunnan Institute of Parasitic Diseases, No. 6 Xiyuan Road, Puer 665000, Yunnan Province, China. libefu@163.com
Received: October 5, 2023
Peer-review started: October 5, 2023
First decision: October 28, 2023
Revised: November 18, 2023
Accepted: December 14, 2023
Article in press: December 14, 2023
Published online: February 27, 2024
Processing time: 145 Days and 10.5 Hours
Abstract
BACKGROUND

Echinococcosis is prevalent in 9 provinces in Western and Northern China. An epidemiological survey of echinococcosis in 2012 and 2016 showed cases of echinococcosis in Yunnan Province.

AIM

To understand the spatial distribution and epidemiological characteristics of echinococcosis in Yunnan for the prevention and control of echinococcosis and to reduce the risk of infection in Yunnan Province.

METHODS

Based on the China Information System for Disease Control and Prevention (CISDCP), echinococcosis cases reported from 36 hospitals and 34 Centers for Disease Control were investigated and epidemiologically analyzed from 2021 to 2022. The exclusion criteria included suspected cases, same case only counted once and cases not from Yunnan. A total of 705 cases were investigated, of which 397 cases were suitable for statistical analysis. In these 397 cases, epidemiological investigation was tracked in 187 cases. All data were inputted using double entry in the Excel database, with error correction by double-entry comparison. The data on echinococcosis cases in Yunnan Province were analyzed by ArcGIS 10.1 software to generate a density map of echinococcosis distribution. All statistical analyses were conducted using SPSS 17.0, including the chi-square test, linear regression test and logistic univariate and multivariate regression analyses.

RESULTS

A total of 397 cases were found in 89 counties in Yunnan Province. The number of cases in the top three prefectures were Dali (38.1%), Diqing (10.1%), and Kunming (8.3%), and the top five counties were Jianchuan (9.1%), Shangri La (8.3%), Eryuan (7. 6%), Heqing (6.9%), and Dali Districts (5.0%). There were significant differences between the different areas. The case reporting rate by CISDCP (33.8%) was low; the first case was reported by CISDCP in 2002, and the highest number of cases was 50 (2017). Confirmed and clinical cases accounted for 62.5% and 37.5%, respectively. However, 90.9% of the cases of hydatid disease were reported by the hospital system, and only 9.1% of the cases of hydatid disease were found in the community through active screening. The difference between the two methods of case detection was statistically significant. Most of the cases of echinococcosis were found in farmers/herdsmen (75.1%) and students (9.1%). In addition, Han (43.6%) and Bai (26.2%) had a higher incidence of infection than other nationalities, and the liver (87.7%) and lung (6.8%) were the most common sites of cyst formation. Among the analyzed cases, 187 were epidemiologically analyzed and the clinical symptoms were not obvious in the early stage in 47.1% of cases. The results of logistic regression analysis showed that the age group, education level, presence of dogs in the family (either previously or currently), and handwashing (occasionally or not) were factors related to echinococcosis infection. 55.6% of cases were in endemic areas, and 44.4% of cases were in non-endemic areas. Among 83 cases in non-endemic areas, only 4 cases had been to endemic areas and had a history of living, working, travelling, or hunting in echinococcosis epidemic areas.

CONCLUSION

Cases of echinococcosis were reported throughout the entire Yunnan province, with the majority distributed in Western Yunnan, suggesting that echinococcosis control should be strengthened in this area. We suggest that an epidemiological investigation should be carried out in the future, based on the clues from newly discovered cases in hospitals or from the CISDCP. The newly discovered cases in the hospital provided clues to comprehensively determine the location of cases and where epidemic spot investigation should be conducted.

Keywords: Echinococcosis; Cases; Epidemiological analysis; Yunnan province

Core Tip: Seventy medical institutions, including 36 hospitals, 34 Centers for Disease Control (CDCs), and China Information System for Disease Control and Prevention, were surveyed from 2021 to 2022. The 36 hospitals included 4 provincial hospitals (the First and Second-People’s Hospital of Yunnan, and the First and Second Affiliated Hospitals of Kunming Medical University), 8 prefectural hospitals, and 24 county hospitals. The 34 CDCs included the Yunnan Institute of Parasitic Diseases, 9 prefectural CDCs, and 24 county CDCs. Information on echinococcosis cases from the ultrasound department, hepatobiliary surgery department, and case archives in the hospitals was retrospectively surveyed and recorded. The registration and management information on echinococcosis was consulted through the CDCs. The collected information on cases was organized and summarized before being entered into the database. Patient-privacy data were not included.