Epidemiological characteristics and risk factors for cystic and alveolar echinococcosis in China: an analysis of a national population-based field survey

Abstract

Background Human cystic and alveolar echinococcosis are neglected tropical diseases that WHO has prioritized for control in recent years. Both diseases impose substantial burdens on public health and the socio-economy in China. In this study, which is based on the national echinococcosis survey from 2012 to 2016, we aim to describe the spatial prevalence and demographic characteristics of cystic and alveolar echinococcosis infections in humans and assess the impact of environmental, biological and social factors on both types of the disease. Methods We computed the sex-, age group-, occupation- and education level-specific prevalences of cystic and alveolar echinococcosis at national and sub-national levels. We mapped the geographical distribution of echinococcosis prevalence at the province, city and county levels. Finally, by analyzing the county-level echinococcosis cases combined with a range of associated environmental, biological and social factors, we identified and quantified the potential risk factors for echinococcosis using a generalized linear model. Results A total of 1,150,723 residents were selected and included in the national echinococcosis survey between 2012 and 2016, of whom 4161 and 1055 tested positive for cystic and alveolar echinococcosis, respectively. Female gender, older age, occupation at herdsman, occupation as religious worker and illiteracy were identified as risk factors for both types of echinococcosis. The prevalence of echinococcosis was found to vary geographically, with areas of high endemicity observed in the Tibetan Plateau region. Cystic echinococcosis prevalence was positively correlated with cattle density, cattle prevalence, dog density, dog prevalence, number of livestock slaughtered, elevation and grass area, and negatively associated with temperature and gross domestic product (GDP). Alveolar echinococcosis prevalence was positively correlated with precipitation, level of awareness, elevation, rodent density and rodent prevalence, and negatively correlated with forest area, temperature and GDP. Our results also implied that drinking water sources are significantly associated with both diseases. Conclusions The results of this study provide a comprehensive understanding of geographical patterns, demographic characteristics and risk factors of cystic and alveolar echinococcosis in China. This important information will contribute towards developing targeted prevention measures and controlling diseases from the public health perspective. Graphical Abstract

Serological Comparison of Native Antigen ELISAs with Rapid ICT Test Kits for the Diagnosis of Human Alveolar and Cystic Echinococcosis in China

“…US is useful for assessing the presence and staging of a cystic or alveolar lesion [ 3 , 9 ] and for differentiating echinococcosis from other liver-occupying lesions such as cancer [ 19 ], but AE and CE serology is a valuable adjunct for correct clinical diagnosis and the epidemiological surveillance of high-risk populations [ 20 ]. Positive AE/CE serology can be correlated with the progressive development of a lesion [ 15 ], an aborted lesion, spontaneous cure without any apparent lesion, or an early infection before any lesion is detectable by imaging [ 1 , 2 ].…”

“…Based on the ultrasound observations, CE patients were classified into five groups (CE1–CE5) according to the WHO informal working group on echinococcosis [ 1 , 5 , 9 ]. Due to the limited numbers of patients with either CE4 or CE5, these categories were combined.…”

“…An antibody response to E. granulosus or E. multilocularis , detectable by serological methods, can occur for the following reasons: (I) as a result of a new infection through the ingestion of eggs and the hatching of oncospheres that penetrate the intestinal mucosa and release antigens [ 1 , 9 ]; or (II) by an established infection whereby larval antigens are released from established cystic or alveolar lesions [ 2 , 9 ]. The current study aimed to evaluate the value of serology for the specific diagnosis of new and established infections of E. granulosus and E. multilocularis using panels of Chinese sera, native antigen ELISAs and the ADAMU-AE and ADAMU-CE commercial ICT test kits, which incorporate recombinant antigens.…”

China’s prevention and control experience of echinococcosis: A 19-year retrospective

“…Interventions adapted to local conditions can be implemented based on several factors, including sex, occupation, education level, geography, animal density, numbers of animals slaughtered, altitude, pasture and forest area, temperature, and gross domestic product (GDP). These factors were found to be associated with the prevalence of echinococcosis (Ma et al 2023). In regions with high incidence rates, it is essential to promote disease awareness among the population, especially through health education of preschool children and promotion of scientific knowledge among the elderly.…”

“…A 2012-2016 national survey conducted in China revealed a total of 4,161 cases of CE and 1,055 cases of AE among 1,150,723 residents. Among the regions affected by echinococcosis, there were nine endemic provinces (autonomous regions): Inner Mongolia, Sichuan, Tibet, Gansu, Qinghai, Ningxia, Yunnan, Shaanxi, and Xinjiang (Ma et al 2023). Currently, these nine provinces continue to bear the highest burden of human echinococcosis (Supplementary data).…”