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Objective: To explore a new prevention and control model on soil-borne parasitic diseases in rural areas of China., Methods: Eight provinces and autonomous regions were selected in China as demonstration areas implementing integrated control on soil-borne parasitic diseases. The integrated control measures included authority organization and harmonization, health education, deworming, and environment modification., Results: After three years, the infection rates of soil-borne parasitic diseases were significantly decreased in these areas. There were three safe guard and organization modes, three health education modes, four mass worming medication modes, and two modes of water, toilet and environment changes., Conclusion: The work in the various demonstration areas was summarized which pointed out a new model with efficiency and local characteristics on soil-borne parasitic disease prevention and control.

Background: Hookworm disease is endemic in China and is widespread globally. The disease burden to humans is great. Methods: The study described the national surveillance of hookworm implemented in 31 provinces/autonomous regions/municipalities (P/A/Ms) of China in 2019. Each P/A/M determined the number and location of surveillance spots (counties). A unified sampling method was employed, and at least 1000 subjects were investigated in each surveillance spot. The modified Kato-Katz thick smear method was employed for stool examination. Fifty samples positive with hookworm eggs were cultured in each surveillance spot to discriminate species between A. duodenale and N. americanus. Twenty-five soil samples were collected from each surveillance spot and examined for hookworm larva. The 2019 surveillance results were analyzed and compared with that of 2016–2018. Results: A total of 424766 subjects were investigated in 31 P/A/Ms of China in 2019, and the overall hookworm infection rate was 0.85% (3580/424766). The weighted infection and standard infection rates were 0.66% (4288357/648063870) and 0.67% (4343844/648063870), respectively. Sichuan province had the highest standard infection rate (4.75%) in 2019, followed by Chongqing (2.54%) and Hainan (2.44%). The standard infection rates of other P/A/Ms were all below 1%, with no hookworm detected in 15 P/A/Ms. The standard hookworm infection rate in the males and the females were 0.61% (2021216/330728900) and 0.71% (2267141/317334970), respectively, with a significant difference between different genders (χ2 = 17.23, P<0.0001). The highest standard hookworm infection rate (1.97%) was among age ≥ 60 years, followed by 45~59 years (0.77%), 15~44 years (0.37%), and 7~14 years (0.20%). The lowest standard infection rate was among the 0~6 years age group (0.12%). A significant difference was observed among different age groups (χ2 = 2 305.17, P<0.0001). The constitute ratio for N. americanus, A. duodenale, and coinfection was 78.70% (1341/1704), 2.03% (346/1704), and 1.00% (17/1704), respectively. The detection rate of hookworm larva from soil was 3.45% (71/2056). Conclusion: The national surveillance showed that the hookworm infection rate has been decreasing annually from 2016 to 2019, and it is now below 1%. China has made significant progress in controlling hookworm. The national surveillance system is an important way to understand the endemic status and provide important information in this process and thus needs to be continually optimized. Author summary: Hookworm disease is endemic in China. The national surveillance system on important parasitic diseases including hookworm infection has been established in China. Stool samples were collected from participants, and the Kato-Katz method was applied to detect helminth eggs while samples with hookworm eggs were further cultured to differentiate the species of the parasite. Additionally, soil samples were collected and examined for hookworm larva. In 2019, the overall infection rate of hookworm in China was 0.85% (3580/424766). High prevalence was demonstrated in Western and Southern China, including Sichuan (4.75%), Chongqing (2.54%) and Hainan (2.44%). The prevalence was high in the females (0.71%) than in the males (0.61%), while it was high in older population especially those age over 60 years. N. americanus dominated the hookworm species. The prevalence of hookworm in soil was 3.45%. Overally, hookworm infection decreased to a low level in China. However, there still exist high endemic areas. Thus, intervention needs to be applied in the high endemic areas and elder population. [ABSTRACT FROM AUTHOR]

Clonorchiasis is caused by ingestion of raw freshwater fish containing infective larvae of Clonorchis sinensis. China harbours the largest number of people with C. sinensis infection. During the past three decades, the National Institute of Parasitic Diseases, affiliated to the Chinese Center for Disease Control and Prevention (NIPD) conducted many studies to facilitate the control on clonorchiasis. Three national surveys have shown the updated epidemiology of clonorchiasis in China. Recently, a national surveillance system has also been established, which will enable the production of high-resolution map. The evaluation of the disease burden has enhanced the awareness on clonorchiasis. Diverse diagnosis techniques including rapid screening by questionnaire, serological tests, faecal examination and a molecular method have been developed or evaluated. The NIPD also participated in the early evaluation of praziquantel against clonorchiasis, which enhanced its application in China. Also, the NIPD has verified the efficacy of tribendimidine against clonorchiasis. A new sustainable strategy is also being explored. However, more research is expected to further facilitate control of clonorchiasis in China, as well as international cooperation in fighting human liver fluke infections in Asia. [ABSTRACT FROM AUTHOR]

Soil-transmitted helminthiases (STHs) have been widely transmitted in China and the control of STHs was initiated by NIPD-CTDR since its foundation. Three national surveys on STHs have been carried out in China, and the infection rate has dropped from 53.58% in the first national survey (1988-92) to 4.49% in the third national survey (2014-16) due to strong interventions including mass drug administration, health education and environment improvement. National surveillance of STHs started in 2006 and has been implemented successively until now, which allows to understand the endemic status and trends of STHs prevalence in China. Surveillance has been expanded to 30 provinces of China since 2016. Integrated pilot programmes have been implemented between 2006 and 2009, in which an integrated strategy, with health education and control of infection sources as key components, was adopted. Since 2019, new control pilots have been started, which will be continued for five successive years to further explore appropriate control strategies in the current "new era". With the decline of infection rate of STHs, China is approaching the elimination stage for STHs. In order to achieve this final target, poverty alleviation programmes should be integrated with precise control measures, according to real situations. [ABSTRACT FROM AUTHOR]

During 1989-2011, three parasitic disease surveys were conducted in Hengxian County, China, where soil-transmitted helminthiases and foodborne clonorchiasis are endemic. We compared the data and found that the prevalence of helminthiases decreased and the prevalence and intensity of clonorchiasis increased over time, especially among men. Clonorchiasis control/intervention measures are urgently needed in this area. [ABSTRACT FROM AUTHOR]

Clonorchiasis is an important food-borne parasitic disease in China, and infection with C. sinensis can cause hepatobiliary diseases. Comprehensive and systematic prevention and control of clonorchiasis requires the establishment of an effective surveillance. A total of 301 surveillance points were set up in 30 provinces across China in 2016, and 1000 people were selected by cluster sampling at each surveillance point annually for C. sinensis infection screening using Kato-Katz thick smear method. C. sinensis infection was detected in 6226 people following screening of 305081 people at the 301 surveillance points in 2016. Infection rate was 2.04%; with C. sinensis infection detected in 70 counties spread across 15 provinces, 89.37% of the infected people were distributed in Jilin, Heilongjiang, Guangdong and Guangxi provinces. Highest infection rate was observed in Da'an city, Jilin Province (49%). The national infection rate in male and female was 2.70% and 1.40% respectively. Infection rate between male and female was significantly different (P <0.01). Disease prevalence increases with age in both male and female, reaches peak in age group 40–49. Result obtained indicate that major C. sinensis endemic areas are distributed in the north and south of China, and areas with high prevalence are distributed along the river system at county level. Result, also, shows that middle-aged men are at high-risk of infection. These results suggest that surveillance activities should be sustained nationwide and highlight the need for an integrated approach to control C. sinensis transmission in regions with high disease prevalence in China. [ABSTRACT FROM AUTHOR]