Advances in research on echinococcoses epidemiology in China.

Echinococcoses are serious zoonotic diseases in China's vast, western and north-western pastoral areas that has one of the highest prevalence in the world. The two most common forms, cystic echinococcosis (CE) and alveolar echinococcosis (AE), are co-epidemic in some areas causing a grave threat to people's health and economic development. Echinococcus spp. are transmitted through domestic, sylvatic and mixed cycles involving many kinds of host. Successful transmission requires a favourable environment for the growth of the parasites and survival of their eggs, while the unique customs and religious beliefs in the endemic areas pose a challenge to the prevention and control of these parasites. Based on previous epidemiological studies, this paper reviews the particular factors affecting the transmission of Echinococcus parasites in China, with a focus on biological (parasite genotype and the species, age, sex and density of hosts), environmental (landscape and climate) and social (age, gender, ethnicity, education, occupation, life style, cultural customs, living conditions and hygiene practices of humans in the endemic areas). These three factors interact with each other and jointly determine the parasites' transmission intensity, the study of which supports the formulation of the strategies and measures that are significant for control of these infections.

Assessment of China's contributions to the Regional Network for Asian Schistosomiasis and Other Helminth Zoonoses: a questionnaire survey.

BACKGROUND: The Regional Network for Asian Schistosomiasis and Other Helminth Zoonoses (RNAS+) was established in 1998, which has developed close partnerships with Asian countries endemic for schistosomiasis and other helminthiasis in Asia. RNAS+ has provided an ideal regional platform for policy-makers, practitioners and researchers on the prevention, control and research of parasitic diseases in Asian countries. China, one of the initiating countries, has provided significant technical and financial support to the regional network. However, its roles and contributions have not been explored so far. The purpose of this study was to assess China's contributions on the supporting of RNAS+ development. METHODS: An assessment research framework was developed to evaluate China's contributions to RNAS+ in four aspects, including capacity building, funding support, coordination, and cooperation. An anonymous web-based questionnaire was designed to acquire respondents' basic information, and information on China's contributions, challenges and recommendations for RNAS+development. Each participant scored from 0 to 10 to assess China's contribution: "0" represents no contribution, and "10" represents 100% contribution. Participants who included their e-mail address in the 2017-2019 RNAS+ annual workshops were invited to participate in the assessment. RESULTS: Of 71 participants enrolled, 41 responded to the survey. 37 (37/41, 90.24%) of them were from RNAS+ member countries, while the other 4 (4/41, 9.76%) were international observers. Most of the respondents (38/41, 92.68%) were familiar with RNAS+. Respondents reported that China's contributions mainly focused on improving capacity building, providing funding support, coordination responsibility, and joint application of cooperation programs on RNAS+ development. The average scores of China's contributions in the above four fields were 8.92, 8.64, 8.75, and 8.67, respectively, with an overall assessment score of 8.81 (10 for a maximum score). The challenge of RNAS+ included the lack of sustainable funding, skills, etc. and most participants expressed their continual need of China's support. CONCLUSIONS: This survey showed that China has played an important role in the development of RNAS+ since its establishment. This network-type organization for disease control and research can yet be regarded as a great potential pattern for China to enhance regional cooperation. These findings can be used to promote future cooperation between China and other RNAS+ member countries.

From parasitic disease control to global health: New orientation of the National Institute of Parasitic Diseases, China CDC.

As the only specialized institution for research and control of parasitic diseases at the national level in China for almost 70 years, the National Institute of Parasitic Diseases (NIPD) at the Chinese Center for Disease Control and Prevention (China CDC) has been instrumental in supporting the remarkable progress from high prevalence to transmission interruption or low endemicity of several diseases, lymphatic filariasis, malaria and schistosomiasis in particular. This has taken place through technical guidance, emergency response and scientific research as well as providing technical service, education, training, health promotion and international cooperation. With China's increasing involvement in international cooperation and the increased risk for (re)emerging tropical diseases in mind, the Chinese Government designated in 2017 a new Chinese Center for Tropical Disease Research to NIPD. Responding to the expanded responsibilities, the institute is scaling up its activities in several ways: from parasitic diseases to the wider area of tropical diseases; from disease control to disease elimination; from biological research to policy evidences accumulation; and from public health to global health. Based on this new vision and China's previous accomplishments in the areas mentioned, the institute is in a position to move forward with respect to global health and equitable development according to the central principles of the United Nations' Sustainable Development Goals.

A path to cooperation between China and Mongolia towards the control of echinococcosis under the Belt and Road Initiative.

Health is the core of development. Health cooperation between countries plays a pivotal role under the Belt and Road Initiative (B&R). In 2013, China launched its B&R to improve the international cooperation of which health was an important component. As one of the neglected zoonotic diseases, echinococcosis has become a public health concern and is on top of the government agenda among neglected zoonosis in Mongolia. The transmission of the disease involves animal husbandry, and its characteristics determine the prevention and control of such diseases which requires cross-sector collaboration and comprehensive prevention and control strategies. Taking echinococcosis as an entry point and adopting a 'Mongolia-led, China-supported, and results-sharing' approach to public health cooperation will not only contribute to the advancement of Mongolia's national health coverage, but also promoting China's capacity to engage in global health. In this way, it contributes to meeting the sustainable development goals, especially goal 3, target 3.3: by 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other communicable diseases. This paper provides an overview on how the cooperation between China and Mongolia under the context of B&R was initiated, planned and moved forward to implementation. The experience may provide a good model and inform policy and practice for other bilateral cooperations.

New insights on serodiagnosis of trichinellosis during window period: early diagnostic antigens from Trichinella spiralis intestinal worms.

The clinical diagnosis of trichinellosis is difficult because its clinical manifestations are nonspecific. Detection of anti-Trichinella IgG by ELISA using T. spiralis muscle larval excretory-secretory (ES) antigens is the most commonly used serological method for diagnosis of trichinellosis, but the main disadvantage is false negativity during the early stage of infection. There is an obvious window period between Trichinella infection and antibody positivity.During the intestinal stage of Trichinella infection, the ES antigens of intestinal worms (intestinal infective larvae and adults) are exposed to host's immune system at the earliest time and elicit the production of specific anti-Trichinella antibodies. Anti-Trichinella IgG antibodies in infected mice were detectable by ELISA with ES antigens of intestinal worms as soon as 8-10 days post infection (dpi), but ELISA with muscle larval ES antigens did not permit detection of infected mice before 12 dpi. Therefore, the new early antigens from T. spiralis intestinal worms should be screened, identified and characterized for early serodiagnosis of trichinellosis.

Spatial analysis of visceral leishmaniasis in the oases of the plains of Kashi Prefecture, Xinjiang Uygur Autonomous Region, China.

BACKGROUND: Kashi Prefecture of Xinjiang is one of the most seriously affected areas with anthroponotic visceral leishmaniasis in China. A better understanding of space distribution features in this area was needed to guide strategies to eliminate visceral leishmaniasis from highly endemic areas. We performed a spatial analysis using the data collected in Bosh Klum Township in Xinjiang China. METHODS: Based on the report of endemic diseases between 1990 and 2005, three villages with a high number of visceral leishmaniasis cases in Bosh Klum Township were selected. We conducted a household survey to collect the baseline data of kala-azar patients using standard case definitions. The geographical information was recorded with GIS equipment. A binomial distribution fitting test, runs test, and Scan statistical analysis were used to assess the space distribution of the study area. RESULTS: The result of the binomial distribution fitting test showed that the distribution of visceral leishmaniasis cases in local families was inconsistent (χ(2) = 53.23, P < 0.01). The results of runs test showed that the distribution of leishmaniasis infected families along the channel was not random in the group of more than five infected families. The proportion of this kind of group in all infected families was 63.84 % (113 of 177). In the Scan statistical analysis, spatial aggregation was analyzed by poisson model, which found 3 spatial distribution areas 1) Zone A was located in a center point of 76.153447°E, 39.528477°N within its 1.11 mile radius, where the cumulative life-incidence of leishmaniasis was 1.95 times as high as that in surrounding areas (P < 0.05); 2) Zone B was located in a center point of 76.111968°E, 39.531895°N within its 0.54 mile radius, where the cumulative life-incidence of leishmaniasis was 1.82 times as high as that in surrounding areas (P < 0.01); and 3) Zone C was located in a center point of 76.195427°E, 39.563835°N within its 0.68 mile radius, where the cumulative life-incidence of leishmaniasis was 1.31 times as high as that in surrounding areas (P < 0.05). CONCLUSIONS: The spatial distribution of visceral leishmaniasis-infected families was clustered. Thus, the proper use of this finding would be an improvement in highly endemic areas, which could help identify the types of endemic areas and population at high risk and carry out appropriate measures to prevent and control VL in this area as well.

[Cost Analysis of Dog Deworming in Echinococcosis Control Program in Daofu，Sichuan Province].

Objective: To estimate the cost of dog deworming in Daofu, Sichuan Province and analyze the factors influencing the cost, in order to provide a scientific basis for the investment for echinococcosis control. Methods: Thirty villages were randomly selected in Daofu, Sichuan Province in November 2015, according to the proportion of agricultural and pastoral areas. Data concerning the cost during each step of dog deworming were collected. The unit cost was estimated, the cost composition in each step, element, and institution were described, and the main cost-influencing factors were analyzed using the linear regression method. Results: The mean cost of dog deworming in the 30 surveyed villages was 3.76 yuan/dog-times, comprising drug cost of 0.38 yuan/dog-times, bait cost of 0.37 yuan/dog-times, drug delivery cost of 0.09 yuan/dog-times, mobilization cost of 0.19 yuan/dog-times, household deworming cost of 2.05 yuan/dog-times, faeces disposal cost of 0.35 yuan/dog-times, training cost of 0.29 yuan/dog-times, and supervision cost of 0.04 yuan/dog-times. Among the deworming steps, household deworming cost occupied the most （2.05 yuan/dog-times）; among the cost elements, labour cost had the highest proportion （2.55 yuan/dog-times）; among the different-leveled institutions, village-level cost was the most important part（2.82 yuan/dog-times）. Linear regression analysis revealed that the type of production and the distance among households were the major influencing factors. The labour price was the most sensitive factor for cost-estimation in the dog deworming activities. Conclusion: The labor cost of dog deworming is very high. Governments should increase investment according to local situations.

[Dog Fecal Contamination by Echinococcus in Cuomei County of Tibet in 2015].

Objective: To understand dog fecal contamination by Echinococcus in Lhoka Prefecture of Tibet and provide basis for development of prevention and control strategies. Methods: Survey spots were sampled around the Zhegu Village of Zhegu Town in Cuomei County of Tibet using the mechanical sampling method in May, 2015. The positions of spots, amount of dog feces, types of camps, pastures, terrains, vegetations and land cover, as well as information concerning the existence of household garbage, were recorded. The linear distance from survey spot to the center of the village was calculated. Dog feces were sampled in survey spot and examined the copro-antigen for Echinococcus contamination by ELISA. The distribution characteristics of fecal contamination were analyzed by chi-square test, Fisher's exact test, Kruskal-Wallis test and Nemenyi test. Results: Seventy-nine survey spots were selected for sampling. A total of 226 feces samples were obtained in 37 of the spots. ELISA results showed that the copro-antigen positive rate was 23.9%（54/226）, the averaged density of feces and the averaged density of positive feces were 0.317 9/100 m2 and 0.075 9/100 m2, with a maximum of 2.555 6/100 m2 and 0.555 6/100 m2 respectively. The density of feces and the density of positive feces were both higher in summer camps（0.601 9/100 m2 and 0.157 4/100 m2 respectively） than in non-camps（0.170 2/100 m2 and 0.033 1/100 m2）（χ2=18.248 4，P<0.01；χ2=15.274 3，P<0.01）. In addition, the density of feces and the density of positive feces were both higher in survey spots with household garbage（0.679 0/100 m2, 0.177 0/100 m2） than in those without household garbage （0.130 3/100 m2 and 0.023 5/100 m2）（χ2=34.634 7，P<0.01；χ2=26.109 1，P<0.01）; as well as higher in survey spots ≥10 km from the center of the village（0.403 7/100 m2, 0.107 4/100 m2） than in those <10 km（0.265 3/100 m2, 0.056 7/100 m2）（χ2=4.432 7，P<0.05；χ2=4.045 5，P<0.05）. Conclusion: The Cuomei County of Tibet is facing a serious situation of dog fecal contamination by Echinococcus. Summer camps, areas with household garbage, and districts with a ≥10 km linear distance from the village center may provide reference for determining the regions for hydatidosis prevention and control.

[Interpretation of Criteria for Diagnosis of Toxoplasmosis].

The criteria for Diagnosis of Toxoplasmosis (WS/T 486-2015)（referred to as the Criteria） was compiled following the Management Measures for Health Criteria and GBT 1.1-2009 Standardization Working Guidelines. The Criteria is composed of six chapters, including the range of application, terms and definitions, diagnostic principle, diagnostic standard, and differential diagnosis. Four informative appendices (etiology, epidemiology, clinical manifestation, and differential diagnosis) and one normative appendix (laboratory examination) are appended. The Criteria was issued by the National Health and Family Planning Commission of the People's Republic of China through No.21 of Chinese Health Announcement in 2015. The Criteria provides for the first time technical reference for diagnosis of toxoplasmosis in medical institutions and disease control institutions.

[Implementation Situation and Application Evaluation of "Standards for Control and Elimination of Malaria"].

The application evaluation of "Standards for Control and Elimination of Malaria" was carried out in 11 epidemic provinces/autonomous regions by questionnaires, field investigation and special interviews from January to May, 2014. Two hundred and forty questionnaires were completed by the personnel from the health administrations and the institutions of disease control and prevention. The questionnaire response rate was 84% (240/285). Totally 90% participants had known and used this standards. In detail, managers from the health administration departments had a percent of 100.0% (26/26), while professionals in the institutions of disease control and prevention had a percent of 88.8% (190/214). In malaria-endemic provinces/autonomous regions/municipalities, 18 training classes of malaria control and prevention were held from January 2012 to December 2013. This standards was one of the main contents. One hundred and fifty-two pieces of suggestion and recommendation were obtained, with 84.2% (128/152) relating to personnel and supporting conditions, and 15.8% (24/152) on technical issues.

[Gaps on China's Engagement in Global Governance of Neglected Tropical Diseases].

In this review, we used gap analysis to find out the inadeqency of China's engagement in global elimination and control of neglected tropical diseases (NTDs). Meanwhile, important facets on which our work should concentrate and some abilities that need to be improved were proposed, in the aim to stimulate the progress of global prevention and control of NTDs.

China-Africa cooperation initiatives in malaria control and elimination.

Malaria has affected human health globally with a significant burden of disease, and also has impeded social and economic development in the areas where it is present. In Africa, many countries have faced serious challenges in controlling malaria, in part due to major limitations in public health systems and primary health care infrastructure. Although China is a developing country, a set of control strategies and measures in different local settings have been implemented successfully by the National Malaria Control Programme over the last 60 years, with a low cost of investment. It is expected that Chinese experience may benefit malaria control in Africa. This review will address the importance and possibility of China-Africa collaboration in control of malaria in targeted African countries, as well as how to proceed toward the goal of elimination where this is technically feasible.

[Academic influence of institutes in field of schistosomiasis control and research in China].

OBJECTIVE: To assess the academic influence of schistosomiasis control and research institutions in China. METHODS: The papers (including original articles and reviews) pertaining to schistosomiasis in Science Citation Index Expanded (SCIE) of Web of Science (WOS) during the period from 2002 to 2012 were searched. The number of published papers, h index and citation frequencies of the papers of Chinese institutes and authors were analyzed by a bibliometric method, and the academic influences of the institutes and authors were assessed according to the number of published papers and h index. In addition, the scientific knowledge network map was plotted by using the CiteSpace II software to analyze the inter-institution academic collaboration network. RESULTS: From 2002 to 2012, totally 610 papers pertaining to schistosomiasis were published by Chinese scholars, accounted for 16.7% of the published papers in global, and the quantity increased year by year. The number of published papers and h index of the National Institute of Parasitic Diseases (NIPD), China Center for Disease Control and Prevention (China CDC) were 114 and 27, respectively, both of which were ranked at the first position among all the Chinese institutes, and in the academic collaboration network, the NIPD played a central and dominate part. Xiao-Nong Zhou with the h index of 17 became the outstanding academic leader in the research field of schistosomiasis control. CONCLUSIONS: Both number of published papers in SCIE and h index of the Chinese institutes for schistosomiasis control are far inferior to the leading institutions in the world. It suggests that when strengthening the research and control of schistosomiasis, we should pay an attention to the output and sharing of the control experience and achievements.

[Retrospective analysis of granted projects of the National Institute of Parasitic Disease, China CDC during 2002-2012].

In this paper, the granted projects of the National Institute of Parasitic Diseases (NIPD), China CDC, was analyzed. The results showed that from 2002 to 2012, 126 projects were granted to NIPD. 28.6% (36/126) of the projects were at the national level; 27% (34/126) were at provincial and ministrerial level. International cooperation projects and those supported by state key laboratory and enterprises accounted for 28.6% (36/126) and 15.8% (20/126), respectively. 94 projects belonged to applied researches and 32 belonged to basic researches. Most project leaders were young and middle-aged researchers with senior professional titles.

[Cluster analysis of cystic echinococcosis in non Tibetan Plateau regions].

OBJECTIVE: To understand the endemic characteristics and regularity of cystic echinococcosis by evaluating and classifying its endemic situation in Non Tibetan Plateau regions, so as to provide the evidence for formulating effective preventive and control measures. METHODS: The prevalence data of cystic echinococcosis in 174 counties (cities, districts, banners) in Non Tibetan Plateau regions from a national survey were collected and analyzed by the sample cluster method in 2012. RESULTS: The 174 counties (cities, districts, banners) could be classified into 4 clusters by spatial distribution. The first cluster with human high prevalence rate, low infection rate of livestock, and positive rate of dog stool antigen included 3 counties. The second cluster with high infection rate of livestock, low prevalence rate of human, and positive rate of dog stool antigen included 20 counties (cities). The third cluster with high positive rate of dog stool antigen, low prevalence rate of human, and low infection rate of livestock included 39 counties (cities, districts, banners). The fourth cluster with low rates of the above 3 indices included the rest 112 counties. CONCLUSIONS: The results of the cluster analysis conform to the current epidemiological status of cystic echinococcosis in the Non Tibetan Plateau regions. The epidemiological characteristics and geographical distributions of the four area types will provide a basis for the classified management and guidance of cystic echinococcosis control in these areas.

[Brief discussion on experiences from laboratory certification and accreditation on detection of parasitic diseases].

The laboratory certification and accreditation is the development trend of domestic and international laboratories. The National Institute for Parasitic Diseases, Chinese Center for Disease Control and Prevention passed through the site assessment in September 2012 successfully, 26 items in 8 fields declared were all adopted. This article summarizes some work experiences during carrying out the laboratory certification and accreditation.

[Risk assessment on laboratory biosafety of Leishmania].

OBJECTIVE: To provide the evidence for improving the risk assessment and personal protective equipment and techniques to laboratory staff related to Leishmania. METHODS: The laboratory biosafety of Leishmania was preliminarily assessed based on the biological background information, potential hazards in experimental activities, the risk analyses of laboratory personnel and other relevant factors. RESULTS: The risk assessment on laboratory biosafety of Leishmania was helpful for the establishment of the laboratory standard operating procedure, and was helpful for protecting the staff from infection of Leishmania. CONCLUSION: The risk assessment on laboratory biosafety is important to the safety of laboratory activity related to Leishmania, and is of a great significance to protect the laboratory staff.

[Geographical distribution of echinococcosis among children in Qinghai Province].

OBJECTIVE: To analyze the epidemiological status of echinococcosis among children in three different zones of Qinghai Province. METHODS: B-ultrasound and ELISA were used in the survey to evaluate echinococcus infection among 6 to 15 year old children in the three zones, namely, Qinghai southern plateau, Qilian mountain-Hehuang valley and Chaidamu basin. RESULTS: The prevalence of echinococcus infection scanned by B-ultrasound and sera positive rate detected by ELISA in children were 1.5% (320/20 730) and 6.5% (1024/15 762) respectively, and the prevalence of cystic echinococcosis and alveolar echinococcosis by ultrasound were 1.0% (206/20730) and 0.6% (114/20730), respectively. The prevalence and sera positive rate were 9.5% (707/7 453) and 2.3% (269/11 618) in Qinghai southern plateau, 3.8%(289/7 544) and 0.6% (50/8 275) in Qilian mountain-Hehuang valley, and 3.7% (28/765) and 0.1% (1/837) in Chaidamu basin, respectively. The southern plateau showed the highest prevalence, with a significant statistical difference among the three areas (P < 0.01). The prevalence of alveolar echinococcosis was 1.0% (114/11 618) in the southern plateau, but no alveolar echinococcosis patients were found in other two areas. Correlation analysis showed that the prevalence increased with the altitude (r(s-e) = 0.96, P < 0.05, R2 = 0.93; r(p-e) = 0.82, P < 0.05, R2 = 0.67). CONCLUSION: The prevalence of echinococcosis among children shows an apparent geographical difference in Qinghai Province.

Distribution of the intermediate hosts of Echinococcus multilocularis in Shiqu County, Sichuan, China.

BACKGROUND: The rodentia and lagomorpha animals are the intermediate hosts of Echinococcus multilocularis, their distribution and infection of this parasite may facilitate the infection of definitive hosts such as dogs. The aim of this study was to determine the distribution of the intermediate hosts of Echinococcus multilocularis in Shiqu County, Sichuan, China. METHODS: A systematic sampling method was used to investigate the density of burrows of rodents and lagomorphs at 97 pasture sites in winter and summer pastureland and remote sensing (RS) technology was used to correlate their densities to the distribution of these animals in different landscape types. RESULTS: Based on the densities of Ochotona curzoniae, Microtus fuscus (dependent variable) and their burrow densities (independent variable) in survey points, regression equations were fitted respectively (Ochotona curzoniae, P < 0.0001, R(2) = 0.8705; Microtus fuscus, P < 0.0001, R(2) = 0.9736). Their burrow density in summer pastureland was higher than in winter pastureland (F = 36.65, P < 0.0001). The burrow densities of Ochotona curzoniae and Microtus fuscus in bareland and half-bareland are higher than in grassland (F = 7.73, P < 0.001). CONCLUSIONS: The regression relationship between the densities of Ochotona curzoniae and Microtus fuscus and their burrow densities indicate that the burrow densities could reflect the animal densities and that the burrow density was greater in summer pastureland than in winter pastureland. The main distribution areas of the intermediate hosts were in bareland and half-bareland.