Review of risk factors for human echinococcosis prevalence on the Qinghai-Tibet Plateau, China: a prospective for control options

A regressive analysis of the main environmental risk factors of human echinococcosis in 370 counties in China

BACKGROUND

Echinococcosis is a natural focal, highly prevalent disease in China. Factors influencing the spread of echinococcosis are not only related to personal exposure but also closely related to the environment itself. The purpose of this study was to explore the influence of environmental factors on the prevalence of human echinococcosis and to provide a reference for prevention and control of echinococcosis in the future.

METHODS

Data were collected from 370 endemic counties in China in 2018. By downloading Modis, DEM and other remote-sensing images in 2018. Data on environmental factors, i.e., elevation, land surface temperature (LST) and normalized difference vegetation index (NDVI) were collected. Rank correlation analysis was conducted between each environmental factor and the prevalence of echinococcosis at the county level. Negative binomial regression was used to analyze the impact of environmental factors on the prevalence of human echinococcosis at the county level.

RESULTS

According to rank correlation analysis, the prevalence of human echinococcosis in each county was positively correlated with elevation, negatively correlated with LST, and negatively correlated with NDVI in May, June and July. Negative binomial regression showed that the prevalence of human echinococcosis was negatively correlated with annual LST and summer NDVI, and positively correlated with average elevation and dog infection rate. The prevalence of human cystic echinococcosis was inversely correlated with the annual average LST, and positively correlated with both the average elevation and the prevalence rate of domestic animals. The prevalence of human alveolar echinococcosis was positively correlated with both NDVI in autumn and average elevation, and negatively correlated with NDVI in winter.

CONCLUSION

The prevalence of echinococcosis in the population is affected by environmental factors. Environmental risk assessment and prediction can be conducted in order to rationally allocate health resources and improve both prevention and control efficiency of echinococcosis.

Global, Regional and National Burden of Human Cystic Echinococcosis from 1990 to 2019: A Systematic Analysis for the Global Burden of Disease Study 2019

BACKGROUND

Cystic echinococcosis (CE) is a neglected tropical parasitic disease that poses huge disease, social and economic burdens worldwide; however, there has been little knowledge on the global morbidity, mortality and disability-adjusted life years (DALYs) of CE until now. This study aimed to collect the most up-to-date data about the global, regional and national disease burden due to CE from 1990 to 2019 and to project trends in the next 10 years.

METHODS

We measured the global, regional and national morbidity, mortality and DALYs of CE from 1990 to 2019 based on the Global Burden of Disease Study 2019 (GBD 2019) data, and we examined the correlation between socioeconomic development levels and the disease burden of CE. In addition, the disease burden due to CE was projected from 2020 to 2030.

RESULTS

The age-standardized incidence rate (ASIR) of CE reduced from 2.65/105 [95% UI: (1.87/105 to 3.7/105)] in 1990 to 2.6/105 [95% UI: (1.72/105 to 3.79/105)] in 2019 (EAPC = -0.18%). The number of deaths, DALYs, age-standardized mortality rate (ASMR) and age-standardized DALY rate due to CE all showed a tendency to decline from 1990 to 2019. A higher disease burden of CE was measured in women than in men in 2019. There was a significant difference in the ASMR of CE by region according to the socio-demographic index (SDI), and lower burdens of CE were estimated in high-SDI regions. The global ASIR of CE is projected to decline from 2020 to 2030; however, the ASMR and age-standardized DALY rate are projected to rise.

CONCLUSIONS

The global burden of CE remains high, and it is recommended that more health resources are allocated to low-SDI regions, women and the elderly aged 55 to 65 years to reduce the disease burden of CE.

Epidemiology and Clinical Characteristics of Cerebral Alveolar Echinococcosis in the Tibetan Region of Sichuan, China

This study aimed to examine the epidemiology and clinical characteristics of cerebral alveolar echinococcosis in the Tibetan region of Sichuan, China. A retrospective analysis of hospitalized cases of cerebral alveolar echinococcosis from six medical units in the Garze Tibetan Autonomous Prefecture, Sichuan Province, from January 2016 to June 2021 was conducted. The study focused on the characteristics, clinical presentation, and imaging features of the disease. Of 119 cerebral alveolar echinococcosis patients, 76 were male and 43 were female. Occupationally, 62 were farmers, 46 were herdsmen, nine were monks, and two were students. The mean age was 43.9 (± 13.9) years. The primary clinical manifestations were dizziness, headaches, and epilepsy. The incidence of cerebral alveolar echinococcosis was most concentrated within 4 years after the diagnosis of hepatic alveolar echinococcosis (77/119, 64.7%). There were 86 cases (72.3%) with multiple intracranial echinococcosis lesions, with an average size of 2.0 cm × 2.5 cm. The imaging features showed that the lesion was mainly concentrated in the anterior circulation blood supply area, and the lesion had multiple aggregated small vesicular structures as its unique imaging feature. Among 98 follow-up cases, 62 could live independently (63.3%); 18 deaths were recorded (18.4%), with an approximate 5-year survival rate of 81.6%. Regular examination of patients with first diagnosis of hepatic alveolar echinococcosis without a combination of echinococcosis in other parts of the body can help monitor and prevent the occurrence of cerebral alveolar echinococcosis, improve the understanding of cerebral alveolar echinococcosis in Tibetan areas of Sichuan.

Association between radical versus conservative surgery and short-term outcomes of hepatic cystic echinococcosis in Nyingchi, China: a retrospective cohort study

BACKGROUND

Radical or conservative surgical treatment for hepatic Cystic Echinococcosis (hepatic CE) is controversial. We aimed to measure the association between radical surgery (RS) versus conservative surgery (CS) and short-term outcomes in our cohort.

METHODS

Medical records of hepatic CE patients' demographic, clinical, radiological, operative and postoperative details who underwent surgical treatment between January 3, 2017 and January 3, 2018 at the Department of General Surgery, Nyingchi People's Hospital, Nyingchi, China, were retrieved and analyzed. The primary outcome was overall morbidity. The secondary outcomes included: (i) bile leakage; (ii) complications of lung, pleura, heart, liver, pancreas and biliary tract; (iii) incision infection and residual cavity abscess formation; (iv) anaphylactic reaction and shock; (v) tear of surrounding tissues; (vi) hospital and post-operative length of stay (LOS); (vii) length of surgery; (viii) blood loss during surgery. Multivariable logistic/linear regression models with various adjustment strategies for confounders were performed to evaluate the association.

RESULTS

A total of 128 hepatic CE patients were included with 82 (64.1%) and 46 (35.9%) receiving CS and RS, respectively. After fully adjusted, RS was associated with 60% lower risk of overall complication (aOR 0.4; 95%CI, 0.2-0.9) and 0.6-h shorter surgical time (aβ 0.4; 95%CI,-0.0-0.8) comparing to CS. However, RS was associated with more blood loss during surgery (aβ 179.3; 95%CI, 54.2-304.5).

CONCLUSION

To conclude, RS was associated with a 60% reduction in developing overall complication in the short term, but may result in more blood loss during surgery than CS.

Seroprevalence of Anti-Echinococcus granulosus Antibodies and Risk Factors for Infection in Blood Donors from Western Romania

Cystic echinococcosis is a worldwide-distributed zoonotic parasitic disease. This cross-sectional study aimed to assess the seroprevalence and risk factors potentially associated with Echinococcus granulosus in healthy blood donors from Timis County, an endemic region in Western Romania. Serum samples were collected from 1347 Romanian blood donors. Serologic tests to determine the presence of anti-Echinococcus antibodies were performed using an anti-Echinococcus-ELISA immunoassay. Anti-Echinococcus antibodies were detected in 38 blood donors, indicating an overall seroprevalence of 2.8%. The seropositivity rate was 3.7% in females and 3.1% in blood donors residing in urban areas. The highest seropositivity was found in the age group of 31-40 years (3.6%). There were no significant differences between Echinococcus seropositivity and gender, area of residence, age, contact with dogs, or raising sheep. This serologic survey evaluated for the first time the presence of Echinococcus antibodies in healthy blood donors from Western Romania and the potential risk factors associated with echinococcosis. Our results suggest that this zoonotic infection might evolve asymptomatically in apparently healthy individuals. Further studies should be conducted in the general population to estimate the true extent of human echinococcosis and its risk factors.

Societal drivers of human echinococcosis in China

BACKGROUND

Echinococcosis is a parasitic zoonotic disease that threatens human health and economic development. In China, 370 counties are endemic for echinococcosis. Qinghai-Tibet Plateau has the most patients and people at risk. Therefore, analyzing the societal factors related to susceptibility to the disease is critical for efficient prevention and control of echinococcosis.

METHODS

The demographic characteristics and lifestyle of echinococcosis cases were clustered using K-means cluster analysis to determine the main factors of risk of echinococcosis.

RESULTS

Middle-aged and young people as well as those with a low education level and herdsmen are at risk of contracting echinococcosis. Nomadism, domestic and feral dogs in the surrounding environment, and drinking heavily polluted natural surface water are the main behavioral risk factors. The cystic echinococcosis (CE) and alveolar echinococcosis (AE) cluster analysis focused on female, middle-aged, and young people, winter settlement and summer nomadism, and domestic and feral dogs in the surrounding environment. There were significant differences in lifestyle between Qinghai-Tibet Plateau cases and non-Qinghai-Tibet-Plateau cases.

CONCLUSION

According to the distribution of cases and CE and AE, this study identified the factors of risk of echinococcosis in the Qinghai-Tibet Plateau and non-Qinghai-Tibet Plateau. Adapted control techniques appropriate for the various epidemic areas should be established to serve as a reference for echinococcosis prevention.

Analysis of Ultrasonographic Characteristics of Early Hepatic Alveolar Echinococcosis

Objective

This study aims to investigate the ultrasonographic characteristics of early hepatic alveolar echinococcosis (HAE) and improve the qualitative diagnostic ability of sonographers.

Methods

The data of 80 positive cases of HAE screened and diagnosed by ultrasonography and serum immunology (33 males and 44 females with a mean age of 44.12 ± 14.31 y) were used in the study. The imaging characteristics of the lesions (i.e., intrahepatic distribution, shape, size, echo, blood flow, and growth characteristics) were analyzed retrospectively, and the ultrasonographic characteristics of early lesions were discussed in combination with their basic pathological changes.

Results

Patients with lesions of the proliferative infiltration type accounted for 57.5% (46/80), the fibrous calcification type accounted for 26.25% (21/80), the necrotic liquefaction type accounted for 6.25% (5/80), and the mixed type accounted for 10% (8/80). Patients with lesions involving the right lobe and the left lobe accounted for 76.25% (61/80) and 11.25% (9/80), respectively, and with lesions involving both the left and right lobes accounted for 12.5% (10/80). There were statistically significant differences in diameter between all types of lesions (n = 88; F = 5.926 and P = 0.004). Focal hyperechoic and diffuse heterogenous nodular changes were the main manifestations of early proliferative infiltration lesions.

Conclusion

Ultrasonography is extremely valuable in the diagnosis of early HAE. Capillary hemangioma-like changes and hailstorm sign are the main characteristics of early lesions of HAE, and calcification is a common concomitant sign.

A Multi-diagnostic Screening Study of the Prevalence and Risk Factors of Echinococcosis in First-degree Family Members of Infected Patients Undergoing Surgical Treatment

Background: Echinococcosis is a zoonotic infection caused by Echinococcus tapeworms. About 60% of patients remain asymptotic until severe stages. Early diagnosis of the infection in high-risk populations is of medical importance. Objectives: This study was designed to investigate the prevalence of echinococcosis among first-degree family members of the infected patients who underwent surgical treatment. Methods: A cross-sectional study was conducted to screen the first-degree family members of 96 patients who underwent surgical intervention at Imam Reza hospital, Mashhad, Iran, from September 2016 to March 2017. All family members were invited by phone calls to perform the serologic test, ultrasound examination, and chest X-ray test. Results: Forty-six (47.9%) patients participated in the study. A total of 114 family members performed the screening tests. Seven participants from five families (6.14%) were found to be infected in ultrasound examination (five females with a mean age of 36 years). There were no significant differences between the infected and non-infected groups concerning age (P = 0.921) and gender (P = 0.457). Conclusions: Screening the first-degree family members of patients with a confirmed echinococcosis infection results in the early diagnosis of infected patients, which is economically significant, especially in endemic areas.

Alterations in the Gut Microbiota of Tibetan Patients With Echinococcosis

There are two main types of echinococcosis, namely alveolar echinococcosis (AE) and cystic echinococcosis (CE). They are zoonotic parasitic diseases caused by the metacestodes of Echinococcus multilocularis and Echinococcus granulosus. In order to explore the gut microbiome composition of patients with echinococcosis, we analyzed fecal samples of seven patients with AE, six patients with CE, and 13 healthy individuals from the Qinghai-Tibetan Plateau, China. Using metagenomic next-generation sequencing, we identified fecal bacteria in the patients with AE and CE. The gut microbiota was analyzed by next-generation metagenomic sequencing (mNGS) to compare patients with either AE or CE against healthy individuals. We found there were some differences between them in abundant bacteria. Our results led to five findings: (1) Between patients with echinococcosis and healthy individuals, the differential bacteria were from four phyla: Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria. (2) Rothia mucilaginosa, Veillonella dispar, Veillonella atypica, Streptococcus parasanguinis, Streptococcus salivarius, and Alistipes finegoldii were abundant in the feces of patients with AE. (3) Bacteroides dorei, Parabacteroides distasonis, Escherichia sp_E4742, and Methanobrevibacter smithii were abundant in the feces of the patients with CE. (4) At the phylum and class level, compared to the AE group, the healthy group was characterized by higher numbers of Actinobacteria. (5) At the family level, Lachnospiraceae and Eubacteriaceae were more abundant in the feces of healthy individuals than in AE patients. The genera Coprococcus, Eubacterium, and Bilophia were more abundant in the healthy group, while the genus Rothia was more abundant in the AE group. The results of this study enrich our understanding of the gut microbiome composition of patients with AE and CE in the Qinghai-Tibetan Plateau.

Seroprevalence of Cystic Echinococcosis in Yaks and Sheep During 2017 on the Qinghai–Tibet Plateau, China

Cystic echinococcosis (CE) is a livestock disease caused by a parasite known as Echinococcus granulosus. It is one of the primary cause for illness and poverty especially for herders on the Qinghai–Tibet plateau, China. Meanwhile, the Qinghai–Tibet plateau has been a key area for echinococcosis control in China. Here in current study, we determined the seroprevalence of E. granulosus in ruminants on this region. A total of 2,730 serum samples (1,638 samples from yaks and 1,092 samples from sheep) were collected on the plateau during the period of 2017. The samples were assayed for E. granulosus antibodies by commercial enzyme-linked immunosorbent assay kits. Our results exhibited a prevalence percentage of 52.2% in Tibetan yaks and 38.2% in Tibetan sheep. Moreover, there was more chance of being infected with E. granulosus infection in old animals due to more exposure to contaminated sources of infection. However, no significant difference was observed. Furthermore, we observed that the rainfall and presence of several lakes has increased the risk of CE infection in yaks and sheep in the Qinghai, Qinglong, and Baingoin areas. Hence, with this investigation, it was possible to determine the frequency and distribution of CE in yaks and Tibetan sheep on the Qinghai-Tibet plateau, that laying the groundwork for its prevention and management.

Prevalence rate and risk factors of human cystic echinococcosis: A cross-sectional, community-based, abdominal ultrasound study in rural and urban north-central Chile

Background

Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is a neglected and underdiagnosed parasitic zoonosis that has a significant socioeconomic impact on rural communities relying on livestock farming. CE is endemic across Latin America, including Chile, where the Coquimbo region exhibits a relatively high record of hospital-based human cases and infected animals. However, the incidence of hospitalized CE cases may underestimate the real burden of infection in a population, since the majority of cases never reach medical attention or official disease records.

Methodology/Principal findings

In 2019, a cross-sectional, community-based study was conducted with the objectives of estimating for the first time the prevalence of human abdominal CE using abdominal ultrasound (US) screening in volunteers residing in urban and rural localities of the Monte Patria municipality located in Limarí province, Coquimbo region, Chile, and identifying the risk factors associated with human infection. Pre-screening activities included a 16-h lecture/hands-on training aimed at rural physicians that focused on the diagnosis of CE by US, based on current WHO recommendations. A total of 2,439 (~8% of municipality inhabitants) people from thirteen target localities were screened by abdominal US in June-July 2019. We found an overall CE prevalence of 1.6% (95% CI 1.1–2.2) with a significantly higher likelihood of infection in rural localities, older age classes and people drinking non-potable water; 84.6% of infected volunteers were newly diagnosed with CE. Cysts were either in active or inactive stages in equal proportions; active cysts were detected in all age classes, while 95.7% of inactive cysts occurred in >40 years-old subjects.

Conclusions/Significance

This is the first US survey aimed at detecting human infection caused by Echinococcus granulosus s.l. in Chile. Our findings indicate a high CE prevalence in the area, and contribute to define the demographic and behavioral risk factors promoting the transmission of the parasitic infection within target communities. Our results support the implementation of cost-effective strategies for the diagnosis, treatment and control of CE, and the need to improve the epidemiological surveillance system in Chile.

Human cystic echinococcosis (CE) is a parasitic disease caused by Echinococcus granulosus s.l. complex; its cycle involves canids and livestock, mainly sheep. It is endemic in areas with extensive livestock breeding activities, where close contact occurs between humans and the domestic dog-livestock parasite cycle. After ingestion of parasite eggs, people may develop fluid-filled cysts, mainly in the liver. CE is a neglected disease, which causes significant socioeconomic impact mainly on poor communities worldwide. Prevalence data in many affected areas is lacking or largely underestimated, partly because human cases typically do not reach medical attention or official disease records. We determined the prevalence of abdominal CE by ultrasound population-based screening in volunteers residing in urban and rural localities of the Monte Patria Municipality, Limarí province, Coquimbo region, which is an E. granulosus s.l. endemic area of northern Chile, and assessed the risk factors associated with human infection. We performed an ultrasound survey on 2,439 people residing in thirteen localities and found an overall prevalence of 1.6% (95% CI 1.1–2.2). A higher risk of infection was associated with residing in rural localities, older age and drinking non-potable water. CE cysts were either in active or inactive stages in equal proportions and 84.6% of infected volunteers were newly diagnosed with CE. Our findings will serve to support the implementation of cost-effective diagnostic, treatment and control strategies and to improve the epidemiological surveillance system for CE in Chile.

DEVELOPMENT OF A TRIPLEX REAL-TIME PCR ASSAY TO DETECT ECHINOCOCCUS SPECIES IN CANID FECAL SAMPLES

Echinococcosis is a zoonotic disease with great significance to public health, and appropriate detection and control strategies should be adopted to mitigate its impact. Most cases of echinococcosis are believed to be transmitted by the consumption of food and/or water contaminated with canid stool containing Echinococcus spp. eggs. Studies assessing Echinococcus multilocularis, Echinococcus granulosus sensu stricto, and Echinococcus shiquicus coinfection from contaminated water-derived, soil-derived, and food-borne samples are scarce, which may be due to the lack of optimized laboratory detection methods. The present study aimed to develop and evaluate a novel triplex TaqMan-minor groove binder probe for real-time polymerase chain reaction (rtPCR) to simultaneously detect the 3 Echinococcus spp. mentioned above from canid fecal samples in the Qinghai-Tibetan Plateau area (QTPA). The efficiency and linearity of each signal channel in the triplex rtPCR assay were within acceptable limits for the range of concentrations tested. Furthermore, the method was shown to have good repeatability (standard deviation ≤0.32 cycle threshold), and the limit of detection was estimated to be 10 copies plasmid/μl reaction. In summary, the evaluation of the present method shows that the newly developed triplex rtPCR assay is a highly specific, precise, consistent, and stable method that could be used in epidemiological investigations of echinococcosis.

Prevalence and spatial distribution characteristics of human echinococcosis in China

Background

Echinococcosis is a zoonotic parasitic disease caused by larval stages of cestodes belonging to the genus Echinococcus. The infection affects people’s health and safety as well as agropastoral sector. In China, human echinococcosis is a major public health burden, especially in western China. Echinococcosis affects people health as well as agricultural and pastoral economy. Therefore, it is important to understand the prevalence status and spatial distribution of human echinococcosis in order to advance our knowledge of basic information for prevention and control measures reinforcement.

Methods

Report data on echinococcosis were collected in 370 counties in China in 2018 and were used to assess prevalence and spatial distribution. SPSS 21.0 was used to obtain the prevalence rate for CE and AE. For statistical analyses and mapping, all data were processed using SPSS 21.0 and ArcGIS 10.4, respectively. Chi-square test and Exact probability method were used to assess spatial autocorrelation and spatial clustering.

Results

A total of 47,278 cases of echinococcosis were recorded in 2018 in 370 endemic counties in China. The prevalence rate of human echinococcosis was 10.57 per 10,000. Analysis of the disease prevalence showed obvious spatial positive autocorrelation in globle spatial autocorrelation with two aggregation modes in local spatial autocorrelation, namely high-high and low-high aggregation areas. The high-high gathering areas were mainly concentrated in northern Tibet, western Qinghai, and Ganzi in the Tibetan Autonomous Region and in Sichuan. The low-high clusters were concentrated in Gamba, Kangma and Yadong counties of Tibet. In addition, spatial scanning analysis revealed two spatial clusters. One type of spatial clusters included 71 counties in Tibet Autonomous Region, 22 counties in Qinghai, 11 counties in Sichuan, three counties in Xinjiang Uygur Autonomous Region, two counties in Yunnan, and one county in Gansu. In the second category, six types of spatial clusters were observed in the counties of Xinjiang Uygur Autonomous Region, and the Qinghai, Gansu, and Sichuan Provinces.

Conclusion

This study showed a serious prevalence of human echinococcosis with obvious spatial aggregation of the disease prevalence in China. The Qinghai-Tibet Plateau is the "hot spot" area of human echinococcosis in China. Findings from this study indicate that there is an urgent need of joint strategies to strengthen efforts for the prevention and control of echinococcosis in China, especially in the Qinghai-Tibet Plateau.

Echinococcosis is a zoonotic parasitic disease caused by larval stages of cestodes belonging to the genus Echinococcus. In China, human echinococcosis is a major public health burden, especially in western China. Therefore, it is important to understand the prevalence status and spatial distribution of human echinococcosis in order to provide basic information for prevention and control measures reinforcement. To describe the distribution and analyze the prevalence and spatial distribution characteristics of human echinococcosis in China, report data of echinococcosis were collected in 370 counties in 2018. For the year 2018, there were 47,278 cases of echinococcosis recorded in 370 endemic counties in China. Analysis of the disease prevalence showed obvious spatial positive autocorrelation in global spatial autocorrelation with two aggregation modes in local spatial autocorrelation, namely high-high and low-high aggregation areas. The high-high gathering areas were mainly concentrated in northern Tibet, western Qinghai, and Ganzi in the Tibetan Autonomous Region and in Sichuan. This study showed obvious spatial aggregation of human echinococcosis prevalence in China. The Qinghai-Tibet Plateau is the "hot spot" area of human echinococcosis in China. Such findings indicate that here is an urgent need of joint strategies to strengthen efforts for the prevention and control of echinococcosis in China, especially in the Qinghai-Tibet Plateau.

Epidemiological Characteristics of Echinococcosis in Non-Endemic PLADs - China, 2017-2020

What is already known about this topic?

Echinococcosis, also known as hydatid disease, is a zoonotic parasitic disease caused by the larvae of Echinococcus granulosus. Western China has one of the most severe epidemics worldwide. Echinococcosis is endemic in 370 counties of 9 provincial-level administrative divisions (PLADs) including Inner Mongolia, Sichuan, Yunnan, Tibet, Shaanxi, Gansu, Qinghai, Ningxia, Xinjiang and Xinjiang Production and Construction Corps (XPCC).

What is added by this report?

From 2017 to 2020, 244 cases were reported in 21 non-endemic PLADs. Of the cases reported in non-endemic PLADs, the majority were imported from endemic areas. Cases reported from non-endemic PLADs have been sporadic, and the number has increased in some areas.

What are the implications for public health practice?

Migrant workers and livestock from endemic areas may have contributed to the increased incidence of locally acquired infections in non-endemic PLADs, suggesting that health education among workers and livestock quarantine is important for the control of spread in non-endemic PLADs.

Prevalence of Echinococcus Species in Wild Foxes and Stray Dogs in Qinghai Province, China

Echinococcosis is a zoonotic parasitic disease that is highly endemic to the Qinghai province of China. Limited data are available on the prevalence of the causal pathogen, Echinococcus spp., in definitive hosts in this region. Thus, the aim of this study was to evaluate the prevalence of Echinococcus spp. in wild foxes and stray dogs in Qinghai province. Five hundred and twenty-eight feces from wild foxes and 277 from stray dogs were collected from 11 counties in the Golog, Yushu, and Haixi prefectures and screened for Echinococcus spp. using copro-DNA polymerase chain reaction (PCR). In total, 5.5% of wild foxes and 15.2% of stray dogs tested positive for Echinococcus spp. The prevalence rates of Echinococcus spp. in wild foxes in Golog, Yushu, and Haixi were 7.3%, 5.2%, and 1.9%, respectively. In stray dogs, these rates were 13.3%, 17.3%, and 0%, respectively. Sequencing analysis determined that Echinococcus multilocularis was the most prevalent species, occurring in 4.0% and 12.6% of wild foxes and stray dogs, respectively. Echinococcus shiquicus was observed in 1.5% of wild foxes and 0.7% of stray dogs. Echinococcus granulosus was observed only in wild dogs, with a prevalence rate of 1.8%. To our knowledge, this is the first report on the prevalence of E. shiquicus in dogs in Qinghai province. The current results improve our understanding of the transmission and dissemination of human echinococcosis and suggest that exposure to the eggs of E. multilocularis harbored by wild foxes and stray dogs may pose a great risk of alveolar echinococcosis to humans in Qinghai province.

Haplotype comparisons of Echinococcus granulosus sensu lato via mitochondrial gene sequences (co1, cytb, nadh1) among Pakistan and its neighbouring countries

Echinococcus granulosus sensu lato (s.l.) is a zoonotic parasite that causes cystic echinococcosis (CE) in humans. However, E. granulosus sensu stricto (s.s.) is considered the predominant species in CE infections worldwide. According to the population genetic diversity and structure of E. granulosus s.l., gene flow can explain the parasite drift among the neighbouring countries of Pakistan. The mitochondrial (mt) co1 (n = 47), nadh1 (n = 37) and cytb (n = 35) nucleotide sequences of E. granulosus s.l. isolates from Pakistan, Iran, China and India were retrieved from the National Centre for Biotechnology Information database to determine the genealogical relationships. The sequences were grouped as the mt-co1 (genotypes G1 and G3, G6-G7), mt-cytb (genotypes G1 and G3), and mt-nadh1(genotypes G1 and G3). The data were analysed using bioinformatic tools. A total of 19 polymorphic sites for the mt-co1 sequence (374 bp) were observed of which 31.6% (6/19) were parsimony-informative sites. Unique singleton haplotypes within the E. granulosus s.s. haplotype network based on the mt-co1 gene were highly prevalent (68.4%; 13/19) in Pakistani isolates followed by Chinese, Indian and Iranian isolates; four polymorphic sites were detected in the E. canadensis (G6/G7). In E. canadensis mt-co1 haplotype network, 75% (3/4) unique singleton haplotypes were from the Iranian isolates. Twelve polymorphic sites were found using the mt-cytb sequence (547 bp); 25% (3/12) were parsimony-informative and there were 66.7% (8/12) unique singleton haplotypes within the mt-cytb haplotype network in E. granulosus s.s. with the most reported from Pakistan followed by Iran and China. 20 polymorphic sites were detected in E. granulosus s.s. mt-nadh1 sequences (743 bp); 20% (4/20) were parsimony-informative. There were 66.7% (8/12) main single haplotypes within the mt-nadh1 haplotype network, with the most reported from Pakistan followed by that from India, Iran and China. The sequence analyses show low nucleotide diversity and high haplotype diversity in general.

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.

Effects of management of infection source of echinococcosis in Linzhi, Tibet Autonomous Region of China

Background

Echinococcosis is highly endemic in western and northern China. Tibet Autonomous Region (TAR) is the most serious prevalent area. Linzhi is located in southeastern part of TAR. Dogs are the primary infection source for the transmission of echinococcosis to humans. A control and prevention campaign based on dog management has been implemented in the past three years. This study aims to evaluate the effects of dog management on the infection rate of dogs.

Methods

Data of dog population, registration and de-worming of seven counties/district in Linzhi between 2017 and 2019 were obtained from the annual prevention and control report. Domestic dog fecal samples were collected from each endemic town of seven counties/district in Linzhi in 2019 to determine the infection of domestic dogs using coproantigen enzyme-linked immunosorbent assay (ELISA). Data analysis was processed using SPSS statistics to compare dog infection rate between 2016 and 2019 by chi-square test, and maps were mapped using ArcGIS.

Results

In Linzhi, domestic dog population has decreased from 17 407 in 2017 to 12 663 in 2019, while the registration rate has increased from 75.9% in 2017 to 98.6% in 2019. Similarly, stray dog population has decreased from 14 336 in 2017 to 11 837 in 2019, while sheltered rate has increased from 84.6% in 2017 to 96.6% in 2019. Dog de-worming frequency has increased from 4 times per annum in 2017 to 12 times in 2019, indicating that approximately every dog was dewormed monthly. A total of 2715 dog fecal samples were collected for coproantigen ELISA assay. The dog infection rate was 2.8% (77/2715) in 2019, which was significantly lower than 7.3% (45/618) in 2016 (P < 0.05).

Conclusions

Increased dog registration, decreased dog population, and increased dog de-worming frequency contributed to significantly decrease the dog infection rate in Linzhi. Control and prevention campaign based on dog management could significantly decrease dog infection with Echinococcus spp. in echinococcosis endemic areas.

Association between echinococcosis-specific health literacy and behavioural intention to prevent echinococcosis among herdsmen on the Tibet Plateau in China: a cross-sectional study

Background

Echinococcosis is considered a neglected zoonotic disease and has been a major worldwide public health problem. Although it is known that health literacy is closely related to health behaviours and health outcomes, few studies have paid attention to echinococcosis related health literacy. This study aims to examine the association between echinococcosis-specific health literacy (ES-HL) and behavioural intention to prevent echinococcosis (BIPE) among herdsmen on the Tibet Plateauin in China.

Methods

A cross-sectional study of 401 Tibetan herdsmen was conducted in Gande county of Qinghai Province, China. Participants were recruited from August to September 2018 and from February to March 2019. A self-developed questionnaire was used to measure demographic information, ES-HL and BIPE. Hierarchical regression analysis was done to identify the factors associated with BIPE.

Results

In the hierarchical regression analysis, we entered age, sex, education level, marital state and family monthly income per capita into model 1 which explained a significant amount of variance in BIPE (Adjusted R² change = 0.029, P = 0.006). Sex (β = − 0.125, P = 0.013) and family monthly income per capita (β = − 0.133, P = 0.009) were found to be associated with BIPE. Subsequently, the three factors of ES-HL were added to Model 1 to create Model 2. In Model 2, the two factors of ES-HL, perceived echinococcosis information support (β = 0.229, P < 0.001) and echinococcosis-specific self-management ability (β = 0.252, P < 0.001), were significantly associated with BIPE, while the information acquisition and evaluation ability factor (β =0.093, P = 0.089) was not found to be associated with BIPE. The model improved significantly when ES-HL was included (Model 2) explaining the 25.8% of variance of BIPE (Adjust R² change =0.229, P < 0.001).

Conclusions

ES-HL is an important predictor of whether individuals take preventive actions against echinococcosis. An ES-HL promotion action project should be developed targeting specific populations to enhance the prevention of echinococcosis.

Cystic echinococcosis in humans and animals in Egypt: An epidemiological overview

Cystic echinococcosis (CE), caused by the cestode Echinococcus granulosus (sensu lato), is a serious neglected zoonotic disease in many parts of the world, including Egypt. Thus far, the actual incidence of CE in the Egyptian population remains unknown. Infection with E. granulosus (s.l.) is common among stray dogs in rural and suburban areas owing to the spread of parasite eggs. Herein, we present an updated review of published data on the incidence of CE in humans and animals as well as the genotypes prevalent in Egypt. CE occurs in most parts of Egypt; however, available data are mostly from northern Egypt, particularly Cairo and Giza. In southern Egypt, the disease is likely to be underdiagnosed or underreported. A few risk factors were studied. In the Egyptian population, residency in rural areas, farming, and age were significant factors for acquiring CE. In livestock, age, sex and season have been associated with high prevalence of CE. Several genotypes have been identified among livestock (G1, G4, G5, G6 and G7) and humans (G1, G6 and G7). This literature review underscores the need for a precise national surveillance system to track CE distribution in humans and animals and design appropriate preventive and control strategies for this disease.

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A review summarizing the epidemiological data for Echinococcus granulosus (s.l.) infections in Egypt.

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Egypt is an endemic area for cystic echinococcosis in the human population and livestock.

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Genotypes G1, G4, G5, G6 and G7 of E. granulosus (s.l.) were reported in Egypt.

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A national surveillance system to track cystic echinococcosis in Egypt is needed.

Assessment of a 10-year dog deworming programme on the transmission of Echinococcus multilocularis in Tibetan communities in Sichuan Province, China

Human alveolar echinococcosis (AE) is considered a neglected zoonotic disease by the World Health Organization (WHO). The causative pathogen, Echinococcus multilocularis, lives as an adult tapeworm in the intestinal tract of canines. AE was identified as an emerging public health issue in Tibetan communities of Shiqu County 20 years ago. On St. Lawrence Island, Alaska (USA), in the 1980s peri-domestic transmission of E. multilocularis was controlled by regular deworming of owned dogs over a 10-year period. In Tibetan communities, on the Tibetan Plateau, control of E. multilocularis transmission is challenging due to the continental setting, complex epidemiology, disease ecology, geography, and socio-cultural factors. However, a control programme based on deworming owned dogs using praziquental (PZQ) has been carried out since 2006. Assessment was conducted in townships where baseline data were available 10 years prior. Purging of dogs by oral administration of arecoline was used to measure E. multilocularis prevalence, trapping small mammals around communities was employed to assess the change in infection of pikas and voles, and analysis of human AE abdominal ultrasound-based data was used to understand the change in prevalence in the past decade. In all three evaluated townships, the E. multilocularis prevalence in owned dogs was significantly (P < 0.01) reduced from 7.23% (25/346) during 2000-2003 to 0.55% (1/181) in 2016. Human AE ultrasound-based prevalence (adjusted for age and sex) in five evaluated townships decreased significantly (P < 0.01) from 6.25% (200/3,198) during 2000-2002 to 3.67% (706/19,247) during 2015-2017. The 2016 prevalence of E. multilocularis metacestodes in small mammal intermediate hosts was not significantly different from the prevalence in 2008. The control programme was effective in reducing E. multilocularis infection in owned dogs and human AE prevalence, but did not significantly impact infection in wildlife intermediate hosts.

Identification of vulnerable populations and knowledge, attitude, and practice analysis of echinococcosis in Tibet Autonomous Region of China

Echinococcosis is one of the 17 neglected tropical diseases recognized by the World Health Organization and causes a huge global disease burden. The Tibet Autonomous Region (Tibet) of China is the most epidemic area of echinococcosis worldwide. Echinococcosis poses an enormous threat to local public health and economic development. Identifying vulnerable populations and analyzing people's knowledge, attitudes, and practices (KAP) with respect to echinococcosis is necessary to prevent and control echinococcosis. Based on reported cases and questionnaire responses, we first used a k-prototypes clustering algorithm to identify vulnerable populations according to human demographics (including gender, age, education level, and occupation). We then used a KAP analysis to evaluate the Tibetan people's understanding of echinococcosis. The results identified three types of vulnerable population. Vulnerable population I comprised illiterate middle-aged and older women engaged in agriculture and animal husbandry. Vulnerable population II comprised illiterate middle-aged male herdsmen. Vulnerable population III comprised young male farmers with a low education level. The KAP analysis indicated that the pass rate for all participants was 72.6%, 6.4%, 95.0%, and 75.8% for KAP, K, A, and P, respectively. The pass rates were significantly different among different age and gender groups. Based on these results, it is necessary to improve public health education and professional training, and to implement effective control and management measures targeting typical hosts of echinococcosis. This study provides a direct reference for the prevention and control of echinococcosis in Tibet.

Progress on the national echinococcosis control programme in China: analysis of humans and dogs population intervention during 2004-2014

Background

A national control program for echinococcosis has been in effect since 2005 in China. This program has applied a comprehensive strategy, and good control results have been achieved. Human echinococcosis prevalence rate decrease from 1.08% in 2004 to 0.24% in 2012. The objective of this study is focusing on assessment of the programme with two indices, including patient treatment and registered dogs deworming, in endemic areas of echincoccosis control over the period of 10 years (2004–2014) in China.

Methods

We established the database including demography at county and township levels with coverage for ten provinces and autonomous regions of China in this study. We using methods of epidemiological descriptive, instead the expectation-maximization for missing value filling for grouping available patients into those subjected to surgery and those receiving drug treatment after population screening and the dogs population after registered by deworming. We performed Microsoft Excel software and SPSS software on the results as percentages with the corresponding 95% confidence intervals (95% CIs). We also statistically analyzed the economics data on patient treatment and dogs deworming after the corresponding discount with annual bank interest rates (USD 1 = CNY 6.5, bank discount average changes of 2.3–3.3%).

Results

During 2004–2014, the grant total average rate of surgical patient (after surgical operation) treatment had increased with 32.4% and with 81.3% for medical treatment with albendazole. Meanwhile, it increased by 58.6% for the deworming of registered dog since 2007. The accumulated costs amounted to USD 27.03 million after discount for patients and registered dog treatment, which is 1/4 of the total accumulated financial inputs (USD 110.67 million from the Chinese Government). Since the implementation of the national program, it has increased 57 times with respect to the annual financial inputs (costs) and 368 times with respect to all accumulated financial inputs (costs).

Conclusions

This study showed that in endemic areas, patient diagnosis and management, dog management and treatment over this period helped reduce the parasite load to control the disease. More attention should be paid to controlling wild canines during the ongoing program period and sustainable follow-up evaluations are crucial for success and continued implementation of the national program.

Prevalence of human alveolar echinococcosis in China: a systematic review and meta-analysis

Background

Human alveolar echinococcosis (HAE), caused by the larvae of Echinococcus multilocularis, is a severe parasitic disease that is a major public health concern. New HAE cases in China account for 91% of the global HAE burden every year. Although there are a few studies and systematic reviews (SRs) on the prevalence of HAE in China, trends in the prevalence have not been estimated. This study aims to describe the overall variation in the trend of HAE prevalence in China, and provide evidence for preventive measures in the future.

Methods

Thirty-five eligible studies were retrieved from PubMed, Web of Science, EMBASE, CNKI, Wanfang Data, and VIP, and included in the SR and meta-analysis. An adjusted Agency for Healthcare Research and Quality checklist was used to evaluate study quality. The arcsine transformation was used to adjust the individual reported prevalence, and the pooled HAE prevalence was calculated. Heterogeneity was evaluated using the chi-square test and I² statistic. Forest plots were generated for the meta-analysis, and publication bias of the studies was assessed using the Egger’s test and funnel plots. We conducted subgroup analyses, sensitivity analyses, and meta-regression analyses to analyze the source of heterogeneity and factors potentially influencing the prevalence of HAE.

Results

The meta-analysis indicated that the pooled HAE prevalence in China was 0.96% (95% CI: 0.71 to 1.25%). Factors potentially influencing HAE prevalence were female sex (OR = 1.60, 95% CI: 1.35 to 1.91, P<0.01), being ≥30 years old (OR = 4.72, 95% CI: 2.29 to 9.75, P<0.01), and being farmers and/or herdsmen (OR = 2.54, 95% CI: 1.60 to 4.02, P<0.01). The results of the meta-regression analysis (R² = 38.11%, P < 0.01) indicated that HAE prevalence is on a downward trend.

Conclusions

HAE prevalence has decreased over time and maintained low levels after 2005 in China. This decline was influenced by the utilization of One Health strategies as intervention measures. Therefore, these One Health strategies should be used as references to formulate future programs for HAE control. More high-quality epidemiological investigations and surveillance programs should be conducted in order to improve HAE control in the future.

Contribution of NIPD-CTDR to the parasitic diseases control and elimination in China: Memory of the 70th anniversary for NIPD-CTDR

China has achieved a great success in control and elimination of key parasitic diseases. In 2007, the elimination of lymphatic filariasis was verified by WHO. The schistosomiasis incidence and snail-distributed areas have reduced to the lowest level in the history. The transmission and disease burden of echinococcosis have been contained largely, and the populations infected with soil-transmitted trematode and food-borne parasites have also shown a significantly declining trend. Because of rapid globalization and climate changes, however, many new challenges have arisen. In his paper, the 2020-2030 roadmaps towards the control and elimination of these key parasitic diseases are described. Moreover, China is actively implementing its global health strategy, and will be more and more engaged into global health affairs, in which a series of China-Africa health cooperation projects have been in planning with a wish of making a greater contribution to the SDGs.

Contribution to the echinococcosis control programme in China by NIPD-CTDR

As a zoonotic parasitosis caused by the parasitism of Echinococcus larvae, echinococcosis imposes serious disease and economic burdens on human beings and society, and is thus a global public health issue. Its complex life history, wide distribution, the combined influence of various epidemic factors, coupled with the unique natural environment, customs, and religious beliefs in endemic areas, pose a huge challenge to the national echinococcosis control programme in China. Accurate early detection and confirmation of diagnosis of echinococcosis, the use of effective drugs, real-time surveillance of the infection status of populations and various hosts, controlling the source of infection, and blocking the route of transmission are of enormous significance for control. In this paper, the work by NIPD-CTDR on the prevention and control of echinococcosis in China is reviewed, with a view to providing reference for the further promotion of the national echinococcosis control programme.

The effects of dog management on Echinococcus spp. prevalence in villages on the eastern Tibetan Plateau, China

BACKGROUND

The pastoral area of the eastern Tibetan Plateau is highly endemic for human echinococcosis. Domestic dogs are the main definitive host for the transmission of both Echinococcus granulosus (sensu lato) and E. multilocularis to humans. To control the infection risks, a national-level canine echinococcosis prevention and control programme has been implemented since 2015 in Shiqu County, Ganze Tibetan Autonomous Prefecture, Sichuan, China. The objective of this study was to evaluate its effect on Echinococcus spp. prevalence in dogs.

METHODS

We surveyed 69 households with 84 owned dogs, for dog fecal samples and dog keeping information in the villages of Rizha and Eduoma. A total of 105 dog fecal samples (75 from owned dogs and 30 unknown dog fecal samples) were collected between 2015-2017 to determine Echinococcus spp. prevalence using copro-PCR. Eight variables based on household surveys were included into a logistic regression model for significant risk factors to canine echinococcosis prevalence in dogs.

RESULTS

Between 2015-2017, the overall Echinococcus spp. copro-DNA prevalence decreased significantly in dogs from 51.2% (2015) to 20.0% (2017) in Rizha, and insignificantly from 11.5% (2016) to 4.3% (2017) in Eduoma. Echinococcus multilocularis was the most prevalent species continually copro-DNA detected during the entire study period, while E. granulosus was rare and not detected in 2017. Echinococcus shiquicus copro-DNA prevalence (a probable non-zoonotic wildlife species) was as high in dogs as that of E. multilocularis, although only detected in 2015 in Rizha. Unleashed dog feces were mainly collected in Rizha in 2015. Although 93.2% of owned dogs were leashed, and the monthly praziquantel dosing rate reached 97%, E. multilocularis infection could still be detected in 11.1% of owned dogs in 2017. Monthly deworming, leashing dogs 24 h per day, and the avoidance of dogs feeding on livestock viscera were significant measures to prevent canine echinococcosis infection in owned dogs.

CONCLUSIONS

Carrying out a canine echinococcosis prevention and control programme can significantly decrease Echinococcus spp. prevalence. The potential contact between leashed dogs and wild small mammals is still a risk for re-infection of owned dogs with E. multilocularis. This study shows that the long-term application of regular dog treatment with praziquantel in the vast and remote echinococcosis endemic areas of the eastern Tibetan Plateau can reduce transmission in dogs but remains a challenging intervention.

Epidemiological characteristics of hepatic echinococcosis, concurrent cerebral echinococcosis, and pulmonary echinococcosis in Ganzi County, Sichuan Province, China

Human echinococcosis has become a major public health problem in most parts of the world. The objective of this article was to study the demographics of patients with hepatic echinococcosis in Ganzi County to elucidate the main risk factors, as well as to report the concurrent prevalence of cerebral echinococcosis and pulmonary echinococcosis.We recruited 195 patients with hepatic echinococcosis from the Datongma area of Ganzi County from January 2018 to November 2018. The patients' demographics, living environments, supported medical resources, knowledge of echinococcosis prevention and control, and hygienic practices were investigated and analyzed. The prevalence of cerebral echinococcosis and pulmonary echinococcosis were also investigated.The data were analyzed to identify risk factors for human echinococcosis. Our analysis showed that the herding Tibetan population within the 20 to 60 age group, and females, in particular, were at the highest risk of human echinococcosis infection. Having stray dogs around habitations and intimate activities with dogs and livestock were also behavioral risk factors. People with poor health literacy and low educational qualifications had possible risks of infection. In terms of hygiene, not using tap water as the drinking water source and lack of medical staff were significantly correlated with echinococcosis prevalence. Four patients were diagnosed with cerebral echinococcosis. Among them, 1 patient had both cerebral echinococcosis and pulmonary echinococcosis.Possible high-risk factors for echinococcosis were being female, herding population, in the 20 to 60 age group, having stray dogs around habitations, having activities with dogs and livestock, having poor health literacy, having low educational qualifications, and not using tap water as a drinking water source. The detection rate for brain echinococcosis in patients with hepatic echinococcosis was high (2.05%). Effective preventive strategies should be implemented in epidemic areas. Head CT scans should be applied for early detection of cerebral echinococcosis to carry out the treatment.

Disease burden of echinococcosis in Tibetan communities-A significant public health issue in an underdeveloped region of western China

Echinococcosis is considered by the World Health Organization (WHO) to be a neglected zoonotic disease in the world. Some Tibetan communities were found to be highly endemic for echinococcosis just 20 years ago. Until recently, we were able to understand the overall disease burden of echinococcosis in Tibetan communities after prevalence data being available from nationwide investigations from 2012 to 2016. Data were abstracted from 9 publications regarding to echinococcosis prevalence between 2016-2018; from 10 data bases on echinococcosis prevalence for 151 Tibetan counties; and statistics of population, Gross Domestic Product (GDP) and health staff from 44 local statistic bureaus and government websites at provincial, prefecture and county level, and 2 books of provincial yearly statistics. These data were used to estimate the Disability Adjusted Life Years (DALYs) due to cystic echinococcosis (CE) and alveolar echinococcosis (AE). The distribution of DALYs was presented geographically and economically. The echinococcosis DALYs in the Tibetan communities were estimated to be 126,159 (95%UI 122,415-137,675) annually using the method recommended by WHO. AE DALYs were estimated to be 105,829 (95%UI 101,969-117,090), which were more than CE DALYs of 20,330 (95%UI 19,690-21,581). Echinococcosis affects people more in underdeveloped areas. There was a tendency that a higher echinococcosis DALYs were usually correlated a higher altitude. Health services are also poorly provided in terms of number of health staff of 5.05 per 1000 population in comparison with the national average of 5.8 per 1000 population. The data suggest that the echinococcosis burden in the center region of Qinghai-Tibet plateau is higher than that of other regions, and consequently more control and health services should be provided to the region.

Review of Cystic Echinococcosis in Nigeria: A Story of Neglect

Purpose

Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato is a widespread zoonotic disease of global concern. In Nigeria, the exact picture/status of CE is unclear, as most of the states are largely uninvestigated. Yet, as with every parasitic zoonosis, the first step towards planning a comprehensive management and control programme involves assessment of available national/regional prevalence data, host range, and risk factors at play in the transmission dynamics.

Methods

Published articles on echinococcosis were searched on PubMed and Africa Journal Online (AJOL) databases. Inclusion criteria were based on studies reporting prevalence of echinococcosis in animals and humans (including case reports) from 1970 to 2018.

Results

In this study, we evaluated and summarized cystic echinococcosis reports in Nigeria and found that post 1970–80s, studies on cystic echinococcosis have remained sparse regardless of the high prevalence recorded in the early years of CE investigation. In addition, information on the genetic population structure and the role of wildlife in CE transmission is still lacking.

Conclusions

This study appraises the prevalence and distribution of CE in Nigeria and identified areas where surveillance and control efforts should be focused and intensified.

Contamination of wastewater with Echinococcus multilocularis - possible implications for drinking water resources in the QTP China

Echinococcus multilocularis is a parasite that causes a dangerous zoonosis, alveolar echinococcosis (AE). Its presence in water sources, however, has scarcely been studied heretofore. Accordingly, 222 samples of different origin including wastewater from wastewater treatment plants (WWTPs) (n = 137), slaughterhouse (n = 49) as well as water from rivers (n = 26) and a cattle farm (n = 10) were collected from Xining City and a rural area in Qinghai-Tibet Plateau (QTP), an endemic area. Material obtained after processing of 10 L volume samples was subsequently analysed using three molecular detection methods: nested PCR, real-time PCR and LAMP. E. multilocularis DNA was found in 13 (5.85%) water samples; including 8 (5.8%), 3 (6%), 2 (20%) and 0 positive samples found in WWTPs, a slaughterhouse, a cattle farm and rivers, respectively. All three (LAMP, PCR, RT-PCR) molecular tools displayed high agreement and effectiveness in their ability of detecting the parasite's DNA in environmental material. This is the first investigation describing E. multilocularis detection in wastewater samples, using three sensitive molecular diagnostic tools. Results indicate the role of wastewater in dissemination of E. multilocularis and the risk of contamination of water sources.

Correlates of School Children's Handwashing: A Study in Tibetan Primary Schools

Hand hygiene, including handwashing by children, has been reported to contribute to the prevention of various infectious conditions. This study aims to explore the correlates of handwashing behavior among 1690 fourth to sixth grade primary school students in 19 Tibetan primary schools (Golog, Qinghai, China). The theory of reasoned action (TRA) was applied. Data was collected by questionnaire. Structural equation modeling (SEM) analysis showed that students' attitude (β = 0.22, 95% CI 0.13-0.31) and subjective norms in terms of compliance to teachers', parents' and peers' suggestions to wash hands (β = 0.09, 95% CI 0.01-0.18) were directly associated with students' handwashing behavior. Students' knowledge (β = 0.04, 95% CI 0.03-0.07) had an indirect association with handwashing behavior, mediated by students' attitudes and subjective norms. Subjective norms (β = 0.12, 95% CI 0.07-0.17) were also indirectly correlated with handwashing through students' attitudes. Therefore, our study supported the theory of reasoned action through our findings that students' attitude and knowledge, and also attitudes from teachers, parents and peers were correlated with student handwashing behavior. Students reported higher level of compliance to teachers than to their parents and classmates. Based on this information, we recommend teacher-involved participatory hygiene education to promote students' handwashing behaviors in areas at high risk for infectious diseases that can be prevented by handwashing.

First detection of Echinococcus multilocularis in environmental water sources in endemic areas using capsule filtration and molecular detection methods

Water is one of the possible transmission routes for water- and foodborne parasites to humans. Echinococcus multilocularis is a parasite, which causes alveolar echinococcosis (AE). Nevertheless, no environmental studies have been performed as yet to confirm the occurrence of E. multilocularis in water supplies. Accordingly, 105 water samples of 50 L volume were collected from surface waters (lakes, rivers, canals) and wells in the Warmia-Masuria Province (Echinococcus endemic area) and Pomerania Province (Echinococcus non-endemic area), Poland. The water was filtered and subsequently analysed with nested PCR and real-time PCR. E. multilocularis DNA was found in two (1.9%) samples, which originated from two lakes localised in the Warmia-Masuria Province. Sequencing of the positive samples confirmed that the PCR products were fragments of the E. multilocularis mitochondrial 12S rRNA gene. This is the first investigation describing E. multilocularis detection in environmental water samples, using molecular diagnostic tools. The results indicate that water could be considered as a potential source of E. multilocularis infections in humans and animals, in endemic areas.

The efficacy of an alternative mebendazole formulation in mice infected with Echinococcus multilocularis

This study was conducted to investigate the efficacy of a new formulation of MBZ oily suspension (MBZ-OS) in experimentally Echinococcus multilocularis-infected mice. MBZ-OS was prepared and administered to mice infected with E. multilocularis at 12.5 and 25 mg/kg for 14 consecutive days. Then, the cysts were collected, weighed and histologically examined. The results showed that the reduction rate of cyst weight induced by MBZ-OS at two doses was 95.23% and 92.67%, which was significantly higher than that of MBZ-1% tragacanth (positive control) at corresponding concentrations (87.41% and 69.47%), indicating that the treatment of alveolar echinococcosis at lower doses could be achieved by the use of MBZ-OS. This finding shows that MBZ-OS is also a promising formulation for alveolar echinococcosis as well as cystic echinococcosis and deserves to be investigated in clinical applications against echinococcosis.

Genetic characterization of Echinococcus isolates from various intermediate hosts in the Qinghai-Tibetan Plateau Area, China

This study examined Echinococcus spp. genotypes and genetic variants isolated from humans as well as domestic and wild animals from the Qinghai-Tibetan Plateau Area using the cox1 gene. All samples except the pika isolates were identified as the Echinococcus granulosus sensu stricto. Sixteen different haplotypes with considerable intraspecific variation were detected and characterized in mitochondrial cox1 sequences. The parsimonious network of cox1 haplotypes showed star-like features, and the neutrality indexes computed via Tajima's D and Fu's Fs tests showed high negative values in E. granulosus s. s., indicating deviations from neutrality; the Fst values were low among the populations, implying that the populations were not genetically differentiated. The pika isolates were identified as E. multilocularis and E. shiquicus. Only one haplotype was recognized in the pika isolates. E. granulosus s. s. was the predominant species found in animals and humans, followed by E. multilocularis and E. shiquicus, with high genetic diversity circulating among the animals and humans in this area. Further studies are needed to cover many sample collection sites and larger numbers of pathogen isolates, which may reveal abundant strains and/or other haplotypes in the hydatid cysts infecting human and animal populations of the QTPA, China.

Case Report: Rare Presentation of Multivisceral Echinococcosis

Cystic echinococcosis (CE) is a common, chronic, and endemic zoonotic disease usually localized in a single organ; multivisceral cases are rare, especially outside the liver or lung. Here, we describe an unusual case of a 43-year-old Tibetan man with echinococcosis of the infratemporal fossa, heart, liver, pancreas, abdomen, and pelvic cavity. He only presented with diminished vision of the left eye, especially when chewing. Computed tomography and magnetic resonance imaging revealed multivisceral CE. The patient underwent surgery for the excision of a cyst in the infratemporal fossa, as well as chemotherapy, and the diagnosis was confirmed by histopathological examination. The diagnosis, clinical features, treatment, and follow-up in this case are discussed. In areas with high echinococcosis prevalence, examination by full imaging is necessary for an accurate diagnosis, especially in cases of atypical localization. Chemotherapy for treatment, as well as prophylaxis against recurrence, can be effective when surgery is not possible.

Epidemiological survey of echinococcosis in Tibet Autonomous Region of China

BACKGROUND

The echinococcosis is prevalent in 10 provinces /autonomous region in western and northern China. Epidemiological survey of echinococcosis in China in 2012 showed the average prevalence of four counties in Tibet Autonomous Region (TAR) is 4.23%, much higher than the average prevalence in China (0.24%). It is important to understand the transmission risks and the prevalence of echinococcosis in human and animals in TAR.

METHODS

A stratified and proportionate sampling method was used to select samples in TAR. The selected residents were examined by B-ultrasonography diagnostic, and the faeces of dogs were tested for the canine coproantigen against Echinococcus spp. using enzyme-linked immunosorbent assay. The internal organs of slaughtered domestic animals were examined by visual examination and palpation. The awareness of the prevention and control of echinococcosis among of residents and students was investigated using questionnaire. All data were inputted using double entry in the Epi Info database, with error correction by double-entry comparison, the statistical analysis of all data was processed using SPSS 21.0, and the map was mapped using ArcGIS 10.1, the data was tested by Chi-square test and Cochran-Armitage trend test.

RESULTS

A total of 80 384 people, 7564 faeces of dogs, and 2103 internal organs of slaughtered domestic animals were examined. The prevalence of echinococcosis in humans in TAR was 1.66%, the positive rate in females (1.92%) was significantly higher than that in males (1.41%), (χ² = 30.31, P < 0.01), the positive rate of echinococcosis was positively associated with age (χ²_trend = 423.95, P < 0.01), and the occupational populations with high positive rates of echinococcosis were herdsmen (3.66%) and monks (3.48%). The average positive rate of Echinococcus coproantigen in TAR was 7.30%. The positive rate of echinococcosis in livestock for the whole region was 11.84%. The average awareness rate of echinococcosis across the region was 33.39%.

CONCLUSIONS

A high prevalence of echinococcosis is found across the TAR, representing a very serious concern to human health. Efforts should be made to develop an action plan for echinococcosis prevention and control as soon as possible, so as to control the endemic of echinococcosis and reduce the medical burden on the population.

Echinococcosis transmission on the Tibetan Plateau

Since the mid-1990s detailed studies and field investigations on the Tibetan Plateau have revealed human echinococcosis to be an under-reported major public health problem, particularly in the dominant pastoral communities in the eastern and central regions. Human prevalence surveys showed that cystic echinococcosis (CE, caused by Echinococcus granulosus) and alveolar echinococcosis (AE, caused by Echinococcus multilocularis) are co-endemic with higher burdens of each disease than other endemic world regions. Epidemiological investigations identified some major risk factors for human CE and AE including dog ownership, husbandry practices and landscape features. Dogs appear to be the major zoonotic reservoir for both E. granulosus and E. multilocularis, but the latter is also transmitted in complex wildlife cycles. Small mammal assemblages especially of vole and pika species thrive on the Plateau and contribute to patterns of E. multilocularis transmission which are influenced by landscape characteristics and anthropogenic factors. Tibetan foxes are a principal definitive host for both E. multilocularis and E. shiquicus. In 2006 a national echinococcosis control programme was initiated in Tibetan communities in northwest Sichuan Province and rolled out to all of western China by 2010, and included improved surveillance (and treatment access) of human disease and regular deworming of dogs with annual copro-testing. Control of echinococcosis in Tibetan pastoral communities poses a difficult challenge for delivery and sustainability.

Geographic distribution of echinococcosis in Tibetan region of Sichuan Province, China

BACKGROUND

Echinococcosis is a parasitic zoonosis caused by Echinococcus larvae parasitism causing high mortality. The Tibetan Region of Sichuan Province is a high prevalence area for echinococcosis in China. Understanding the geographic distribution pattern is necessary for precise control and prevention. In this study, a spatial analysis was conducted to explore the town-level epidemiology of echinococcosis in the Sichuan Tibetan Region and to provide guidance for formulating regional prevention and control strategies.

METHODS

The study was based on reported echinococcosis cases by the end of 2017, and each case was geo-coded at the town level. Spatial empirical Bayes smoothing and global spatial autocorrelation were used to detect the spatial distribution pattern. Spatial scan statistics were applied to examine local clusters.

RESULTS

The spatial distribution of echinococcosis in the Sichuan Tibetan Region was mapped at the town level in terms of the crude prevalence rate, excess hazard and spatial smoothed prevalence rate. The spatial distribution of echinococcosis was non-random and clustered with the significant global spatial autocorrelation (I = 0.7301, P = 0.001). Additionally, five significant spatial clusters were detected through the spatial scan statistic.

CONCLUSIONS

There was evidence for the existence of significant echinococcosis clusters in the Tibetan Region of Sichuan Province, China. The results of this study may assist local health departments with developing better prevention strategies and prompt more efficient public health interventions.

Geographical Environment Factors and Risk Mapping of Human Cystic Echinococcosis in Western China

The study aimed to reveal the risk factors and predict the prevalence of human cystic echinococcosis (CE) in Western China. To do this, we analyzed county-wide data relating to the prevalence of human CE in seven provinces of Western China, along with associated human, natural geographical environmental data. We then used spatial analysis and multiple regression analysis to investigate the correlation between the prevalence of human CE and associated environmental factors and to create a risk map of the disease in the seven provinces. Our analysis showed that grassland area ratio and Tibetan population ratio were independent variables positively correlated with the prevalence of human CE and that gross domestic product (GDP) and land surface temperature (LST; Spring) were negative independent variables. We also created a predictive risk map of human CE that revealed that the high-risk areas were mainly located in the south of Qinghai, the Northwest of Sichuan and most of the Tibet Autonomous Region. Knowledge of the spatial distribution and risk factors associated with human CE could help to prevent and control echinococcosis in China.

Rural and urban distribution of wild and domestic carnivore stools in the context of Echinococcus multilocularis environmental exposure

In zoonotic infections, the relationships between animals and humans lead to parasitic disease with severity that ranges from mild symptoms to life-threatening conditions. In cities and their surrounding areas, this statement is truer with the overcrowding of the protagonists of the parasites' life cycle. The present study aims to investigate the distribution of a parasite, Echinococcus multilocularis, which is the causative agent of alveolar echinococcosis, using copro-sampling in historically endemic rural settlements of the eastern part of France and in newly endemic areas including urban parks and settlements surrounding Paris. Based on 2741 morphologically identified and geolocalized copro-samples, the density of fox faeces was generally higher in the surrounding settlements, except for one rural area where the faeces were at larger density downtown in the winter. Fox faeces are rare but present in urban parks. Dog faeces are concentrated in the park entrances and in the centre of the settlements. DNA was extracted for 1530 samples that were collected and identified from fox, dog, cat, stone marten and badger carnivore hosts. Echinococcus multilocularis diagnosis and host faecal tests were performed using real-time PCR. We failed to detect the parasite in the surroundings of Paris, but the parasite was found in the foxes, dogs and cats in the rural settlements and their surroundings in the historically endemic area. A spatial structuring of the carnivore stool distribution was highlighted in the present study with high densities of carnivore stools among human occupied areas within some potentially high-risk locations.

Novel techniques and preliminary results of ex vivo liver resection and autotransplantation for end-stage hepatic alveolar echinococcosis: A study of 31 cases

Ex vivo liver resection combined with autotransplantation is a recently introduced approach to cure end-stage hepatic alveolar echinococcosis (HAE), which is considered unresectable by conventional radical resection due to echinococcal dissemination into the crucial intrahepatic conduits and adjacent structures. This article aims discuss the manipulation details and propose reasonable indications for this promising technique. All patients successfully underwent liver autotransplantation with no intraoperative mortality. The median weight of the autografts was 636 g (360-1300 g), the median operation time was 12.5 hours (9.4-19.5 hours), and the median anhepatic phase was 309 minutes (180- 460 minutes). Intraoperative blood loss averaged 1800 mL (1200-6000 mL). Postoperative complications occurred in 13 patients during hospitalization; 5 patients experienced postoperative complications classified as Clavien-Dindo grade III or higher, and 2 patients died of intraabdominal bleeding and acute cerebral hemorrhage, respectively. Twenty-nine patients were followed for a median of 14.0 months (3-42 months), and no HAE recurrence was detected. The technique requires neither an organ donor nor any postoperative immunosuppressant, and the success of the treatment relies on meticulous preoperative assessments and precise surgical manipulation.

Cystic echinococcosis in animals and humans of Maharashtra State, India

Echinococcosis/hydatidosis which is a neglected parasitic zoonosis in the developing country like India. The study was conducted during April, 2010 to March, 2017 to determine the prevalence among slaughtered food animals, dogs and human. The samples were collected from the various slaughterhouses situated in different regions of Maharashtra state. A total of 9464 cattle (male), 3661 buffalo, 47189 sheep, 33350 goats and 13579 pigs were scientifically examined during PM inspection at different slaughterhouses. The study revealed that the prevalence of disease in cattle (3.00%) was highest followed by buffalo (2.05%), pig (1.28%), sheep (0.09%) and goat (0.01%), by PM examination. The average estimated economic losses (direct and indirect) due to hydatidosis were Rs. 8,65,83,566 in cattle, Rs. 44,33,93,900 in buffalo, Rs. 7,24,50,615 in sheep, Rs. 1,88,29,359 in goat and Rs. 5,20,49,081 in pigs. Dog faecal samples analyzed and showed the prevalence of echinococcosis as 4.34% (19/438) by sedimentation method and positive samples were confirmed by PCR assay, whereas in high risk human, 11.09% sera samples were found to be positive for echinococcosis. However, based on data collection for seven years, 58 patients were found to be surgically operated for hydatid cyst removal. The results of the present study indicated that cystic echinococcosis/hydatidosis is prevalent in both human and animal population in study areas which attracts serious attention from veterinary and public health authority to reduce economic burden and in designing appropriate strategy for prevention and control of disease.

Field evaluation of an immunochromatographic test for diagnosis of cystic and alveolar echinococcosis

Background

The larval stages of the tapeworms Echinocoocus granulosus and Echinococcus multilocularis are the causative agents of human cystic echinococcosis (CE) and human alveolar echinococcosis (AE), respectively. Both CE and AE are chronic diseases characterised by long asymptomatic periods of many years. However, early diagnosis of the disease is important if treatment and management of echinococcosis patients are to be successful.

Methods

A previously developed rapid diagnostic test (RDT) for the differential detection of CE and AE was evaluated under field conditions with finger prick blood samples taken from 1502 people living in the Ganzi Tibetan Autonomous Prefecture, China, a region with a high prevalence for both forms of human echinococcosis. The results were compared with simultaneously obtained abdominal ultrasonographic scans of the individuals.

Results

Using the ultrasonography as the gold standard, sensitivity and specificity, and the diagnostic accuracy of the RDT were determined to be greater than 94% for both CE and AE. For CE cases, high detection rates (95.6–98.8%) were found with patients having active cysts while lower detection rates (40.0–68.8%) were obtained with patients having transient or inactive cysts. In contrast, detection rates in AE patients were independent of the lesion type. The positive likelihood ratio of the RDT for CE and AE was greater than 20 and thus fairly high, indicating that a patient with a positive test result has a high probability of having echinococcosis.

Conclusions

The results suggest that our previously developed RDT is suitable as a screening tool for the early detection of human echinococcosis in endemic areas.

Identification of emu-TegP11, an EF-hand domain-containing tegumental protein of Echinococcus multilocularis

Tegumental proteins (TegPs) are a group of proteins that coat on the surface of worms, mainly being involved in ion uptake and immune evasion. Echinococcus species have many TegPs, but none of them have been characterized and their role remains unclear. The genome-wide analysis revealed that there were at least 14 tegp genes (tegp1 - 14) in Echinococcus species, the majority of which were found to contain an EF-hand domain or a dynein light chain-like domain or both. Despite low identity, all TegP11 proteins from 25 flatworms were conserved in structure. Echinococcus multilocularis TegP11 (emu-TegP11) was verified to be secreted by extracellular vesicles and to be localized in different spatiotemporal patterns in protoscoleces. Moreover, emu-TegP11 was also shown to have weak or no Ca²⁺-binding capacity. In treated macrophages, emu-TegP11 interfered with the small RNA-induced silencing pathway via inducing ectopic expression of some key component genes. Additionally, emu-TegP11 remarkably promoted NO secretion possibly by upregulation of inos gene expression (p < 0.05). It was further shown that emu-TegP11 acted as a suppressor of inflammation, with il-12B and il-1β being significantly down-regulated (p < 0.01), and il-10 and il-4 being significantly upregulated (p < 0.05). The study demonstrates a regulatory role of emu-TegP11, likely acting as a immunomodulator to be involved in regulation of host immune system during Echinococcus infection.

Lasiopodomys fuscus as an important intermediate host for Echinococcus multilocularis: isolation and phylogenetic identification of the parasite

BACKGROUND

Echinococcus multilocularis causes alveolar echinococcosis (AE) and is widely prevalent in Qinghai Province, China, where a number of different species have been identified as hosts. However, limited information is available on the Qinghai vole (Lasiopodomys fuscus), which is hyper endemic to Qinghai Province and may represent a potential intermediate host of E. multilocularis. Thus, L. fuscus could contribute to the endemicity of AE in the area.

METHODS

Fifty Qinghai voles were captured from Jigzhi County in Qinghai Province for the clinical identification of E. multilocularis infection via anatomical examination. Hydatid fluid was collected from vesicles of the livers in suspected voles and subjected to a microscopic examination and PCR assay based on the barcoding gene of cox 1. PCR-amplified segments were sequenced for a phylogenetic analysis. E. multilocularis-infected Qinghai voles were morphologically identified and subjected to a phylogenetic analysis to confirm their identities.

RESULTS

Seventeen of the 50 Qinghai voles had E. multilocularis-infection-like vesicles in their livers. Eleven out of the 17 Qinghai voles presented E. multilocularis infection, which was detected by PCR and sequencing. The phylogenetic analysis showed that all 11 positive samples belonged to the E. multilocularis Asian genotype. A morphological identification and phylogenetic analysis of the E. multilocularis-infected Qinghai voles confirmed that all captured animals were L. fuscus.

CONCLUSIONS

L. fuscus can be infected with E. multilocularis and plays a potential role in the life cycle and epidemiology of E. multilocularis in the Qinghai-Tibetan Plateau of China.

A study to assess the awareness of risk factors of cystic echinococcosis in Turkey

OBJECTIVES

To determine the knowledge, attitudes, practices, and awareness for risk factors associated with cystic echinococcosis (CE) among animal breeders, nurses, nursing students, dietitians, food professionals and other public groups in Turkey. Methods: Questionnaire forms were prepared in compliance with the individuals' diversity, and a survey was created about agents, transmission modes, epidemiology, treatment, and risk factors for CE. The descriptive survey was performed between May 2015 and May 2016 by face-to-face communication. Data were collected from a total of 647 individuals, including 95 animal breeders, 92 nurses, 249 nursing students, 49 dietitians, 28 food professionals and 134 people from other public groups from Turkey. Survey data were evaluated in terms of percentages and means and analyzed by the Pearson's chi-square test and Mann-Whitney U test to determine the relationships between questionnaire answers and socio-demographic attributes, such as age, gender, educational level, and profession. Non-categorical variables were compared via Spearman's rho correlation analysis with statistical significance set at the 0.05 level. Results: We determined low awareness for vegetable washing, raw vegetables and offal consumption, informative courses, contact with dogs, and administration of antiparasitic drugs to dogs. Conclusion: The participants of this survey were found to be with insufficient knowledge regarding risk factors of CE. We advocate the implementation of training programs to improve public awareness on this important disease.

Spatiotemporal patterns and environmental drivers of human echinococcoses over a twenty-year period in Ningxia Hui Autonomous Region, China

BACKGROUND

Human cystic (CE) and alveolar (AE) echinococcoses are zoonotic parasitic diseases that can be influenced by environmental variability and change through effects on the parasites, animal intermediate and definitive hosts, and human populations. We aimed to assess and quantify the spatiotemporal patterns of human echinococcoses in Ningxia Hui Autonomous Region (NHAR), China between January 1994 and December 2013, and examine associations between these infections and indicators of environmental variability and change, including large-scale landscape regeneration undertaken by the Chinese authorities.

METHODS

Data on the number of human echinococcosis cases were obtained from a hospital-based retrospective survey conducted in NHAR for the period 1 January 1994 through 31 December 2013. High-resolution imagery from Landsat 4/5-TM and 8-OLI was used to create single date land cover maps. Meteorological data were also collected for the period January 1980 to December 2013 to derive time series of bioclimatic variables. A Bayesian spatio-temporal conditional autoregressive model was used to quantify the relationship between annual cases of CE and AE and environmental variables.

RESULTS

Annual CE incidence demonstrated a negative temporal trend and was positively associated with winter mean temperature at a 10-year lag. There was also a significant, nonlinear effect of annual mean temperature at 13-year lag. The findings also revealed a negative association between AE incidence with temporal moving averages of bareland/artificial surface coverage and annual mean temperature calculated for the period 11-15 years before diagnosis and winter mean temperature for the period 0-4 years. Unlike CE risk, the selected environmental covariates accounted for some of the spatial variation in the risk of AE.

CONCLUSIONS

The present study contributes towards efforts to understand the role of environmental factors in determining the spatial heterogeneity of human echinococcoses. The identification of areas with high incidence of CE and AE may assist in the development and refinement of interventions for these diseases, and enhanced environmental change risk assessment.