Transmission Of Echinococcosis Research Articles

Evaluation of protective immune responses induced by DNA vaccines encoding Echinococcus granulosus EgM123 protein in Beagle dogs.

Echinococcus granulosus, known as cystic echinococcosis, is a prominent zoonotic parasitic disease of significant global concern. The definitive hosts serves as the primary reservoir for the transmission of echinococcosis, as well as a main factor in the prevention and control of the disease. Unfortunately, there is currently no commercially available vaccine for these hosts. Nevertheless, DNA vaccines show potential as a feasible strategy for the control and management of parasitic diseases. In this study, the EgM123 antigen was selected for its well-documented immunogenic properties to develop a DNA vaccine aimed at combating E. granulosus infection in canines. The results showed a marked increase in IgG levels in the group vaccinated with pVAX1-EgM123 DNA compared to the PBS group. Additionally, the cytokines IL-1, IFN-γ, IL-4, and IL-6 were significantly upregulated in the pVAX1-EgM123 DNA vaccine group. Furthermore, in comparison to the PBS control group, the EgM123 DNA vaccine group exhibited a notable 87.85% reduction in worm burden and a 65.00% inhibition in segment development. These findings indicate that the pVAX1-EgM123 DNA vaccine shows promising immunogenicity, successfully eliciting a targeted immune response in canines. Moreover, it significantly diminishes the worm burden and hinders the progression of tapeworms in the pVAX1-EgM123 DNA vaccine group. These findings suggest that the pVAX1-EgM123 DNA vaccine holds promise as a potential candidate vaccine for combating E. granulosus infection in dogs.

Species Composition of a Small Mammal Community and Prevalence of Echinococcus spp. in the Alpine Pastoral Area of the Eastern Tibetan Plateau.

We aimed to investigate the species composition of a small mammal community and the prevalence of Echinococcus spp. in a typical endemic area of the Tibetan Plateau. One pika and five rodent species were identified based on the morphological characteristics of 1278 small mammal specimens collected during 2014-2019. Detection of Echinococcus DNA in tissue samples from small mammal specimens revealed that Ochotona curzoniae (pika, total prevalence: 6.02%, 26/432), Neodon fuscus (5.91%, 38/643), N. leucurus (2.50%, 3/120), and Alexandromys limnophilus (21.74%, 10/46) were infected by both E. multilocularis and E. shiquicus; Cricetulus longicaudatus (16.67%, 1/6) was infected by E. shiquicus; and no infection was detected in N. irene (0/15). Neodon fuscus and O. curzoniae were the two most abundant small mammal species. There was no significant difference in the prevalence of pika and the overall rodent species assemblage (6.26%, 53/846); however, the larger rodent populations suggested that more attention should be paid to their role in the transmission of echinococcosis in the wildlife reservoir, which has long been underestimated. Moreover, although DNA barcoding provides a more efficient method than traditional morphological methods for identifying large numbers of small mammal samples, commonly used barcodes failed to distinguish the three Neodon species in this study. The close genetic relationships between these species suggest the need to develop more powerful molecular taxonomic tools.

Dynamics of an Echinococcosis transmission model

Dynamics of an Echinococcosis transmission model

Surveillance of echinococcosis in Bayingolin Mongol Autonomous Prefecture, Xinjiang Uygur Autonomous Region from 2017 to 2022

To analyze the echinococcosis surveillance results in Bayingolin Mongol Autonomous Prefecture, Xinjiang Uygur Autonomous Region from 2017 to 2022, so as to provide insights into formulation of echinococcosis control measures in the prefecture. Villagers were randomly sampled using a multistage sampling method from class I and II echinococcosis endemic counties in Bayingolin Mongolian Autonomous Prefecture from 2017 to 2022 for detection of human echinococcosis, while all patients undergoing ultrasound examinations in medical institutions in class III endemic counties received active echinococcosis screening. In addition, livestock in centralized slaughterhouses or slaughtering sites were screened for echinococcosis using the palpation and necropsy method, and fresh domestic dog feces samples were collected from randomly selected dog owners in each administrative village for detection of Echinococcus copro-antigen in domestic dogs. The trends in detection of human and livestock echinococcosis, detection of newly diagnosed human echinococcosis cases and detection of Echinococcus coproantigen in domestic dogs were analyzed in Bayingolin Mongol Autonomous Prefecture from 2017 to 2022. The mean detection rate of human echinococcosis was 0.13% (540/407 803) in Bayingolin Mongol Autonomous Prefecture from 2017 to 2022, which appeared a tendency towards a decline over years (χ2trend = 1 217.21, P < 0.001), and the highest detection of newly diagnosed echinococcosis cases was seen in Hejing County (0.28%, 191/67 865). The detection of livestock echinococcosis appeared a tendency towards a decline over years from 2017 to 2022 (χ2trend = 147.02, P < 0.001), with the highest detection rate seen in Hejing County (3.44%, 86/2 500), and the detection of Echinococcus copro-antigen in domestic dogs appeared a tendency towards a decline over years from 2017 to 2022 (χ2trend = 302.46, P < 0.001), with the highest detection rate in Qiemo County (2.74%, 118/4 313). The detection of human and livestock echinococcosis and dog feces antigens Echinococcus copro-antigen in domestic dogs all appeared a tendency towards a decline in Bayingolin Mongol Autonomous Prefecture, Xinjiang Uygur Autonomous Region from 2017 to 2022; however, there is still a high echinococcosis transmission risk in local areas. Sustainable integrated echinococcosis control is required in Bayingolin Mongol Autonomous Prefecture.

Modeling and analysis of Cystic Echinococcosis epidemic model with health education

&lt;abstract&gt;&lt;p&gt;The prevention and control of the spread of Cystic Echinococcosis is an important public health issue. Health education has been supported by many governments because it can increase public awareness of echinococcosis, promote the development of personal hygiene habits, and subsequently reduce the transmission of echinococcosis. In this paper, a dynamic model of echinococcosis is used to integrate all aspects of health education. Theoretical analysis and numerical model fitting were used to quantitatively analysed by the impact of health education on the spread of echinococcosis. Theoretical findings indicate that the basic reproduction number is crucial in determining the prevalence of echinococcosis within a given geographical area. The parameters of the model were estimated and fitted by using data from the Ningxia Hui Autonomous Region in China, and the sensitivity of the basic reproduction number was analysed by using the partial rank correlation coefficient method. These findings illustrate that all aspects of health education demonstrate a negative correlation with the basic reproduction number, suggesting the effectiveness of health education in reducing the basic reproduction number and mitigating the transmission of echinococcosis, which is consistent with reality. Particularly, the basic reproduction number showed a strong negative correlation with the burial rate of infected livestock ($ b $) and the incidence of infected livestock viscera that is not fed to dogs ($ q $). This paper further analyzes the implementation plan for canine deworming rates and sheep immunity rates, as well as the transmission of infected hosts over time under different parameters $ b $ and $ q $. According to the findings, emphasizing the management of infected livestock in health education has the potential to significantly reduce the risk of echinococcosis transmission. This study will provide scientific support for the creation of higher quality health education initiatives.&lt;/p&gt;&lt;/abstract&gt;

Presence of Echinococcus granulosussensulato in the endoparasitic fauna of feral dogs in Tierra del Fuego, Argentina.

The feral dog population from Tierra del Fuego (Argentina) has affected provincial sheep production, and is responsible for the decrease of 43% of the sheep stock. In addition, feral dogs preys on the native fauna, especially the guanaco (Lama guanicoe), a species protected by law. Except for some data on the aforementioned impact, very little is known about feral dogs features in this region, such as distribution, abundance, diet, reproduction, health status, among others. Therefore, a descriptive observational study was carried out in the period 2018-2021 in Tierra del Fuego, with the aim to recognize the endoparasitic fauna of these dogs, with emphasis on Echinococcus granulosus sensu lato (s.l.). Feces samples were collected from 83 feral dogs captured in 15 farms, which were evaluated using flotation and sedimentation coproparasitological techniques, and optical microscope observation. These qualitative methods showed that 66.3% of the samples were positive. Nine parasitic forms were found, including eggs of taenids, Toxocara canis and Toxascaris leonina, and Sarcocystis spp. oocysts and Giardia spp. cysts. Samples with more than one parasitic form were also observed, among which the Taenia/Sarcocystis spp. association was the most frequent. For the diagnosis of canine echinococcosis, the detection of Echinococcus spp. antigens by Copro-ELISA and the molecular confirmation by Copro-PCR were performed. The Copro-ELISA test was positive in 10/80 (12.5%) of the samples processed, while 11 samples (13.8%) were positive by Copro-PCR. Their distribution showed that 9 (81.8%) corresponded to farms with sheep farming, and 2 (18.2%) with cattle farming. The presence of E. granulosus s.l. in feral dogs from Tierra del Fuego is the most relevant finding in this study. These results confirm that feral dogs have access to viscera infected with hydatid cysts. However, the intermediate hosts involved (sheep, cattle or guanacos) should be investigated. Its impact on the transmission of cystic echinococcosis in this region should be evaluated, as well as the adequacy of the disease prevention and control actions implemented in Tierra del Fuego should be considered. Finally, the existence of a wild cycle of the disease should be evaluated, in which feral dogs would act as a source of infection for other animals and humans.

Infection of sheep by Echinococcus multilocularis in Gansu, China: evidence from mitochondrial and nuclear DNA analysis

BackgroundIn the normal life cycle of the parasite (Echinococcus multilocularis) that causes alveolar echinococcosis, domestic and wild carnivores act as definitive hosts, and rodents act as intermediate hosts. The presented study contributes to the research on the distribution and transmission pattern of E. multilocularis in China having identified sheep as an unusual intermediate host taking part in the domestic transmission of alveolar echinococcosis in Gansu Province, China.MethodsFrom 2020 to 2021, nine whitish different cyst-like were collected from the liver of sheep in Gansu Province for examination. A near complete mitochondrial (mt) genome and selected nuclear genes were amplified from the cyst-like lesion for identification. To confirm the status of the specimen, comparative analysis with reference sequences, phylogenetic analysis, and network analysis were performed.ResultsThe isolates displayed ≥ 98.87% similarity to E. multilocularis NADH dehydrogenase sub-unit 1 (nad1) (894 bp) reference sequences deposited in GenBank. Furthermore, amplification of the nad4 and nad2 genes also confirmed all nine samples as E. multilocularis with > 99.30% similarity. Additionally, three nuclear genes, pepck (1545 bp), elp-exons VII and VIII (566 bp), and elp-exon IX (256 bp), were successfully amplified and sequenced for one of the isolates with 98.42% similarity, confirming the isolates were correctly identified as E. multilocularis. Network analysis also correctly placed the isolates with other E. multilocularis.ConclusionsAs a result of the discovery of E. multilocularis in an unusual intermediate host, which is considered to have the highest zoonotic potential, the result clearly demonstrated the necessity for expanded surveillance in the area.Graphical

Sliding motion control of Echinococcosis transmission dynamics model

Hydatid disease is a chronic zoonotic parasitic disease caused by Echinococcus. This paper proposes and analyzes a mathematical model of Echinococcosis disease system with a piecewise control function concerning threshold policy. The model is represented the control measures being triggered once the total number of infected hosts and human reaches the tolerant level. Model solutions are able to approach either one real equilibrium or the pseudo-equilibrium, depending on the tolerant threshold. Our results suggest that in order to diminish the outbreak of Echinococcosis or lead the number of infecteds to an expected level, it requires not only adequate hospital resources and certain government interventions, but also a good threshold policy.

Stability Analysis and Optimal Control Strategies of an Echinococcosis Transmission Model

This paper presents a deterministic compartmental model for echinococcosis transmission dynamics. The basic reproduction number of the model determines the existence and stability of the disease-free and disease-endemic equilibrium points. We further formulate the optimal control problem and obtain the necessary conditions to minimize the number of infected individuals and the associated costs. Numerical simulations show that optimal control strategies can significantly reduce the number of infected individuals to lower levels. Environmental disinfection may be essential for the elimination of infections. The results of this study will be beneficial for the prevention and control of echinococcosis in the Ganzi Tibetan Autonomous Prefecture and other areas of China.

Progress of researches on infection with two species of Echinococcus causing human diseases in animal hosts and influencing factors

Echinococcosis is a serious zoonotic parasitic disease caused by infections with larval Echinococcus. The life cycle of Echinococcus involves a variety of animal hosts, including hoofed animals and rodents as intermediate hosts and carnivores as definitive hosts. The transmission of human echinococcosis is closely associated with the life cycle of E. granulosus and E. multilocularis among animal hosts in nature. This review summarizes the recent advances in the prevalence and influencing factors of E. granulosus and E. multilocularis infections in animal hosts, so as to provide insights into precision control of echinococcosis.

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

ABSTRACT.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.

Investigation on population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province

To investigate the population dynamics and Echinococcus infections in small rodents around human settlement in Yushu City, Qinghai Province. Rodents were captured using the mouse trap method in pastures from Batang Township and Longbao Township of Yushu City, Qinghai Province on May, August and October, 2018. The body weight and snout-vent length of all captured rodents were measured, and the species was identified according to the rodent morphology. Genomic DNA was extracted from rodent liver specimens and lesion specimens, and the mitochondrial cox1 gene of Echinococcus was amplified using PCR assay for identification of parasite species. In addition, the tissue specimens positive for PCR assay were sampled for pathological examinations. The prevalence of Echinococcus infections was estimated in rodents, and a phylogenetic tree was created based on Echinococcus cox1 gene sequences. A total of 285 small rodents were captured, including 143 Ochotona curzoniae (50.2%), 141 Lasiopodomys fuscus (49.5%), and 1 Neodon irene (0.3%), and there was a remarkable variation in habitat selection among these three rodent species. The number of L. fuscus correlated positively with vegetation coverage (r = 0.350, P = 0.264), with the greatest number seen in August, and the number of O. curzoniae negatively with vegetation coverage (r = -0.371, P = 0.235), with the highest number seen in August and the lowest number in May. The female/male ratios of O. curzoniae and voles were 1:0.96 and 0.82:1, respectively. The body weight (r = 0.519, P < 0.01) and snout-vent length (r = 0.578, P < 0.01) of O. curzoniae showed a tendency towards a rise with month, while the body weight (r = -0.401, P < 0.01) and snout-vent length (r = -0.570, P < 0.01) of voles presented a tendency towards a reduction with month. No Echinococcus infection was detected in voles, while 2.1% prevalence of E. shiquicus infection was seen in O. curzoniae. Phylogenetic analysis revealed consistent sequences of cox1 gene from E. shiquicus in Yushu City of Qinghai Province and Shiqu County, Ganzi Tibetan Autonomous Prefecture of Sichuan Province. The small rodents around the human settlement in Yushu City of Qinghai Province mainly include O. curzoniae and L. fuscus, with the greatest numbers seen in May and August, respectively. Following the concerted efforts for echinococcosis control, the prevalence of Echinococcus infections is low in small rodents around the human settlement in Yushu City; however, there is still a risk of echinococcosis transmission.

A dynamical model of echinococcosis with optimal control and cost-effectiveness

A dynamical model of echinococcosis transmission with optimal control strategies is first presented. The basic reproduction number of the model is determined and employed to study the global stability of the disease-free and endemic equilibrium points. The optimal control problem is formulated and solved analytically. Numerical simulations show that optimal control strategies could effectively reduce the transmission of echinococcosis. The cost-effectiveness analysis suggests that a combination of health education, anthelmintic treatment, and home slaughter inspection could provide the best cost-effective strategy to control the transmission of echinococcosis. Furthermore, it finds that anthelmintic treatment and environmental disinfection may shorten the time of eliminating the disease. The results may be helpful for prevention and control of echinococcosis in Ganzi Tibetan Autonomous Prefecture, China and other areas of echinococcosis.

A local case with alveolar echinococcosis in Nanzhang County, Hubei Province

The diagnosis and treatment of a local case with alveolar echinococcosis was presented. Based on clinical data and epidemiological surveys, this is a rare, local case with alveolar echinococcosis in Nanzhang County, suggesting the possibility of local transmission of echinococcosis. The prevention, control and surveillance of echinococcosis requires to be reinforced in nonendemic areas.

A remote management system for control and surveillance of echinococcosis: design and implementation based on internet of things

BackgroundAs a neglected cross-species parasitic disease transmitted between canines and livestock, echinococcosis remains a global public health concern with a heavy disease burden. In China, especially in the epidemic pastoral communities on the Qinghai-Tibet Plateau, the harsh climate, low socio-economic status, poor overall hygiene, and remote and insufficient access to all owned dogs exacerbate the difficulty in implementing the ambitious control programme for echinococcosis. We aimed to design and implement a remote management system (RMS) based on internet of things (IoT) for control and surveillance of echinococcosis by combining deworming devices to realise long-distance smart deworming control, smooth statistical analysis and result display. New methods and tools are urgently needed to increase the deworming coverage and frequency, promote real-time scientific surveillance, and prevent transmission of echinococcosis in remoted transmission areas.MethodsFrom 2016 to 2019, we had cooperated and developed the smart collar and smart feeder with the Central Research Institute of Shanghai Electric Group Co., Ltd. (Shanghai, China) and Shenzhen Jizhi Future Technology Co., Ltd. (Shenzhen, China). From September 2019 to March 2020, We had proposed the RMS based on IoT as a novel tool to control smart deworming devices to deliver efficient praziquantel (PZQ) baits to dogs regularly and automatically and also as a smart digital management platform to monitor, analyse, and display the epidemic trends of echinococcosis dynamically, in real time in Hezuo City, Gannan Tibetan Autonomous Prefecture, Gansu Province, China. Starting from January 2018, The RMS has been maintained and upgraded by Shanghai Yier Information Technology Co., Ltd (Shanghai, China). The database was based on MySQL tools and the Chi-square test was used to probe the difference and changes of variables in different groups.ResultsThe smart collars are fully capable of anti-collision, waterproof, and cold-proof performance, and the battery’s energy is sufficient, the anti-collision rate, water-proof rate, cold-proof rate and voltage normal rate is 99.6% (521/523), 100.0% (523/523), 100.0% (523/523) and 100.0% (523/523), respectively. The RMS can accurately analyse the monitoring data and parameters including positive rates of canine faeces, and the prevalence of echinococcosis in the general population livestock, and children. The data of dogs deworming and surveillance for echinococcosis is able to be controlled using RMS and has expanded gradually in townships to the whole Hezuo region. The automatic delivering PZQ rate, collar positioning rate, deliver PZQ reminding rate, and fault report rate is 91.1% (1914/2102), 92.1% (13 580/14 745), 92.1% (1936/2102) and 84.7% (1287/1519), respectively. After using the RMS from 2019, the missing rate of monitoring data decreased from 32.1% (9/28) to 0 (0/16). A total of 48 administrators (3, 3, 8, 11, 23 at the provincial, municipal, county, township, village levels, respectively) participated in the questionnaire survey, with 93.8% of its overall satisfaction rate.ConclusionsThe existing difficulties and challenges in the way of prevention and control for echinococcosis can partially be resolved using the innovative, IoT-based technologies and tools. The proposed RMS advance the upgrade of existing manual prevention and control models for echinococcosis, especially in the current ongoing COVID-19 pandemic, as social distance and community blockade continue.Graphic abstract

Dynamic modeling and optimal control of cystic echinococcosis

BackgroundCystic echinococcosis is one of the most severe helminth zoonosis with a drastic impact on human health and livestock industry. Investigating optimal control strategy and assessing the crucial factors are essential for developing countermeasures to mitigate this disease.MethodsTwo compartment models were formulated to study the dynamics of cystic echinococcosis transmission, to evaluate the effectiveness of various control measures, and to find the optimal control strategy. Sensitive analyses were conducted by obtaining PRCCs and contour plot was used to evaluate the effect of key parameters on the basic reproduction number. Based on forward–backward sweep method, numerical simulations were employed to investigate effects of key factors on the transmission of cystic echinococcosis and to obtain the optimal control strategy.ResultsThe food resources of stray dog and invalid sheep vaccination rate, which are always neglected, were significant to the transmission and control of cystic echinococcosis. Numerical simulations suggest that, the implementation of optimal control strategy can significantly reduce the infections. Improving the cost of health education and domestic dog deworming could not decrease human infections.ConclusionsOur study showed that only a long-term use of the optimal control measures can eliminate the disease. Meanwhile, during the intervention, sheep vaccination and stray dogs disposing should be emphasized ahead of domestic dogs deworming to minimize the control cost. Simultaneously reducing other wild intermediate hosts and strengthening the sheep vaccination as well as disposing the stray dogs would be most effective.

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

BackgroundEchinococcosis 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.MethodsData 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.ResultsIn 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).ConclusionsIncreased 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.

Evaluation of the effect of the integrated echinococcosis control program in Ningxia Hui Autonomous Region from 2011 to 2018

To evaluate the effect of the integrated echinococcosis control program in Ningxia Hui Autonomous Region from 2011 to 2018. A package of integrated interventions were employed for echinococcosis control in 22 counties (districts) of Ningxia Hui Autonomous Region from 2011 to 2018, including screening of human echinococcosis, treatment of echinococcosis patients, deworming of domestic dogs and monitoring of infections, surveillance of echinococcosis in bovines and sheep, health education. The detection of human echinococcosis, seroprevalence of anti-Echinococcus antibody in children at ages of 6 to 12 years, the Echinococcus coproantigen-positive rate in domestic dogs, prevalence of echinococcosis in bovines and sheep, and the awareness of echinococcosis control knowledge were investigated and compared during the period between 2011 and 2018. The detection of human echinococcosis appeared a decline tendency in Ningxia Hui Autonomous Region over years during the period from 2011 to 2018 (χ2trend = 82.22, P < 0.05), and the prevalence of human echinococcosis decreased from 0.31% in 2011 to 0.15% in 2018. The seroprevalence of anti-Echinococcus antibody appeared a decline tendency in children at ages of 6 to 12 years over years (χ2trend = 439.64, P < 0.01), and the prevalence of anti-Echinococcus antibody decreased from 6.12% in 2011 to 0.67% in 2018. The Echinococcus coproantigen-positive rate appeared a decline tendency in domestic dogs over years (χ2trend = 260.33, P < 0.05), and the prevalence of anti-Echinococcus antibody decreased from 7.11% in 2011 to 0.75% in 2018. The prevalence of bovine and sheep echinococcosis reduced from 3.26% and 5.08% in 2011 to 1.35% and 0.76% in 2018, and Echinococcus predominantly parasitized in bovine (92.00%) and sheep (93.94%) livers. A total of 63 stool samples were collected from red fox, wolf and badger in Xiji and Haiyuan counties of Ningxia Hui Autonomous Region in 2013 and 2014, with no Echinococcus coproantigen-positives detected, and 107 domestic cats and 3 domestic dogs were dissected in these two counties, with no Echinococcus found. A total of 6 046 wild mice were dissected in Xiji County, Yuanzhou District and Haiyuan County of Ningxia Hui Autonomous Region from 2016 to 2019, and the prevalence of E. multilocularis was 0.31%. The awareness of echinococcosis control knowledge appeared an increasing tendency in Ningxia Hui Autonomous Region over years from 2011 to 2018 (χ2trend = 3 367.97, P < 0.01), and the awareness increased from 21.83% in 2011 to 72.24% in 2018. The integrated echinococcosis control program achieves a remarkable effect in Ningxia Hui Autonomous Region, and the transmission of echinococcosis has been preliminarily controlled. However, the echinococcosis transmission risk remains in few regions, and the integrated echinococcosis control program remains to be reinforced.

The threshold dynamics of a discrete-time echinococcosis transmission model

<p style='text-indent:20px;'>In this paper, based on the transmission mechanism of echinococcosis in China, we propose a discrete-time dynamical model for the transmission of echinococcosis. The research results indicate that transmission dynamics of this discrete-time model are determined by basic reproduction number <inline-formula><tex-math id="M1">\begin{document}$ R_{0} $\end{document}</tex-math></inline-formula>. It is shown that when <inline-formula><tex-math id="M2">\begin{document}$ R_{0}\leq1 $\end{document}</tex-math></inline-formula> then the disease-free equilibrium is globally asymptotically stable and when <inline-formula><tex-math id="M3">\begin{document}$ R_{0}&gt;1 $\end{document}</tex-math></inline-formula> then the model is permanent while the disease-free equilibrium is unstable. Finally, on the basis of the theoretical results established in this paper, we come up with some specific measures to control the transmission of echinococcosis.

Mathematical Modeling of Echinococcosis in Humans, Dogs, and Sheep

In this paper, a model for the transmission dynamics of cystic echinococcosis in the dog, sheep, and human populations is developed and analyzed. We first model and analyze the predator-prey interaction model in these populations; then, we propose a mathematical model of the transmission dynamics of cystic echinococcosis. We calculate the basic reproduction number R 0 and prove that the disease-free equilibrium is globally asymptotically stable, and hence, the disease dies out if R 0 &gt; 1 . We further show that the endemic equilibrium is globally asymptotically stable, and hence, the disease persists if R 0 &lt; 1 . Numerical simulations are performed to illustrate our analytic results. We give sensitivity analysis of the key parameters and give strategies that are helpful to control the transmission of cystic echinococcosis, from which the most sensitive parameter is the transmission rate of Echinococcus’ eggs from the environment to sheep ( β es ). Thus, the effective controlling strategies are associated with this parameter.