Control of Cystic Echinococcosis in Iran: Where Do We Stand?

Harmine derivative H-2-168 induces the death of Echinococcus granulosus by regulating mitochondrial fusion and fission

CONTEXT

H-2-168 has pharmacological effects similar to those of harmine, with less toxicity. The health of cells and organisms depends on a delicate balance between mitochondrial fusion and fission.

OBJECTIVE

This study investigated the roles of H-2-168 and mitochondrial fusion and fission in Echinococcus granulosus.

MATERIALS AND METHODS

Notably, E. granulosus were isolated from fresh sheep livers, and then treated with H-2-168 (25 μg/mL), mitochondrial division inhibitor 1 (Mdivi-1, 25 μg/mL) or the combination of H-2-168:Mdivi-1 (25 μg/mL:12.5 μg/mL). After 24 h of culture, the indices related to E. granulosus were measured. Additionally, Drp1 was knocked down to explore its effects on E. granulosus growth.

RESULTS

The EC50 values of H-2-168, Mdivi-1 and H-2-168:Mdivi-1 against E. granulosus were 44.171, 117.882 and 32.924 μg/mL, respectively. Compared with H-2-168 or Mdivi-1, the combination of H-2-168 and Mdivi-1 showed better inhibitory effects on E. granulosus viability, as well as increased levels of ROS and LDH, decreased ATP levels, inhibited mitochondrial activity and reduced mitochondrial membrane potential (p < 0.05), with the upregulation of Caspase-3, Cyt-c, Drp1, Fis1 and downregulation of Bcl-2, Mfn2 and OPA1. Additionally, Drp1 knockdown was successfully performed in E. granulosus, which significantly inhibited E. granulosus viability (p < 0.05) and further downregulated Mfn2 expression induced by H-2-168.

DISCUSSION AND CONCLUSION

Drp1 is closely associated with mitochondrial fusion and fission, and H-2-168 may promote E. granulosus death through disrupting the balance between mitochondrial fusion and fission.

Genetic profile of Echinococcus granulosus isolated from the livestock and human in northwest Iran

Cystic echinococcosis (CE) is categorized among the highly important zoonoses, occurring in many regions of the world. Iran is a significant endemic focus of CE, where it poses substantial economic and public health challenges to local communities. The current study aimed to identify the genotype and species profile of E. granulosus among the patients and livestock in Qazvin, Iran. A total of 80 hydatid cyst samples were collected from humans as well as farm animals including sheep, cattle, and goats. DNA extraction and PCR-sequencing were conducted targeting the mitochondrial CO1 and ND1 regions. Molecular phylogeny and haplotype network analysis was calculated for the isolates. Out of 79 evaluated samples, 97.5% belonged to G1 genotype and 2.5% to G3 genotype. The G1 genotype was present in all infected participants. Also, the study showed the G1 to be the most common genotype of E. granulosus among both the humans and the animals examined. Furthermore, our results emphasize on the importance of the sheep-dog cycle in public health.

A ten-year evaluation of central nervous system cystic echinococcosis in a highly endemic area of Iran: Molecular epidemiology and clinicopathological characteristics

Cystic echinococcosis can involve various organs in humans with the brain and spine being particularly vulnerable. This research aimed to study clinicopathological features and molecular analysis of the central nervous system (CNS) echinococcosis cases in a central hospital for hydatid cyst surgery in northeastern Iran. CNS echinococcosis cases from surgically managed human CE cases at Ghaem hospital in northeastern Iran were analyzed from 2012 to 2022. Demographic and clinicopathological data were collected for CNS echinococcosis cases and formalin-fixed paraffin-embedded (FFPE) blocks were used for molecular analysis. The total prevalence of CNS echinococcosis cases was 1. 8 %. Most of the CE cases were reported in women (64. 7 %) and from rural areas (58. 8 %). The highest number of cases (41. 2 %) were aged ≤18 years, with majority being ranchers (47. 1 %). Thirteen cases (76.5 %) were found to have cysts in their brain, particularly in the supratentorial site. Headache was the most commonly reported sign in cases (9/13, 69.2 %). Infiltration of eosinophils, polymorphic inflammatory cells, and giant cells, gliosis, and foreign body granulomatous reaction, along with mild infiltration of mononuclear cells showing degeneration and necrotic foci in the brain infections. Spine infections included bone cartilage, ligaments, and hydatid cyst wall fragments. PCR analysis conducted on 17 samples revealed the presence of 13 isolates of E. granulosus sensu lato. Among these, 11 were classified within the E. granulosus sensu stricto (G1 and/or G3) complex, while 2 isolates were identified as belonging to the E. canadensis G6/G7. Cerebrospinal infection is a significant aspect of CE cases in northcentral Iran, with a higher prevalence among women and in rural areas. Children were the most affected age group, with the E. granulosus s.s. genotypes being the most common.

A scoping review on control strategies for Echinococcus granulosus sensu lato

Background

Cystic echinococcosis (CE) is a widespread neglected zoonotic disease caused by Echinococcus granulosus sensu lato (EG) with a global burden of control in the billions of dollars. E. granulosus' life cycle involves definitive, intermediate, and humans as dead-end hosts. Echinococcosis control programs use strategies that focus on any of these hosts. We aimed to provide a comprehensive and up-to-date overview of the EG control interventions worldwide.

Methods

We conducted a scoping review by mapping all studies on interventions for EG control following the Arksey and O'Malley Framework. We screened identified articles, and charted and coded selected papers. We classified the data based on target host, type of study, and control mechanism. We described the efficacy or safety outcomes, and the associated barriers/facilitators for the intervention. Critical appraisal was conducted.

Results

From 7,853 screened studies, we analyzed 45: seven centered on human interventions, 21 on animals, and 17 on both. Studies on humans focused on educational strategies and human CE monitoring. The studies on animals were field trials and most were based on Praziquantel (PZQ) for dogs. Studies focused on both animals and humans had, in general, more participants, lasted longer, and covered larger geographical areas. Overall, the quality of studies was moderate to low.

Conclusions

Available evidence suggests that long-term interventions aimed at both animals and humans can achieve significant reduction in EG transmission, particularly when PZQ treatment for dogs is included. Higher quality evidence, standardization of methodologies, and better reporting on post-intervention outcomes are necessary for drawing stronger conclusions. Further evidence is needed to assess the sustainability and scalability of control measures. Nonetheless, an integrative One Health approach is essential for overcoming the multiple challenges associated with sustaining long-term control efforts for Echinococcosis.

Funding

RCN was supported by the National Institute of Allergy and Infectious Diseases (grant nos. K01AI139284 and R01AI168291). LOC, JAB, and RCN were supported by the Fogarty International Center (grant no. D43TW012741). TAD, CG and JAB were supported by the Fogarty International Center (grant no. D43TW001140).

Author Summary

Cystic echinococcosis is a disease caused by the parasite Echinococcus granulosus sensu lato . This parasite can be found in specific areas on all continents, especially in poverty-stricken regions, increasing costs and losses. Some countries have achieved control, but most are still in the process. Our review provides a clear picture of what we currently know about these control strategies and points out where more research is needed. It highlights how the findings can improve control practices by showing what works best and address practical challenges. The review also identifies gaps in current knowledge and suggests that comparing different control methods could help find the most effective and cost-efficient solutions. Key areas needing attention include increasing support and funding for echinococcosis, as the disease is often overlooked. More research from different fields is needed to better understand and manage the disease's complexities. Better and ongoing surveillance is crucial for maintaining effective control strategies. Finally, comprehensive reviews that bring together findings from different studies are needed to identify what works best and improve and combine future control efforts.

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.

Understanding the research and practical needs required to control toxocariasis in Iran

Human toxocariasis (HT) is a widespread zoonotic infection globally, notably prevalent in tropical areas. Enhancing our understanding of toxocariasis can lead to increased attention towards the socioeconomic impact and control of this neglected zoonosis. We conducted a comprehensive review of all available articles and official documents on toxocariasis in Iran to identify research gaps and critical needs for its control. This review highlights that despite numerous studies exploring various aspects of toxocariasis in definitive and paratenic hosts, as well as humans and environmental contamination, significant data deficiencies and gaps persist across different regions in the country. These gaps involve investigating the worm burden and reinfection rates in definitive hosts, developing more sensitive methods to detect and differentiate of Toxocara species, and understanding the behavior of definitive host animals. Additionally, identifying potential paratenic hosts for HT and exploring the organ-specific affinity and survival duration of Toxocara larvae within these hosts are essential areas for exploration. It's also imperative to comprehend the sylvatic and domestic cycles of the parasite in paratenic hosts. Furthermore, assessing egg density in the environment, exploring potential new sources such as water, and identifying regions with optimal climatic conditions for the survival and development of Toxocara eggs are crucial for the formulation of effective prevention and control strategies. Identifying at-risk groups, developing early diagnosis techniques, employing imaging methods, and identifying long-term complications in humans are also crucial. Community health organizations should prioritize health education for the public and professionals. Furthermore, accurately estimating definitive host populations, monitoring and preventing their movements in public places, implementing regular deworming practices for pets and stray hosts, and recognizing the infection's significance as a health priority are critical. This comprehensive understanding advocates for a holistic "one health" approach to control of HT.

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.

Iranian Hydatid Disease Registry: Establishment and Implementation of a Neglected Tropical Disease Registry

BACKGROUND

Cystic echinococcosis (CE) or hydatid disease is a global public health concern which imposes considerable economic costs on the communities in endemic regions. CE surveillance data are not adequately reliable. The present study reports the development and outcomes of a CE registry in Iran.

METHODS

Hydatid Registry (HydatidReg) was initially established as a single-center registry in 2014 after the ethical approval of KMU. Following a call from MoHME to promote registry of different diseases and health outcomes, a call for participation was announced and all the Iranian Universities of Medical Sciences were requested to contribute to the registry. Subsequently, a nation-wide registry of hydatid disease was established in 2016. With a global perspective, HydatidReg joined the European Register of Cystic Echinococcosis (ERCE). A data collection form based on minimum dataset was designed and standard operating procedures (SOPs) were prepared to ensure standardized patient enrolment in the registry. A biobank system with two-dimensional barcoding was established along with HydatidReg for management and organization of biological specimens.

RESULTS

As of March 2021, a total of 690 patients were enrolled in the registry. HydatidReg registered 362 (17.3%) out of the total 2097 patients enrolled in ERCE. Quality control (QC) of the data demonstrated 91.2% completeness and 80% timeliness. In the biobank, 322 biological specimens from 184 CE patients have been deposited including 70 blood, 96 sera and 156 parasite materials.

CONCLUSION

High-quality data in the HydatidReg registry provided opportunities for health professionals to improve quality of care and organize meaningful research.

Expression profiling of exosomal miRNAs derived from different stages of infection in mice infected with Echinococcus granulosus protoscoleces using high-throughput sequencing

Echinococcosis is a worldwide zoonosis. The mechanism of the establishment, growth, and persistence of parasites in the host has not been fully understood. Exosomes are found to be a way of information exchange between parasites and hosts. They exist in various body fluids widely. There are few studies on host-derived exosomes and their miRNA expression profiles at different infection time points. In this study, BALB/c mice were intraperitoneally infected with protricercariae. Exosomes were extracted from plasma (0, 3, 9, and 20 weeks post infection), and the expression profiles of exosome miRNA in the peripheral blood of mice were determined using RNA-sequencing. Compared to the 0 week groups, 24, 35, and 22 differentially expressed miRNAs were detected in infected mouse at the three infection stages, respectively. The results showed that there were significant differences in the miRNAs of exosomes at different infection time points. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to annotate the different miRNAs. The results showed that the biological pathways of parasites changed significantly at different stages of infection, with many significant and abundant pathways involved in cell differentiation, inflammation, and immune response, such as MAPK signaling pathway, Th17 cell differentiation, Wnt signaling pathway, FoxO signaling pathway, Notch signaling pathway, etc. These results suggest that miRNA may be an important regulator of interactions between Echinococcus granulosus and host. The data provided here provide valuable information to increase understanding of the regulatory function of microRNAs in the host microenvironment and the mechanism of host-parasite interaction. This may help us to find targets for Echinococcus granulosus to escape host immune attack and control Echinococcus granulosus infection in the future.

The Common Occurrence of Theileria ovis in Tibetan Sheep and the First Report of Theileria sinensis in Yaks from Southern Qinghai, China

PURPOSE

The tick-borne protozoa piroplasms, including Theileria and Babesia, are the cause of substantial economic losses to the livestock industry. However, in southern Qinghai province, China, there are limited information on the molecular characteristics of piroplasms. This study therefore aimed at determining the prevalence and genetic diversity of piroplasms.

METHODS

In order to detect piroplasms, we examined 330 yaks and 236 Tibetan sheep blood samples by nested PCR. The differences in piroplasms prevalence in relation to different risk factors was analyzed using SPSS 26. Phylogenetic analysis based on 18S rRNA sequences was inferred using MEGA 7.

RESULTS

During this study, Theileria spp. were detected in 33.6% (111/330) of yaks and 94.1% (222/236) of Tibetan sheep, but no Babesia was identified. Importantly, a comparison study revealed that T. ovis infection was highly prevalent in sheep (94.1%) but infrequent in yaks (6.1%), while T. sinensis was host-specific to yaks with an infection rate of 27.6%. In addition, male animals were more likely to be infected by T. sinensis and female animals were more likely to be infected by T. ovis. And animals below 4000 m areas reported a higher infection rate with T. sinensis (26.1% vs. 2.9%, p < 0.001). Alongside these differences in prevalence, we found a significantly higher T. sinensis infection rate in separated-grazing livestock (22.2% vs. 3.7%, p < 0.001), while mixed-grazing ruminants had a higher T. ovis infection rate (50.0% vs. 39.0%, p = 0.014). Furthermore, sequence analysis revealed that the 18S rRNA sequences obtained in this study shared 86.9-100.0% identities with each other and they were clustered into T. sinensis or T. ovis.

CONCLUSION

To our knowledge, this is the first report of T. sinensis in Qinghai region. In addition, high prevalence of the generally sub-clinical T. ovis in sheep indicates extensive exposure to ticks and transmission of tick-borne pathogens with a significant economic impact. This study provides insights into the distribution and genetic diversity of Theileria in China.

Echinococcoses in Iran, Turkey, and Pakistan: Old Diseases in the New Millennium

Echinococcosis is considered a cosmopolitan zoonosis caused by different species of small taeniid tapeworms of the genus Echinococcus and is regarded as a neglected zoonosis. Cystic and alveolar echinococcoses are endemic diseases of Tibetan, Pamir, and Iranian plateaus. All of the countries within the Iranian plateau are affected by echinococcosis. Pakistan, Turkey, and Iran are the three most populous countries of the region, in which echinococcosis is highly endemic. The three neighboring countries share strong cultural and socioeconomic ties. The present study aimed to provide a broad review of the status of cystic and alveolar echinococcosis, summarizing the current knowledge about geographical distribution, molecular epidemiology, and transmission dynamics of Echinococcus granulosus sensu lato and Echinococcus multilocularis in this region. Additionally, we aimed to understand disease burden and risk factors as basic requirements for establishing a surveillance system and planning prevention and control programs. A considerable body of information is available on different aspects of echinococcosis in this region; however, several information and research gaps need to be filled before planning control programs. None of the countries in the region have an elaborate echinococcosis control program. Effective control programs require multi/intersectoral coordination within a One Health approach with a long-term political and administrative commitment and enhanced international collaboration among the three countries.

Pulmonary hydatidosis genotypes isolates from human clinical surgery based on sequencing of mitochondrial genes in Fars, Iran

BACKGROUND

Cystic echinococcosis (CE)/hydatidosis is an important neglected parasitic zoonotic disease caused by the metacestode of Echinococcus granulosus s.l. The present study was designed to identify the pulmonary CE species/genotypes in isolated human underwent to surgery in our center in Southern Iran.

METHODS

The study population of this study were all patients in Fars province who were admitted to Namazi Hospitals for pulmonary hydatid cyst surgery. Thoracic surgery was performed in the thoracic ward and the cyst/s was removed by open surgery via posterolateral or lateral thoracotomy. DNA was extracted from the germinal layer or the protoscoleces. PCR technique was performed using the cytochrome C oxidase subunit1 (cox1) gene, and the products were sequenced.

RESULTS

A total of 32 pulmonary hydatid cyst samples were collected from 9 (28%) female and 23 (72%) male aged from 4 to 74 years old. A total of 18(56%) cyst/s were in the left lobe and 14 (44%) cysts in the right lobe. Sequence analysis of the cysts showed that 24 samples (75%) were E. granulosus s.s (G1-G3) genotype and 8 (25%) were E. canadensis (G6/G7) genotype.

CONCLUSION

E.granulosus s.s genotype was the most prevalent genotype followed by E. canadensis (G6/G7) genotype. There was no significant statistical correlation between cysts' size, location, genotype strain, and patients' age and gender.