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Background: Cystic echinococcosis (CE) is a zoonotic neglected tropical disease (zNTD) which imposes considerable financial burden to endemic countries. The 2021–2030 World Health Organization's roadmap on NTDs has proposed that intensified control be achieved in hyperendemic areas of 17 countries by 2030. Successful interventions for disease control, and the scale-up of programmes applying such interventions, rely on understanding the associated costs and relative return for investment. We conducted a scoping review of existing peer-reviewed literature on economic evaluations of CE control strategies focused on Echinococcus granulosus zoonotic hosts. Methodology/Principal findings: Database searches of Scopus, PubMed, Web of Science, CABI Direct and JSTOR were conducted and comprehensively reviewed in March 2022, using predefined search criteria with no date, field or language restrictions. A total of 100 papers were initially identified and assessed for eligibility against strict inclusion and exclusion criteria, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. Bibliography review of included manuscripts was used to identify additional literature. Full review of the final manuscript selection (n = 9) was performed and cost data for control interventions were extracted. Conclusions/Significance: There are very little published data pertaining to the cost and cost effectiveness of CE control interventions targeting its zoonotic hosts. Data given for costs are often incomplete, thus we were unable to perform an economic analysis and cost effectiveness study, highlighting a pressing need for this information. There is much scope for future work in this area. More detailed information and disaggregated costings need to be collected and made available. This would increase the accuracy of any cost-effective analyses to be performed and allow for a greater understanding of the opportunity cost of healthcare decisions and resource allocation by stakeholders and policy makers for effective and cost-effective CE control. Author summary: Cystic echinococcosis (CE) is a zoonotic neglected tropical disease which predominantly affects poor pastoral communities globally. The parasite cycles between farm dogs and livestock, and is associated with livestock farming and feeding of infected offal to dogs. Although no noticeable clinical signs are seen in livestock, some production losses, such as reduced milk yield and live weight gain may be observed, and offal condemnation at slaughter is common. The disease can also affect people, due to accidental ingestion of parasite eggs on contaminated food and contact with dogs. Human morbidity and mortality occur due to cyst formation in body organs, exerting a substantial health and financial burden to the health sector of affected countries. Control interventions to reduce CE transmission include sheep vaccination and dog deworming. Long-term control programmes are often expensive, and the true costs of such programmes poorly documented. This scoping review aims to examine published literature on the costs of CE control in zoonotic hosts and report detailed costs of individual elements of a control programme, thereby furthering our understanding of the true economic cost of CE control. [ABSTRACT FROM AUTHOR]

Background: Cystic echinococcosis (CE) is a parasitic zoonosis caused by infection with the larval stage of Echinococcus granulosus (s.l.). This study investigated the prevalence and potential risk factors associated with human CE in the towns and rural areas of Ñorquinco and Ramos Mexia, Rio Negro province, Argentina. Methods: To detect abdominal CE cysts, we screened 892 volunteers by ultrasound and investigated potential risk factors for CE using a standardized questionnaire. Prevalence ratio (PR) with 95% confidence intervals (CI) was used to measure the association between CE and the factors investigated, applying bivariate and multivariate analyses. Results: Abdominal CE was detected in 42/892 screened volunteers (4.7%, 95% CI 3.2–6.1), only two of whom were under 15 years of age. Thirteen (30.9%) CE cases had 25 cysts in active stages (CE1, CE2, CE3a, according to the WHO Informal Working Group on Echinococcosis [WHO-IWGE] classification). The most relevant risk factors identified in the bivariate analysis included: living in rural areas (P = 0.003), age > 40 years (P = 0.000), always drinking water from natural sources (P = 0.007), residing in rural areas during the first 5 years of life (P = 0.000) and having lived more than 20 years at the current address (P = 0.013). In the multivariate final model, the statistically significant risk factors were: frequently touching dogs (P = 0.012), residing in rural areas during the first 5 years of life (P = 0.004), smoking (P = 0.000), age > 60 years (P = 0.002) and living in rural areas (P = 0.017). Conclusions: Our results point toward infection with CE being acquired since childhood and with constant exposure throughout life, especially in rural areas with a general environmental contamination. [ABSTRACT FROM AUTHOR]

Background: Cystic echinococcosis (CE) is a parasitic zoonosis caused by infection with the larval stage of Echinococcus granulosus (s.l.). This study investigated the prevalence and potential risk factors associated with human CE in the towns and rural areas of Ñorquinco and Ramos Mexia, Rio Negro province, Argentina. Methods: To detect abdominal CE cysts, we screened 892 volunteers by ultrasound and investigated potential risk factors for CE using a standardized questionnaire. Prevalence ratio (PR) with 95% confidence intervals (CI) was used to measure the association between CE and the factors investigated, applying bivariate and multivariate analyses. Results: Abdominal CE was detected in 42/892 screened volunteers (4.7%, 95% CI 3.2–6.1), only two of whom were under 15 years of age. Thirteen (30.9%) CE cases had 25 cysts in active stages (CE1, CE2, CE3a, according to the WHO Informal Working Group on Echinococcosis [WHO-IWGE] classification). The most relevant risk factors identified in the bivariate analysis included: living in rural areas (P = 0.003), age > 40 years (P = 0.000), always drinking water from natural sources (P = 0.007), residing in rural areas during the first 5 years of life (P = 0.000) and having lived more than 20 years at the current address (P = 0.013). In the multivariate final model, the statistically significant risk factors were: frequently touching dogs (P = 0.012), residing in rural areas during the first 5 years of life (P = 0.004), smoking (P = 0.000), age > 60 years (P = 0.002) and living in rural areas (P = 0.017). Conclusions: Our results point toward infection with CE being acquired since childhood and with constant exposure throughout life, especially in rural areas with a general environmental contamination. [ABSTRACT FROM AUTHOR]

The analysis of zoonotic disease risk requires tshe consideration of both human and animal geo-referenced disease incidence data. Here we show an application of joint Bayesian analyses to the study of echinococcosis granulosus (EG) in the province of Rio Negro, Argentina. We focus on merging passive and active surveillance data sources of animal and human EG cases using joint Bayesian spatial and spatio-temporal models. While similar spatial clustering and temporal trending was apparent, there appears to be limited lagged dependence between animal and human outcomes. Beyond the data quality issues relating to missingness at different times, we were able to identify relations between dog and human data and the highest 'at risk' areas for echinococcosis within the province. Author summary: This work focuses on utilizing animal disease data to try and inform our understanding of the spread of diseases in humans. We implement predictive models to estimate the relationship between the distribution of disease in animal populations and the distribution of disease in human populations. Development of a better understanding of this relationship could inform animal and public health interventions aiming to mitigate against human disease before it spreads. Missing data and limited data resources made discovery of these relationships difficult, but we fit multiple model types to try and identify any connection between these two populations. We found specific areas with elevated risk of human disease and changes in disease risk over time. Finally, there was some indication of an association between previous years' levels of animal disease and human disease when using animals as covariables. [ABSTRACT FROM AUTHOR]

Cystic echinococcosis (CE), caused by Echinococcus granulosus, is a chronic and debilitating zoonotic larval cestode infection in humans, which is principally transmitted between dogs and domestic livestock, particularly sheep. Human CE occurs in almost all pastoral communities and rangeland areas of the underdeveloped and developed world. Control programmes against CE have been implemented in several endemic countries to reduce or eliminate the disease. New Zealand and Tasmania are examples of some of the first programmes to be undertaken (in insular territories) and which were very successful in the elimination of CE. The advent and proven effectiveness of praziquantel, plus the experience of insular models, produced high expectations for rapid advances in a second generation of control programmes undertaken in continental areas (Argentina, Uruguay and Chile). Nevertheless, only moderate gains in CE control have been made and the impact on prevalence among humans has been slight. A major impediment to the adoption of procedures that were successful in New Zealand and Tasmania has been the requirement to administer praziquantel to dogs in rural areas eight times per year over numerous years. In addition, there have been clear technological improvements made in the diagnosis of canine echinococcosis for surveillance, the genetic characterization of parasite strains and in vaccination against CE infection in livestock. In order to establish new paradigms and appropriate combinations of control strategies, we have carried out a review and discussion of the available control tools and control models. Control strategies must be suitable and sustainable to benefit the Echinococcosis–endemic areas primarily, which at the same time are the poorest regions of the world. [ABSTRACT FROM AUTHOR]

Background Río Negro Province is endemic for cystic echinococcosis (CE). A CE control program includes early diagnosis in humans. During 1980–1996, screening was done with serology and surgery was the unique choice of treatment. Since 1997, ultrasound (US) has been the method of choice for screening, and new choices of treatment for asymptomatic carriers are discussed in the CE guidelines. Methods Between 1997 and 2016, 42 734 abdominal USs were performed, 192 new asymptomatic cases were diagnosed and underwent a protocol according to the size, location and type of cyst. Treatment options included active surveillance (US monitoring, 83 [43.3%]), antiparasitic (albendazole, 92 [47.9%]) and surgery (17 [8.8%], including percutaneous treatment). Results After 7.7 y of follow-up, of the cases under active surveillance, 28 (33.7%) had to change treatment: 5 (6%) to surgery and 22 (26.5%) to albendazole. Of the patients treated with albendazole, 3 (3.2%) were operated on and 13 (14%) were treated with a second cycle of albendazole. Conclusion As a result of the present study, resolution of CE in a non-surgical way with albendazole is confirmed to be effective in asymptomatic carriers with CE1 or CE3a cysts. An update eliminates the strategy of active surveillance in type CE1 cysts <3 cm and is replaced by treatment with antiparasitic in all asymptomatic cases with CE1 or CE3a cysts <10 cm. The update also limits follow-up to 12–18 months to evaluate those cases with non-response to antiparasitic and switch to a surgical option. [ABSTRACT FROM AUTHOR]

Background: Cystic echinococcosis (CE) is an important zoonotic disease caused by the cestode parasite Echinococcus granulosus. It occurs in many parts of the world where pastoral activities predominate, including the Rio Negro province of Argentina. Although CE control activities have been undertaken in the western regions of Rio Negro for more than two decades, the disease continues to remain prevalent in both the human and livestock animal populations. Vaccination of animal intermediate hosts of CE with the EG95 vaccine may provide a new opportunity to improve the effectiveness of CE control measures, although data are lacking about field application of the vaccine. Aims: Evaluate the impact of EG95 vaccination in sheep on the transmission of Echinococcus granulosus in a field environment. Methodology: Two trial sites were established in western Rio Negro province within indigenous communities. Vaccination of lambs born into one trial site was introduced and continued for 6 years. Prior to initiation of the trial, and at the end of the trial, the prevalence of CE in sheep was determined by necropsy. Weaned lambs received two injections of EG95 vaccine, approximately one month apart, and a single booster injection one year later. Vaccination was not implemented at the second trial site. A total of 2725 animals were vaccinated in the first year. Animals from this cohort as well as age-matched sheep from the control area were evaluated by necropsy. Key results: Introduction of the vaccine led to a statistically significant in the number and size of hydatid cysts in comparison to the situation prior to the introduction of the vaccine, or compared to CE prevalence in the control area where the vaccine was not applied. The prevalence of infection in the vaccinated area was also significantly reduced by 62% compared to the re-intervention level, being lower than the prevalence seen in the control area, although the difference from the control area after the intervention was not significant possibly due to limitations in the numbers of animals available for necropsy. Conclusions: Vaccination of sheep with the EG95 vaccine provides a valuable new tool which improves the effectiveness of CE control activities. Vaccination was effective even in a difficult, remote environment where only approximately half the lambs born into the communities were fully vaccinated. [ABSTRACT FROM AUTHOR]

Cystic echinococcosis (CE) is a chronic, complex and neglected disease caused by the larval stage of Echinococcus granulosus. The effects of this neglect have a stronger impact in remote rural areas whose inhabitants have no chances of being diagnosed and treated properly without leaving their jobs and travelling long distances, sometimes taking days to reach the closest referral center. Background: In 1980 our group set up a control program in endemic regions with CE in rural sections of Rio Negro, Argentina. Since 1997, we have used abdominopelvic ultrasound (US) as a screening method of CE in school children and determined an algorithm of treatment. Objectives: To describe the training system of general practitioners in early diagnosis and treatment of CE and to evaluate the impact of the implementation of the field program. Materials and Methods: In 2000, to overcome the shortage of radiologists in the area, we set up a short training course on Focused Assessment with Sonography for Echinococcosis (FASE) for general practitioners with no previous experience with US. After the course, the trainees were able to carry out autonomous ultrasound surveys under the supervision of the course faculty. From 2000 to 2008, trainees carried out 22,793 ultrasound scans in children from 6 to 14 years of age, and diagnosed 87 (0.4%) new cases of CE. Forty-nine (56.4%) were treated with albendazole, 29 (33.3%) were monitored expectantly and 9 (10.3%) were treated with surgery. Discussion: The introduction of a FASE course for general practitioners allowed for the screening of CE in a large population of individuals in remote endemic areas with persistent levels of transmission, thus overcoming the barrier of the great distance from tertiary care facilities. The ability of local practitioners to screen for CE using US saved the local residents costly travel time and missed work and proved to be an efficacious and least expensive intervention tool for both the community and health care system. Author Summary: Cystic echinococcosis (CE) is an important and widespread disease that affects sheep, cattle, and humans living in areas where sheep and cattle are raised. CE is highly endemic in rural sections of Rio Negro, Argentina, where our group is based. However, it requires continuous monitoring of both populations with human disease best assessed by means of ultrasound (US) screening. This is challenging in remote rural areas due to the shortage of imaging specialists. To overcome this hurdle, we set up a two-day training program of Focused Assessment with Sonography for Echinococcosis (FASE) on CE for family medicine practitioners with no previous experience in US. After the course, they were equipped with portable US scanners and dispatched to remote rural areas in Rio Negro where they screened patients, located and staged the cysts and decided on the treatment with the help of surgeons and radiologists in local tertiary care centers. The need to travel to referral hospitals for traditional surgical interventions was therefore limited to a few cases. US was instead brought to rural areas thereby extending affordable healthcare to people who would otherwise not have access to it. [ABSTRACT FROM AUTHOR]

Cystic echinococcosis (CE) is a chronic, complex and neglected disease caused by the larval stage of Echinococcus granulosus. The effects of this neglect have a stronger impact in remote rural areas whose inhabitants have no chances of being diagnosed and treated properly without leaving their jobs and travelling long distances, sometimes taking days to reach the closest referral center. Background: In 1980 our group set up a control program in endemic regions with CE in rural sections of Rio Negro, Argentina. Since 1997, we have used abdominopelvic ultrasound (US) as a screening method of CE in school children and determined an algorithm of treatment. Objectives: To describe the training system of general practitioners in early diagnosis and treatment of CE and to evaluate the impact of the implementation of the field program. Materials and Methods: In 2000, to overcome the shortage of radiologists in the area, we set up a short training course on Focused Assessment with Sonography for Echinococcosis (FASE) for general practitioners with no previous experience with US. After the course, the trainees were able to carry out autonomous ultrasound surveys under the supervision of the course faculty. From 2000 to 2008, trainees carried out 22,793 ultrasound scans in children from 6 to 14 years of age, and diagnosed 87 (0.4%) new cases of CE. Forty-nine (56.4%) were treated with albendazole, 29 (33.3%) were monitored expectantly and 9 (10.3%) were treated with surgery. Discussion: The introduction of a FASE course for general practitioners allowed for the screening of CE in a large population of individuals in remote endemic areas with persistent levels of transmission, thus overcoming the barrier of the great distance from tertiary care facilities. The ability of local practitioners to screen for CE using US saved the local residents costly travel time and missed work and proved to be an efficacious and least expensive intervention tool for both the community and health care system. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Epidemiology, diagnosis, treatment and follow-up of cystic echinococcosis in asymptomatic carriers" which appeared in a previous issue.