Echinococcosis in Tunisia: a cost analysis

Zoonotic threat of cystic echinococcosis in Tunisia: insights into livestock prevalence and identification of the G1 genotype

Introduction

Cystic echinococcosis (CE) is a zoonosis caused by the larval stage of the Echinococcus granulosus sensu lato (s.l.) complex. CE is globally distributed, with a particularly high prevalence in North African countries, especially Tunisia. Despite its significant public health impact and the economic burden it places on livestock production, recent data on CE prevalence in Tunisian livestock remain scarce. This study aimed to assess the prevalence of CE in livestock, investigate potential differences across host species, and identify risk factors contributing to the CE transmission dynamics.

Methods

The study was conducted in two governorates located in the North-Eastern region of Tunisia. A multidimensional approach included post-mortem inspection of slaughtered animals, fertility and viability analyses of the isolated CE cysts, and molecular genotyping of the parasite was conducted.

Results and discussion

A total of 21,487 animals were examined, 15.86% of the sheep and 9.57% of the cattle were infected with at least one CE cyst, with females showing higher prevalence rates. No CE cases were detected in goats or dromedaries. In all infected animals, the infection rate increased with the age of the host. CE cysts were predominantly found in both the liver and lung of the same animal in sheep and cattle. Aborted lesions were the most common stage of infection, and multiple CE cysts were frequently observed in affected animals. Fertile CE cysts were highly prevalent in both sheep and cattle, with rates increasing with host age, confirming the critical role of sheep in the parasite transmission cycle and demonstrating that cattle in Tunisia also play a significant role in the propagation of CE. Molecular analysis confirmed the predominance of the zoonotic G1 genotype of E. granulosus sensu stricto. This is particularly concerning as the G1 genotype is also the most common genotype affecting humans. This underscores a strong zoonotic potential and highlights the need for integrated control strategies. The findings emphasize the role of the livestock-dog cycle in CE transmission, posing risks to humans living near infected animals. Effective measures, including slaughter regulations, dog deworming, public education, and enhanced veterinary surveillance within a One Health approach, are essential for reducing CE's impact on human and animal health.

Cystic echinococcosis (Echinococcus granulosus sensu lato infection) in Tunisia, a One Health perspective for a future control programme

The emergence of pandemics with dramatic consequences for human health has obscured endemic diseases that continue to pose a problem for human and animal health in several regions of the world. Among these diseases, cystic echinococcosis, a zoonotic parasitic infection caused by a group of cestodes, Echinococcus granulosus sensu lato, remains a real human and animal health problem in several regions of the world, including the Mediterranean Basin. Despite the implementation of a number of governmental control programmes using several tools (dog treatment, meat inspection, etc.), this infection is still highly prevalent in North Africa. Here we present a review of the epidemiology of cystic echinococcosis in Tunisia, an analysis of the constraints limiting the effectiveness of the control programmes implemented, and finally argue for the use of the One Health framework to improve the effectiveness of future programmes.

Estimating the production losses due to cystic echinococcosis in water buffaloes (Bubalus bubalis) in Turkey

The current study aimed at estimating the direct (condemned offal) and indirect (meat, milk, and fecundity losses) production losses due to cystic echinococcosis (CE) in water buffaloes in Turkey. A spreadsheet loss model was constructed, and the mean prevalence ratio of CE was accepted as 3.8% in male and 21.7% in female buffaloes. The annual financial losses were estimated with official and previously published data under expected (mean value), optimistic (lowered by 10%), and pessimistic (increased by 10%) scenarios with the prices current in 2021. The production losses in an infected male and female water buffalo were estimated at $54.5 ($49.1-59.9) and $89.9 ($80.9-98.9), respectively. Due to CE, the nationwide annual total production losses were estimated at $1.5 million ($1.3-1.6) for water buffaloes in Turkey. In conclusion, farmers, policymakers, and the public need to be informed about CE's risks and financial impact. Control/eradication programs should be included in government policies at the national level after a cost/benefit analysis.

A One-Health evaluation of the burden of cystic echinococcosis and its prevention costs: Case study from a hypo-endemic area in Italy

An integrated model, based on a One Health approach, was implemented to estimate the epidemiological and economic outcomes of cystic echinococcosis (CE) in Veneto region, an hypo-endemic area of Northern Italy, and the costs for its prevention. Data and information needed to populate the model were retrieved from published literature, official statistics, expert opinions, or actively searched through data mining (i.e., Hospital and slaughterhouse data), when fundamental data were not available. Human-health and animal-health costs, both public and private, were considered. The overall impact of CE in the study area was estimated in an yearly cost of about 0.5 million €, due to an average of 19.5 human hospitalized cases and about 200 infected animals among cattle and sheep, per year. The human:animal costs ratio was about 8:1. Most of the infected animals were autochthonous, while the identification of an autochthonous source of the infection for the human cases was extremely difficult, and unlikely in most cases. No specific action resulted to be in place for human surveillance, while veterinary surveillance accounted for a yearly cost of about 22,000 €. Sheepherders were found to pay privately an overall amount of around 2000 € for the preventive treatment of their dogs every year, but the applied protocol proved to be sub-optimal. The source of most of the human cases was likely external to the study area, and their economic impact accounts for a cost that is far exceeding that of surveillance and preventive actions in place in the veterinary sector. Although autochthonous human cases appeared to be very rare, the strengthening of preventive actions and surveillance systems can reduce the risk of their increment.

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The study integrated epidemiology and economic aspects in a One Health perspective.

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The research estimates in detail the overall impact of CE in a hypo-endemic region in Italy.

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The study provided data for evidence-based actions to control CE in the study area.

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The investigated case study represents a reproducible model for zoonotic diseases evaluation.

Human and animal cystic echinococcosis in Tataouine governorate: hypoendemic area in a hyperendemic country, myth or reality?

BACKGROUND

Cystic echinococcosis (CE) has a worldwide distribution and is especially prevalent in North African countries. With a mean annual surgical incidence (ASI) of CE of 12.7 per 100,000 inhabitants, Tunisia is one of the most CE endemic countries in the Mediterranean area. Tataouine governorate is considered to be the most CE hypoendemic region in Tunisia (ASI = 0.92) despite favourable socioeconomic conditions that enable maintenance of the Echinococcus granulosus sensu lato (s.l.) life-cycle and a significant environmental contamination with E. granulosus s.l. eggs. The aim of this study was to assess human CE seroprevalence, prevalence of CE in food animals and environmental contamination by E. granulosus s.l. eggs in different districts of Tataouine governorate.

METHODS

This study was conducted from January to December 2018. A total of 374 human sera samples were tested for the presence of immunoglobulin G antibodies against E. granulosus using a commercial ELISA kit. Specimens were also collected from animals slaughtered at the Tataouine abattoir (n = 8609) and examined for the presence of hydatid cysts; 111 hydatid cysts were genotyped. Eggs of E. granulosus s.l. were identified by PCR and DNA sequencing from dog faecal samples (n = 288).

RESULTS

Serological tests showed that 8.5% of the sera samples tested were positive for E. granulosus-specific antibodies. The average prevalence of hydatidosis in livestock was 1.6%, and CE infection was more prevalent in cattle than in sheep, goats and dromedaries. The contamination rate of dog faeces by E. granulosus sensu stricto eggs varied significantly from 0 to 23.5% depending on the collection area. Molecular analyses only revealed the presence of the G1 genotype for cysts and eggs.

CONCLUSIONS

Based on our findings, CE is likely to be more endemic in the Tataouine governorate than previously described. Thus, to implement an effective control programme against CE, a national survey should be carried out to determine human CE prevalence in the different Tunisian governorates.

Feline-Human Zoonosis Transmission in North Africa: A Systematic Review

Throughout human history, domestic animal species have represented a unique zoonotic disease risk for the transmission of pathogens ranging from viral, bacterial, parasitic, and fungal. In North Africa, cats have a particularly long record and occupy a specialized niche within many communities. This systematic review was conducted to analyze the current and historical literature documenting the breadth and variety of zoonoses in North Africa, specifically relating to the domesticated feline. Multiple electronic databases were searched on January 16, 2019, for published reports on feline zoonoses in North Africa. A total of 76 studies met the inclusion criteria for a full assessment. Articles selected for the review ranged in publication dates from 1939 to 2019 and included a case study, cross-sectional surveys, genomic analyses, and a book chapter. The most commonly studied pathogen was Toxoplasma gondii (n = 17) followed by a variety of helminths (n = 10). Of the countries in the target region, most publications were of studies conducted in Egypt (n = 53) followed by Tunisia (n = 12), Algeria (n = 11), Morocco (n = 5), and Libya (n = 3). The results of this review identify a variety of viral, bacterial, fungal, and parasitic zoonotic diseases associated with cats in North Africa, ranging from historically endemic diseases in both human and animal populations in the region, to emerging infections with recent confirmatory diagnoses. This review describes reported feline zoonoses in North Africa and provides recommendations for their prevention and control. In addition to vaccination campaigns for domesticated felines and postexposure prophylaxis for humans, prompt veterinary and medical care of exposure risks and subsequent infections are essential in limiting the zoonotic disease burden in North African communities of humans and cats.

The socio-economic burden of cystic echinococcosis in Morocco: A combination of estimation method

Cystic echinococcosis (CE) is a major zoonosis in Morocco despite the launch of a national control programme in 2005. As its economic consequences have not been studied yet in Morocco, this study estimated CE impact in terms of monetary losses, disability-adjusted life years (DALY), and DALY for zoonotic diseases (zDALY) in the entire country and in specific regions for the 2011 to 2014 period. The direct monetary losses were related to organ seizure from infected animal in slaughterhouses, and to healthcare expenses as well as lost wages for infected humans. Animal production losses concerned milk yield, fertility, carcass weight, and wool production. Losses due to human infection were also composed of disability and productivity losses at work. Monte Carlo simulations were used to estimate monetary losses and zDALY values. Nationwide, the estimated DALY was 0.5 years per 100,000 persons per year, and the zDALY was 55 years per 100,000 persons per year. Total yearly losses were estimated at 73 million USD (54–92 million USD). However, losses differed significantly among regions. Most of the economic losses consisted of unperceived consequences, i.e. decreased animal production and reduced productivity of asymptomatic individuals. Future studies should determine the socioeconomic and epidemiological factors underlying the differences in economic losses among regions to develop better adapted control programmes.

Cystic echinococcosis (CE) is a major neglected zoonosis in Morocco, despite the launch of a national control programme in 2005. The first study on CE in Morocco dates back to 1924. However, no evaluation of economic losses was made until now. The present study estimated the economic losses caused by CE in Morocco, at the national and regional scale, by combining financial and non-financial methods. Estimation of the direct and indirect losses caused by CE infection in humans and livestock (sheep, cattle, goats and camels) highlighted the important disease burden nationwide, amounting to 0.07% of Morocco Gross Domestic Product. The combination of methods brought information on the different CE-linked economic losses, including the unperceived consequences. These results indicate that the national CE control strategy did not result in a decrease of the disease burden, which calls for its evaluation and improvement.

Assessment of the direct economic losses associated with hydatid disease (Echinococcus granulosus sensu stricto) in beef cattle slaughtered at an Australian abattoir

Bovine hydatid disease, characterised by fluid-filled hydatid cysts, is regularly found in the offal of beef cattle at slaughter. Organs found to be infected at slaughter are removed to preclude them from entering the human food chain. The organs are either downgraded to pet food or condemned. Previous studies have focussed on total economic losses, but have not calculated the cost of disease per animal, which would be useful information for producers when determining how best to manage hydatid disease. This study estimated the direct losses associated with hydatid disease in beef cattle slaughtered at an Australian beef abattoir both at the population (all cattle slaughtered) and individual animal level. Data on annual prevalence of hydatid disease in beef cattle were obtained from an Australian abattoir for the years 2011-2017. The direct losses resulting from the condemnation and downgrading of offal infected with hydatid cysts at the abattoir were estimated using data stratified by age, sex and feed-type. Official and literature-based sources of organ weight and price were used to estimate direct losses associated with hydatid disease in beef cattle slaughtered at the abattoir. Uncertainty and variability in input parameters were represented using uniform distributions and Monte Carlo sampling was used to model output parameter uncertainty. Out of 1,097,958 beef cattle slaughtered between January 2011 and December 2017, 97,832 (8.9%) were reported infected with hydatid disease. The median estimated direct loss to the abattoir for the duration of the study period was AU$655,560 (95% confidence interval [CI] AU$544,366-787,235). This equated to approximately AU$6.70 (95% CI AU$5.56-8.05) lost per infected animal. The annual median estimated direct losses due to hydatid disease at the abattoir were AU$93,651 (95% CI AU$77,767-112,462). Direct losses varied each year of the study and ranged from AU$38,683 in 2016 to AU$163,006 in 2014. This estimate of the direct losses associated with bovine hydatid disease most likely underestimates the true extent of the overall losses because indirect losses such as reduced carcass weights were not estimated in this study. Nevertheless, these estimates illustrate the negative economic impact of bovine hydatid disease and demonstrate that improved surveillance to enable control of hydatid disease should be considered both in Australia and globally. It would be worthwhile to estimate the losses in other beef abattoirs for the same time period to compare results, and to investigate the cost-benefit of control programs for bovine hydatid disease.

zDALY: An adjusted indicator to estimate the burden of zoonotic diseases

The burden of human diseases in populations, or for an individual, is frequently estimated in terms of one of a number of Health Adjusted Life Years (HALYs). The Disability Adjusted Life Year (DALY) is a widely accepted HALY metric and is used by the World Health Organization and the Global Burden of Disease studies. Many human diseases are of animal origin and often cause ill health and production losses in domestic animals. The economic losses due to disease in animals are usually estimated in monetary terms. The monetary impact on animal health is not compatible with HALY approaches used to measure the impact on human health. To estimate the societal burden of zoonotic diseases that have substantial human and animal disease burden we propose methodology which can be accommodated within the DALY framework. Monetary losses due to the animal disease component of a zoonotic disease can be converted to an equivalent metric using a local gross national income per capita deflator. This essentially gives animal production losses a time trade-off for human life years. This is the time required to earn the income needed to replace that financial loss. This can then be assigned a DALY equivalent, termed animal loss equivalents (ALE), and added to the DALY associated with human ill health to give a modified DALY. This is referred to as the "zDALY". ALEs could also be estimated using willingness-to-pay for animal health or survey tools to estimate the replacement time value for animals with high societal or emotional value (for example pets) that cannot be calculated directly using monetary worth. Thus the zDALY estimates the impact of a zoonotic disease to animal and human health. The losses due to the animal disease component of the modified DALY are straightforward to calculate. A number of worked examples such as echinococcosis, brucellosis, Q fever and cysticercosis from a diverse spectrum of countries with different levels of economic development illustrate the use of the zDALY indicator.

Prevalence of Echinococcus granulosus taeniasis in stray dogs in the region of Constantine (North-East Algeria)

In North Africa, the domestic dog is regarded as the main reservoir for infection by Echinococcus granulosus of domestic livestock and man. In Algeria, there is very little data on the rate of infestation of dogs, while the prevalence of E. granulosus in the definitive host is a very reliable marker of the potential risk of transmission of cystic tapeworm to humans and livestock. To find out this information, a survey was conducted to assess the prevalence of infection with E. granulosus in stray dogs in the region of Constantine (North-East Algeria). We autopsied and examined 120 stray dogs, 22 (18.3%) of which were infected with E. granulosus, with an average intensity of infestation of 249 worms. The prevalence in the area of survey was evaluated: 15.5% (14/90) and 26.6% (8/30) dogs were parasitized by E. granulosus in urban and rural areas respectively. The influence of age on the rate of infection was very marked. In addition, the appreciation of the prevalence of parasitism by cestodes as a whole showed that 56 (46.6%) animals out of 120 were infected. Facing such a situation of endemic tapeworm parasitism, with a potential risk of transmission to humans, there is an urgent need to take measures to control and break the epidemiological cycles of the parasite.

The Echinococcoses: Diagnosis, Clinical Management and Burden of Disease

The echinococcoses are chronic, parasitic diseases that are acquired after ingestion of infective taeniid tapeworm eggs from certain species of the genus Echinococcus. Cystic echinococcosis (CE) occurs worldwide, whereas, alveolar echinococcosis (AE) is restricted to the northern hemisphere, and neotropical echinococcosis (NE) has only been identified in Central and South America. Clinical manifestations and disease courses vary profoundly for the different species of Echinococcus. CE presents as small to large cysts, and has commonly been referred to as 'hydatid disease', or 'hydatidosis'. A structured stage-specific approach to CE management, based on the World Health Organization (WHO) ultrasound classification of liver cysts, is now recommended. Management options include percutaneous sterilization techniques, surgery, drug treatment, a 'watch-and-wait' approach or combinations thereof. In contrast, clinical manifestations associated with AE resemble those of a 'malignant', silently-progressing liver disease, with local tissue infiltration and metastases. Structured care is important for AE management and includes WHO staging, drug therapy and long-term follow-up for at least a decade. NE presents as polycystic or unicystic disease. Clinical characteristics resemble those of AE, and management needs to be structured accordingly. However, to date, only a few hundreds of cases have been reported in the literature. The echinococcoses are often expensive and complicated to treat, and prospective clinical studies are needed to better inform case management decisions.

Global Distribution of Alveolar and Cystic Echinococcosis

Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are severe helminthic zoonoses. Echinococcus multilocularis (causative agent of AE) is widely distributed in the northern hemisphere where it is typically maintained in a wild animal cycle including canids as definitive hosts and rodents as intermediate hosts. The species Echinococcus granulosus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus intermedius are the causative agents of CE with a worldwide distribution and a highly variable human disease burden in the different endemic areas depending upon human behavioural risk factors, the diversity and ecology of animal host assemblages and the genetic diversity within Echinococcus species which differ in their zoonotic potential and pathogenicity. Both AE and CE are regarded as neglected zoonoses, with a higher overall burden of disease for CE due to its global distribution and high regional prevalence, but a higher pathogenicity and case fatality rate for AE, especially in Asia. Over the past two decades, numerous studies have addressed the epidemiology and distribution of these Echinococcus species worldwide, resulting in better-defined boundaries of the endemic areas. This chapter presents the global distribution of Echinococcus species and human AE and CE in maps and summarizes the global data on host assemblages, transmission, prevalence in animal definitive hosts, incidence in people and molecular epidemiology.

Canine echinococcosis: the predominance of immature eggs in adult tapeworms of Echinococcus granulosus in stray dogs from Tunisia

Canine echinococcosis is caused by the adult tapeworm of Echinococcus granulosus. As intermediate hosts, humans and livestock become infected following ingestion of eggs that are passed in the faeces of dogs. Mature eggs develop into hydatid cysts in different organs, leading to hydatid disease, which is a serious public health problem. In the present study, we investigated the proportion of mature eggs of E. granulosus in 140 dogs from three regions of Tunisia. The results showed the predominance of immature E. granulosus eggs in infected dogs and the occurrence of a small proportion of oncospheres. The ability of immature eggs to infect humans and livestock is discussed.

The Economic Impact of Cystic Echinococcosis in Rio Negro Province, Argentina

Cystic echinococcosis (CE), a parasitic zoonosis with substantial human health and economic consequences, is highly endemic in Rio Negro Province, Argentina. The objective of this study was to estimate the direct and indirect human and livestock-associated monetary losses attributable to CE, in Rio Negro Province, for the year 2010. Human costs were estimated using data obtained from hospital chart reviews, patient interviews, and government reports. Livestock-associated losses were estimated using data from government reports and scientific publications. Spreadsheet models were developed utilizing Latin Hypercube sampling to account for uncertainty in the input parameters. In 2010, the estimated total cost of CE, in Rio Negro Province, ranged from US$4,234,000 (95% credible interval [CI]: US$2,709,000-US$6,226,000) to US$5,897,000 (95% CI: US$3,452,000-US$9,105,000), with livestock-associated losses representing between 80% and 94% of the total losses, depending on whether non-healthcare-seeking human cases were included and if livestock slaughter values were adjusted to account for underreporting. These estimates suggest that CE is responsible for considerable human and livestock-associated monetary losses in Rio Negro Province. Stakeholders and policymakers can use these data to better allocate public health and agricultural resources for this region.

Echinococcosis: An Economic Evaluation of a Veterinary Public Health Intervention in Rural Canada

Echinococcosis is a rare but endemic condition in people in Canada, caused by a zoonotic cestode for which the source of human infection is ingestion of parasite eggs shed by canids. The objectives of this study were to identify risk factors associated with infection and to measure the cost-utility of introducing an echinococcosis prevention program in a rural area. We analyzed human case reports submitted to the Canadian Institutes for Health Information between 2002 and 2011. Over this 10 year period, there were 48 cases associated with E. granulosus/E. canadensis, 16 with E. multilocularis, and 251 cases of echinococcosis for which species was not identified (total 315 cases). Nationally, annual incidence of echinococcosis was 0.14 cases per 100 000 people, which is likely an underestimate due to under-diagnosis and under-reporting. Risk factors for echinococcosis included female gender, age (>65 years), and residing in one of the northern territories (Nunavut, Yukon, or Northwest Territories). The average cost of treating a case of cystic echinococcosis in Canada was $8,842 CAD. Cost-utility analysis revealed that dosing dogs with praziquantel (a cestocide) at six week intervals to control cystic echinococcosis is not currently cost-effective at a threshold of $20,000-100,000 per Quality Adjusted Life Year (QALY) gained, even in a health region with the highest incidence rate in Canada ($666,978 -755,051 per QALY gained). However, threshold analysis demonstrated that the program may become cost-saving at an echinococcosis incidence of 13-85 cases per 100,000 people and therefore, even one additional CE case in a community of 9000 people could result in the monetary benefits of the program outweighing costs.

In Canada, Echinococcus spp. tapeworms cycle primarily among wildlife hosts. People are infected with this parasite when they accidentally consume microscopic eggs spread by canids (e.g. dogs, wolves, coyotes, and foxes), and develop larval cysts, often in the liver or lungs. Echinococcosis can be a life-threatening medical condition with long-term health consequences and can be an economic burden for infected individuals and for the public health system. We analysed national health records to measure echinococcosis incidence and risk factors in Canada, and then used this information to determine if a program that facilitated dog deworming to prevent human infection might be economically feasible. Our model suggested that treating infected individuals is currently less expensive than preventing infection, even in the highest risk regions of Canada. However, deworming dogs might be feasible in small rural communities where at least one case was identified. Furthermore, the prevention program has many add-on benefits that contribute to overall community health, but are not measured by our model.

Infection of dogs with Echinococcus granulosus: causes and consequences in an hyperendemic area

Background

Tunisia is a hyper endemic country for human echinococcosis. The infection is transmitted via the eggs of Echinococcus granulosus which are passed in the faeces of the definitive canid host.

Methods

This study evaluated the contamination rate of the dog faeces in different climatic conditions at eight different geographic regions throughout Tunisia. Dog faecal samples were collected from the soil and the Echinococcus eggs were identified using microscopic and molecular (Eg1121/1122 PCR, Egss1 PCR and Nad1 PCR-RFLP) tools.

Results

The contamination index of dog faeces by E. granulosus eggs ranged from 8.3% to 41.3% depending on the region. Comparisons of the dog faecal contamination rate against human incidence found them to be independent. Neither human prevalence nor dog contamination index appeared to be related to climatic conditions or geographic characteristics. The genetic variability of E. granulosus samples was different within each region but was not related to geographic distance which is indicative of local divergent evolutions rather than isolation by distance.

Conclusions

A high environmental dog contamination index does not necessarily correspond to high prevalence in humans as transmission is strongly linked to human behavior and hygiene.

Economic and financial evaluation of neglected tropical diseases

Economic and financing studies are particularly important for decision-making when resources are scarce or considerably limited. This is the case for neglected tropical diseases (NTDs). In fact, the definition of NTDs is an economic one. The shortage of resources for NTD control may be due in large part to the fact that the burden of NTDs and economic value of control measures have not been fully characterized. A number of economic study methodologies are available: cost of illness can quantify the extent, magnitude, and change of a problem; cost of intervention studies can outline the feasibility and guide the design of a policy or intervention; and cost-benefit, cost-effectiveness, and return-on-investment studies can determine the potential value of different interventions and policies. NTDs have unique characteristics that require special consideration in such analyses. Hence, approaches used for other diseases may need modifications to capture the full impact of NTDs. While the existing literature has made important findings, there is a need for substantially more work, as many NTDs and their associated interventions and policies require more evaluation. With increasing work in this area, NTDs may not be as 'neglected' in the future as they are now.

Cystic echinococcosis in the Province of Álava, North Spain: the monetary burden of a disease no longer under surveillance

Cystic echinococcosis (CE) is endemic in Spain but has been considered non-endemic in the province of Álava, Northern Spain, since 1997. However, Álava is surrounded by autonomous regions with some of the highest CE prevalence proportions in the nation, casting doubts about the current classification. The purpose of this study is to estimate the frequency of CE in humans and animals and to use this data to determine the societal cost incurred due to CE in the Álava population in 2005. We have identified epidemiological and clinical data from surveillance and hospital records, prevalence data in intermediate (sheep and cattle) host species from abattoir records, and economical data from national and regional official institutions. Direct costs (diagnosis, treatment, medical care in humans and condemnation of offal in livestock species) and indirect costs (productivity losses in humans and reduction in growth, fecundity and milk production in livestock) were modelled using the Latin hypercube method under five different scenarios reflecting different assumptions regarding the prevalence of asymptomatic cases and associated productivity losses in humans. A total of 13 human CE cases were reported in 2005. The median total cost (95% credible interval) of CE in humans and animals in Álava in 2005 was estimated to range between €61,864 (95%CI%: €47,304-€76,590) and €360,466 (95%CI: €76,424-€752,469), with human-associated losses ranging from 57% to 93% of the total losses, depending on the scenario used. Our data provide evidence that CE is still very well present in Álava and incurs important cost to the province every year. We expect this information to prove valuable for public health agencies and policy-makers, as it seems advisable to reinstate appropriate surveillance and monitoring systems and to implement effective control measures that avoid the spread and recrudescence of the disease.

Cystic echinococcosis in Mundari tribe-members of South Sudan

Many neglected tropical diseases, including the zoonotic disease cystic echinococcosis (hydatidosis), are endemic to East Africa. However, their geographical distribution is heterogenous and incompletely characterized. The aim of this study was to determine if Mundari pastoralists harbor endemic human hydatidosis. The survey was conducted in cattle camps randomly selected from accessible sites provided by officials in Terekeka, South Sudan. Following informed consent, a questionnaire collected demographic data and hydatid exposure risk. A systematic sonographic abdominal exam was performed using General Electric's LOGIQ Book XP with a 3C-RS 2-5 MHz curvilinear transducer. Six hundred and ten individuals were screened from 13 camps. Four infections were identified, all in women. The prevalence of abdominal hydatid disease in the Mundari tribe-members in cattle camps was 0·7% and all individuals reporting at least one high-risk exposure to hydatid disease. Cystic echinococcosis is endemic among Mundari pastoralists; however, it would appear to be less endemic than in neighboring tribes.

One world health: socioeconomic burden and parasitic disease control priorities

Parasitic diseases present a considerable socio-economic impact to society. Zoonotic parasites can result in a considerable burden of disease in people and substantive economic losses to livestock populations. Ameliorating the effects of these diseases may consist of attempts at eradicating specific diseases at a global level, eliminating them at a national or local level or controlling them to minimise incidence. Alternatively with some parasitic zoonoses it may only be possible to treat human and animal cases as they arise. The choice of approach will be determined by the potential effectiveness of a disease control programme, its cost and the cost effectiveness or cost benefit of undertaking the intervention. Furthermore human disease burden is being increasingly measured by egalitarian non-financial measures which are difficult to apply to livestock. This adds additional challenges to the assessment of socio-economic burdens of zoonotic diseases. Using examples from the group of neglected zoonotic diseases, information regarding the socio-economic effects is reviewed together with how this information is used in decision making with regard to disease control and treatment.

The economic impact of pig-associated parasitic zoonosis in Northern Lao PDR

The parasitic zoonoses human cysticercosis (Taenia solium), taeniasis (other Taenia species) and trichinellosis (Trichinella species) are endemic in the Lao People's Democratic Republic (Lao PDR). This study was designed to quantify the economic burden pig-associated zoonotic disease pose in Lao PDR. In particular, the analysis included estimation of the losses in the pork industry as well as losses due to human illness and lost productivity. A Markov-probability based decision-tree model was chosen to form the basis of the calculations to estimate the economic and public health impacts of taeniasis, trichinellosis and cysticercosis. Two different decision trees were run simultaneously on the model's human cohort. A third decision tree simulated the potential impacts on pig production. The human capital method was used to estimate productivity loss. The results found varied significantly depending on the rate of hospitalisation due to neurocysticerosis. This study is the first systematic estimate of the economic impact of pig-associated zoonotic diseases in Lao PDR that demonstrates the significance of the diseases in that country.

The monetary burden of cystic echinococcosis in Iran

Cystic echinococcosis (CE) is a globally distributed parasitic infection of humans and livestock. The disease is of significant medical and economic importance in many developing countries, including Iran. However, the socioeconomic impact of the disease, in most endemic countries, is not fully understood. The purpose of the present study was to determine the monetary burden of CE in Iran. Epidemiological data, including prevalence and incidence of CE in humans and animals, were obtained from regional hospitals, the scientific literature, and official government reports. Economic data relating to human and animal disease, including cost of treatment, productivity losses, and livestock production losses were obtained from official national and international datasets. Monte Carlo simulation methods were used to represent uncertainty in input parameters. Mean number of surgical CE cases per year for 2000-2009 was estimated at 1,295. The number of asymptomatic individuals living in the country was estimated at 635,232 (95% Credible Interval, CI 149,466-1,120,998). The overall annual cost of CE in Iran was estimated at US$232.3 million (95% CI US$103.1-397.8 million), including both direct and indirect costs. The cost associated with human CE was estimated at US$93.39 million (95% CI US$6.1-222.7 million) and the annual cost associated with CE in livestock was estimated at US$132 million (95% CI US$61.8-246.5 million). The cost per surgical human case was estimated at US$1,539. CE has a considerable economic impact on Iran, with the cost of the disease approximated at 0.03% of the country's gross domestic product. Establishment of a CE surveillance system and implementation of a control program are necessary to reduce the economic burden of CE on the country. Cost-benefit analysis of different control programs is recommended, incorporating present knowledge of the economic losses due to CE in Iran.

Cystic echinococcosis in slaughtered domestic ruminants from Tunisia

A total of 10,818 domestic ruminants (3913 cattle, 2722 sheep, 3779 goats, 404 dromedaries) slaughtered in various abattoirs in Tunisia between 2003 and 2010 were examined for the presence of Echinococcus granulosus hydatid cysts. The prevalence of cystic echinococcosis (CE) was 16.42% in sheep, 8.56% in cattle, 5.94% in dromedaries and 2.88% in goats. CE prevalence increased with age according to an asymptotic model and there was evidence of variation in infection pressure depending on the region of Tunisia where the animals were slaughtered. Cattle appeared to have the highest infection pressure of the species examined. The mean intensity of hepatic cysts was higher than that of pulmonary cysts in all species. The highest mean intensity of infection with E. granulosus larvae was observed in cattle (18.14) followed by sheep (9.58), goats (2.31) and dromedaries (2.12). The abundance of infection increased in a linear fashion with age in all animal species. Cyst abundance varied with species of animal and district of Tunisia. Cysts from dromedaries were more fertile (44.44%) than those from sheep (30.25%), goats (30.32%) and cattle (0.95%). The viability of the protoscoleces from fertile cysts from cattle (78.45%) was higher than those from sheep (70.71%) and camels (69.57%). The lowest protoscolex viability was recorded for hydatid cysts from goats (20.21%). This epidemiological study confirms the importance of CE in all domestic ruminant species, particularly in sheep, throughout Tunisia and emphasizes the need to interrupt parasite transmission by preventive integrated approaches in a CE control programme.

A retrospective study on burden of human echinococcosis based on Hospital Discharge Records from 2001 to 2009 in Sardinia, Italy

Cystic Echinococcosis (CE) is an infective zoonosis that represents a worldwide important public health problem. In humans, its manifestations may range from asymptomatic infection to severe disease and possible death, and lead to economic losses from treatment costs and lost wages. Recent studies suggest that this disease has a large social impact in endemic areas, and estimates of burden in terms of monetary and no-monetary impact on human health are essential to allocate financial and technical resources. In Sardinia, the most affected Italian region per number of inhabitants, CE is still endemic, although three eradication campaigns have been carried out in 1962, 1978, and 1987, respectively. To date, the burden of human CE in Sardinia remains poorly defined. In this work, a retrospective study was carried out using public Hospital Discharge Records spanning from 2001 to 2009. During these years, a total of 1409 discharges were recorded: 1196 (84.88%) records corresponding to patients hospitalized for symptoms directly correlated to CE (primary diagnosis), and 213 (15.11%) records corresponding to patients hospitalized for symptoms not directly correlated to CE and with an afterwards or concurrent diagnosis of echinococcosis made during the hospitalization (secondary diagnosis). The annual regional average record (discharge rate) was 9.3/100,000 inhabitants. Direct cost associated with diagnosis, surgery or chemotherapy, medical care, and hospitalization in humans were evaluated in this work. Furthermore, burden of disease was also evaluated by using the disability-adjusted life years (DALYs), the preferred disease-burden measure of the World Health Organization. Knowing the burden of human CE in Sardinia is extremely important to enable the prioritization of control measures for this preventable neglected disease. This is the first study describing the measure of the overall disease burden in an Italian region endemic for this disease, performed by calculating the number of CE patients from Hospital Discharge Records.

Economic impact of cystic echinococcosis in peru

Background

Cystic echinococcosis (CE) constitutes an important public health problem in Peru. However, no studies have attempted to estimate the monetary and non-monetary impact of CE in Peruvian society.

Methods

We used official and published sources of epidemiological and economic information to estimate direct and indirect costs associated with livestock production losses and human disease in addition to surgical CE-associated disability adjusted life years (DALYs) lost.

Findings

The total estimated cost of human CE in Peru was U.S.$2,420,348 (95% CI:1,118,384–4,812,722) per year. Total estimated livestock-associated costs due to CE ranged from U.S.$196,681 (95% CI:141,641–251,629) if only direct losses (i.e., cattle and sheep liver destruction) were taken into consideration to U.S.$3,846,754 (95% CI:2,676,181–4,911,383) if additional production losses (liver condemnation, decreased carcass weight, wool losses, decreased milk production) were accounted for. An estimated 1,139 (95% CI: 861–1,489) DALYs were also lost due to surgical cases of CE.

Conclusions

This preliminary and conservative assessment of the socio-economic impact of CE on Peru, which is based largely on official sources of information, very likely underestimates the true extent of the problem. Nevertheless, these estimates illustrate the negative economic impact of CE in Peru.

Cystic echinococcosis (CE), caused by infection with the larval stage of the cestode Echinococcus granulosus, constitutes an important public health problem in Peru. Despite its high prevalence in endemic communities no studies have attempted to estimate the economic impact of CE in Peruvian society. We used official and published sources of epidemiological and economic information to estimate direct and indirect costs associated with livestock production losses and human disease. We also used disability adjusted life years (DALYs) which is an overall measure of disease burden, expressed as number of years lost due to ill-health, disability or early death due to CE. We found that the total estimated cost of human CE in Peru was U.S.$2,420,348 per year. Total estimated livestock-associated costs due to CE ranged from U.S.$196,681 to U.S.$3,846,754. An estimated 1,139 DALYs were also lost due to surgical cases of CE which is comparable to DALY losses from Amebiasis or Malaria in Peru. This conservative assessment found significant economic losses caused by this CE in Peruvian society. The findings of this study are important as these data can serve to prioritize those areas that may need to be targeted in a control program.

Echinococcosis/hydatidosis: a severe threat in Mediterranean countries

Echinococcosis/hydatidosis is one of the most important parasitic zoonotic diseases in the world. Both cystic hydatidosis (CE) caused by Echinococcus granulosus and alveolar echinococcosis (AE) caused by E. multilocularis have been reported in several countries of the Mediterranean region (MR). E. granulosus has always been present in the MR and is the most common species. This parasite depends on the dog-sheep cycle and is actively transmitted in all pastoral regions where sheep, cattle and camelids predominate. E. multilocularis occurs only sporadically in limited areas of France, Serbia and Montenegro, Turkey, Tunisia and Morocco. However recent evidence indicates that it is spreading into other regions of the Mediterranean. Due to the lack of well-documented data, and to the fact that CE is not a notifiable disease in the majority of M countries, the precise incidence and prevalence of CE in humans and animals are not known. Published data suggests that prevalence is rather high in North Africa, Turkey, Greece, and in several regions of Italy and Spain. CE is an increasing public health and socio-economic concern due to the considerable morbidity rates that give rise to high economic losses both in the public health sector and in the livestock industry. Hospitalisation for human CE lasts from 2 weeks to more than 1 month in case of surgery. A number of factors contribute to the increase of prevalence and to the spreading of CE in the MR. These include the diversity of livestock production systems (predominantly extensive, traditional animal husbandry), small, ill-equipped and unsupervised slaughter-houses, illegal and family slaughtering, low public awareness of hydatid diseases, and the high population of stray dogs. Cyprus is the only country where an eradication programme has been successfully implemented. There have been, however, important developments in the last decade in CE epidemiology, in the diagnosis of canine infection, in strain characterisation and in immune strategies against CE in animals. This scientific progress, together with effective health education programmes, will likely improve control programmes and reduce the time required to achieve significant decreases in prevalence or eradication.

Analysis of the economic impact of cystic echinococcosis in Spain

OBJECTIVE

To estimate the overall economic losses due to human and animal cystic echinococcosis (CE) in Spain in 2005.

METHODS

We obtained data on annual CE incidence from surveillance and abattoir records, and on CE-related treatment and productivity losses (human and animal) from the scientific literature. Direct costs were those associated with diagnosis, surgical or chemotherapeutic treatment, medical care and hospitalization in humans, and condemnation of offal in livestock (sheep, goats, cattle and pigs). Indirect costs comprised human productivity losses and the reduction in growth, fecundity and milk production in livestock. The Latin hypercube method was used to represent the uncertainty surrounding the input parameters.

FINDINGS

The overall economic loss attributable to CE in humans and animals in 2005 was estimated at 148 964 534 euros (euro) (95% credible interval, CI: 21 980 446-394 012 706). Human-associated losses were estimated at euro133 416 601 (95% CI: 6 658 738-379 273 434) and animal-associated losses at euro15 532 242 (95% CI: 13 447 378-17 789 491).

CONCLUSION

CE is a neglected zoonosis that remains a human and animal health concern for Spain. More accurate data on CE prevalence in humans (particularly undiagnosed or asymptomatic cases) and better methods to estimate productivity losses in animals are needed. CE continues to affect certain areas of Spain, despite several control initiatives since 1986. Given the high economic burden of CE, additional funding is needed to reduce human and animal infection rates through improved disease surveillance, regular treatment of dogs and greater cooperation between agencies.

An abattoir-based study on the prevalence and economic losses due to cystic echinococcosis in slaughtered herbivores in Ahwaz, south-western Iran

A 10-year (1998–2008) retrospective study was carried out to investigate the prevalence and long-term trend of hydatid disease in slaughtered herbivores in the large complex abattoir of Ahwaz (the capital of Khuzestan province, south-western Iran). A total of 3,583,417 animals including 2,815,982 sheep, 427,790 goats and 339,645 cattle were inspected macroscopically for hydatid cysts in the 10-year period, and overall 155,555 (4.24%) livers and 228,172 (6.37%) lungs were condemned. Cystic echinococcosis (CE) was responsible for 36.08% and 48.04% of total liver and lung condemnations, respectively. The prevalence of pulmonary hydatid disease in sheep, goats and cattle was 2.22, 5.43 and 6.99%, respectively; on the other hand, the prevalence of hepatic hydatid disease for those animals was 1.26, 2.57 and 2.80%, respectively. Data showed an overall downward long-term trend for CE in all livestock slaughtered during the study period (P < 0.01). Lung condemnation due to CE was significantly more common than liver condemnation for each animal separately (P < 0.001). The prevalence of liver and lung hydatidosis in sheep was significantly lower than that in other livestock (P < 0.001). The prevalence of hydatid disease recovered from the sheep, cattle and goats varied in different seasons, but there was no statistical difference between various seasons. The odds ratio of lung and liver condemnations due to hydatidosis showed a slightly different pattern in some years; however, the overall declining trend was still observed. The total annual economic loss incurred due to hydatidosis in all ruminants slaughtered at Ahwaz municipal abattoir was estimated to be US$459,659.6, based on the market prices in the year 2008. This number corresponds to a loss of US$300,620.4 for cattle, US$123,490.0 for sheep and US$35,549.2 for goats. The current results provide baseline data for the future monitoring of this potentially important disease in the region, and also suggest that a thorough investigation leading to a disease control strategy is required to reduce the economic and public health consequences of CE.

[Complicated hydatid cysts of the lung]

BACKGROUND

Hydatid disease which is caused by the parasite Echinococcus granulosis is one of the most important helminthic diseases. The parasitic infection is endemic in many areas worldwide, including the Mediterranean region. The lung is the second most common involved organ. In the present study, we review cases of complicated pulmonary hydatidosis, discussing pathophysiological mechanisms and the clinical, radiological features, as well as natural history and therapeutic options.

METHODS

A retrospective study was conducted in the adult pulmonary department of The Tunis Chest Diseases and Surgery Training Hospital, a tertiary referral hospital for pulmonary diseases in Tunisia.

RESULTS

52 cases (mean age=34.6 years) were evaluated between 1998 and 2008. Rupture of the hydatid cyst occurred into the bronchi in the majority of cases (86.5%) and into the pleura in 9.6%. Extrathoracic involvement was found in 17.3% of the cases. Diagnosis of pulmonary hydatidosis was based on a consistent clinical and radiological presentation. Recourse to CT scan of the chest was helpful for diagnosis in 28% of the patients. Fibre-optic bronchoscopy (performed in 64.5% of cases) confirmed the diagnosis in 4 patients with total endoscopic extraction of hydatid cyst membrane in 2 cases. Surgical treatment was performed in 44 cases; resection of lung parenchyma was necessary in 8 patients (18.2%). Medical treatment was associated in 2 cases. Outcome revealed recurrence of pulmonary hydatidosis in 3 patients, and the death of 1 patient with chronic pulmonary hypertension due to chronic hydatid pulmonary embolism.

CONCLUSION

Complicated pulmonary hydatidosis may present some diagnostic difficulties, even in endemic regions. Management may be difficult, costly, and may require pulmonary resections.

Decision-model estimation of the age-specific disability weight for schistosomiasis japonica: a systematic review of the literature

Schistosomiasis is among the most prevalent parasitic infections worldwide. However, current Global Burden of Disease (GBD) disability-adjusted life year estimates indicate that its population-level impact is negligible. Recent studies suggest that GBD methodologies may significantly underestimate the burden of parasitic diseases, including schistosomiasis. Furthermore, strain-specific disability weights have not been established for schistosomiasis, and the magnitude of human disease burden due to Schistosoma japonicum remains controversial. We used a decision model to quantify an alternative disability weight estimate of the burden of human disease due to S. japonicum. We reviewed S. japonicum morbidity data, and constructed decision trees for all infected persons and two age-specific strata, <15 years (y) and ≥15 y. We conducted stochastic and probabilistic sensitivity analyses for each model. Infection with S. japonicum was associated with an average disability weight of 0.132, with age-specific disability weights of 0.098 (<15 y) and 0.186 (≥15 y). Re-estimated disability weights were seven to 46 times greater than current GBD measures; no simulations produced disability weight estimates lower than 0.009. Nutritional morbidities had the greatest contribution to the S. japonicum disability weight in the <15 y model, whereas major organ pathologies were the most critical variables in the older age group. GBD disability weights for schistosomiasis urgently need to be revised, and species-specific disability weights should be established. Even a marginal increase in current estimates would result in a substantial rise in the estimated global burden of schistosomiasis, and have considerable implications for public health prioritization and resource allocation for schistosomiasis research, monitoring, and control.

Schistosomiasis is a parasitic infection caused by a flatworm that disproportionately affects the world's poorest populations. Schistosomiasis is one of the most common infections worldwide, affecting over 207 million people in 76 countries. Current international estimates indicate that schistosomiasis has a minimal impact at the population level. This has contributed to its low prioritization in global health and subsequent resource allocation for disease control. However, recent studies indicate that these measures underestimate the extent of neglected tropical diseases, including schistosomiasis. Despite World Health Organization recommendations, the burden of schistosomiasis has not been re-examined in over a decade, and there are no established estimates for different types of schistosomiasis. The impact of symptoms associated with the Asian strain, Schistosoma japonicum, remains controversial. This study was conducted to provide an alternate measure of the burden of S. japonicum. We reviewed the literature and calculated a summary estimate for S. japonicum which was seven to 46 times greater than current measures for schistosomiasis. Findings suggest that current measures severely underestimate the extent of schistosomiasis, and urgently need to be revised. Further research is needed to examine the burden of schistosomiasis and other forgotten tropical diseases affecting the world's poorest people in endemic countries.

Screening for Echinococcus granulosus in dogs: Comparison between arecoline purgation, coproELISA and coproPCR with necropsy in pre-patent infections

Echinococcus granulosus is an important zoonotic infection of dogs. The purpose of the present study assessed the performance of two laboratory diagnostic methods with arecoline purgation and necropsy in infected dogs. In total 65 dogs were successfully experimentally infected with protoscoleces of E. granulosus from ovine infection. At 14-34 days post-infection groups of dogs were purged with arecoline hydrobromide and then necropsied. Faecal samples were tested at weekly intervals by coproantigen ELISA and coproPCR. The necropsy infection rate with E. granulosus was 89.2 per cent. Only 43 per cent of dogs were successfully purged after one arecoline dose; this percentage increased to 76.9% for two doses of arecoline purgation. E. granulosus coproantigen was detected by coproELISA in 82.8% of faeces. The positive and negative predictive values for coproantigen ELISA were 96 and 44.4% respectively. E. granulosus DNA was detected in pre-patent faecal samples by coproPCR in 25.9% of dogs. These results indicate that coproELISA is more sensitive than arecoline purgation for the detection of pre-patent E. granulosus infection in dogs. CoproPCR detected E. granulosus DNA in dog faeces by 21 days post-infection before egg production.

Ultrasonographic screening for cystic echinococcosis in sheep in Tunisia

Sheep from the areas of Fondouk-Jeddid, Bir Mchergua and El Fahs, located in the Northeast of Tunisia, were examined by ultrasonography between 2001 and 2004 in order to assess their infection with Echinococcus granulosus, the agent of hydatid disease, and to evaluate this method as an efficient aire for hydatid cysts. A total of 1039 sheep, aged between 1 and 14 years was examined. The highest prevalence was found in sheep aged more than 8 years. The least infected animals were aged between 1 and 2 years. All hydatid cysts detected by ultrasound were located in the liver. In all age-groups, the dead cysts were more numerous than viable cysts. Eighteen positive sheep were autopsied and a comparison between ultrasound and autopsy results was performed. The results showed a prevalence of about 40% for the three areas. Ultrasonography allowed the cysts, deep or superficial to localize in the central or left part in relation to the caudal vena cava of the animals. Consequently, all the cysts were not detected with this technique. This work shows that ultrasonography confirms the importance of ovine hydatid cyst in Tunisia and that its use as a mass screening approach for cystic echinococcosis in sheep could be helpful for the monitoring of this disease in a hydatid control program without great stress for the animals.

Global socioeconomic impact of cystic echinococcosis

Because the human and economic losses of cystic echinococcosis are substantial, global prevention and control measures should be increased.

Cystic echinococcosis (CE) is an emerging zoonotic parasitic disease throughout the world. Human incidence and livestock prevalence data of CE were gathered from published literature and the Office International des Epizooties databases. Disability-adjusted life years (DALYs) and monetary losses, resulting from human and livestock CE, were calculated from recorded human and livestock cases. Alternative values, assuming substantial underreporting, are also reported. When no underreporting is assumed, the estimated human burden of disease is 285,407 (95% confidence interval [CI], 218,515–366,133) DALYs or an annual loss of US $193,529,740 (95% CI, $171,567,331–$217,773,513). When underreporting is accounted for, this amount rises to 1,009,662 (95% CI, 862,119–1,175,654) DALYs or US $763,980,979 (95% CI, $676,048,731–$857,982,275). An annual livestock production loss of at least US $141,605,195 (95% CI, $101,011,553–$183,422,465) and possibly up to US $2,190,132,464 (95% CI, $1,572,373,055–$2,951,409,989) is also estimated. This initial valuation demonstrates the necessity for increased monitoring and global control of CE.

Present situation of echinococcosis in the Middle East and Arabic North Africa

Echinococcosis is one of the major zoonotic parasitic diseases in the Middle East and Arabic North Africa from Morocco to Egypt. Both cystic and alveolar echinococcosis has been reported from these areas. However, cystic echinococcosis is more prevalent and has been reported from all countries in the Middle East and Arabic North Africa. Alveolar echinococcosis is less prevalent and has been reported only from Iran, Turkey, Iraq and Tunisia. Present situation of echinococcosis in dogs and other definitive hosts, animal intermediate hosts and humans in the Middle East and Arabic North Africa has been reviewed. Echinococcus granulosus is highly prevalent in Iran, Turkey, Iraq, Morocco, Tunisia, and Libya. In the Levant countries, the cystic echinococcosis is also highly endemic. In Oman, it is endemic with low prevalence and a very low level in Cyprus. Various surveys have indicated that hydatid cysts are commonly found in sheep, cattle, goats and camels throughout the Middle East and Arabic North Africa. Sheep are the most infected animals of these regions. Most of studies on human have been focused on surgical reports although several population studies have been performed using serological and imaging techniques. Human cystic echinococcosis (CE) is prevalent in the Middle East and Arabic North Africa. It is hyper endemic in Iran, Turkey, Iraq, Jordan, Morocco, Libya, Tunisia, and Algeria, and endemic in Egypt. Studies on the strain specificities of E. granulosus in the Middle East revealed sheep strain (G1) present in sheep, goats, cattle, camels and humans, and the camel strain (G6) in camels, sheep, cattle as well as humans. Dog/sheep strain seems to be more prevalent in the foregoing regions in documented reports from Iran and Jordan. However, a strain of E. granulosus, which resembles the horse strain (G4) strain, has been reported from Jordan. Strain specifications of E. granulosus in Arabic North Africa showed that sheep/dog strain (G1) have been reported from Tunisia and Libya both from humans and animals. However, in Egypt the human cases reported are of camel/dog strain.

Methods for assessing the burden of parasitic zoonoses: echinococcosis and cysticercosis

Cysticercosis and echinococcosis cause illness and productivity losses in human and agricultural animal populations. Recent studies suggest that these diseases have large societal impacts on endemic areas. Estimates of burden provide essential, evidence-based data for conducting cost-benefit and cost-utility analyses that will secure political will, and financial and technical resources. To evaluate the burden, the monetary and non-monetary impacts of these zoonoses on human health, agriculture and society must be considered comprehensively. In this article, we review the framework used to assess the burden of cysticercosis and echinococcosis, and the data needed to estimate the extent of the problem for societies.