[Hydatid cyst sampling by FTA Card method for characterizing Echinococcus granulosus sensu lato in Algeria. Preliminary results]

Introduction and objectives

Cystic echinococcosis is highly endemic in Algeria and constitutes a major socio-economic problem. Typing the species of the Echinococcus granulosus sensu lato complex circulating in cattle requires the use of a hydatid cyst sampling method adapted to difficult field conditions (high heat and humidity, long transport time). The FTA Card method currently constitutes an effective means of preserving biological samples before their molecular analysis. In the present study, the FTA Card method was used in the collection of hydatid cysts to identify the species of E. granulosus sensu lato circulating in ruminants (intermediate hosts) in eastern Algeria.

Material and methods

A PCR was carried out for 41 samples of hydatid cysts taken from six slaughterhouses in eastern Algeria, targeting the cox1 mitochondrial gene. PCR products were visualized by electrophoresis in a 1% agarose gel.

Results and conclusion

The results of the molecular analysis of all hydatid cyst samples confirmed the presence of E. granulosus sensu stricto in sheep, cattle and camels. The ubiquitous nature of the G1 genotype has been demonstrated. The use of FTA Card sampling is an efficient and simple method to obtain a biological sample in order to characterize the species of E. granulosus sensu lato in Algeria. The good preservation of the DNA in this matrix will make it easier to obtain new molecular data from difficult regions. The identification of the species of the E. granulosus sensu lato complex involved in the biological cycle is an essential prerequisite for the implementation of control measures, since different host species participate in their evolutionary cycle. The characterization of E. granulosus genotypes is essential to define an appropriate control strategy against cystic echinococcosis.

Prevalence, risk factors and zoonotic potential of intestinal parasites in dogs from four locations in Morocco

Dogs can harbor various intestinal parasites that have serious clinical, economic, and zoonotic impact. In Morocco, the epidemiological status of those parasites is largely unknown. This study aimed to obtain data on the prevalence of intestinal parasites in various Moroccan dog populations, to identify associated risk factors, to evaluate people's knowledge regarding zoonotic parasites and to estimate the risk of human infection. A total of 291 fecal samples were analyzed using a 33% Zinc Sulphate (ZnSO4) centrifugal flotation and a sheather's sugar simple flotation techniques. In addition, 100 dog owners were asked to fill out a questionnaire about their knowledge regarding canine zoonotic intestinal parasites. Overall, 58% of sampled dogs were positive for at least one parasite species. Ancylostoma/Uncinaria spp. (31.9%), Toxascaris leonina (27.4%), Toxocara canis (27.1%), Cystoisospora spp. (13.4%) and Giardia spp. (7.2%) were the most frequently isolated parasites. The overall prevalence was associated with the dogs' activity, and feces consistency. More specifically, the prevalence of Ancylostoma/Uncinaria spp., Toxascaris leonina and Cystoisospora spp. was associated with dogs' activity and feces consistency and, additionally with age for Cystoisosporaspp.Toxocara canis prevalence was associated with age and feces consistency, while Giardia spp. prevalence was associated with dogs' activity. A weak awareness among dog owners regarding the zoonotic potential of canine intestinal parasites was noticed (33%) especially when their knowledge was compared to another endemic zoonotic disease, i.e. rabies (85%). Furthermore, the rate of respecting the vaccination protocol (82%) was significantly higher than the rate of respecting the deworming protocol (47%). We conclude that intestinal parasites, including the zoonotic ones, were highly prevalent in the dogs sampled in this study whereas people's knowledge about those parasites was very limited. These findings suggest that the risk of human infection is very likely, which highlights the need for effective control programs and health education.

A retrospective analysis of surgical techniques and outcomes of hydatid disease in Wasit, Iraq

Echinococcosis is a parasitic infestation with high prevalence in Iraq. Surgical treatment remains the standard gold method for treating this disease. The selection of surgical approach depends on the general condition of the patient and characters of the cyst, e.g., size, location, number of cysts, intraoperative findings, and complications such as adhesion, bile leakage, and bleeding. Our study aimed (1) to summarize the most common surgical approaches for treating liver hydatid cyst (HC) in our locality, and (2) to highlight common intraoperative and postoperative complications and the duration of hospital stay. We analyzed the clinical data of 42 patients operated for liver HC. We found that the highest incidence rate of HC was anatomically in the right hepatic lobe with or without synchronous cysts in other organs. The most frequent type of surgery was partial pericystectomy with external tube drainage (ETD) or simple endocystectomy with omentoplasty and ETD. The most important intraoperative finding was cystic-biliary communication. The majority of patients had uneventful postoperative recovery. There is no standardized surgical procedure for hepatic HC. The surgical technique should be modified according to the cyst size, anatomic location of cyst/cysts, number of cysts, cystobiliary communications, cystic infection, and the presence of extrahepatic hydatid cyst or cysts. The surgeon's experience plays a vital role in selecting the surgical technique for hepatic hydatid cystectomy.

A systematic review and meta-analysis on prevalence and distribution of Taenia and Echinococcus infections in Ethiopia

Background

Tapeworm infections are among the tropical neglected parasitic diseases endemically occurring in Ethiopia. This systematic review and meta-analysis aims at estimating the pooled prevalence and distribution of Taenia and Echinococcus infections in humans and animals from reports from Ethiopia.

Methods

The systematic search was conducted in four bibliographic databases (PubMed, Google Scholar, Africa Journal Online and Science Direct). Additional data were retrieved from grey literature. Studies that met the inclusion criteria were considered for the systematic review and meta-analysis. The meta-analysis was conducted using MetaXL add-in for Microsoft Excel. Heterogeneity and inconsistency were evaluated using Cochran’s Q and I² statistics, respectively.

Results

The study provides a country-based database of Taenia and Echinococcus infections consisting of 311 datasets from 201 publications which were mostly abattoir surveys; of these, 251 datasets were subjected to meta-analysis. Most of the studies were from Oromia (32.8%) followed by Amhara (22.9%) regional states. The pooled prevalence of cystic echinococcosis in intermediate and accidental hosts was calculated as 22% (95% CI 18–26%) and high study variability (Q = 24,420.65, I² = 100%, P = 0.000). Moreover, a pooled prevalence of Echinococcus infections in final hosts was calculated as 33% (95% CI 20–48%) and low study variability (Q = 17.24, I² = 65%, P = 0.001). Similarly, study subjects (human, cattle, sheep, goat and wolf) were infected by Taenia spp. with pooled prevalence of 3% (95% CI 2–4%) and moderate study variability (Q = 279.07, I² = 89, P = 0.000). Meanwhile, the pooled prevalence of Taenia hydatigena, T. ovis and T. multiceps infections in intermediate hosts were calculated as 38%, 14% and 5%, respectively. The random effect meta-analysis of bovine cysticercosis showed a pooled prevalence of 7% (95% CI 5–9%) and high study variability was of (Q = 4458.76; I² = 99%, P = 0.000). Significant differences in prevalence of Taenia and Echinococcus infections between study sites or different livestock origins have been reported.

Conclusion

The study evidenced a comprehensive dataset on the prevalence and distribution of Taenia and Echinococcus infections at different interfaces by regions and hosts and hence can aid in the design of more effective control strategies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04925-w.

Cystic echinococcosis in sheep and goats of Lebanon

Cystic echinococcosis (CE), a zoonotic disease caused by the species complex of Echinococcus granulosus sensu lato (s.l.), is endemic in Middle East and the Mediterranean basin, where pastoral activity is widespread. Despite the chronic endemicity of the disease in Lebanon and neighbouring countries, recent data are scant. The objectives of this survey were to evaluate the current epidemiology of CE in Lebanon, investigate the prevalence and determine the infecting genotypes in locally raised sheep and goats. A multidimensional approach combining post-mortem inspection of slaughtered animals and molecular diagnosis of the parasite was conducted to this end. From 2018 to 2020, 62.9% of the sheep and 20.9% of the goats were found positive for CE. The presence of hydatids varied between organs, showing higher prevalence in the liver of sheep vs the lungs of goats, however, a higher fertility rate of hydatid cyst was observed in lungs for both animals. Molecular diagnosis based on partial mitochondrial cox1 gene (795 bp) showed that the majority of isolates were identified as E. granulosus sensu stricto (98.7%) and only one isolate from goat was identified as Echinococcus canadensis (genotype G7; 1.3%). Echinococcus granulosus s.s. population among the sheep and goats was represented by 22 haplotypes having very little genetic differentiation and relatively moderate haplotype diversity. Population demographics explored through neutrality indices suggested expanding population within the intermediate hosts. These results document the high prevalence of CE in the livestock of Lebanon and reveal for the first time the presence of three different genotypes G1, G3 and G7.

Feasibility and acceptability of a new integrated approach to control cystic echinococcosis in Morocco: Vaccination of sheep and anthelmintic treatment of dogs

Cystic echinococcosis (CE) or hydatidosis is a common parasitic disease worldwide, especially in poor and developing countries. In Morocco, CE is a major zoonosis, despite the implementation of a national control program since 2007. Therefore, in 2016, a field trial that associates the EG95 vaccine (lambs) and anthelmintic treatment (dogs) was started in the Mid Atlas, the most endemic region in Morocco, with preliminary positive results. Here, a qualitative approach was used to analyze the feasibility and social acceptability of this strategy. Fifteen focus group discussions were separately conducted with breeders and with their wives, and forty-two individual interviews were performed with private-sector veterinarians and officers from structures responsible for the CE control program. Recordings were transcribed and analyzed with the R software, using the RQDA package. This qualitative research was validated using the credibility, transferability, dependability and confirmability criteria. This study showed that the professionals' views on sheep vaccination and anthelmintic treatment were divided between acceptability and concerns. Conversely, breeders and their wives highlighted the issue of the costs of procedures the utility of which was not immediately clear to them. All participants proposed solutions to improve this strategy, and also stressed the lack of education on CE. By bringing together the views of the communities and the professionals, this study traced the main lines (targeting the different aspects of CE and taking into account the local socio-cultural beliefs) that must be taken into account to ensure the short- and long-term CE control in Morocco.

Control of cystic echinococcosis in the Middle Atlas, Morocco: Field evaluation of the EG95 vaccine in sheep and cesticide treatment in dogs

BACKGROUND

Cystic echinococcosis (CE) is an important cause of human morbidity and mortality worldwide, particularly in Morocco and other North African countries.

METHODOLOGY/PRINCIPAL FINDINGS

We investigated the potential of three strategies to reduce Echinococcus granulosus transmission: (1) 4-monthly treatment of dogs with praziquantel, (2) vaccination of sheep with the EG95 vaccine and (3) a combination of both measures. These measures were implemented during four consecutive years in different areas of the Middle Atlas Mountains in Morocco. The outcome of the interventions was assessed through hydatid cyst (viable and non-viable) counts in liver and lungs using necropsy or in vivo ultrasound examination of the liver. A total of 402 lambs were recruited for annual vaccination with the EG95 anti-E. granulosus vaccine and 395 similar lambs were selected as non-vaccinated controls. At approximately four years of age the relative risk (estimated as odds ratio) for vaccinated sheep to have viable hydatid cysts compared with non-vaccinated controls was 3% (9.37% of the vaccinated sheep were found infected while 72.82% of the controls were infected; p = 0.002). The number of viable cysts in vaccinated animals was reduced by approximately 97% (mean counts were 0.28 and 9.18 respectively; p<0.001). An average of 595 owned dogs received 4-monthly treatment during the 44 months trial, corresponding to 91% of the owned dog population. Approximately, 5% of them were examined for E. granulosus adult worms by arecoline purge or eggs in feces (confirmed by PCR). The proportion of infected dogs significantly decreased after treatment (12% versus 35%; p<0.001). Post-treatment incidence of re-infestation corresponded to a monthly risk of 4% (95% CI: 3-6%). Treatment of owned dogs on a 4-monthly basis did not reduce the level of transmission of E. granulosus to sheep, nor did it enhance the level of control generated by vaccination of sheep with EG95, possibly because of unowned dogs and wild canids were not treated.

CONCLUSIONS/SIGNIFICANCE

These data suggest that vaccination of sheep with EG95 has the potential to reduce the level of CE in Morocco and in other parts of the world with similar transmission dynamics. Under the epidemiological circumstances existing in the trial area, 4-monthly treatment of owned dogs with praziquantel was insufficient to have a major impact of E. granulosus transmission to sheep.

Evaluation of integrated control of three dog transmitted zoonoses: Rabies, visceral leishmaniasis and cystic echinococcosis, in Morocco

The present study is a component of a major European research project, ICONZ (Integrated Control of Neglected Zoonoses). The objective of this component was to implement, and then evaluate an Integrated Control Intervention (ICI) against three dog transmitted zoonoses, namely rabies, visceral leishmaniasis, and cystic echinococcosis. This was undertaken in Sidi Kacem Province (northwestern Morocco) where 22 control and 22 treated douars (villages) were randomly allocated to two control and one evaluation interventions over a period of 13 months. Across the 44 douars, an overall total of 6922 dogs were registered, 4519 were vaccinated against rabies, and 2885 persons attended the complementary health education campaigns; whereas, within the 22 treated douars, 466 dogs received anti-sandfly collars (deltamethrin-impregnated) and 2487 were dewormed (praziquantel). Evaluation of the ICI, revealed that (i) a canine rabies vaccination coverage of 65.0% was achieved, (ii) the use of deltamethrin-impregnated collars for dogs provided highly significant protection (p = 0.01) against leishmaniasis infection of more than 44%, and up to 100% for dogs that had kept the collar until the end of the intervention, (iii) despite a non-significant difference (p>0.05), dog-deworming with praziquantel yielded a reduction in the rate of Echinococcus granulosus infection, and (iv) health education was successful in improving respondents' knowledge; However, the target communities remained unconvinced of the necessity of changing some of their risky behaviours. Lastly, the estimated total cost of the global intervention, including its research components, was US$ 143,050, of which 67% was for disease control work with clear evidence of significant economies of scale due to targeting three diseases together. It appears from this study that the integrated control approach against the three zoonoses was effective on both economic and logistical levels.

Zoonotic implications of camel diseases in Iran

Approximately 60% of all human pathogens and 75% of emerging infectious diseases are zoonotic (of animal origin). Camel zoonotic diseases can be encountered in all camel-rearing countries. In this article, all studies carried out on camel zoonotic diseases in Iran are reviewed to show the importance of camels for public health in this country. More than 900 published documents were systematically searched to find relevant studies from 1,890 until late 2018. The collected articles were classified according to the aetiological agents. In this study, 19 important zoonotic diseases were reported among Iranian camels including listeriosis, leptospirosis, plague, Q fever, brucellosis, campylobacteriosis, tuberculosis, pasteurellosis, clostridiosis, salmonellosis, Escherichia coli infections, rabies, camelpox, Middle East respiratory syndrome coronavirus, Crimean-Congo haemorrhagic fever, echinococcosis, cryptosporidiosis, toxoplasmosis and dermatophytosis, most of which belong to bacterial, viral, parasitic and fungal pathogens, respectively. Results show that camels are one of the most important sources of infections and diseases in human; therefore, continuous monitoring and inspection programs are necessary to prevent the outbreak of zoonotic diseases caused by this animal in humans.

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.

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.

Echinococcus granulosus infection in dogs in Sidi Kacem Province (North-West Morocco)

This study was undertaken in the Province of Sidi Kacem in northwest Morocco between April 2010 and March 2011. The main objective of the study was to determine the prevalence of Echinococcus granulosus (Eg) infection in owned dogs. This province was selected as a case study because of the social conditions, geographic and climatic diversity making it a model representative of many parts of Morocco. The survey was carried out in 23 rural communes and in the 5 municipalities (urban districts) of the Province and sampling was undertaken in randomly selected households. A total of 273 owned dogs comprising 232 from the 23 rural communes (rural dogs) and 41 from the 5 municipalities (urban dogs) were tested. Arecoline hydrobromide purgation was selected as the diagnostic method of choice to enable visualisation of expelled worms by dog owners, thereby imparting messages on the transmission mode of Eg to humans and farm animals. Of the 273 dogs tested, purgation was effective in a total of 224 dogs (82.1%). The overall estimated prevalence of Eg infection was 35.3% (79/224, 95% CI 22.3-47.0%). Dogs inhabiting rural communes were at greater risk of infection (38.0%, 95% CI 31.1-45.3%) than dogs roaming in municipalities or urban areas (18.8%, 95% CI 7.2-36.4%) and the prevalence of infection was higher in those inhabiting rural communes with slaughterhouses (62.7%, 95% CI 48.1-75.9%) than in communes without (29.1%, 95% CI 21.7-37.2%). This first assessment of Eg infection in Sidi Kacem Province indicates a key role of rural slaughterhouses in parasite transmission to dogs.

Molecular characterization of Echinococcus granulosus sensu stricto and Echinococcus canadensis in humans and livestock from Algeria

In Algeria, previous studies investigated genotypes of Echinococcus granulosus sensu lato in animals and identified E. granulosus sensu stricto (s.s.) genotypes G1 and G3 whereas Echinococcus canadensis genotype G6 was only reported from dromedary cysts. Molecular data on human cystic echinococcosis (CE) were limited. We implemented a large genotyping study of hydatid cysts from humans and livestock animals to specify CE's molecular epidemiology and the genetic diversity in Algeria. Fifty-four human CE cysts from patients predominantly admitted in surgical units from Mustapha Hospital, Algiers, and 16 cysts from livestock animals gathered in two geographically distinct slaughterhouses, Tiaret and Tamanrasset, were collected. Molecular characterization was performed using sequencing of two mitochondrial genes, cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit I (NDI). In humans, G1 of E. granulosus s.s. was the main genotype (90.7 %); four samples (7.4 %) were characterized as E. granulosus s.s. G3 and one cyst as E. canadensis G6 (1.8 %). This molecular confirmation of E. canadensis G6 human infection in Algeria was observed in a Tuareg female living in a desertic area in Tamanrasset. All cysts from sheep, cattle, and goat were identified as E. granulosus s.s. G1 and the two cysts originating from dromedary as E. canadensis G6. Twenty concatenated haplotypes (COI + NDI) were characterized. Among E. granulosus s.s., one haplotype (HL1) was highly predominant in both humans and animals cysts (71.6 %). This study revealed main occurrence of E. granulosus s.s. in humans and livestock animals, with description of a predominant shared haplotype corresponding to the main worldwide observed haplotype E.granulosus s.s. G1. E. canadensis G6 was limited to South Algeria, in dromedary as well as in human.

Knowledge, attitudes and practices with regard to the presence, transmission, impact, and control of cystic echinococcosis in Sidi Kacem Province, Morocco

BACKGROUND

This study is a component of a large research project on five major neglected zoonotic diseases (NZDs) including cystic echinococcosis and was undertaken in the Province of Sidi Kacem over a period of four years (April 2009-March 2013).

METHODS

Questionnaires were administered at community level in a total of 27 communes and visits were made to all of the 10 abattoirs situated in the Province, to collect qualitative data on determinants of transmission for disease in humans and animals. More specifically, community knowledge, attitudes and practices related to cystic echinococcosis were assessed, as well as the extent to which local customs and behaviours may promote transmission. Abattoir infrastructure and practices, and their role in perpetuating disease transmission were also critically evaluated.

RESULTS

The results show that only 50 % of people have heard of the disease, and of those, only 21 % are aware of the dog's role in disease transmission. Sixty-seven per cent of respondents stated that dogs are fed ruminant organs deemed unfit for human consumption. Owned dogs have access to the family home, including the kitchen, in 39 % of households. The extent of this close proximity between humans and animals is even more pertinent when one considers that dogs are omnipresent in the community, with an average of 1.8 dogs owned per household. The unrestricted access of dogs to abattoirs is a huge issue, which further promotes disease transmission.

CONCLUSION

This study would suggest that the high prevalence of cystic echinococcosis in humans and animals in Morocco is largely due to three factors: 1) abundance of dogs 2) engagement in risky behaviour of the local population and 3) poor abattoir infrastructure and practices. This has serious implications in terms of the socio-economic impact of the disease, especially for rural poor communities.