The changing epidemiology of echinococcosis in Kazakhstan due to transformation of farming practices

Food-borne zoonotic echinococcosis: A review with special focus on epidemiology

Echinococcosis is a neglected, WHO-listed cyclozoonotic parasitic disease that is caused by a number of species belonging to the genus Echinococcus. This disease is widespread across the globe, resulting in heavy economic losses for farmers and cystic disease in aberrant human hosts. This review paper briefly discussed taxonomy, a brief history, the magnitude of economic losses, host spectrum and life cycle, risk factors, and clinical manifestations. Furthermore, the copro- and sero-ELISA-based prevalence of echinococcosis on different continents was summarized. Finally, the authors analyzed the frequency and use of molecular epidemiology in the taxonomy of Echinococcus species based on molecular markers. This review will serve as a quick reference to Echinococcus.

One Health evaluation of brucellosis control in Kazakhstan

Brucellosis is one of the main livestock disease risks in Kazakhstan. It's been endemic there since 1930, accounting for over 1300 human cases per annum. The economic loss was 45 million USD in 2015 alone. Since 1952, Kazakhstan has implemented various control strategies with little success. One Health approaches have been suggested to tackle brucellosis, however, there is a lack of evidence for best practices to operationalise One Health in the literature, and methods for implementation are not established. The intention of this study was to introduce the One Health approach during the evaluation phase of the policy cycle. A two-day workshop was organized by the authors to familiarize participants with the evaluation methodology. Twenty-one specialists representing veterinary and public health sector, together with researchers, took part in this study. For two weeks following the workshop, first author conducted individual interviews with workshop participants to obtain individual scorings to assess knowledge integration capacity (One Health-ness). The evaluation results show that there is a lack of knowledge about the perceived damage caused by brucellosis to animal owners and other stakeholders. There is insufficient data available about farmers' practices, interests and motivations, and also data is missing for important transmission processes such as the amount of unsafe dairy consumption. The absence of such data illustrates the extent of the uncertainty to which decision-makers are exposed despite well-elaborated transmission models and supports the importance of co-producing solutions with participatory methods. The results suggest the need for broader involvement of stakeholders. Outputs of this study could help navigate the initial stages of One Health operationalization.

Surveillance of the Efficacy of Artemisinin-Piperaquine in the Treatment of Uncomplicated Plasmodium falciparum Malaria Among Children Under 5 Years of Age in Est-Mono District, Togo, in 2017

Background

Malaria is a major public health concern in Togo. The Est-Mono district of Togo has a population of 150,000. Accordingly, the Guangzhou University of Chinese Medicine, China and the Ministry of Health and Social Security, Togo launched a nationwide Mass Drug Administration Project with artemisinin-piperaquine (AP) in Est-Mono. Before launching this project, the sensitivity test of AP was conducted in a general clinic in Elawagnon, Togo. With this background, we evaluated the efficacy and safety of AP for the treatment of uncomplicated falciparum malaria in children under the age of 5 years.

Methods

Children aged 6-59 months with uncomplicated falciparum malaria were enrolled in this study. The selected patients were treated with a combination regime of artemisinin-piperaquine. The patients were followed up for 28 days, during which signs of the following were observed for: the duration for fever clearance, parasitemia density, gametophyte generation, cure rate, hemoglobin level, and merozoite surface protein-2 (msp-2) polymorphism. The primary end point was a 28-day cure rate and polymerase chain reaction (PCR)-corrected reinfection and recrudescence. This research followed the standardized World Health Organization (WHO) protocol for the assessment of the efficacy of antimalarial drugs.

Results

A total of 91 children with uncomplicated falciparum malaria were enrolled in this study. Adequate clinical and parasitological responses (ACPRs) before and after PCR-correction were 66 (73%) and 90 (99%), respectively. The average hemoglobin level in the patient increased by 0.05 g/dl per day (p < 0.0001) after the treatment. The gametophyte generation did not decline at the beginning of the treatment; however, after 14 days, it declined (day 21: p < 0.05; day 28: p < 0.01). In the msp-2 polymorphism study of 24 children treated for parasite infection, one case of msp-2 with 3D7 haplotype and FC27 haplotype was noted, indicating its recrudescence, with a frequency of 4%. The remaining 23 cases could have been of reinfection, with a frequency of 96%. No serious adverse reactions occurred, and AP was well-tolerated by all patients.

Conclusion

Artemisinin-piperaquine was found to be an effective combination for treating uncomplicated falciparum malaria in children aged <5 years in Togo, and the drugs were well-tolerated. In Togo, Plasmodium falciparum remains sensitive to artemisinin-piperaquine, necessitating its trial in this region.

Clinical Trial Registration

Trial registration: ECGPHCM No. B2017-054-01; MHSST AVIS N° 0001/2016/CBRS du 07 janvier 2016. Registered 17 March 2014, http://www.chinadrugtrials.org.cn/eap/main.

Incidence Rates of Surgically Managed Cystic Echinococcosis in Kazakhstan, 2007-2016

Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of the cestode Echinococcus granulosus. The parasite typically infects dogs and ungulates, with humans acting as dead-end hosts. Information on the epidemiology of CE is lacking from Central Asia, including from Kazakhstan where CE cases are reported centrally. This study presents data from the Kazakhstan Scientific and Practical Center for Sanitary and Epidemiological Evaluation and Monitoring on CE patients treated surgically, with a diagnosis confirmed by pathology. Evaluation of data from 2007 to 2016 indicated that the CE incidence rate decreased during this time period in most areas of Kazakhstan (country-level incidence rate of 5.6 versus 4.7 cases/100,000 population in 2007 and 2016, respectively). Cystic echinococcosis had a higher incidence in southern Kazakhstan, with an incidence rate between 7.0 and 10.5 cases per 100,000 population, whereas northern regions had rates less than 4.0 cases per 100,000 population. Moreover, despite the overall decrease, CE incidence continues to increase in the south. Cystic echinococcosis surveillance is needed, particularly in the south, to help inform policymakers and orient disease control efforts.

Epidemiology of Taenia saginata taeniosis/cysticercosis: a systematic review of the distribution in central and western Asia and the Caucasus

Background

The zoonotic parasite Taenia saginata transmits between humans, the definitive host (causing taeniosis), and bovines as the intermediate host (causing cysticercosis). Central and western Asia and the Caucasus have large cattle populations and beef consumption is widespread. However, an overview of the extent of human T. saginata infection and bovine cysticercosis is lacking. This review aims to summarize the distribution of T. saginata in this region.

Methods

A systematic review was conducted, that gathered published and grey literature, and official data concerning T. saginata taeniosis and bovine cysticercosis in central and western Asia and the Caucasus published between January 1st, 1990 and December 31st, 2018. Where no data were available for a country within this period, published data from 1985–1990 were also accessed.

Results

From 10,786 articles initially scanned, we retrieved 98 full-text articles from which data were extracted. In addition, two unpublished datasets were provided on the incidence of human taeniosis. Data for human taeniosis and bovine cysticercosis were found for all countries except Turkmenistan. Human taeniosis prevalence varied from undetected to over 5.3%, with regional variations. Where bovine cysticercosis was detected, prevalences varied from case reports to 25%.

Conclusions

The public health burden of T. saginata is assumed to be small as the parasite is of low pathogenicity to humans. However, this review indicates that infection continues to be widespread and this may result in a large economic burden, due to the resources utilized in meat inspection and condemnation or processing with subsequent downgrading of infected carcasses.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3438-3) contains supplementary material, which is available to authorized users.

Policies and Livestock Systems Driving Brucellosis Re-emergence in Kazakhstan

Brucellosis is a considerable public health and economic burden in many areas of the world including sub-Saharan Africa, the Middle East and former USSR countries. The collapse of the USSR has been cited as a driver for re-emergence of diseases including brucellosis, and human incidence rates in the former Soviet republics have been estimated as high as 88 per 100,000 per year. The aim of this paper is to examine the historical trends in brucellosis in Kazakhstan and to explore how livestock systems, veterinary services and control policies may have influenced them. In conclusion, a brucellosis epidemic most likely began before the collapse of the USSR and high livestock densities may have played an important role. Changes to the livestock systems in Kazakhstan, as well as other factors, are likely to have an impact on the success of brucellosis policies in the future. Incentives and practicalities of different policies in smallholder settings should be considered. However, the lack of reliable estimates of brucellosis prevalence and difficulties in understanding exactly how policy is being applied in Kazakhstan, which is a vast country with low population density, prevent firm conclusions from being drawn.

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.

Ecology and Life Cycle Patterns of Echinococcus Species

The genus Echinococcus is composed of eight generally recognized species and one genotypic cluster (Echinococcus canadensis cluster) that may in future be resolved into one to three species. For each species, we review existing information on transmission routes and life cycles in different geographical contexts and - where available - include basic biological information of parasites and hosts (e.g., susceptibility of host species). While some Echinococcus spp. are transmitted in life cycles that involve predominantly domestic animals (e.g., dog - livestock cycles), others are wildlife parasites that do or do not interact with domestic transmission. In many cases, life cycle patterns of the same parasite species differ according to geography. Simple life cycles contrast with transmission patterns that are highly complex, involving multihost systems that may include both domestic and wild mammals. Wildlife transmission may be primary or secondary, i.e., resulting from spillovers from domestic animals. For most of the species and regions, existing information does not yet permit a conclusive description of transmission systems. Such data, however, would be highly relevant, e.g., for anticipation of geographical changes of the presence and frequency of these parasites in a warming world, or for initiating evidence-based control strategies.

Limited Knowledge About Hydatidosis Among Farmers in Northwest Portugal: A Pressing Need for a One Health Approach

Hydatidosis is a re-emerging disease. Farmers are a vulnerable population; however, little is known about their awareness of this disease. The purpose of this study was two-fold: (1) to assess sheep and goat farmers' awareness of, perceptions of, and attitudes towards parasitic zoonoses and hydatidosis and (2) to identify the preferred means for promotion of information about hydatidosis. A cross-sectional study was conducted. An in-person questionnaire was constructed and administered to 279 individuals. A coprological survey in shepherd dogs was performed using 88 faecal samples. SPSS version 18.0 was used for statistical analysis. Farmers reported several risk practices (69% practice home slaughtering, 46% do not deworm the dogs, 58% of these dogs have contact with other animals) and very little knowledge about hydatidosis (97% have never heard about it). Nevertheless, 75% of the farmers demonstrated interest in receiving information, mainly from a veterinarian. A wide diversity of potentially zoonotic parasites (Trichuris spp., Ancylostomatidae, Toxocara spp., Taeniidae) was found in 61% of the dogs. This survey revealed farmers' lack of knowledge in relation to hydatidosis and a high prevalence of potentially zoonotic parasites in dogs, thus pointing to the need for health education and a closer collaboration between veterinarian and public health professionals.

Rabies in Kazakhstan

BACKGROUND

Rabies is a neglected zoonotic disease. There is a sparsity of data on this disease with regard to the incidence of human and animal disease in many low and middle income countries. Furthermore, rabies results in a large economic impact and a high human burden of disease. Kazakhstan is a large landlocked middle income country that gained independence from the Soviet Union in 1991 and is endemic for rabies.

METHODOLOGY/PRINCIPAL FINDINGS

We used detailed public health and veterinary surveillance data from 2003 to 2015 to map where livestock rabies is occurring. We also estimate the economic impact and human burden of rabies. Livestock and canine rabies occurred over most of Kazakhstan, but there were regional variations in disease distribution. There were a mean of 7.1 officially recorded human fatalities due to rabies per year resulting in approximately 457 Disability Adjusted Life Years (DALYs). A mean of 64,289 individuals per annum underwent post exposure prophylaxis (PEP) which may have resulted in an additional 1140 DALYs annually. PEP is preventing at least 118 cases of human rabies each year or possibly as many as 1184 at an estimated cost of $1193 or $119 per DALY averted respectively. The estimated economic impact of rabies in Kazakhstan is $20.9 million per annum, with nearly half of this cost being attributed to the cost of PEP and the loss of income whilst being treated. A further $5.4 million per annum was estimated to be the life time loss of income for fatal cases. Animal vaccination programmes and animal control programmes also contributed substantially to the economic losses. The direct costs due to rabies fatalities of agricultural animals was relatively low.

CONCLUSIONS/SIGNIFICANCE

This study demonstrates that in Kazakhstan there is a substantial economic cost and health impact of rabies. These costs could be reduced by modifying the vaccination programme that is now practised. The study also fills some data gaps on the epidemiology and economic effects of rabies in respect to Kazakhstan.

ZOONOTIC ENCOUNTERS AT THE SLAUGHTERHOUSE: PATHWAYS AND POSSIBILITIES FOR THE CONTROL OF CYSTIC ECHINOCOCCOSIS IN NORTHERN MOROCCO

This study traces the biosocial dynamics of Echinococcus granulosus – a zoonotic tapeworm spread between dogs, livestock and people – at slaughterhouses in Morocco. One of the most important parasitic zoonoses worldwide, this neglected cestode is responsible for a debilitating, potentially life-threatening, human disease and significant livestock production losses. Transmission can be interrupted, among other ways, by restricting dogs from eating cyst-infected livestock viscera. Recent epidemiological studies in Sidi Kacem province, northern Morocco, found that government-operated slaughterhouses were ‘hotspots’ for hydatid cysts in livestock and infection in dogs. An ethnographic approach was used to compliment these studies, exploring ‘how’ and ‘why’ cysts were being openly discarded. All seven visited slaughterhouses had low levels of hygiene, oversight and infrastructure. This was described locally as perpetuating a sense of ‘chaos’ that normalized (un)hygienic practices and justified the ignoring of state rules and regulations. However deference to ‘poor’ infrastructure, both physically and symbolically, served to under-emphasize local institutional logics, which were mediated by prevailing risk perceptions, economic practices and local socio-political norms. These included inter-departmental government relationships, the motivation of veterinary technicians, the political lobbying of butchers and market-based mitigation strategies. The study shows the importance of understanding E. granulosus from a biosocial perspective, and the need for more long-term, participatory and integrated ‘One Health’ approaches for neglected zoonotic diseases.

Risk factors for Echinococcus coproantigen positivity in dogs from the Alay valley, Kyrgyzstan

Echinococcosis, caused by the zoonotic cestodes Echinococcus granulosus (sensu lato) and Echinococcus multilocularis, is highly endemic in the Central Asian Republic of Kyrgyzstan, and is being identified increasingly as a public health problem, especially amongst pastoral communities. As domestic dogs are considered to be the main source of human infection, the identification of potential transmission pathways is of relevance when considering implementing an echinococcosis control scheme. The current report describes the results of an analytical study of canine Echinococcus coproantigen enzyme-linked immunosorbent assay (ELISA) prevalence in the Alay valley of southern Kyrgyzstan prior to the commencement of regular praziquantel dosing of dogs. A logistic regression model using a form of Bayes modal estimation was used to identify possible risk factors for coproantigen positivity, and the output was interpreted in a Bayesian context (posterior distributions of the coefficients of interest). The study found that sheepdogs had lower odds of coproantigen positivity, as did dogs in households with donkeys, where owners had knowledge of echinococcosis, and households which engaged in home slaughtering. Surprisingly, there was no evidence of an association between free roaming or previous praziquantel dosing and coproantigen positivity, as has been found in previous studies. Possible reasons for these findings are discussed in the context of the epidemiology of echinococcosis and potential intervention approaches.

Echinococcus granulosus: Epidemiology and state-of-the-art of diagnostics in animals

Diagnosis and detection of Echinococcus granulosus (sensu lato) infection in animals is a prerequisite for epidemiological studies and surveillance of echinococcosis in endemic, re-emergent or emergent transmission zones. Advances in diagnostic approaches for definitive hosts and livestock, however, have not progressed equally over the last 20 years. Development of laboratory based diagnostics for canids using coproantigen ELISA and also coproPCR, have had a huge impact on epidemiological studies and more recently on surveillance during hydatid control programmes. In contrast, diagnosis of cystic echinococcosis (CE) in livestock still relies largely on conventional post-mortem inspection, despite a relatively low diagnostic sensitivity especially in early infections, as current serodiagnostics do not provide a sufficiently specific and sensitive practical pre-mortem alternative. As a result, testing of dog faecal samples by coproantigen ELISA, often combined with mass ultrasound screening programmes for human CE, has been the preferred approach for monitoring and surveillance in resource-poor endemic areas and during control schemes. In this article we review the current options and approaches for diagnosis of E. granulosus infection in definitive and animal intermediate hosts (including applications in non-domesticated species) and make conclusions and recommendations for further improvements in diagnosis for use in epidemiological studies and surveillance schemes.

Epidemiology of echinococcosis in Kazakhstan: an update

Kazakhstan is highly endemic for echinococcosis. Both Echinococcus granulosus and E. multilocularis are widely distributed in the country. Official records of human cystic echinococcosis over the past 5–10 years suggest a stable incidence of approximately 800–1000 cases per year, which is 5 cases per 100,000 per year. This followed a rapid increase in the incidence following the dissolution of the Soviet Union. Between 2007 and 2013, 5949 cases were reported in the national surveillance data. The prevalence in sheep, based on slaughterhouse studies, suggests that between 30 and 50% of sheep are infected with hydatid cysts, while cattle have a prevalence of approximately 7%. Rural dogs have a high prevalence of infection of between 5 and 10%, with shepherd dogs having prevalences of over 20%. G1 and G6/7 strains of E. granulosus have been isolated from dogs in Kazakhstan. Wolves are also infected, with one prevalence estimate of approximately 20%. The incidence of human alveolar echinococcosis is less clear, although estimates from Kazakhstani expatriates living in Germany and the hospital records of a single referral centre in Almaty suggest 34 or 130 cases per year (or an annual incidence of 0.20 or 0.76 cases per 100,000), respectively, could be occurring in Kazakhstan. Studies suggest that in some rural dog populations the prevalence may be about 5%. The parasite is widely distributed in foxes and small mammals through much of Kazakhstan.

Epidemiology and control of echinococcosis in central Asia, with particular reference to the People's Republic of China

At least 270 million people (58% of the total population) are at risk of cystic echinococcosis (CE) in Central Asia including areas of Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, Afghanistan, Iran, Pakistan and western China. The annual surgical incidence rate in Uzbekistan and Tadjikistan has been estimated to be as high as 25-27 cases/100,000 with the highest prevalence reaching 10% (range from 0.8 to 11.9%) in some Tibetan communities in western China. Echinococcus transmission in the region is largely associated with social factors including limited community knowledge of echinococcosis, small-scale household animal production, home killing of livestock, and the feeding of dogs with uncooked offal. Alveolar echinococcosis (AE) is also endemic in Central Asia and is recognized as a major problem in some Tibetan communities with up to 6% of villagers infected in some villages. In western China, 5-30% of the population are seropositive against E. granulosus antigens, indicating that a large number of individuals have been exposed to the parasite. Although echinococcosis control programs have been initiated in some countries in Central Asia, control efforts are generally fragmented and uncoordinated. Monthly deworming of dogs with praziquantel (PZQ), as a key measure to control the Echinococcus parasites, has been used in western China. However, the approach has proven difficult in local semi-nomadic communities. Additional control measures including health education, domestic livestock animal treatment/vaccination and dog vaccination are needed in CE-endemic areas to accelerate progress.

Impact of echinococcosis on quality of sheep meat in the South eastern Kazakhstan

A survey of 2,123 slaughtered adult sheep in markets of the south-east Kazakhstan established that the average contamination of animals by Echinococcus granulosus is 9.1% with primary localization of cysts in livers and lungs. The histologic structure of the muscle tissue of infected sheep displayed destructive changes with a prevalence of granular dystrophy. The amount of protein, fat, calcium and energetical value of such meat considerably decreased. Besides in the muscle tissue of the animals infected with echinococcosis there was a substantial increase of humidity and amount of ash as well as qualitative and quantitative changes of the amino acids profile. Along with damage to the synthesis of proteins and sharp insufficiency of vitamins A, E, B₁, and B₂ there was a shift in a lipidic exchange that was expressed as a noticeable reduction in the level of monounsaturated and polyunsaturated fatty acids. The data support the conclusion that the meat from the sheep infected with echinococcosis is of inferior quality and quantity compared to that of healthy animals.

A systematic review of the epidemiology of echinococcosis in domestic and wild animals

BACKGROUND

Human echinococcosis is a neglected zoonosis caused by parasites of the genus Echinococcus. The most frequent clinical forms of echinococcosis, cystic echinococcosis (CE) and alveolar echinococcosis (AE), are responsible for a substantial health and economic burden, particularly to low-income societies. Quantitative epidemiology can provide important information to improve the understanding of parasite transmission and hence is an important part of efforts to control this disease. The purpose of this review is to give an insight on factors associated with echinococcosis in animal hosts by summarising significant results reported from epidemiological studies identified through a systematic search.

METHODOLOGY AND PRINCIPAL FINDINGS

The systematic search was conducted mainly in electronic databases but a few additional records were obtained from other sources. Retrieved entries were examined in order to identify available peer-reviewed epidemiological studies that found significant risk factors for infection using associative statistical methods. One hundred studies met the eligibility criteria and were suitable for data extraction. Epidemiological factors associated with increased risk of E. granulosus infection in dogs included feeding with raw viscera, possibility of scavenging dead animals, lack of anthelmintic treatment and owners' poor health education and indicators of poverty. Key factors associated with E. granulosus infection in intermediate hosts were related to the hosts' age and the intensity of environmental contamination with parasite eggs. E. multilocularis transmission dynamics in animal hosts depended on the interaction of several ecological factors, such as hosts' population densities, host-prey interactions, landscape characteristics, climate conditions and human-related activities.

CONCLUSIONS/SIGNIFICANCE

Results derived from epidemiological studies provide a better understanding of the behavioural, biological and ecological factors involved in the transmission of this parasite and hence can aid in the design of more effective control strategies.

The emergence of echinococcosis in central Asia

Following the collapse of the Soviet Union in 1991, there was an increase in the number of cases of human echinococcosis recorded throughout central Asia. Between 1991 and 2001 incidence rates of cystic echinococcosis (CE) increased by 4 fold or more. There also appeared to be increases in prevalence of CE in livestock and prevalences of Echinococcus granulosus reported in dogs. The increase in human echinococcosis was associated with changes in livestock husbandry, decline in veterinary public health services, increases in dog populations and increased poverty, all of which served to promote transmission of E. granulosus. A few years after reports of increased transmission of E. granulosus, the first reports of E. multilocularis infection in dogs were recorded. Further studies indicated that in both Kazakhstan and Kyrgyzstan prevalences of up to 18% were present. Recently there has been a dramatic increase in the number of cases of human alveolar echinococcosis recorded in Kyrgyzstan with over 60 cases reported in 2011.

Advances in liver echinococcosis: diagnosis and treatment

Echinococcosis or hydatid cyst disease is a zoonosis caused by the larval cestode Echinococcus granulosus. It consists of a parasitic tapeworm disease affecting mainly liver. Nevertheless, the disease might well spread to more unusual sites such as lungs and brain. The definitive diagnosis of liver echinococcosis requires a combination of imaging, serologic, and immunologic studies. Despite the fact that a number of scolecoidal agents have been developed against liver hydatid disease, the cornerstone of the definitive treatment remains surgery. Both the classic surgical techniques and the recently developed minimally invasive and laparoscopic methods target the eradication of the disease by simultaneously avoiding perioperative spillage and dissemination or recurrence of echinococcosis. The present article constitutes a review of the biology of the parasite as well as the epidemiology, diagnosis, and therapeutic options of the liver hydatid disease.

Dog echinococcosis in northern Spain: comparison of coproantigen and serum antibody assays with coprological exam

A large sheep-dog population from the province of Alava (northern Spain) has been investigated in order to determine the prevalence of the cestode parasite Echinococcus granulosus. Worms were detected in 14.0% of 721 dog faecal supernatants by coproantigen ELISA, and in 9.1% of 754 dog serum samples by serum antibody ELISA. A weak but statistically significant correlation (Spearman's rho=0.103, 95% CI: 0.023-0.178) between the two immunoassay results was found. In addition, eggs of the family Taeniidae were detected in 10.3% of 726 faecal samples examined by coproparasitological (flotation and sedimentation) tests. The overall E. granulosus infection rate, based on a Bayesian latent class model that accounts for the imperfect sensitivities and specificities of all diagnostic tests used, was estimated to be 8.0% (95% credible interval: 5.4-11.4%), corroborating that sheep-dog is the dog class most vulnerable to acquiring the infection. Dog sex did not influence the prevalence of E. granulosus, independently of the diagnostic test used or the dog region of origin. No significant linear correlation was found between the coproantigen ELISA OD values and the dog age (Spearman's rho=-0.049, 95% CI: -0.234 to 0.135), suggesting that there were no differences in prevalence of E. granulosus between old and young dogs. The obtained results highlight the importance of initiating a control program based on regular treatment of the sheep-dogs with praziquantel in the province of Alava.

Agricultural restructuring and gastrointestinal parasitism in domestic ruminants on the rangelands of Kazakhstan

In order to evaluate the epidemiology of parasitism in farmed ruminants in the changed agricultural context in Kazakhstan, 505 cattle, sheep and goats were surveyed for gastrointestinal parasitism using coprological examination, and a further thirty sheep and four goats using post mortem extraction of helminths. The dominant helminth genera were Marshallagia, Nematodirus and Trichostrongylus. Haemonchus was also present. Faecal egg counts were low (mean abundance 0-115 eggs per gram in different groups), and there was no relationship between faecal egg density and body condition score. Eggs of Nematodirus spp. were more common in sheep less than 1 yr of age, whereas those of the Trichostrongylidae were generally more common in adult sheep. Based on faecal egg counts, sheep grazing on common land close to permanent human settlements were generally no more heavily infected than those grazing the remote open plains. This could be due to a non-linear relationship between livestock numbers and stocking density. We suggest that cessation of strategic nematode control in the region following post-Soviet agricultural reform was offset by a general reduction in stocking density, such that parasite burdens remained low. However, recovery in livestock numbers is likely to lead to increased levels of infection and production loss unless sustainable control strategies are put in place.

Genetic typing of Echinococcus granulosus in Romania

In Romania, cystic echinococcosis is endemic and affects, besides humans, various animal species including sheep, cattle, and swine. As yet, no molecular-genetic typing has been carried out to clearly identify the putative strains being transmitted there. Parasite samples (protoscoleces or germinal layers) were collected from infected intermediate hosts and subsequently analyzed by comparing the PCR-amplified DNA sequences of three targets: one nuclear (BG1/3) and two mitochondrial (cox1 and nadI). Three strains were identified with the mitochondrial sequences: (i) the common sheep strain (G1) which circulates between sheep and cattle and is infective for humans, (ii) the Tasmanian sheep strain (G2) infecting sheep and cattle, and (iii) the pig strain (G7) predominantly found in swine. To our knowledge, this is the first report which demonstrates the occurrence of the Tasmanian sheep strain in cattle and the sympatric occurrence of these three strains (G1, G2, and G7) in Europe.