Human Cystic Echinococcosis Cases Research Articles

Species and genotypes belonging to Echinococcus granulosussensu lato complex causing human cystic echinococcosis in Europe (2000\u20132021): a systematic review

BackgroundThis study aimed to fill a gap of knowledge by providing a quantitative measure of molecularly identified species and genotypes belonging to Echinococcus granulosussensu lato (s.l.) causing human cystic echinococcosis (CE) in Europe during the period 2000–2021. As these species and genotypes are characterized by genetic, animal host and geographical differences, studying the E. granulosuss.l. complex is epidemiologically relevant.MethodsA systematic review (SR) was conducted on the basis of both scientific and grey literature considering primary studies between 2000 and 2021 in four databases. From a total of 1643 scientific papers, 51 records were included in the SR. The main inclusion criterion for this study was the molecular confirmation of E. granulosuss.l. at the genotype/species level as a causative agent of human CE cases in selected European countries.ResultsRelevant data were obtained from 29 out of 39 eligible European countries. This SR identified 599 human molecularly confirmed echinococcal cysts: 460 (76.8%) identified as E. granulosussensu stricto (s.s.), 130 (21.7%) as E. canadensis cluster (G6/7 and G10), 7 (1.2%) as E. ortleppi (G5), and 2 as E. vogeli (0.3%). Three geographical hotspots of human CE caused by different species of the E. granulosuss.l. complex were identified: (1) E. granulosuss.s. in Southern and South-eastern Europe (European-Mediterranean and Balkan countries); (2) E. canadensis (G6/7) in Central and Eastern Europe; (3) E. ortleppi in Central and Western Europe. This SR also identified data gaps that prevented a better definition of the geographical distribution of the Echinococcus granulosuss.l. species complex in Europe: western Balkan countries, part of Central Europe, and Baltic countries.ConclusionsThese results mandate longitudinal, multi-centre, intersectoral and transdisciplinary studies which consider both molecular and clinical epidemiology in animals and humans. Such studies would be valuable for a better understanding of the transmission of the E. granulosuss.l. species complex and their potential clinical impact on humans.Graphical

Human Cystic Echinococcosis in Lebanon: A Retrospective Study and Molecular Epidemiology

PurposeHuman cystic echinococcosis (CE) is a zoonotic parasitic disease that constitutes a public health challenge and a socio-economic burden in endemic areas worldwide. No specific surveillance system of CE infections in humans exists in Lebanon. The incidence and trends over time have not been documented. The current study aimed to assess the demographic and epidemiologic features of human CE surgical cases over a 14-year period in the five main regions of Lebanon.MethodsFrom 2005 to 2018, a total of 894 surgically confirmed cases of hydatidosis were recorded from five anatomy and pathology laboratories.ResultsThe mean annual surgical incidence was 1.23/100,000 inhabitants. Over the span of these years, the incidence increased from 0.53 to 1.94 cases/100,000 inhabitants in 2005 and 2018, respectively. CE is present in Lebanon with an uneven distribution from one region to the other with higher prevalence in Bekaa (29.0%), a rural area where sheep raising is widespread. Human CE cases were more common in females (60.1%) than in males (39.9%) and a high burden of infection was reported for the age group of 30–39 years. Besides, 66.7% of the cases expressed only liver complications whereas, 20.5% showed predilection towards lungs. The 7.8% of cases presented cysts in other organs, and 1.3% showed multiple localizations. Additionally, predominant involvement of Echinococcus granulosus sensu stricto was recorded in human infections. Comparison of Echinococcus granulosus s.s. populations from different Mediterranean countries also revealed high gene flow among this region and sharing of alleles.ConclusionThe current study is a step forward to fill the gap of knowledge for the hydatidosis in Lebanon where the lack of epidemiological data and control measures have resulted in higher incidence of human CE.Graphic

Factors influencing the spatial distribution of cystic echinococcosis in Tibet, China

Cystic echinococcosis (CE), which is caused by Echinococcus granulosus, is a worldwide helminthozoonosis that is highly endemic in the Tibet Autonomous Region of China and has important public health and economic impacts. However, the spatial epidemiological characteristics of CE in Tibet are still unclear. Based on recorded human CE cases and the use of a geographic information system, the spatial distribution patterns of CE prevalence at three different scales were analyzed. In addition, a spatial agglomeration map of CE prevalence was generated based on cold/hot spot analysis. By combining maps of environmental and biological covariates with information about known human CE cases, the links between CE prevalence and relevant covariates were explored, revealing that the annual average precipitation, elevation, water accessibility and animal population (dog and yak) were associated with the prevalence of CE at the significance level of P < 0.05. Our results provide a novel insight and better understanding of the current situation of and the factors influencing CE in Tibet, which can help public health authorities develop disease prevention and control strategies.

Molecular Characterization of Echinococcus granulosus sensu lato from Humans in Slovenia.

The larval form of tapeworms of the Echinococcus granulosus sensu lato species cluster cause an important zoonotic infection, cystic echinococcosis (CE). Molecular characterization of the cluster’s isolates from different hosts greatly contributes to a better understanding of its transmission dynamics. To date, no genetic information is available on CE in Slovenia. In this work, we characterized isolates from human CE cases. Parasite samples from 18 patients were collected, together with the patients’ demographic and clinical data. Genomic DNA was analyzed by conventional PCR and sequencing at four mitochondrial loci (cytochrome c oxidase subunit 1, cox1; NADH dehydrogenase subunit 1, nad1; NADH dehydrogenase subunit 5, nad5; and small ribosomal RNA, rrnS). Thirteen isolates were successfully amplified and sequenced. Seven (58.8%) patients were infected with E. granulosus sensu stricto (s.s.) G1, five (38.5%) with E. canadensis G7 and one (7.7%) with E. granulosus s.s. G3. Echinococcus canadensis G7, the pig genotype, was identified exclusively in autochthonous Slovenes, while the patients originating from the Western Balkans were all infected with E. granulosus s.s. Our findings suggest that pigs are important intermediate hosts for human CE in Slovenia.

First report of Echinococcus canadensis (G6/G7) by sequence analysis from the Khyber Pakhtunkhwa province of Pakistan

Cystic echinococcosis (CE) is a zoonotic parasitic disease that can result in human and animal health problems globally. Although the disease is known to be endemic in Asia and the Middle East, there are few epidemiological studies on CE in Pakistan. The purpose of the present study was to identify the Echinococcus granulosus sensu lato species and genotypes contributing to human CE cases in the Khyber Pakhtunkhwa (KPK) province of Pakistan. A total of fifty-six formalin fixed paraffin embedded (FFPE) CE cyst samples of human origin were collected from the Pathology Department, Rehman Medical Institute (RMI), KPK for the years 2012-2017. Cyst samples came from the liver (26/56; 46.4%), lungs (3/56; 5.3%), spleen (3/56; 5.3%), pelvis (1/56; 1.8%), breast (1/56; 1.8%), and thigh (1/56; 1.8%). The organ location for 21 of the cysts was not recorded. World Health Organization-Informal Working Group on Echinococcosis (WHO-IWGE) ultrasound-based cyst staging was available for 17 of the 26 (65.4%) hepatic cysts. Five of these cysts (29.4%) were CE3 (transitional), nine (52.9%) were CE4 (inactive), and three (17.6%) were CE5 (inactive). Most of the cysts were obtained from CE patients that were ethnically Afghan Pashtuns (44/56; 78.6%), while 12.5% (7/56) were from patients that were Pakistani Pashtuns. The majority (41/56; 73.2%) of patients reported having close interactions with dogs. Using 12SrRNA primers, 33 cyst samples were identified as being caused by E. granulosus sensu stricto (s.s.). Mitochondrially encoded cytochrome C oxidase 1 (mt-CO1) was evaluated for the remaining 23 samples. PCR product was obtained from six of these 23 samples. Of these six samples, one was identified as Echinococcus canadensis (G6/7). Haplotype analysis showed high haplotype and low nucleotide diversity for the mt-CO1 gene. There were 26 polymorphic sites for the mt-CO1 sequence, of which 65.3% (17/26) were parsimony informative. The E. canadensis mt-CO1 haplotype network consisted of 11 haplotypes, with a main central haplotype. In conclusion, it appears that E. granulosus s.s. and E. canadensis (G6/7) are circulating in the northwestern region of Pakistan. Further molecular epidemiological studies are needed to explore the local genetic diversity of the parasite.

Genetic diversity of Echinococcus granulosus sensu stricto in Sardinia (Italy).

Cystic echinococcosis (CE) is a severe parasitic zoonosis caused by the metacestode of the tapeworm Echinococcus granulosus sensu lato (s.l.). The disease has a global distribution representing a significant public health concern. Based on mitochondrial DNA analysis E. granulosus s.l. has been subdivided into five species: E. granulosus sensu stricto (s.s.) (G1, G3 genotype), E. equinus (G4 genotype), E. ortleppi (G5 genotype), E. canadensis (G6-G8, G10 genotype) and E. felidis. E. granulosus s.s., and in particular G1, is the most widespread genotype and the major responsible of human CE cases worldwide. In Italy G1 genotype is higly represented with larger percentages in some hyperendemic areas such as Sardinia. Molecular studies represent a valuable tool to improve our understanding of the E. granulosus epidemiology and CE control strategies. In the present study we investigated genetic variability of E. granulosus s.s. in Sardinia. To this purpose 83 hydatid cysts were collected from different animal species including humans and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was partially sequenced (720bp). Nucleotide sequences from Mediterranean basin were also analyzed for comparison. The phylogenetic network revealed 30 haplotypes grouped around a predominant isolate that had been already reported from other world regions. Haplotype diversity (0.8495±0.0336) and nucleotide diversity (0.003305±0.002014) were similar in Sardinia respect to other Mediterranean countries. Neutrality indices obtained by Tajima's D and Fu's Fs test were significantly negative (p≤.01) suggesting expansion of Sardinian population. Low Fixation indices (Fst), ranging from negative values (Algeria, Greece, Spain, other part of Italy) to 0.089 (Albania, France), indicated absence of genetic differentiation, and gene flow between Sardinia and other Mediterranean countries.

The epidemiology and medical care costs of Echinococcus granulosusis in Jahrom, southern Iran from 2007 to 2017

ABSTRACT Background: Echinococcus granulosus is a rare parasitic infection causing Cystic Echinococcosis, which can be dangerous due to involving the body. This parasitic infection is a significant health problem in Iran. However, little is known about this disease, specifically in Jahrom city; thus, we aimed to investigate the epidemiology and the economic impact of the illness. Methods: In this descriptive cross-sectional study, the files of 137 patients who were under the care, and treatment of the final diagnosis of Cystic Echinococcosis were evaluated by reviewing the information such as age, gender, occupation, place of residence was collected, and analyzed. Results: Human cystic echinococcosis cases were more common in females, 57.2% (12 patients) and 42.8% (9 patients) were male. In terms of age, most patients (23.8%) were in the age range from 21 to 30 years. The chief complaint at diagnosis, in all cases, was abdominal pain. Besides, 71.42% of the cases had the liver involvement alone, 9.52% had the lung involvement alone, 9.52% had a co-infection of liver and lung, and 4.74% had the kidney involvement alone. Conclusions: The results of the present study are beneficial in determining the disease status and the epidemiology of hydatid cyst in this area.

Isolated Human and Livestock Echinococcus granulosus Genotypes Using Real-Time PCR of cox1 Gene in Northeast Iran.

Cystic echinococcosis (CE), caused by the metacestode of Echinococcus granulosus, is highly endemic over large parts of Iran. The purpose of this study was to investigate the prevalence rate of hydatidosis and mitochondrial cox1 real-time PCR with high-resolution melting curve (HRM) analysis of E. granulosus isolated from human and livestock. In this cross-sectional study, 61 formalin-fixed paraffin-embedded tissue isolates were collected from human CE cases and 83 hydatid cysts from the liver and lung lesions of the livestock in Khorasan Razavi province, Northeast Iran. DNA was extracted from each isolate and amplified by real-time PCR and analyzed using the HRM method. The HRM analysis using the cox1 gene of 40 E. granulosus human isolates showed that 35 (87.5%), 4 (10%), and 1 (2.5%) of the isolates were categorized as G1, G3, and G6 genotypes, respectively. Out of the total 1342 livestock inspected, 39 (4%) goats and 44(12%) cattle were found harboring hydatid cysts all belonging to E. granulosus sensu stricto. The results confirmed that the high prevalence of E. granulosus sensu stricto in intermediate hosts is remarkable in northeast of Iran coupled with the high prevalence of infection in livestock, which reinforced the need for hydatidosis control programs in this region.

Evidence for camels (Camelus bactrianus) as the main intermediate host of Echinococcus granulosus sensu lato G6/G7 in Mongolia.

Cystic echinococcosis (CE), the parasitic disease caused by the larval stage of Echinococcus granulosus sensu lato (s.l.), is a global public health problem. In Mongolia, despite wide distribution of human CE, not enough information is available on the prevalence and molecular characterization of CE in livestock and its zoonotic linkage with human cases. We investigated the distribution of human CE cases and livestock population using statistical models to get insight into the zoonotic linkage. The incidence of human CE cases increased by a factor of 1.71 for one interquartile range increment in the density of the camel population. No significant association was observed with other livestock species. The samples collected from 96 camels and 15 goats in an endemic region showed a CE prevalence of 19.7% and 6.7%, respectively. All livestock CE were E. granulosus s.l. G6/G7 species of the E. granulosus s.l. complex. The genetic diversity was investigated using the haplotype network based on full cox1 gene analysis of the samples collected from livestock CE and nucleotide sequences previously reported from human CE and wild canids infection in Mongolia. Four haplotypes were identified within the livestock samples, two of which had not been previously reported. A common haplotype was identified among humans, camels, goats, and a wolf, all of which were within the same geographical area. A mixed infection of E. granulosus s.l. G6/G7 with different haplotypes in the intermediate host was identified. To the best of our knowledge, this is the most comprehensive description of the current epidemiological situation of CE in Mongolia with substantial evidence that camels might be the main intermediate host of E. granulosus s.l. G6/G7 in Mongolia. Moreover, our result presents the first report in the country to provide insight into the prevalence of E. granulosus s.l. G6/G7 in livestock.

Analysis of nad2 and nad5 enables reliable identification of genotypes G6 and G7 within the species complex Echinococcus granulosus sensu lato

The larval stages of tapeworms in the species complex Echinococcus granulosus sensu lato cause a zoonotic disease known as cystic echinococcosis (CE). Within this species complex, genotypes G6 and G7 are among the most common genotypes associated with human CE cases worldwide. However, our understanding of ecology, biology and epidemiology of G6 and G7 is still limited. An essential first step towards this goal is correct genotype identification, but distinguishing genotypes G6 and G7 has been challenging. A recent analysis based on complete mitogenome data revealed that the conventional sequencing of the cox1 (366 bp) gene fragment mistakenly classified a subset of G7 samples as G6. On the other hand, sequencing complete mitogenomes is not practical if only genotype or haplogroup identification is needed. Therefore, a simpler and less costly method is required to distinguish genotypes G6 and G7. We compared 93 complete mitogenomes of G6 and G7 from a wide geographical range and demonstrate that a combination of nad2 (714 bp) and nad5 (680 bp) gene fragments would be the best option to distinguish G6 and G7. Moreover, this method allows assignment of G7 samples into haplogroups G7a and G7b. However, due to very high genetic variability of G6 and G7, we suggest to construct a phylogenetic network based on the nad2 and nad5 sequences in order to be absolutely sure in genotype assignment. For this we provide a reference dataset of 93 concatenated nad2 and nad5 sequences (1394 bp in total) containing representatives of G6 and G7 (and haplogroups G7a and G7b), which can be used for the reconstruction of phylogenetic networks.

A systematic review and meta-analysis of the genetic characterization of human echinococcosis in Iran, an endemic country.

Human echinococcosis is an infectious disease caused by tapeworms belonging to the species Echinococcus. This parasite has a worldwide distribution and is considered a neglected tropical disease by the World Health Organization. Due to the diversity of Echinococcus spp. hosts, as well as variation in geographical, climatic, and socio-ethnic conditions, the question of the strains or genotypes of Echinococcus spp. that are involved in human infections is important. The aim of this study was to provide a summary of the available data on genotypes of Echinococcus obtained from the Iranian population. Four international databases (PubMed, Scopus, Science Direct, and Web of Science) and 4 Persian databases (Magiran, Scientific Information Database, Iran Medex, and IranDoc) were searched for cross-sectional studies that reported the genotypes of Echinococcus spp. in human echinococcosis cases using molecular methods in Iran through July 2018. The Newcastle-Ottawa Scale was used to assess the quality of the selected studies. A total of 559 cases of human cystic echinococcosis were reported in the 21 included articles. The majority of cases belonged to genotype G1 (89.2%; 95% confidence interval [CI], 80.1 to 95.8), genotype G6 (8.2%; 95% CI, 2.8 to 15.9), and genotype G3 (2.3%; 95% CI, 1.1 to 3.9). Since genotype G1 of Echinococcus appears to be the most prevalent genotype affecting humans in Iran, disease control initiatives aimed at sheep intermediate hosts may be the most beneficial. In addition, educational programs and serological screening in individuals may help reduce the national impact of the disease.

Surgically managed human cystic echinococcosis in north-eastern Iran: a single center's experience from 2001 to 2008.

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the tapeworm Echinococcus granulosus. Although CE has a large geographic distribution, data are lacking on the frequency of infection and epidemiology of CE in many endemic areas of the world, including the Middle East. Demographic and clinical information on surgically managed human CE cases were evaluated from a referral hospital in north-eastern Iran for the years 2001-2008. Of the 400 CE cases, 218 (54.5%) were male. The median age of patients was 35years (range 2-83years). The lungs (41.0%) and liver (37.7%) were the most commonly infected organs. However, 12.7% of patients had multiple organ involvement. The majority of cases (54.3%) were diagnosed using ultrasound, with only 12.0% diagnosed with the help of serology. Total white blood cell count was elevated in 26.8% (107/400) of patients, neutrophil count was elevated in 24.0% (96/400) of patients, and eosinophil count was elevated in 13.3% (53/400) of patients. Lymphocyte count was the only complete blood count (CBC) value that differed based on organ location (P=0.001). Despite some successes in the control of CE, the number of surgical CE cases in north-eastern Iran remains high. Although not diagnostic alone, CBC values allow for clinicians to obtain a more complete clinical picture of CE before, during, and after treatment. While serology has its place, the use of diagnostic imaging continues to be the most commonly used tool for the diagnosis of CE cases.

Echinococcus infections in the Baltic region

In the Baltic countries, the two zoonotic diseases, alveolar echinococcosis (AE) caused by Echinococcus multilocularis, and cystic echinococcosis (CE) caused by Echinococcus granulosus, are of increasing public health concern. Observations from Estonia, Latvia and Lithuania indicate that the distribution of both parasites is wider in the Baltics than previously expected. In this paper, we review and discuss the available data, regarding both parasitoses in animals and humans, from the Baltic countries and selected adjacent regions. The data are not easily comparable but reveal a worrisome situation as the number of human AE and CE cases is increasing. Despite improvements in diagnostics and treatment, AE has a high morbidity and mortality in the Baltic region. For the control of both zoonoses, monitoring transmission patterns and timely diagnosis in humans as well as the development of local control programs present major challenges.

Epidemiology of cystic echinococcosis in Al-Najaf province

Cystic echinococcosis (CE) is a zoonosis disease of worldwide distribution caused mainly by the metacestodeEchinococcusgranulosus. In Najaf, its distribution reaches endemic levels. This is results of this study were to investigate the trends in suspected cases of human CE recorded in Al-Sadder Medical City, Al-Hakim General Hospital and Al-Zahraa Teaching Hospital in Najaf city during a period November 2013to September 2014 and to study demographic and clinical characteristics of cases together with epidemiological factors associated with the disease. Clinical records of operated and/or diagnosed patients were reviewed with regard to this disease. 217 cases (68% female; mean age 21-30 years and 32% male; mean 21-30 ) were included in this retrospective study, 79% of which lived in rural areas. Indirect Haemagglutination (IHA) test to detect anti Echinococcusgranulosusantibody, and ultrasonography were used to diagnose the disease. Lung infection is the most common and most cases frequently

Genetic characterization of Echinococcus granulosus from a large number of formalin-fixed, paraffin-embedded tissue samples of human isolates in Iran.

Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus, presents an important medical and veterinary problem globally, including that in Iran. Different genotypes of E. granulosus have been reported from human isolates worldwide. This study identifies the genotype of the parasite responsible for human hydatidosis in three provinces of Iran using formalin-fixed paraffin-embedded tissue samples. In this study, 200 formalin-fixed paraffin-embedded tissue samples from human CE cases were collected from Alborz, Tehran, and Kerman provinces. Polymerase chain reaction amplification and sequencing of the partial mitochondrial cytochrome c oxidase subunit 1 gene were performed for genetic characterization of the samples. Phylogenetic analysis of the isolates from this study and reference sequences of different genotypes was done using a maximum likelihood method. In total, 54.4%, 0.8%, 1%, and 40.8% of the samples were identified as the G1, G2, G3, and G6 genotypes, respectively. The findings of the current study confirm the G1 genotype (sheep strain) to be the most prevalent genotype involved in human CE cases in Iran and indicates the high prevalence of the G6 genotype with a high infectivity for humans. Furthermore, this study illustrates the first documented human CE case in Iran infected with the G2 genotype.

Echinococcus equinus and Echinococcus granulosus sensu stricto from the United Kingdom: genetic diversity and haplotypic variation

Cystic echinococcosis is endemic in Europe including the United Kingdom. However, information on the molecular epidemiology of Echinococcus spp. from the United Kingdom is limited. Echinococcus isolates from intermediate and definitive animal hosts as well as from human cystic echinococcosis cases were analysed to determine species and genotypes within these hosts. Echinococcus equinus was identified from horse hydatid isolates, cysts retrieved from captive UK mammals and copro-DNA of foxhounds and farm dogs. Echinococcus granulosus sensu stricto (s.s.) was identified from hydatid cysts of sheep and cattle as well as in DNA extracted from farm dog and foxhound faecal samples, and from four human cystic echinococcosis isolates, including the first known molecular confirmation of E. granulosus s.s. infection in a Welsh sheep farmer. Low genetic variability for E. equinus from various hosts and from different geographical locations was detected using the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), indicating the presence of a dominant haplotype (EQUK01). In contrast, greater haplotypic variation was observed for E. granulosus s.s. cox1 sequences. The haplotype network showed a star-shaped network with a centrally placed main haplotype (EgUK01) that had been reported from other world regions.

Retrospective study of human cystic echinococcosis in Italy based on the analysis of hospital discharge records between 2001 and 2012

Cystic echinococcosis (CE) is an important zoonotic parasitic infection. The European Centre for Disease Control highlights that Italy lacks a surveillance system for CE. Due to the lack of official data, we analysed the Hospital Discharge Records (HDRs) drawn from the National Ministry of Health. The aim of this study was to analyse data from the HDRs with CE-related diagnoses in Italy from 2001 to 2012 to assess the current status and trend of disease epidemiology. A total of 16,550 HDRs related to the admission of 10,682 Italian patients were examined. The HDRs were analysed according to the patient's region and province code to evaluate the demographic and clinical characteristics of each case, together with the annual incidence rates of hospital cases (AIh) in administrative divisions in rural and urban areas. Lesions occurred frequently in the liver (83.6%) and lungs (8.4%). Patients ranged in age from 1 to 100 years (mean 59.8), and 57% were over 60 years old. The highest average AIh was registered in the Islands with 4.6/105 inhabitants (6.9/105 in Sardinia and 4.3/105 in Sicily), followed by the South with an average AIh of 1.9/105 inhabitants (5.4/105 inhabitants) and the Centre with an average AIh of 1.07/105 inhabitants (there was an AIh of 1.65/105 in Latium). The analysis for trend showed a statistically significant decrease in the AIh throughout the study period (e.g., in the Islands r2=0.98, p<0.001). An AIh over 2/105 inhabitants was observed in 31/110 provinces. Rural areas with comprehensive development problems had a relative risk of CE of 5.7 (95% CI, 5.3 to 6.9) compared to urban areas. The relative risk increased between areas where sheep breeding is widespread compared to those where it is less prevalent. This study shows a detailed picture of the geographic distribution and the epidemiological situation of CE in Italy, indicating that CE continues to be a significant public health problem in Italy. The retrospective study of HDRs is useful for the evaluation of the status of disease epidemiology; however, a surveillance system is needed to report confirmed cases of human CE.

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.

Echinococcus spp. in central Kenya: a different story.

Research on cystic echinococcosis (CE) has a long history in Kenya, but has mainly concentrated on two discrete areas, Turkana and Maasailand, which are known to be foci of human CE in Africa. Here, we report on a survey for CE in livestock from central to northeastern Kenya, from where no previous data are available. A total of 7,831 livestock carcasses were surveyed. CE prevalence was 1.92% in cattle (n = 4,595), 6.94% in camels (n = 216), 0.37% in goats (n = 2,955) and 4.62% in sheep (n = 65). Identification of the parasite was done using an RFLP-PCR of the mitochondrial nad1 gene, which had been validated before against the various Echinococcus taxa currently recognized as distinct species. From a total of 284 recovered cysts, 258 could be identified as Echinococcus granulosus sensu stricto (n = 160), E. ortleppi (n = 51) and E. canadensis (n = 47) by RFLP-PCR of nad1. In cattle, fertile cysts occurred mostly in the lungs and belonged to E. ortleppi (31 of 54), while the vast majority were sterile or calcified cysts of E. granulosus s.s.. Most fertile cysts in camels belonged to E. canadensis (33 of 37); sterile or calcified cysts were rare. Goats harboured fertile cysts of E. ortleppi (n = 3)--which is the first record in that host species--and E. canadensis (n = 1), while all cysts of E. granulosus were sterile. Only sterile cysts were found in the three examined sheep. Typically, all cysts in animals with multiple infections belonged to the same species, while mixed infections were rare. Our data indicate that the epidemiological situation in central to northeastern Kenya is clearly different from the well-studied pastoral regions of Turkana and Maasailand, and the apparently low number of human CE cases correlates with the infrequent occurrence of E. granulosus s.s.

Cystic echinococcoses in Mongolia: molecular identification, serology and risk factors.

BackgroundCystic echinococcosis (CE) is a globally distributed cestode zoonosis that causes hepatic cysts. Although Echinococcus granulosus sensu stricto (s.s.) is the major causative agent of CE worldwide, recent molecular epidemiological studies have revealed that E. canadensis is common in countries where camels are present. One such country is Mongolia.Methodology/Principal FindingsForty-three human hepatic CE cases that were confirmed histopathologically at the National Center of Pathology (NCP) in Ulaanbaatar (UB) were identified by analysis of mitochondrial cox 1 gene as being caused by either E. canadensis (n = 31, 72.1%) or E. granulosus s.s. (n = 12, 27.9%). The majority of the E. canadensis cases were strain G6/7 (29/31, 93.5%). Twenty three haplotypes were identified. Sixteen of 39 CE cases with data on age, sex and province of residence were citizens of UB (41.0%), with 13 of the 16 cases from UB caused by E. canadensis (G6/7) (81.3%). Among these 13 cases, nine were children (69.2%). All pediatric cases (n = 18) were due to E. canadensis with 17 of the 18 cases (94.4%) due to strain G6/7. Serum samples were available for 31 of the 43 CE cases, with 22 (71.0%) samples positive by ELISA to recombinant Antigen B8/1 (rAgB). Nine of 10 CE cases caused by E. granulosus s.s. (90.0%) and 13 of 20 CE cases by E. canadensis (G6/7) (65.0%) were seropositive. The one CE case caused by E. canadensis (G10) was seronegative. CE cases caused by E. granulosus s.s. showed higher absorbance values (median value 1.131) than those caused by E. canadensis (G6/7) (median value 0.106) (p = 0.0137).Conclusion/SignificanceThe main species/strains in the study population were E. canadenis and E. granulossus s.s. with E. canadensis the predominant species identified in children. The reason why E. canadensis appears to be so common in children is unknown.