Prevalence of Hydatidosis in Slaughtered Herbivores in Qom Province, Central Part of Iran

Global Prevalence of Echinococcosis in Goats: A Systematic Review and Meta-Analysis

Echinococcosis is a foodborne parasitic zoonosis caused by the larvae of Echinococcus. This disease can affect goats and other mammals. In this study, a systematic review and meta-analysis for echinococcosis in global goats were performed based on the following five databases (China National Knowledge Infrastructure [CNKI], VIP Chinese Journal Database, Wanfang Data, PubMed, and ScienceDirect). In total, 108,197 samples were collected. The global prevalence of echinococcosis in goats was identified to be 10.85% (3217/108,197). The prevalence of echinococcosis in goats was 6.16% (1369/22,208) and 13.27% (874/5932) in South America and Africa, respectively. The prevalence of echinococcosis in goats before 2010 (9.76%; 112/713) was significantly higher than that from 2010 to 2014 (1.44%; 45/32,145) or after 2014 (2.95%; 154/3889). The prevalence of echinococcosis in goats aged <12 months (4.48%; 70/2911) was higher than that in goats aged ≥12 months (2.88%; 36/819). We also investigated the effects of geographical factors and climates on the prevalence of echinococcosis in goats. The results showed that the prevalence of echinococcosis was higher in the areas with high altitude and cold climate. This meta-analysis indicated that echinococcosis was ubiquitous in goats. Thus, we should improve the feeding conditions for goats, and strengthen the control measures of echinococcosis epidemic in goats, with the aims of reducing the economic losses of animal husbandry and providing protection for humans in the aspects of food security and health.

Epidemiological and Molecular Characterization of Echinococcus granulosus Isolated from Small Ruminants in Kashmir Valley, India

BACKGROUND

Cystic Echinococcosis (CE) is an emergent or re-emergent zoonosis and remains a public health and economic problem all over the world.

METHODS

The present study was carried on the prevalence and genotypes of Echinococcus present in small ruminants in Kashmir valley. A total of 2100, sheep (2052) and goats (48), slaughtered or spontaneously dead, from various areas of Kashmir valley were screened for the presence of hydatidosis. In case of goat none of the cases were found positive for hydatidosis, whereas, all the positive cases (85) were recorded in sheep only. The overall prevalence of hydatidosis was 4.04%. The prevalence was higher in female sheep (5.46%) compared to males (2.83%). Season-wise highest prevalence was in summer (4.55%), followed by autumn (4.1%), spring (3.89%) and winter (2.5%).The liver was observed to be the most frequently infected organ with relative prevalence of 61.17% followed by lungs (38.82%).The rDNA-ITS1 fragment of positive samples was amplified with BD1 / 4S primers.

RESULTS

The length of amplified fragment for all isolated samples was 1000bps. The products obtained on PCR were digested with four restriction enzymes (Rsa 1, Alu 1, Msp 1 and Taq1). Rsa 1, Alu 1, Msp 1 yielded identical fragments, 300 and 700 bp in sheep. TaqI restriction enzyme had no effect on PCR product and after digestion; intact 1000bps fragment was seen.

CONCLUSION

Phylogenetic analysis of ITS1 gene revealed that the common sheep strain (G1) is the predominant genotype in sheep in Kashmir valley.

Echinococcoses in Iran, Turkey, and Pakistan: Old Diseases in the New Millennium

Echinococcosis is considered a cosmopolitan zoonosis caused by different species of small taeniid tapeworms of the genus Echinococcus and is regarded as a neglected zoonosis. Cystic and alveolar echinococcoses are endemic diseases of Tibetan, Pamir, and Iranian plateaus. All of the countries within the Iranian plateau are affected by echinococcosis. Pakistan, Turkey, and Iran are the three most populous countries of the region, in which echinococcosis is highly endemic. The three neighboring countries share strong cultural and socioeconomic ties. The present study aimed to provide a broad review of the status of cystic and alveolar echinococcosis, summarizing the current knowledge about geographical distribution, molecular epidemiology, and transmission dynamics of Echinococcus granulosus sensu lato and Echinococcus multilocularis in this region. Additionally, we aimed to understand disease burden and risk factors as basic requirements for establishing a surveillance system and planning prevention and control programs. A considerable body of information is available on different aspects of echinococcosis in this region; however, several information and research gaps need to be filled before planning control programs. None of the countries in the region have an elaborate echinococcosis control program. Effective control programs require multi/intersectoral coordination within a One Health approach with a long-term political and administrative commitment and enhanced international collaboration among the three countries.

Prevalence of cystic echinococcosis in slaughtered livestock in Iran: a systematic review and meta-analysis

BACKGROUND

Hydatidosis is a zoonotic disease and has a great general and economic health importance in both developed and developing countries. Therefore, this systematic and meta-analytic study was conducted to determine the prevalence of cystic echinococcosis in slaughtered livestock in Iran.

METHODS

The present study was conducted as a systematic review and meta-analysis. The SID & Magiran, MEDLINE (PubMed), ScienceDirect, Scopus, and Google Scholar databases were searched with a view to selecting relevant research works. As a result, 31 articles published from April 1970 to April 2020 were selected. The heterogeneity of the studies was assessed using the I² index. Data analysis was conducted within the Comprehensive Meta-Analysis software (CMA) v.3.0 (Biostat, Englewood, NJ, USA) and Arc map (ArcGIS 10.3) software.

RESULTS

The heterogeneity of the studies was evaluated using the I² test which value was 99% showing a high heterogeneity in the studies. The results of publication bias in studies were evaluated by the Egger test, which were not statistically significant (P = 0.144). The overall prevalence of cystic echinococcosis in slaughtered livestock in Iran is 13.9% (95%CI: 10.7-17.7%). The results of the meta-regression analysis indicate the increasing trend of the hydatid cyst prevalence with the increase of sample size and publication year (P < 0.05).

CONCLUSION

According to the results of this study and the relatively high prevalence of cystic echinococcosis in slaughtered livestock in Iran, health policy makers should make effective decisions in this regard, and implement careful inspections and interventions by experts and health authorities.

Gross and histopathological alterations associated with cystic echinococcosis in small ruminants

Hydatidosis, an important parasitic zoonoses is a major public health as well as economic concern throughout the world. A total of 2100, sheep (2052) and goats (48), slaughtered or spontaneously dead, from various areas of Kashmir valley were screened for the presence of hydatidosis. Out of 2100 cases, 85 were positive for hydatidosis. The frequently infected organs were lungs and liver. The liver was observed to be the most frequently infected organ with relative prevalence of 61.17% followed by lungs (38.82%). The pulmonary cysts were more fertile (55%) compared to hepatic cysts (45%). Histopathologicallly, the cyst wall consisted of the inner germinal, middle lamellated/laminated, and outer fibrous layer. Inflammatory reaction around the cyst was variable and was characterized by an inner zone of loosely arranged fibroblasts infiltrated with mononuclear cells, followed by densely arranged fibroblasts along with mononuclear cells; and an outer layer of fibrous connective tissue. Fibroplasia and calcification were noted at places. In liver besides the cellular reaction against the expanding cyst, hepatocellular degeneration and cirrhosis were observed, the severity of which was inversely related to the distance from the cyst. The structural details of the protoscolices were clearly discernable.

Prevalence of ovine cystic echinococcosis in Kashmir Valley, North India

A total of 1455 local and non-local (originating from other Indian states), slaughtered or spontaneously dead, sheep in various areas of Kashmir Valley were investigated for the presence of cystic echinococcosis over a period of one year. The overall prevalence was 7.97% with higher prevalence in local (14.3%) than in non-local sheep (6.06%). The prevalence of infection, total number of cysts recovered and mean intensity of infection were higher in lungs as 66.2%, 506 & 5.1% respectively, followed by liver (28.5%, 169, 3.9%) and spleen (5.3%, 9, 1.13%). Either single (71.55%) or multiple (28.45%) organ involvements were observed. 66.6% of cysts were of small size, 19.29% medium, 7.01% large and 7.01% calcified. The fertility of cysts was noted to be 65.7% whereas 34.2% were infertile which included 27.1% sterile and 7.01% calcified cysts. The viability percentage of protoscolices from all the fertile cysts was 74.2%. The number of cysts recovered was higher in sheep with body condition score- emaciated, thin and average, and lower in, fat and obesed. The study showed that the local sheep were more vulnerable to contract cystic echinococcosis than non-local sheep which is further aggravated by poor body condition.

Serological evidence of human cystic echinococcosis and associated risk factors among general population in Mazandaran Province, northern Iran

The aim of the present study was to determine the seroprevalence of CE among human referring to Health Centers in Mazandaran Province, northern Iran and to identify the risk factors involved in spreading the disease. Between 2013 and 2014, the serum samples were taken randomly from 600 subjects referring to health centers in Mazandaran Province. After obtaining informed consent for each participant, a questionnaire including demographic characteristics and associated risk factors was filled for each individual. Anti-CE antibody was tested by enzyme-linked immunosorbent assay (ELISA), using native antigen B. Our results showed 31.6% (n = 190) seropositivity. There were significant difference between seropositivity and sex and residence. Males were significantly more seropositive than females (24.6% versus 7%, P = 0.0001). Regression analysis showed that the subjects who are living in rural areas were 4.4 times more likely to be at risk to CE than urban areas (OR = 4.4; 95% CI = 2.91, 6.64). Contact with dogs, soil and consumed raw vegetables was appeared as main risk factors for CE among community in Mazandaran and it may increase the probability of infection. The high prevalence of CE among individuals indicated that hydatidosis is still a major health problem among community in the investigated areas.

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 in humans associated with disease incidence in domestic animals in Kermanshah, west of Iran

Hydatidosis is one of the important zoonotic diseases that cause considerable economic losses and public health problems worldwide. This study was conducted to determine the prevalence Echinococcus granulosus in people and slaughtered animals in Kermanshah province, west of Iran. Hospitals data and meat-inspection records in Kermanshah abattoir were used in this study. A total number of 32,130 slaughtered livestock (7000 cattle, 19,950 sheep and 5180 goats) was inspected in the 3-year period and overall 2043 (6.35 %) were infected. The highest and lowest prevalence was recorded in cattle and goats, respectively. In human, Cystic echinococcosis affected more females (54 %) than males (46 %) with a 1.17 male to female ratio. Rate of disease in urban and rural regions were 46 and 54 %, respectively. The youngest and the oldest patient operated were 7 and 87 years old, respectively, and the age group 21-40 years (41.2 %) were the most affected. A significantly higher number of hydatid cysts were recorded in the liver than in other sites. The ratio of hepatic hydatidosis to pulmonary hydatidosis was 2.46. The results showed that hydatidosis is of great importance in this area and serious attention is needed to prevent and control the disease.

A retrospective survey of hydatidosis based on abattoir data in Kermanshah, Iran from 2008 to 2013

A retrospective study was carried out from 2008 to 2013 to estimate the prevalence of hydatidosis in ruminants slaughtered at the Kermanshah municipal abattoir, in western Iran. A total number of 663,633 livestock (393,585 sheep, 81,080 goats and 188,968 cattle) slaughtered in the 5-year period and overall 9,524 (1.43 %) livers and 13,147 (1.98 %) lungs were condemned. The lungs were more frequently infected with hydatid cysts than the livers in all animal species. The average prevalence of hydatidosis was 2.7 % in this area. The prevalence of Echinococcus granulosus infection recorded in the present study was generally lower than those reported from other regions of Iran. Greater awareness among farmers, destruction of organs containing hydatid cysts, prevention of access of dogs to raw offals and implementation of national rabies control program could be responsible factors. The results showed a significant difference (p < 0.001) in the prevalence of hydatidosis among studied animals with higher prevalence in cattle than sheep, with the lowest prevalence recorded in goats. However the annual prevalence of liver and lung condemnations due to hydatidosis was decreased in some years, but the overall trend had a variable pattern in the prevalence of hydatidosis over the study period. Data showed a significant seasonal pattern for hydatidosis in all studied animals. Liver and lung condemnations due to hydatidosis were higher in the fall for sheep and cattle, whereas in goats were higher in summer. This could be attributed to various factors such as sources of slaughtered animals, changes in management practice and ecological factors. The current results suggest that a systematic investigation that lead to a disease control strategy is required to reduce the economic and public health consequences of hydatidosis. In addition, the present survey provides baseline data for the future monitoring of this potentially important parasitic disease in the region.

Cystic echinococcosis in cattle slaughtered at Gondar Elfora export Abattoir, northwest Ethiopia

A cross sectional and retrospective studies were conducted from November 2010 to April 2011 to determine the prevalence and characteristics of hydatid cysts in cattle slaughtered at Gondar Elfora Abattoir in northern Ethiopia. Out of the 308 cattle examined for the presence of hydatid cysts, 63 (20.5 %) of them were found harboring hydatid cysts in one or more of their internal organs. Results of the study showed higher (P < 0.05) prevalence of cystic echinococcosis in adult (22.4 %; 49/219) than in young (15.7 %; 14/89) cattle. Lowest prevalence of hydatid cysts was observed in cattle from Debark (7.7 %; 2/26) whereas highest prevalence of cystic echinococcosis was recorded in cattle from Fogera (28.2 %; 11/39). The lungs (69.3 %; 61/88) were the most affected organs followed by the livers (28.4 %; 25/88). A total of 230 hydatid cysts from different internal organs of 63 infected cattle were differentiated into 60.4 % calcified, 30 % fertile and 9.6 % sterile cysts. Likewise, a total of 13 % (30/230) small, 15.6 % (36/230) medium, and 10.9 % (25/230) large hydatid cysts were recorded. Lung harbored the highest overall count (76.9 %; 177/230) and greatest proportion of large size cysts (13.5 %; 103/177) than all the other organs. Liver harbored the highest proportion of calcified cysts (68 %; 34/50). An overall proportion of 30 % (69/230) fertile cysts were recorded. The greatest proportion of fertile cysts (33.3 %; 59/177) was recorded in lungs followed by the livers (20 %; 10/50). A retrospective data of 5 years (2004/5-2009/10) revealed an overall prevalence of 30.4 % (9,106/29,951) and highest overall prevalence of 65.5 % hydatid cysts in the lungs followed by livers (33.5 %) and least in spleen (0.04 %). In conclusion the findings reported herein show that cystic echinococcosis is widespread in cattle slaughtered in Gondar export Abattoir and suggests that the lung is the most important source of hydatid cysts for definitive hosts in the area.

The monetary burden of cystic echinococcosis in Iran

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

Epidemiological aspects of cystic echinococcosis in slaughtered herbivores in Sari abattoir, North of Iran

A study was conducted to assess the ruminants' hydatidosis in Mazandaran Province, Northern Iran. A total, 1,799 sheep, 985 goats and 362 cattle slaughtered at Sari industrial slaughter house were examined for hydatid cyst infection. The results indicated that 65.2% of sheep, 37.8% of goats and 40.1% of cattle were infected. The liver and lung infection rate in sheep were 18.8 and 4.3%, goats 17.2 and 12.6% and cattle 44.1 and 7.6%, respectively. The study showed that 766 (45.3%) out of 1,691 infected animals had moderate degree of infection. Geographical zone survey indicated that 1,381 (89.2%) out of 1,546 sheep and goats infected with hydatid cyst were non-indigenous and originated from north-eastern provinces of Iran. On the contrary, 50.3% of infected cattle originated from Mazandaran Province (indigenous).

Molecular characterization of human and animal Echinococcus granulosus isolates in Isfahan, Iran

Cystic hydatid disease (CHD) is one of the most important zoonotic diseases in different parts of Iran. While it causes major health problem, there is limited information about its transmission cycles and reservoirs of human infection. Therefore we aimed to characterize the existence Echinococcus granulosus cysts in humans and animals in the province of Isfahan, central region of Iran. We collected hydatid cysts from the liver and lungs of patients who underwent surgery procedure and also cysts were obtained from domestic animals at slaughterhouses. DNA was extracted from the protoscoleces and examined by polymerase chain reaction (PCR) of rDNA internal transcribed spacer1 (ITS1-PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). In addition, fragments of the genes coding for mitochondrial cytochrome c oxidase subunit 1 (CO1) and NADH dehydrogenase 1 (ND1) were sequenced. Among the two different identified strains/genotypes (sheep and camel), the sheep strain was shown to be the most common genotype of E. granulosus affecting humans, sheep, cattle, goats and occasionally camels. Nine out of 26 camel samples were infected with sheep strain. However the camel genotype was observed in humans, camels and cattle. Seventeen out of 26 camel isolates, 6 out of 31 human and 5 out of 14 cattle samples were infected with the camel genotype. The camel genotypes had PCR and RFLP patterns which were different from the PCR and RFLP patterns of the rest of isolates (sheep strain). The results of this study showed that the 'camel' strain was actual source of infection to humans which circulates between intermediate hosts including camels and cattle, and it confirms the camel-dog transmission cycle in Isfahan.

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

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

Hydatidosis of sheep and goats slaughtered at Addis Ababa Abattoir: prevalence and risk factors

Abattoir survey was conducted on 1,053 sheep and 639 goats slaughtered at Addis Ababa Abattoir, Ethiopia, between October 2007 and May 2008, with the objective to determine the prevalence of hydatidosis and assess the associated risk factors. Routine meat inspection procedure was employed to detect the presence of the cyst in visceral organs (lung, liver, and omentum). Hydatid cysts were found in 206 (19.94%) and 102 (16%) of the sheep and goats inspected, respectively. Statistically significant difference in infection rates was noted between the two species. Likewise, there was significant difference in infection rates between the two sexes and different age groups in both sheep and goats (P < 0.5). The study showed that hydatidosis is prevalent in Ethiopia. Thus, there is a need to introduce appropriate control measures to minimize the rate of infection and reduce the ensuing economic losses.

Human cystic echinococcosis in Yasuj District in Southwest of Iran: an epidemiological study of seroprevalence and surgical cases over a ten-year period

Cystic echinococcosis is a zoonotic infection of humans and domestic animals caused by the larval stages of the cestode Echinococcus granulosus. Cystic echinococcosis is one of the most important zoonotic diseases in Iran, where human cases are frequently reported from different regions of the country. The objective of this study was to determine the sero-epidemiological and surgical cases of human hydatidosis in the Yasuj district, a region in southwest of Iran. Serum samples were taken from 500 individuals attending Yasuj health centers. Anti-hydatid cyst antibody was checked by enzyme-linked immunosorbent assay (ELISA), using antigen B. Moreover, retrospective studies were carried out using local hospital records of CE patients between 1997 and 2006. Results of the sero-epidemiological study showed that 36 out of 500 cases (7.2%) have antibody against hydatid cyst. Of these 36 cases, 49.6% were women and 50.4% were men. The highest rate of infection was recorded in individuals aged between 30 and 39 years. Hospital records showed that during the 10 years, 105 cases of hydatidosis were admitted in Yasuj hospitals. Of all cases, 70 (66.7%) were women and 35 (33.3%) were men. Hepatic cyst was recorded in 81% of the cases where nephrotic cysts were the second most prevalent ones. Recurrence of the disease was noted in 14.3% of all cases. Results of this study demonstrated that hydatidosis is an important endemic disease, with a nearly constant prevalence rate during the last 10 years, in Yasuj district in Iran. Further studies are needed to investigate the reasons for high rate of surgical cases in housewives and striking prevalence of hydatidosis in a specific (30-40 years) age group.