Epidemiological distribution of Echinococcus granulosus s.l. infection in human and domestic animal hosts in European Mediterranean and Balkan countries: A systematic review

Abstract

Cystic echinococcosis (CE) is a neglected zoonosis caused by infection with the cestode Echinococcus granulosus sensu lato. We carried out a systematic literature review on E. granulosus s.l. human and animal (cattle, sheep, dog) infection in European Mediterranean and Balkan countries in 2000-2019, to provide a picture of its recent epidemiology in this endemic area. MEDLINE, EMBASE, Scopus, Google Scholar and Open Grey databases were searched. Included cases were: i) for humans, data from hospital records and imaging studies; ii) for dogs, data from necropsy and coprological studies; iii) for ruminants, cases based on slaughter inspection. The NUTS (Nomenclature of Territorial Units for Statistics) classification was used to categorize extracted data in epidemiological units, defined as data referred to one NUTS2 (basic region) in one year time. Data were then aggregated to NUTS1 level (major regions), calculating the average incidence value of included epidemiological units. For prevalence studies covering different epidemiological units, the pooled prevalence was estimated. Data were extracted from 79 publications, 25 on human infection (covering 437 epidemiological units), and 54 on animal infection (52 epidemiological units for cattle, 35 for sheep and 25 for dogs). At NUTS1 level, average annual incidence rates of human CE ranged from 0.10-7.74/ 100,000; pooled prevalence values ranged from 0.003-64.09% in cattle, 0.004-68.73% in sheep, and 0-31.86% in dogs. Southern and insular Italy, central Spain, Romania and Bulgaria reported the highest values. Bovine data showed a more similar pattern to human data compared to sheep and dogs. Limitation of evidence included the paucity of human prevalence studies, data heterogeneity, and the patchy geographical coverage, with lack of data especially for the Balkans. Our results confirm Italy, Spain, and Eastern Europe being the most affected areas, but data are extremely heterogeneous, geographical coverage very patchy, and human prevalence studies extremely scant. Results also highlight the notorious problem of underreporting of E. granulosus s.l. infection in both humans and animals.

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

“…The findings of the present study allow for an improved understanding of the impact of CE in the study area, laying the foundations for an evidence-based decision-making process on the measures to control this disease. The analysis of the HDRs showed an estimated incidence rate in the human population of 0.4/100,000 people per year, which is in line with what already reported for northern Italy and for other hypo-endemic regions in wealthy and industrialized economies [ 7 , 9 , 25 ]. More importantly, our findings suggested that the source of the infection for most of the human cases is external to the study area, although few cases were possibly autochthonous.…”

“…In Spain, an overall economic impact of about 150 million € was estimated in 2005 [ 33 ], meaning a monetary estimation 300 times higher than that obtained in the present study. This difference depends on the different size of the considered study areas (about 43 million inhabitants in Spain in 2005 vs 5 million in Veneto) and can be partly due to the higher incidence of hospitalized human CE cases recorded in most regions of Spain [ 7 ], compared to Veneto. Besides, this study included different costs (reduction in carcass weight, reduction in milk production and decrease in fecundity) associated to four domestic species (sheep, goats, cattle, pigs).…”

“…The disease is particularly widespread in areas where traditional sheep herding still represents an important source of income [ 5 , 6 ]. Indeed, this kind of sheep farming is common in most areas of Central, Southern and insular Italy, which are considered hyper-endemic or endemic [ 7 ]. On the contrary, Northern Italy, which is characterised by a more industrialized livestock sector, was historically considered free from the disease or with a hypoendemic/sporadic presence.…”

Raw meat based diet (RMBD) for household pets as potential door opener to parasitic load of domestic and urban environment. Revival of understated zoonotic hazards? A review

“…The lifecycle of echinococcosis, biologically perpetuate when dogs are fed on raw organs of infected domestic ungulates and dog remain asymptomatic but contain residual worm burden [ 22 ]. Epidemiological evidence, verify that humans are dead-end intermediate hosts and acquire infection through inadvertent consumption of eggs shed by the dogs or by physical contact with them [ 23 ].CE constitutes a rising public health threat, with average annual incidence in humans estimated to be as high as 7.74 cases/100,000 population in different countries, around the world [ 24 ]. High CE infection in humans is circumstantially linked to environmental dissemination of eggs on various matrices and surfaces by infected dogs [ 25 ].…”

Human and animal cystic echinococcosis in Konya, Turkey: molecular identification and the first report of E. equinus from human host in Turkey

“…E. granulosus causes an accidental human infection; adult tapeworms are found in the intestines of canines (dog, wolf); the larval cyst stage is present in the viscera of herbivores (sheep, cattle, horse, deer, pig, camel) (King 2005). Transmission to human occurs via the fecal-oral route (Tamarozzi et al 2020).…”