Biology subjects

Casulli, A.

Publications and source records attributed to Casulli, A..

3 recordsLinked to original sources

bioRxiv2024

Detection of Echinococcus spp. and other taeniid species in lettuces and berries: two international multicenter studies from the MEmE project

Cystic and alveolar echinococcosis are severe zoonotic diseases characterized by long asymptomatic periods lasting months or years. Viable Echinococcus eggs released into the environment through the feces of canids can infect humans through accidental ingestion via hand-to-mouth contact or consumption of contaminated food or water. Both Echinococcus multilocularis and Echinococcus granulosus sensu lato are considered as foodborne parasites. However, when considering possible pathways of human infection, it appears that food and water-borne related variables do not significantly increase the risk of infection. Providing evidence-based data for the presence of DNA and, potentially, eggs in fresh produce is crucial in understanding foodborne transmission of Echinococcus spp. to humans. Two multicenter and multicountry studies were conducted within the One Health EJP framework to estimate the proportion of lettuces and berries contaminated by E. multilocularis, E. granulosus s.l., and other taeniid DNAs from 12 European countries, Tunisia and Pakistan. A total of 1,117 lettuces, 300 strawberries and 130 blueberries samples were collected and analyzed by washing, sequential sieving and real-time PCRs. Echinococcus multilocularis DNA was detected in 1.2% (7/570) of samples tested from the seven European endemic areas and in 2% (2/100) from Pakistan. In the five European endemic countries for E. granulosus s.l., E. granulosus sensu stricto DNA was identified in 1.3% of lettuces (9/695). The proportion of lettuces contaminated by E. granulosus sensu stricto DNA was 12% (9/75) in Tunisia and 4% (4/100) in Pakistan. Regarding berries, E. multilocularis DNA was detected in 5.4% of strawberries (n=11/202), 7.3% of blueberries (6/82) from the seven European endemic countries and 56% of blueberries (14/25) from Pakistan. High contamination rates of E. granulosus s.s were found outside of Europe, with 12.0% in blueberries (3/25) from Pakistan and 81.3%. DNA in strawberries (13/16) from Tunisia. The total contamination rate of all taeniid species DNA in lettuces (5.3%; 59/1,117) and berries (12.1%; 58/480) suggests that the transfer of taeniid eggs from carnivore feces to food is not uncommon. Although we assume that eggs are the source of the DNA detected in this study, the viability of such eggs is unknown. The detection of Echinococcus species in lettuces and berries suggests a potential risk of foodborne human infection. The relative contribution of this risk remains to be estimated. Further studies on food and environmental contamination are necessary to cover different epidemiological contexts and social habits, leading to a better understanding of human infections by Echinococcus eggs.

microbiology↗

bioRxiv2020

Species detection within the Echinococcus granulosus sensu lato complex by novel probe-based Real-Time PCRs

Infections with eggs of Echinococcus granulosus sensu lato (s.l.) can cause cystic echinococcosis in intermediate host animals and humans. Upon ingestion of viable eggs, oncospheres hatch from the eggs and subsequently develop into fluid-filled larval cysts, most frequently in the liver or the lungs. The slowly growing cysts progressively interfere with organ function. The risk of infection is determined by the host range of the parasite, its pathogenicity and other epidemiologically relevant parameters, which differ significantly among the five species within the E. granulosus s.l. complex. It is therefore essential to diagnose the correct species within E. granulosus s.l. to help understand specific disease epidemiology and to facilitate effective implementation of control measures. For this purpose, simple, fast and cost-effective typing techniques are needed. We developed quantitative Real-Time Polymerase Chain Reactions (qPCRs) and corresponding sequence-specific hydrolysis DNA probes to target polymorphic regions in the mitochondrial genome of E. granulosus s.l.. In a single-step typing approach, we distinguished E. granulosus s.l. members in four epidemiologically relevant subgroups. These were E. granulosus sensu stricto (G1, G3), E. equinus (G4), E. ortleppi (G5) and the E. canadensis cluster (G6 to G8 and G10). The technique also allowed identification and differentiation of these species from other Echinococcus or Taenia taxa for samples isolated from cysts or faeces. Single-step genotyping techniques for the molecular diagnosis of Echinococcus spp. by qPCRs may not only improve diagnostic performance, but also our knowledge on the epidemiology of the parasites and help controlling the various agents of cystic echinococcosis.

molecular biology↗

bioRxiv2019

Potential risk factors associated with human cystic echinococcosis: a semi-structured questionnaire from a large population-based ultrasound cross-sectional study in Eastern Europe and Turkey

BackgroundCystic echinococcosis (CE) is a neglected parasitic zoonosis prioritized by the WHO for control. Hygiene education is included in CE control campaigns but appears of little impact, and the precise risk factors for human infection are still uncertain. Several works investigated potential risk factors for CE through questionnaires, mostly carried out on small samples, providing contrasting results. We present the analysis of risk factors questionnaires administered to participants to the largest prevalence study on CE conducted in Eastern Europe.\n\nMethodology/Principal FindingsA semi-structured questionnaire was administered to 24,687 people from rural Bulgaria, Romania, and Turkey. CE cases were defined individuals with abdominal CE cysts detected on ultrasound. Variables associated with CE infection at p<0.20 in bivariate analysis were included into a multivariable logistic model, with a random effect to account for clustering at village level. Adjusted odds ratio (AOR) with 95%CI were used to describe the strength of associations. Data were weighted to reflect the relative distribution of the rural population in the study area by country, age group and sex. Valid records from 22,027 people were analyzed. According to the main occupation in the past 20 years, \"housewife\" (AOR 3.11 [1.51-6.41]) and \"retired\" (AOR 2.88 [1.09-7.65]) showed significantly higher odds of being infected compared to non-agricultural workers. \"Having relatives with CE\" (AOR 4.18 [1.77-9.88]) was also associated with higher odds of infection. Dog-related and food/water-related factors were not associated with infection.\n\nConclusions/SignificanceOur results point to infection being acquired in a \"domestic\" rural environment and support the view that CE should be considered more a \"soil-transmitted\" than a \"food-borne\" infection, acquired through a \"hand-to-mouth\" mechanism. This result helps delineating the dynamics of infection transmission and have practical implications in the design of specific studies to shed light on actual sources of infection and inform control campaigns.\n\nAUTHOR SUMMARYCystic echinococcosis (CE) is a parasitic disease with high socio-economic impact, mostly affecting pastoral communities. The causative agent, Echinococcus granulosus sensu lato, is naturally transmitted between dogs and livestock; humans acquire infection through accidental ingestion of parasite eggs. Hygiene education is among the strategies of CE control campaigns, but appears of little impact. \"Ingestion of contaminated food/water\", and \"contact with dogs\" are generally mentioned as the sources of human infection, however actual risk factors are still undefined. Several works investigated potential risk factors for human CE infection through questionnaires, mostly carried out on small samples, providing contrasting results. We analysed 22,027 risk factors questionnaires administered to the participants of the largest prevalence study on CE conducted in Eastern Europe. We found that being \"housewife\" and \"retired\" as the main occupation in the past 20 years, and \"having relatives with CE\" were associated with higher odds of CE infection, while dog-related and food/water-related factors were not associated with infection. Our results indicate that CE may be considered more a \"soil-transmitted\" than a \"food-borne\" infection, acquired through a \"hand-to-mouth\" mechanism in a domestic, rural environment. This may help designing specific studies on pathways of transmission of this neglected parasite.

epidemiology↗