Laboratory associated zoonotic parasitic infections: a review of main agents and biosecurity measures.

Laboratory workers are exposed to the risk of acquiring infections due to the manipulation of infectious materials. The biological hazard for researchers is seven times higher when compared with hospital and public health laboratory workers. Despite the implementation of standardized practices to control infections, multiple cases of Laboratory Associated Infections (LAIs) usually go unreported. There has been a lack of comprehensive epidemiological data regarding the situation of LAIs for parasitic zoonosis and besides, the available sources are not completely updated. Since most accounts of laboratory infections are organism-specific, this study has focused on common pathogenic/zoonotic species handled at parasitological laboratories and summarising the standard biosecurity protocols for the infectious agents. The main characteristics of Cryptosporidium spp., Entamoeba spp, Giardia duodenalis, Toxoplasma gondii, Leishmania spp., Echinococcus spp., Schistosoma spp., Toxocara canis, Ancylostoma caninum, Strongyloides stercoralis are considered in this review in order to assess the potential risk of developing occupational infections in the workplace along with stating prevention and prophylactic measures for each species. It was concluded that the LAIs from these agents can be prevented by using personal protective measures and good laboratory practices. However, further studies are necessary to better understand the environmental resistance of cysts, oocysts and eggs, with a view to select the most suitable disinfection methods. Furthermore, it is fundamental to constantly update epidemiological data of infection acquired by laboratory workers, to develop accurate risk indicators.

'Fight the parasite': raising awareness of cystic echinococcosis in primary school children in endemic countries.

BACKGROUND: Cystic echinococcosis (CE) is a widespread zoonosis and a significant economic concern and cause of morbidity in humans. A scarcity of education on the sources of CE infection and containment measures is considered to be a key factor responsible for persistent transmission within communities. Recently, edutainment approaches have captured the attention of health education (HE) professionals due to the benefits of integrating cognitive and emotional learning processes. METHODS: A study was carried out in Sardinia, Italy, between 2020 and 2022, amid the SARS-Covid-19 pandemic. The project, designed to involve primary school children (via remote or face-to-face learning depending on the evolving Covid-19 containment measures) consisted of four distinct phases: (i) creation of material for school children and teachers focused on cystic echinococcosis; (ii) pre-intervention evaluation of CE knowledge (i.e. True False Don't Know [TFD] pre-intervention questionnaire based on CE-related knowledge and practices); (iii) edutainment activity (e.g. interactive lessons enhanced by the comic booklet and the "Fight the parasite" cartoon video, hands-on educational activities and drawing activities on CE); and (iv) post-intervention evaluation of CE knowledge (via TFD post-intervention questionnaire [same questionnaire as used for the pre-intervention assessment] on CE-related knowledge and practices) and on-site edutainment tour in primary schools taking part to the project. RESULTS: The percentage of correct answers increased from 65% for the questionnaire administered pre-intervention to 87.9% for the same questionnaire administered post-intervention (χ2 = 648.12, df = 1, P < 0.0001), while the percentage of uncertain answers (i.e. 'I don't know') decreased from 23% pre-intervention to 5% post-intervention (χ2 = 603.44, df = 1, P < 0.0001). These differences indicate a significantly enhanced understanding of CE among participating school children after the intervention. CONCLUSIONS: The results of the present survey indicate that the use of digital educational tools, the use of video animations as a model for science communication, as well as other participatory teaching methods, enabled children to retain key knowledge of the routes of CE transmission and ways to prevent it.

Taenia multiceps coenurosis: a review.

Taenia multiceps is a taeniid cestode that inhabits the small intestines of both wild and domestic carnivores. The larval stage, Coenurus cerebralis, is typically found in the central nervous system (CNS) of a wide range of livestock and, to a lesser extent, in the extra-cerebral tissues of sheep and goats. This review covers all aspects of the life cycle of T. multiceps and its epidemiology, molecular characterization, pathogenesis, diagnosis, therapy, control and zoonotic potential. Coenurosis caused by the larval stage of T. multiceps has a worldwide distribution and is often fatal in intermediate hosts, which can result in substantial economic losses in livestock farming. Molecular characterization using the mitochondrial genes cytochrome c oxidase subunit 1 and nicotinamide adenine dinucleotide dehydrogenase subunit 1 of different T. multiceps populations has revealed significant genetic variation and the presence of three major haplotypes. The disease mostly affects young sheep and is referred to as either acute or chronic coenurosis. Acute coenurosis occurs as a result of oncospheres migrating through the CNS, while chronic coenurosis occurs as a consequence of the coenurus maturing, which causes displacement and pressure atrophy of brain tissue. Non-cerebral coenurosis has been most commonly reported in goats. The best diagnostic method for cerebral coenurosis involves the interpretation of clinical signs with accurate localization of the cyst using diagnostic imaging techniques. A vaccine based on recombinant oncosphere antigens has proved to be an effective tool against T. multiceps infection in sheep. Additionally, use of anthelmintics during the parasite's migration stages reduces the development of cysts in the sheep brain. Surgery is considered the most effective method for the treatment of cerebral coenurosis in small ruminants, but is often not carried out because of the limited finances of many sheep and goat breeders. However, coenurosis can also be controlled effectively through preventative measures, such as anthelmintic treatment of dogs and the proper disposal of intermediate host carcasses. The parasite is also zoonotic, and cases of coenurosis have been reported in humans with coenuri located in the brain, spinal cord and eyes.

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

PURPOSE: Human 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. METHODS: From 2005 to 2018, a total of 894 surgically confirmed cases of hydatidosis were recorded from five anatomy and pathology laboratories. RESULTS: The 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. CONCLUSION: The 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.

Genetic diversity and transmission patterns of Echinococcus granulosus sensu stricto among domestic ungulates of Sardinia, Italy.

Cystic echinococcosis (CE), a parasitic zoonosis of public health and economic concern, is highly endemic in Sardinia, Italy. The study involved examining the intraspecific variability and demographic structure of Echinococcus granulosus sensu stricto (s.s.) in common hosts of this parasite. Molecular surveillance included the fragment amplification of a partial mitochondrial gene, cox1 (750 bp), for a total of 69 isolates derived from sheep (n = 52), cattle (n = 11), pigs (n = 4), and goats (n = 2). It was ascertained that E. granulosus s.s. was the primary agent of infection among these ungulates and G1 genotype was highly prevalent (79.71%). Considerable intraspecific variation was found, revealing the existence of 22 haplotypes with relatively high haplotype (0.8555 ± 0.033) and low nucleotide diversities (0.00281 ± 0.00030). Population demographics indicated an expanding parasitic population signifying negative deviation from neutrality indices. Little genetic differentiation was found between the subpopulations of E. granulosus s.s. in the island. Moreover, the geographic dispersal of genotypes G1 and G3 also indicated similarity between Sardinian and mainland Echinococcus granulosus s.s. populations reaffirming the sympatric occurrence and efficient transmission of G1 and G3 genotypes. Molecular survey of CE has the potential to yield baseline information on the infective genotypes among the intermediate hosts and helps in devising suitable control strategies for curtailing the disease.

Cystic echinococcosis in sheep and goats of Lebanon.

Cystic echinococcosis (CE), a zoonotic disease caused by the species complex of Echinococcus granulosus sensu lato (s.l.), is endemic in Middle East and the Mediterranean basin, where pastoral activity is widespread. Despite the chronic endemicity of the disease in Lebanon and neighbouring countries, recent data are scant. The objectives of this survey were to evaluate the current epidemiology of CE in Lebanon, investigate the prevalence and determine the infecting genotypes in locally raised sheep and goats. A multidimensional approach combining post-mortem inspection of slaughtered animals and molecular diagnosis of the parasite was conducted to this end. From 2018 to 2020, 62.9% of the sheep and 20.9% of the goats were found positive for CE. The presence of hydatids varied between organs, showing higher prevalence in the liver of sheep vs the lungs of goats, however, a higher fertility rate of hydatid cyst was observed in lungs for both animals. Molecular diagnosis based on partial mitochondrial cox1 gene (795 bp) showed that the majority of isolates were identified as E. granulosus sensu stricto (98.7%) and only one isolate from goat was identified as Echinococcus canadensis (genotype G7; 1.3%). Echinococcus granulosus s.s. population among the sheep and goats was represented by 22 haplotypes having very little genetic differentiation and relatively moderate haplotype diversity. Population demographics explored through neutrality indices suggested expanding population within the intermediate hosts. These results document the high prevalence of CE in the livestock of Lebanon and reveal for the first time the presence of three different genotypes G1, G3 and G7.

Αcute visceral cysticercosis caused by Taenia hydatigena in lambs: ultrasonographic findings.

BACKGROUND: Cysticercosis caused by cysticercus tenuicollis is a metacestode infection that affects several species of ungulates. It is caused by the larval stage of Taenia hydatigena, an intestinal tapeworm in dogs and wild canids. In the intermediate host, the mature cysticerci are usually found in the omentum, mesentery, and peritoneum, and less frequently in the pleura and pericardium. The migrating larvae can be found mostly in the liver parenchyma causing traumatic hepatitis in young animals. Most infections are chronic and asymptomatic, and are diagnosed at the abattoir. The acute form of infection is unusual in sheep and reports of death in lambs are rare. METHODS: In March 2018, fifteen female lambs presented anorexia, weakness, lethargy, and death secondary to acute visceral cysticercosis. Twelve of them underwent hepatic ultrasonography. Examinations were performed on standing or left lateral recumbent animals. RESULTS: Livers of affected animals presented rounded margins and a thickened, irregular and hyperechoic surface. Hepatic parenchyma appeared to be wholly or partially affected by lesions characterized by heterogeneous areas crossed by numerous, irregular, anechoic tracts ranging from 1 to 2 cm in length and 0.1 to 0.2 cm in width. Superficial and intraparenchymal cystic structures were also visualized. The presence of lesions was confirmed by anatomopathological examination, and T. hydatigena cysticerci was identified by morphological and molecular characterization of isolates. CONCLUSIONS: Our results highlighted that hepatic ultrasonography is effective for an intra-vitam diagnosis of acute cysticercosis in lambs.

Cystic echinococcosis in the endemic island of Sardinia (Italy): has something changed?

Cystic echinococcosis (CE) is a disease of livestock and humans caused by the larval stage of the Echinococcus granulosus sensu lato (s.l.) species complex and occurs especially in areas where sheep breeding is widespread. This survey evaluates, after more than a decade since the last epidemiological survey, the current situation and trend of CE in sheep of the highly endemic island of Sardinia (Italy). From 2012 to 2018, out of a total of 1416 sheep, 65.3% were found positive for CE. Cyst fertility has increased slightly from 10.3% in 2006 (Scala et al. 2006) to 11.7% in the present survey (χ2 = 1.07; P = 0.30018) with a peak of 14.0% in the province of Sassari. Overall, 6815 hydatids were found and classified as sterile (26.2%), fertile (14.4%), caseous (5.3%), or calcified (54.1%) based on their morphology. All isolates were identified as E. granulosus sensu stricto (former G1/G3, strains). Results shown as the implementation of new European Council Regulations and in particular of 21/2004 that established a system for the individual identification and tracking of sheep could be a step forward towards a better control of animal movement, preventing illegal slaughtering on the island as well as in other countries experiencing similar problems. Even if at first sight the general situation of Sardinia regarding CE seems a little better compared with the past, our findings indicate that in some Provinces the epidemiological situation is not improved since 2006.

Massive Taenia hydatigena Cysticercosis in a Wild Boar (Sus scrofa) from Italy.

PURPOSE: Taenia hydatigena cysticercosis, due to Cysticercus tenuicollis, is a parasitic disease infecting domestic and wild animals worldwide causing economic and productive losses. Nonetheless, little attention has been paid to the role of the wild ungulates in the epidemiology of this disease. In the last years, the increasing population of wild boars in Europe has raised the attention of researchers on their role in the spreading of several infections, including those caused by cestodes. Herein, we report the description of a massive infection due to T. hydatigena cysticercosis in a wild boar from southern Italy. METHODS: An adult female boar was examined during the hunting season 2018 within the regional project "Piano Emergenza Cinghiali in Campania". A complete necropsy was performed on the boar carcass and all viscera were examined to determine number and location of the cysts. Morphological and molecular analyses of the cysts were performed to confirm the C. tenuicollis identity. RESULTS: The boar examined has revealed an impressive massive infection with 265 cysts. Measurements of the large and small larval hooks showed a mean of length as 200.3 µm and 136.8 µm, respectively. Molecular analysis of Cox1 and ND1 mitochondrial genes confirmed the C. tenuicollis identity. CONCLUSIONS: Our findings suggest that wild boar could be involved in the epidemiology of T. hydatigena, due to the significant amount of boar raw offal available to definitive hosts (i.e., hunting dogs, foxes and wolves), during the hunting seasons.

Cystic echinococcosis in wild boars (Sus scrofa) from southern Italy: Epidemiological survey and molecular characterization.

Cystic Echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is one of the most important parasitic zoonotic diseases in the world and it represents an important public health and socio-economic concern. In the Mediterranean basin, CE is widespread and it is endemic in Italy, with major prevalence in southern areas. Several studies have investigated CE in domestic pigs, however, such data in wild boars are scant. In the last decades the wild boar population in Italy has increased and this ungulate could play an important role in the spreading of CE in the wild. Here we report on the prevalence and fertility rate of hydatid cysts in wild boars that were shot during two hunting seasons (2016-2017) in the Campania region of southern Italy. For each animal, a detailed inspection of the carcass and organs (lungs, liver and spleen) was performed and when cysts were found, their number, morphology and fertility were determined by visual and microscopic examination. Cysts were classified morphologically as fertile, sterile, caseous and calcified. Protoscoleces and germinal layers were collected from individual cysts and DNA was extracted to identify different strains/genotypes of E. granulosus s.l. Out of a total of 2108 wild boars 93 (4.4%) were found positive for CE. Infected animals were 45 males and 48 females, aged between 1 and 8 years. The average number of cysts per wild boar was 1.3 (min 1 - max 13). The total number of cysts collected was 123, of which 118 (95.9%) in the liver, 4 (3.3%) in the lungs and 1 (0.8%) in the spleen. Of all analyzed cysts, 70 (56.9%) were fertile and 53 (43.1%) sterile/acephalous. The presence of fertile cysts in 19.4% of CE-positive animals is noteworthy. Overall, molecular diagnosis showed 19 wild boars infected with the pig strain (G7).

First detection of zoonotic tapeworm Echinococcus granulosus sensu lato genotype G7 in continental Italy.

The larval stage of the species complex Echinococcus granulosus sensu lato (s.l.) is the cause of a widespread zoonotic disease known as cystic echinococcosis (CE). The disease is highly prevalent in southern Italy and represents a serious public health issue. The main aim of this study was to characterize E. granulosus s.l. genotypes from wild boar on a continental area of Italy (Campania region), using recently developed mtDNA markers of nad2 and nad5 for reliable identification of different genotypes. Here, nad5 (680 bp) allowed for a clear identification of G1 and G3, whereas a combination of nad2 (714 bp) and nad5 (1394 bp in total) did the same for genotype G7 and its haplogroups G7a and G7b. The results of this study revealed for the first time the presence of genotype G7 in continental Italy. While haplogroup G7b was previously shown to be restricted to the islands of Corsica and Sardinia, here we demonstrate that haplogroup G7b is also present on the mainland of Italy. This work has implications in designing future strategies to reduce CE in Italy.

Epidemiological survey on cystic echinococcosis in wild boar from Central Italy.

Despite the wide distribution of wild boar populations in Italy and the increase of its diffusion in urbanized areas, only one case report has described the occurrence of Echinococcus granulosus s.l. in a wild boar from Marche (Central Italy). The present study investigated the presence of E. granulosus sensu lato with an epidemiological survey on wild boars from central Italy that had been killed during hunting season. Seven hundred sixty-five (765) adult wild boars were examined during the 2016-2017 hunting season. Of these animals, 1.0% (8/765) were positive to E. granulosus s.l. with a fertility of 0.3% (2/765), and 2.9% animals (22/765) were positive for the metacestode stage of Taenia hydatigena (Cysticercus tenuicollis), while 0.5% (4/765) showed mixed infection (E. granulosus s.l. + T. hydatigena). Sixteen hydatids were found, of which 12.5% were fertile, 37.5% were sterile, 31.3% were caseous, and 18.8% were calcified. Eight hydatids (two fertile and six sterile cysts) were molecularly characterized by analysis of the mitochondrial gene, cytochrome c oxidase subunit 1 (cox1), and the NADH dehydrogenase subunit 1 (ND1). Hydatids found in wild boars were characterized as E. granulosus sensu stricto (G1 genotype). The present survey represents the first epidemiological study on cystic echinococcosis in wild boar in Italy which highlights the need for more extensive epidemiological investigations to determine the causal factors, economic impact, and public health importance of the disease in this livestock-wildlife setting.

Atypical outbreak of acute coenurosis by Taenia multiceps in a sheep flock.

Herein, we examined the brain of adult ewes and lambs less than 30 days old which were found affected by neurological signs in a flock located in Sardinia (Italy). Gross anatomo-pathological examination of all brains of the animals revealed multiple linear reddish-yellow foci of necrotic purulent inflammation due to oncosphere migration. Histologically, we confirmed a multifocal pyo-granulomatous meningo-encephalitis both in ewes and in lambs, confirming acute coenurosis. Morphological examination and DNA sequencing identified the Taenia multiceps we isolated as Tm1 strain. This report describes for the first time a natural acute coenurosis infection in suckling lambs under 30 days of age.

Morphology and genetic variability within Taenia multiceps in ruminants from Italy.

The aim of this study was to investigate the genetic variability and population structure of Taenia multiceps, and to correlate morphological features of individual coenuri with haplotypes. A total of 92 animals (86 sheep; 4 goats; 1 cattle; 1 mouflon, Ovis musimon) aged between 6-36 months showing clinical symptoms of cerebral coenurosis were included in this study. T. multiceps coenuri (n=118) sampled from live animals during routine surgery procedures or at post-mortem inspections were examined morphologically and molecularly identified. Morphological features of the 52 coenuri selected for this study (number and size of large and small hooks) were within the range reported in the literature. Fifty-two of the molecularly confirmed T. multiceps coenuri harboured by 47 animals (sheep=41; cattle=1; goats=4; mouflon=1) were used to determine gene genealogies and population genetic indices and were compared to the 3 T. multiceps genetic variants, Tm1-Tm3 previously described from Sardinia, Italy. For the 379 bp cox1 dataset we identified 11 polymorphic sites of which 8 were parsimony informative. A high haplotype diversity (0.664±0.067) was recorded for the cox1 sequences defining 10 haplotypes (TM01-TM10). The comparison of haplotypes generated in this study with published T. multiceps Tm1 variant pointed to the possible existence of a common lineage for T. multiceps. No correlation was detected between the size of the small and large hooks and the cox 1 haplotypes. Polycystic infestation (2-9 coenuri) was recorded in 27.7% of animals (13/47). No statistical correlation between polycystic T. multiceps infection and haplotypes was detected.

Cross-sectional investigation on sheep sarcosporidiosis in Sardinia, Italy.

An epidemiological survey on sarcosporidiosis was carried out with a cross sectional investigation on macroscopic and microscopic Sarcocystis spp. in Sarda breed sheep slaughtered in different abbatoirs of Sardinia, Italy. For the macroscopic survey, muscular samples (diaphragm, abdominal and intercostals muscles, cutaneous muscles and muscles of the thigh) from 769 slaughtered Sarda sheep, oesophagus (n=365) and laryngeal and pterygoid muscles (n=521) were macroscopically investigated and Polymerase Chain Reaction (PCR) on selected macroscopic cysts was performed for a molecular identification of macroscopic Sarcocystis species. For the microscopic investigation 112 heart samples from slaughtered Sarda sheep were collected and investigated with two different protocols: unstained (compression) examination and a molecular technique. The overall prevalence of infection for macroscopic forms of sarcocysts was of 23.3% (179/769) with prevalences higher in the oesophagus (31.6%; 125/395) compared with the other investigated tissue type; two different morphotypes, classified as large oval (LO) macroscopic cysts, identified as Sarcocystis gigantea, and slender fusiform (SF) sarcocysts, were identified. The examination of heart samples revealed an overall prevalence of 77.7% (87/112) for Sarcocystis spp.; the nested-PCR analysis of heart samples allowed to identify the microscopic species, Sarcocystis tenella and Sarcocystis arieticanis, with prevalences of 95.5% (107/112) and 17.8% (5/112) respectively. Reported results highlight the high prevalence of Sarcocystis infection in the island and suggests the need of an improvement of control and prevention strategies for this parasitosis.

A preliminary investigation into the genetic variation and population structure of Taenia hydatigena from Sardinia, Italy.

Cysticercosis caused by the metacestode stage of Taenia hydatigena is endemic in Sardinia. Information on the genetic variation of this parasite is important for epidemiological studies and implementation of control programs. Using two mitochondrial genes, the cytochrome c oxidase subunit 1 (cox1) and the NADH dehydrogenase subunit 1 (ND1) we investigated the genetic variation and population structure of Cysticercus tenuicollis from Sardinian intermediate hosts and compared it to that from other hosts from various geographical regions. The parsimony cox1 network analysis indicated the existence of a common lineage for T. hydatigena and the overall diversity and neutrality indices indicated demographic expansion. Using the cox1 sequences, low pairwise fixation index (Fst) values were recorded for Sardinian, Iranian and Palestinian sheep C. tenuicollis which suggested the absence of genetic differentiation. Using the ND1 sequences, C. tenuicollis from Sardinian sheep appeared to be differentiated from those of goat and pig origin. In addition, goat C. tenuicollis were genetically different from adult T. hydatigena as indicated by the statistically significant Fst value. Our results are consistent with biochemical and morphological studies that suggest the existence of variants of T. hydatigena.