Trichinellosis is a zoonotic disease caused by the consumption of raw or semiraw meat from different animals harboring Trichinella larvae in their muscles. Since there are no pathognomonic signs, diagnosis can be difficult; for this reason, serology is important. The objective of this study was to validate an enzyme-linked immunosorbent assay (ELISA) using excretory/secretory antigens to detect anti- Trichinella immunoglobulin G antibodies in human sera. A total of 3,505 human serum samples were tested. A receiver-operator characteristic (ROC) curve analysis was performed. The accuracy of the test was determined by calculating the area under the curve, which was equal to 0.999, indicating high accuracy. The coefficient of variation calculated for data from four serum samples in eight working sessions was no higher than 5% for the positive sera or 14% for the negative sera. Moreover, the analysis of the differences in optical density between duplicates indicated a high repeatability for the ELISA. At the ROC optimized cutoff, the sensitivity and specificity of the test were, respectively, 99.2% and 90.6% (specificity of 95.6% when excluding the samples from multiparasitized persons from Tanzania). The validated ELISA showed good performance in terms of sensitivity, repeatability, and reproducibility, whereas the specificity was limited. These results suggest that this test is suitable for detecting anti- Trichinella antibodies in human sera for diagnostic purposes, whereas its use in epidemiological surveys could be questionable.

Nematode parasites of the genus Trichinella are important foodborne pathogens transmitted by ingestion of striated muscles harbouring infective larvae. Wild carnivorous and omnivorous animals are the most important reservoirs of these parasites. Hunting activities play an important role in Trichinella spp. epidemiology. The aim of the present work was to assess if serological detection of anti-Trichinella IgG in hunting dogs can be a tool to indirectly monitor Trichinella spp. infections in wildlife. An ELISA and a Western blot (Wb) were developed and validated. To validate the assays, serum samples were collected from 598 dogs considered to be Trichinella-free, 15 naturally infected dogs, and six experimentally infected foxes. Sera were tested by ELISA with Trichinella spiralis excretory/secretory antigens. The diagnostic sensitivity and specificity of ELISA were 100 % (95 % CI: 83.89–100 %) and 95.65 % (95 % CI: 93.69–97.14 %), respectively. Sera from Trichinella-infected dogs/foxes tested by Wb showed a three-band pattern ranging from 48 to 72 kDa. Since the prevalence of Toxocara canis is very high in dogs, the specificity of the ELISA and Wb was further assessed by testing sera for anti-T. canis IgG using T. canis excretory/secretory antigens. No cross-reactivity was observed. To evaluate the test’s reliability in the field, serum samples were collected from wild boar hunting dogs from Central Italy where Trichinella britovi was circulating among wildlife. Out of 384 hunting dog sera, 189 (49.2 %) tested positive by ELISA and of these, 56 (29.6 %) tested positive by Wb, showing an overall prevalence of 14.6 % (56/384) in the wild boar hunting dog population of the investigated area. The serological prevalence in hunting dogs was significantly (P < 0.001) associated with the hunting district’s altitude. This is in agreement with previous investigations, which had shown that the prevalence of T. britovi in wildlife was higher in mountainous areas than in lowland areas of Italy. The results suggest that the circulation of Trichinella spp. among wildlife can be monitored by testing sera from hunting dogs, which could act as sentinel animals of Trichinella spp. circulation in wildlife.

Trichinella spp. infections in wild boar (Sus scrofa), one of the main sources of human trichinellosis, continue to represent a public health problem. The detection of Trichinella spp. larvae in muscles of wild boar by digestion can prevent the occurrence of clinical trichinellosis in humans. However, the analytical sensitivity of digestion in the detection process is dependent on the quantity of tested muscle. Consequently, large quantities of muscle have to be digested to warrant surveillance programs, or more sensitive tests need to be employed. The use of indirect detection methods, such as the ELISA to detect Trichinella spp. infections in wild boar has limitations due to its low specificity. The aim of the study was to implement serological detection of anti-Trichinella spp. antibodies in meat juices from hunted wild boar for the surveillance of Trichinella spp. infections.

Human cysticercosis (CC) is a parasitic zoonosis caused by the larval stage (cyst) of the Taenia solium. Cysts can establish in the human central nervous system (neurocysticercosis, NCC) and other organs and tissues; they also develop in pigs, the natural intermediate host. Human taeniosis may be caused by T. solium, Taenia saginata and Taenia asiatica tapeworms; these infections are usually asymptomatic, but show a significant relevance as they perpetuate the parasites’ life cycle, and, in the case of T. solium, they are the origin of (N)CC. In European Union (EU) member states and associated countries, the occurrence of autochthonous T. solium cases is debated, and imported cases have significantly increased lately; the status of T. asiatica has been never reported, whereas T. saginata is prevalent and causes an economic impact due to condemned carcasses. Based on their effects on the EU society, the specific diagnosis of these pathologies is relevant for their prevention and control. The aims of this study were to know the diagnostic tests used in European laboratories for human taeniosis/cysticercosis by means of a questionnaire, to determine potential gaps in their detection, and to obtain preliminary data on the number of diagnosed taeniosis/CC cases.

Trichinellosis is a meat-borne zoonotic disease caused by parasites of the genus Trichinella. To date, 12 taxa have been described. The identification of Trichinella species is crucial in order to identify the possible source of infection, the geographical origin of the parasite and to assess risk of infection for domestic pigs and humans. Specific identification of the etiological agent is not always feasible using direct methods since the source of infection can be untraceable. The aim of this study was to develop a diagnostic tool to infer the causative Trichinella species using western blot patterns of sera derived from infected animal and human hosts. Sera from mice experimentally infected with Trichinella spiralis, Trichinella britovi, Trichinella pseudospiralis and Trichinella papuae were tested by western blot using homologous and heterologous crude worm extracts (CWE) and a highly sensitive detection system based on chemiluminescence. In addition, sera from pigs experimentally infected with T. spiralis, T. britovi and T. pseudospiralis and from patients with confirmed T. spiralis, T. britovi and T. pseudospiralis infections, were also included. Sera from mice infected with one Trichinella species reacted with CWE proteins from all four investigated species. Likewise, sera derived from pigs and humans infected with one Trichinella species reacted with CWE proteins from all the three investigated species. Using T. spiralis CWE, sera from T. pseudospiralis-infected hosts yielded a characteristic pattern of reactivity using Wb, which differed to that produced by T. spiralis/T. britovi- or T. papuae-infected host sera. The present study suggests that western blot using T. spiralis CWE may be a useful tool to distinguish Trichinella infections caused by T. pseudospiralis from those caused by T. spiralis or T. britovi. This method may support epidemiological investigations, particularly when the source of infection is not traceable.