Trichinella britovi infection in wild boar in Portugal

Abstract

Trichinella spp. infection occurs when a host ingests muscle tissue containing infective larvae (L1 stage). Wild boar meat and its products represent the second largest source of human trichinellosis worldwide. For this reason, and since that in Portugal wild boar is the most hunted large game specie, the laboratory of Technology, Quality and Food Safety (TQFS) from the University of Trás‐os‐Montes e Alto Douro created a free service to test wild boar meat for Trichinella spp. From December 2015 to February 2020, and 857 samples were analysed. From those, the majority (719/857, 83.9%) were tested after October 2018 when a specific national legislation came into force, demanding that meat from wild boar hunted in a defined risk area should be tested for Trichinella spp. Under TQFS laboratory activity, in January 2020, a positive case was identified, being the first molecular confirmation of Trichinella britovi infection in wild boar in Portugal. Additionally to this activity, in 2019, a questionnaire was submitted to 100 hunters to acquire information about wild boar meat usage and consumption behaviours. From the total respondents, 86% declared they intended to use meat for private consumption. Of those, 93% also stated that have sold part of the meat and/or homemade sausages, the majority (80%) without prior testing for Trichinella spp., as required by EU Regulation. These results alert the hunters to a risk for human infection, which could be extended to outside the hunter's household. Given the actual epidemiological situation, it should be emphasized that testing for Trichinella spp. in wild boar meat should be maintained and reinforced, particularly in the risk area. The results presented in this report strongly support the importance of specific national legislation to mitigate the risk of trichinellosis due to consumption of non‐tested wild boar meat.

Trichinella britovi in wild boar meat from Italy, 2015–2021: A citizen science approach to surveillance

“…Despite this, in European countries few large-scale studies are available on the occurrence of Trichinella spp. in wild boars, even if their meat products are commonly present in local markets and traditional festivals [ 8 ], being considered as a delicacy and touristic attractiveness due to the nutritional and culinary properties [ 9 ]. According to the European legislation on specific rules for official controls of Trichinella in meat (i.e., the Commission Implementing Regulation EU 2015/1375 and 2019/627) [ 10 , 11 ], all quarry susceptible to this parasite should be screened for presence of larvae (L 1 ) in the muscles before being placed on the market for human consumption.…”

The International Trichinella Reference Centre database. Report on thirty-three years of activity and future perspectives

“…Indeed, while the predominant association of T. spiralis with wild boars and domestic pigs (89.4%) agrees with literature ( EFS Agency, 2021 ; Pozio, 2021 ), the large number of T. britov i isolates associated with wild boars (41%), rather than with red foxes (26.3%), does not reflect the real epidemiological situation in which the red fox is the main natural host of this species ( Bilska-Zając et al, 2020 ; Deksne et al, 2016 ; Kärssin et al, 2017 ). This is due to the fact that the T. britovi isolates recorded in the DB mainly originated from surveillance studies with a specific focus on wild boar ( Bilska-Zając et al, 2013 ; Kirjušina et al, 2015 ; Balić et al, 2020 ; Vieira-Pinto et al, 2021 ). Likewise, the high association of T. pseudospiralis with the Florida panther and that of T6 with the wolverine in isolates collected from North America ( Reichard et al, 2008 ; Reichard et al, 2015 ), reflects data derived from surveillance studies focused on specific host species because of their interest as possible Trichinella indicators in a specific geographical region.…”

Investigation of the Food-Transmitted Parasites Trichinella spp. and Alaria spp. in Wild Boars in Greece by Classical and Molecular Methods and Development of a Novel Real-Time PCR for Alaria spp. Detection

“…Nevertheless, the prevalence found in wild boars in Europe may be characterized as low, as it has been found less than 1% in all cases. In some of the most recent, wide-range epizootiological surveys in Europe where AD methods were implemented, hundreds or thousands of wild boars were examined (in most cases these surveys were analysis of national authorities' records); the prevalence of infection was 0.1% in Portugal [48], 0.17% in Croatia [49], 0.04% in Slovakia [50], 0% in Denmark [51], and 0.51% in Poland [52]. In a survey similar to the present study, conducted in Italy, diaphragm muscle samples of 100 wild boars hunted in two hunting seasons were examined, and none (0%) was found positive to Trichinella larvae [53].…”