Trichinella In Pigs Research Articles

Global prevalence of Trichinella in pigs: A systematic review and meta-analysis.

Investigating the global epidemiological patterns of Trichinella in pigs is required for accurate recognition and to establishing proper control programmes and preventive measures, as well as to decrease human exposure. To obtain a better understanding of the global prevalence of Trichinella in domestic pigs and factors that might influence the prevalence, a systematic review and meta-analysis was performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Multiple databases were used to identify literature published between January 2000 and December 2021, representing studies from 1985 to 2021, on Trichinella prevalence in domestic pigs. Prevalence was calculated on a global and country level, by country Human Development Index (HDI), climate, pig management system, and diagnostic test. The global pooled prevalence based on 60 manuscripts representing 32 countries and 65 pig populations was 2.02% (95% confidence interval [CI]: 0.88-3.62) and the estimated pooled prevalence in different continents ranged from 0.00% to 11.8%. Trichinella was highest in low HDI countries (21.6%; 95% CI: 4.3-47.2), tropical wet climates (20.9%; 95% CI: 10.3-34.1), and non-intensive pig farming systems (6.1%; 95% CI: 1.0-15.5). While there were regional differences in Trichinella prevalence in domestic pigs, these were likely driven by country HDI and pig farming systems versus climatic factors. Increased biosecurity in outdoor pig production systems, focused meat inspections and promoting awareness could potentially decrease risk of infection.

Economic evaluation of a program for monitoring and controlling Trichinella in pigs

Introduction. Trichinellosis is a cosmopolitan anthropozoonosis, and is a group of systemic diseases caused by larval forms of Trichinella. This is one of the oldest and most controversial parasitic zoonoses that has been in the forefront of veterinary, medical and biological research for many years. Parasites from the genus Trichinella were diagnosed in more than one hundred species of domestic and wild mammals and birds. The aim of this study was economic evaluation of a program for monitoring and controlling Trichinella in pigs. Materials and Methods. A systematic pest rodent control program deemed suitable for monitoring and controlling Trichinella in pigs was implemented in a representative test zone. The results of the pest rodent control program were analyzed using cost-benefit analysis to determine if a similar program would be suitable for a larger land area. Results and Conclusions. Prior to pest control, the incidence of Trichinella in pigs living in the test zone increased annually, while after systematic pest rodent control, the incidence of Trichinella-positive pigs decreased. These results, as well as relevant economic indicators, enabled us to design two mathematical models describing the control and monitoring of Trichinella in a larger land area. In this area, Srem Region, Serbia, a suitable Trichinella control program in pigs is clearly justified because the profit to cost ratio was positive for both models.

Judul Seroprevalensi Trichinellosis pada Ternak Babi di Wilayah Kabupaten Tangerang, Propinsi Banten (SEROPREVALENCE OF TRICHINELLOSIS IN PIGS IN THE TANGERANG DISTRICT PROVINCE OF BANTEN)

Trichinellosis is a zoonotic disease caused by parasitic roundworms of the nematode class Trichinella spp, which is distributed worldwide. Indonesia is one of the countries with trichinellosis cases. This study aims to determine the seroprevalence of Trichinellosis in pigs in Tangerang Village, Banten Province. The sample size is determined with 95% confidence level, the expected prevalence is 5%, and the error rate is 5%. A total of 80 sera were collected from farm (27 sera) and from the sample banks of Disease Investigation Centre Subang (DIC Subang(53 sera)). The sample collection was examined serologically by the ELISA method for the examination of anti-Trichinella antibodies. The results showed that seroprevalence of trichinellosis in this study was 1.25% (confidence interval (CI) 95%; 0,22-6,75%). This case can be a threat to human health. Pigs that show seropositive results were the pigs with traditional husbandry practices with ground flooring and without fences. The results of the questionnaires that distributed to the farmers indicated that all farmers did not know about trichinellosis, this may affect the presence of Trichinella in pigs.

A bead-based suspension array for the serological detection of Trichinella in pigs

The feasibility of using bead-based suspension arrays to detect serological evidence of Trichinella in pigs was assessed. Trichinella spiralis excretory–secretory antigen was covalently coupled to paramagnetic beads and used to bind serum antibodies, which were subsequently detected using anti-swine antibody. The assay was evaluated by testing pig sera from farms where trichinellosis was endemic and comparing the results with those obtained using two commercially available ELISAs. With cut-offs established by receiver operating characteristic (ROC) analysis, digestion-negative sera from a Trichinella-free population of pigs were deemed seronegative. When anti-swine antibody was replaced with protein A/G, higher test sensitivity (94% vs. 88%) at similar test specificity (95%), was achieved. The potential use of this assay in species other than swine was also demonstrated by testing human sera.

Evaluation of a Western Blot and ELISA for the detection of anti- Trichinella-IgG in pig sera

Human trichinellosis is a foodborne disease caused by ingestion of infective Trichinella muscle larvae via pork or meat of other food animals which are susceptible to this zoonotic parasite. There are new approaches for a risk-oriented meat inspection for Trichinella in pigs which are accompanied by monitoring programmes on herd level to control freedom from this parasite. For this purpose, testing schemes utilizing serological tests with a high sensitivity and specificity are required. This study aimed at the evaluation of an ELISA and a Western Blot (WB) for the detection of anti- Trichinella-IgG in terms of sensitivity and specificity taking results of artificial digestion as gold standard. For this purpose, 144 field sera from pigs confirmed as Trichinella-free as well as 159 sera from pigs experimentally infected with T. spiralis (123), T. britovi (19) or T. pseudospiralis (17) were examined by ELISA (excretory–secretory antigen) and WB (crude worm extract). Sera from pigs experimentally infected with four other nematode species were included to investigate the cross-reactivity of the antigen used in the WB. For all Trichinella-positive pig sera, band pattern profiles were identified in the WB and results were analysed in relation to ELISA OD% values. Testing of pig sera revealed a sensitivity of 96.8% for the ELISA and 98.1% for the WB whereas the methods showed a specificity of 97.9 and 100%, respectively. WB analysis of Trichinella-positive pig sera revealed five specific band patterns of 43, 47, 61, 66, and 102 kDa of which the 43 kDa protein was identified as the predominant antigen. The frequency of the band pattern profile was irrespective of the dose and the period of infection as well as the Trichinella species investigated. In conclusion, monitoring in swine farms for Trichinella antibodies should be based on screening pig sera by means of ELISA followed by confirmatory testing through WB analysis.

Detection and surveillance for animal trichinellosis in GB

The zoonotic disease trichinellosis is considered one of the re-emerging diseases with surveillance and control methods constantly gaining more importance worldwide. Recent change in European Union (EU) legislation introduces Trichinella-free production, and the possibility of risk-based monitoring for Trichinella in pigs. This has increased the role of wildlife surveillance programmes and their impact on protecting human health as well as highlighted the need for harmonised surveillance protocols and test methods for these infections. A modified digest method, based on the EU reference method for Trichinella testing of pig meat, was used to screen foxes present in Great Britain (England, Scotland and Wales) for trichinellosis. The method was validated using batched pools of 10 g foreleg muscle from up to 20 foxes (maximum amount 200 g). The method gave an average trichinae recovery rate of 71% for spiked samples. Assuming this recovery rate applies to all contaminated samples, then the test sensitivity would be 70% for all tissue samples with 0.1 trichinae per 10 g of foreleg muscle, 99.9% for samples with 1 trichinae per 10 g, and 100% for samples with 2 or more trichinae per 10 g. In two separate studies, conducted between 1999 to 2001 ( Smith et al., 2003) and 2003 to 2007, over 3500 wild foxes have been screened for Trichinella with negative results. In the second study reported here, foxes were collected from locations throughout Great Britain using a stratified sampling method based on fox population densities. All work was conducted in compliance with appropriate quality assurance systems, latterly under ISO 9001. Results to date indicate the national prevalence of trichinellosis in foxes is <0.001 based on a 10 g individual sample size, an infection level of 1 larva per gram (lpg) and 95% confidence interval. This, together with no reports of trichinellosis in domesticated pigs, suggests that Britain can be considered a region of negligible risk of trichinellosis.

Infectivity, persistence, and antibody response to domestic and sylvatic Trichinella spp. in experimentally infected pigs

Groups of pigs were inoculated with genotypes of Trichinella belonging to: Trichinella spiralis, Trichinella nativa, Trichinella britovi, Trichinella pseudospiralis (from Caucasus), T. pseudospiralis (from USA), Trichinella murrelli, Trichinella sp. (from North America), and Trichinella nelsoni. The pigs were sacrificed between 5 and 40 weeks p.i., and the number of muscle larvae per gram (l.p.g.) of tissue was determined as an average of 18 muscles. All Trichinella genotypes were infective for pigs, but both their infectivity and persistence varied: 5 weeks p.i., T. spiralis muscle larvae were present in high numbers (mean=427 l.p.g.), while T. britovi, T. nelsoni, and T. pseudospiralis larvae were present in moderate numbers (means=24–52 l.p.g.); larvae of the remaining genotypes were recovered only in low numbers (means=0.05–5.00 l.p.g.). The total larval burden (live weight of pig×l.p.g.) was constant over time for T. spiralis, T. britovi, and T. nelsoni, but declined significantly ( P<0.05) for the other genotypes. Antibody responses could be detected 3–4 weeks p.i. by seven different Trichinella ES antigens, but the antibody levels and dynamics differed significantly among the experimental groups. In pigs inoculated with T. spiralis, T. britovi, or T. nelsoni, the antibody level increased rapidly between weeks 3 and 5 p.i. and was stable or increased slightly throughout the experimental period. In pigs inoculated with T. nativa, T. murrelli, or Trichinella (T6) (from North America), a rapid increase was detected between weeks 3 and 5 p.i., but for these genotypes a reduction in the antibody levels was seen thereafter. In the pigs inoculated with T. pseudospiralis, the antibody level increased more gradually over a period from week 3 p.i. to weeks 15–20 p.i., and decreased thereafter. In general, all species of Trichinella were detected by any of the seven ES antigens, which points to the potential use of one common antigen for surveillance and epidemiological studies on both domestic and sylvatic Trichinella in pigs. Homologous ES antigens were slightly more sensitive in detecting antibodies to the corresponding Trichinella species.