Prevalence Of Trichinella Infection Research Articles

No evidence of Trichinella spp. in domestic pig carcasses at a selected abattoir in southern Botswana.

Trichinellosis is a worldwide zoonosis with genotypes affecting different domestic and wild animals and is widely distributed throughout the world. Species and genotypes of this genus affecting different animals have been identified. Despite its occurrence in Sub-Saharan countries, the presence of trichinellosis in Botswana is yet to be confirmed. The objective of this study was to determine the prevalence of Trichinella infection in domestic pigs slaughtered at an abattoir in Gaborone, Botswana. Of the 111 pig carcasses selected, 5g of crus of the diaphragm was collected from each carcass, trimmed of all fat and fascia and then cut into 1- to 2-g samples. The muscle samples were pooled into 100-g muscle sample and then processed by the OIE prescribed digestion method. A stereomicroscope was used to examine each grid of the Petri dish for the presence of Trichinella larvae. No Trichinella larvae were found in any digested muscle samples. Future studies should target a wider pig population and other host animals.

Trichinella and polar bears: a limited risk for humans.

In this review, we identified 63 cases reported since World War II of human trichinellosis linked to the consumption of parasitized polar bear (Ursus maritimus) meat. This low number contrasts to the numerous cases of human trichinellosis related to consumption of the meat of black (U. americanus) or brown bears (U. arctos). The prevalence of Trichinella infection is high in bears, but larval muscular burden is usually lower in polar bears compared to other bear species. Polar bears, therefore, seem to play a limited role in the transmission of trichinellosis to humans, as native residents living in the Arctic traditionally consume well-cooked bear meat, and travellers and foreign hunters have only limited access to this protected species due to the declining polar bear population.

Survey of Trichinella infection from domestic pigs in the historical endemic areas of Henan province, central China.

The aim of this work was to investigate the current situation of Trichinella infection from domestic pigs in the historical endemic areas of Henan province, central China. A total of 823 diaphragm samples from the indoor-raised pigs were collected in five cities of Henan during 2014-2015 and examined by artificial digestion method. The overall prevalence of Trichinella infection in pigs was 0.61% (5/823). Trichinella larvae were detected in 0.91% (5/550) of pigs from Nanyang city of Henan. The larval burden in infected animals was 0.03 larvae per gram (lpg) of muscles with a range from 0.02 to 0.05lpg. The larvae were identified as Trichinella spiralis by multiple PCR. Our study confirms the existence of swine trichinellosis in Henan, but the infection level was under the minimum level for defining infectious sources for humans. However, the prevalence of swine Trichinella infection in Henan need to be further evaluated with a large scale of pork samples for ensuring meat food safety.

Identification of the Trichinella species by PCR method

Serbia is country with a high prevalence of Trichinella infection in pigs, which continues to be a serious human health problem. In Serbia, only a few isolates of Trichinella found in pork have been genetically specified to date, and all were proven as T. spiralis. New data shows that in the sylvatic cycle in Serbia, at least in the Belgrade district, more than one Trichinella species co-exist (T. spiralis and T. britovi). Increased awareness of the possible overlap among sylvatic and domestic Trichinella cycles indicates the need for continuous monitoring of Trichinella species circulation and strongly points to the need that all isolates of Trichinella found in meat for human consumption should be subject to a determination of the Trichinella species (due to the risk of transmission of infection with T. britovi to domestic pigs and humans). This is why we examined using PCR the Trichinella larvae found in pig meat that caused a human outbreak (Trichinella infection) in Grocka (Belgrade district) during February 2011. The isolated larvae belonged to T. spiralis.

Strayed dogs sentinels ofTrichinella britoviinfection in Kosovo

Strayed dogs sentinels of<i>Trichinella britovi</i>infection in Kosovo

Spatial distribution of Trichinella britovi, T. spiralis and T. pseudospiralis of domestic pigs and wild boars (Sus scrofa) in Hungary

Trichinellosis is a foodborne disease caused by the consumption of raw meat and raw meat-derived products from swine, horse and some game animals infected with nematode worms of the genus Trichinella. Between June 2006 and February 2011, 16 million domestic pigs and 0.22 million wild boars (Sus scrofa) were tested for Trichinella sp. in Hungary. Trichinella infection was not found in any pigs slaughtered for public consumption. Nevertheless, Trichinella spiralis was detected in four backyard pigs when trace back was done following a family outbreak. Trichinella infection was demonstrated in 17 wild boars (0.0077%). Larvae from wild boars were identified as Trichinella britovi (64.7%), T. spiralis (29.4%) and Trichinella pseudospiralis (5.9%). Although the prevalence of Trichinella sp. infection in wild boars and domestic pigs is very low, the spatial analysis reveals that the level of risk differs by region in Hungary. Most of the T. britovi infected wild boars (63.6%) were shot in the north-eastern mountain area of Hungary; whereas domestic pigs and wild boars infected with T. spiralis were detected only in the southern counties bordering Croatia and Romania. In the north-western and central counties, the prevalence of Trichinella infection seems to be negligible.

An epidemiological overview of swine trichinellosis in China

Trichinellosis is a major food-borne zoonosis with health, social, and economic impacts. Epidemiological data on swine trichinellosis in China from 2005 to 2009 were obtained from seven Provinces/autonomous regions/Municipalities (P/A/M) and analyzed and sero-epidemiological data were acquired from five P/A. The seroprevalence ranged from 0.01% to 29.95% as determined by enzyme-linked immunosorbent assay or an immunochromatographic strip method. The prevalence of Trichinella infection in swine slaughtered at abattoirs varied from 0% to 5.75% in five P/A. Between 2005 and 2009, endemic areas of swine trichinellosis were located mainly in the Western (Guangxi and Qinghai), central (Henan and Hubei), and North-eastern parts (Heilongjiang) of China. Swine trichinellosis in China is transmitted mostly through garbage. Pigs infected with Trichinella are predominately from small backyard farms where animals are raised under poor hygienic conditions, and from rural and mountainous areas where they range freely at pasture. The prevalence of Trichinella in pork sold at the market was reported in four P/A, and varied from 0.06% to 5.6% as determined by trichinoscopy or the digestion method. From 2005 to 2009, 15 outbreaks of human trichinellosis, with 1387 cases and 4 deaths, were recorded in three P/A of South-western China. Twelve (85.71%) of these 15 outbreaks were caused by the eating of raw or undercooked pork, which remains the predominant source of trichinellosis in humans. Pig-rearing practices must be improved, and mandatory inspection of pork further strengthened in rural and mountainous areas in Western China for the control of the disease.

Application of GIS in epizootiological surveillance of swine trichinellosis in one endemic district in Serbia

Application of new tools for epizootiological investigations in veterinary medicine, such as Geographical Information Systems (GIS), offers a new approach and possibilities for the eradication or control of infectious diseases. GIS is particularly useful for research conducted in small areas strongly impacted by man. Trichinellosis is a world-wide zoonosis, which is endemic in some European countries, Balkan district and Serbia in particular. There are very few data on GIS application in the field of trichinellosis. We here present the application of GIS for mapping Trichinella spp. occurrence and spatial and temporal patterns of Trichinello infection in one endemic district in Serbia. Settlements with trichinellosis were marked and particular points of interest were designated. Data on prevalence of Trichinella infection in domestic swine accompanied by location of foci indicated the existence of disease geographical stationarity. This first report on GIS application in Serbia will facilitate trichinellosis surveillance and monitoring of Trichinella spp. circulation among domestic pigs, and populations of synanthropic and sylvatic animals.

Vorkommen von Trichinella spp. beim Wildschwein in der Schweiz

Trichinellosis is a worldwide occurring zoonosis caused by the intracellular nematode Trichinella spp. One of the main infection sources in Europe is raw or undercooked meat from wild boar. Trichinella britovi is prevalent in wild carnivores in Switzerland, thus a possible inclusion of wild boar in this wildlife cycle cannot be excluded. In order to assess the prevalence of Trichinella infection in wild boar, we tested 1,458 animals with both parasitological and serological methods. In none of the animals Trichinella-larvae could be recovered by the artificial digestion method (prevalence of larvae: 0 %; 95 % CI 0.0 - 0.3). Antibodies in meat juice were detected in 57 animals using a standardized E/S-Ag-ELISA. However, in the confirmatory westernblot, only 3 animals remained seropositive (seroprevalence: 0.2 %; 95 % CI 0.07 %-0.60 %). The occurrence of wild boar positive for anti-Trichinella-antibodies indicates that meat inspection for Trichinella-larvae in this species is important to prevent human infections.

Trichinella zimbabwensis in wild Nile crocodiles ( Crocodylus niloticus) of South Africa

Recent discovery of Trichinella zimbabwensis in crocodiles from Zimbabwe, Lake Cahora Basa, Mozambique, and from lake Abaja, Ethiopia, prompted strict control measures to curb the possible spread of the infection to humans and also to prevent its introduction to other countries, which were considered free of this pathogen. In 2006, the Chief Directorate Veterinary Services of Mpumalanga Province of South Africa launched a survey to investigate the status of wild and commercial breeding crocodiles in the province. To evaluate if T. zimbabwensis was circulating in the environments where crocodiles are living in South Africa, 9 fish, 36 reptiles (including 27 Nile crocodiles) and 4 mammals have been investigated to detect Trichinella sp. larvae in their muscles. In January 2008, a Nile crocodile from Komatipoort, sampled by means of a tail biopsy, tested positive for Trichinella larvae. In June–July 2008, Trichinella sp. larvae were also detected in four other Nile crocodiles from the Olifants River Gorge. The prevalence of Trichinella infection in the investigated wild Nile crocodiles from South Africa is 38.5%. The larvae were identified as belonging to T. zimbabwensis by multiplex-PCR. These are the first reports of T. zimbabwensis in South Africa and suggest that the distribution area of this parasite species is wider than that believed in the past.

Evaluation of the risk of transmission of Trichinella in pork production systems in Argentina

Recently, there has been interest in programs that certify pork production practices that minimize the risk of exposure of pigs to Trichinella spiralis. Certification might be useful for reducing the risk of human trichinellosis from pork in Argentina, but more information is needed on pig production practices and sources of Trichinella infection in Argentinian pigs. In this study, 21 pig farms were assessed for Trichinella infection including some farms using total and partial confinement management, and others with pigs raised exclusively outdoors. A total of 3224 muscle samples were collected from pigs raised on these farms and tested to determine the presence of T. spiralis larvae by artificial digestion. Serum samples from the same 3224 pigs were tested for antibodies to T. spiralis by ELISA. For each farm, a questionnaire was completed summarizing information about management factors and this information was used to assess risk factors for exposure of T. spiralis. Based on the results, pigs raised outdoors were more likely to be infected than pigs raised in total or partial confinement (p≤0.05). Pigs fed waste products containing meat were 12.5 times more likely to be infected than pigs not fed waste containing meat (p<0.01). The role played by rats in transmission of Trichinella is unclear; however, on farms with evidence of wild animals and access of pigs to wildlife carcasses, the prevalence of Trichinella infection was significantly higher. All pigs raised under good hygienic and sanitary conditions were negative for Trichinella infection by both artificial digestion and ELISA.

The epidemiology of swine trichinellosis in China during 1999–2004

Abstract The epidemiology of swine trichinellosis in China during 1999–2004 was reported in this paper. The seroepidemiological survey of swine trichinellosis was carried out by ELISA in 4 Provinces or Autonomous Regions (P/A), the seroprevalence was from 1.63 % to 15.21 %. The prevalence of Trichinella infection in swine slaughtered at abattoirs varied from 0.0001 % to 23 % in 7 P/A. Both of the seroprevalence and prevalence of swine trichinellosis in China has obviously decreased compared with that in 1990’s. The decrease was probably due to a combination of factors, including development of industrialized pig farms, application of commercial grain forages, the improvement of pig production practices and the shortening of swine feeding time. At present, swine trichinellosis in China still is mainly transmitted by garbage (ie. feeding pigs with raw swill). Trichinella infected pigs are predominately from the small farms of suburbs where pigs are fed on swill from the restaurants and from some mountainous areas where pigs are raised outdoors. Pigs were sometimes slaughtered clandestinely at home in rural and mountainous areas without veterinary inspection. The prevalence of Trichinella infection in pork sold at the market was from 0.52 % to 3.66 % in 3 P/A. 17 outbreaks of human trichinellosis, with 828 cases and 11 deaths, were recorded in 8 P/M of China during 2000–2004. Out of 17 outbreaks, 13 (76.47 %) outbreaks were caused by eating raw or poorly cooked pork. Hence, the pig-rearing mode should be changed and all pigs should be raised in piggery, and the mandatory inspection of meat be further strengthen for the control of trichinellosis.

The epidemiology of human trichinellosis in China during 2000–2003

The endemic foci of trichinellosis continue to be mainly located in the southwestern, the central and northeastern China. The seroepidemiological surveys of T. spiralis infection in humans were carried out in six Provinces or Municipals (P/M) of China during 2000–2003, the overall seroprevalence was 3.57%. From 2000 to 2003, 17 outbreaks of human trichinellosis, with 828 cases and 11 deaths, were recorded in 8 P/A of China. All of 11 deaths occurred in the southwestern China (1 case in Sichuan, 4 cases in Tibet and 6 cases in Yunnan), where the ethnic groups have the habit of eating raw meat. Pork is the predominant source of outbreaks of human trichinellosis in China. Out of 17 outbreaks, 13 (76.47%) outbreaks were caused by eating raw or poorly cooked pork, 2 (11.77%) outbreaks caused by eating raw dog meat and 2 (11.77%) outbreaks by eating game meat (wild boar and bear), suggesting the increasing significance of dog and game meat as source of infection for human trichinellosis. The partial effects of health education interventions for control of trichinellosis have been achieved in some counties of Yunnan province. The number of inhabitants eating raw meat has decreased from 72.74% (1561/2146) before interventions to 47.43% (489/1031) after interventions. The decrease of incidence of trichinellosis in China during the past 4 years was probably due to a combination of factors, including the reduction in the prevalence of Trichinella infection in domestic swine, the strengthened meat inspection, the increased use of home freezers and the development of heath education practice.

The epidemiology of animal trichinellosis in China

The epidemiology of animal trichinellosis in China based mainly upon original Chinese literature published between 1937 and 2004 is reviewed. The seroprevalence of Trichinella infection in herbivores was 0.7% (2/300) in cattle and 0.8% (4/500) in sheep. The prevalence of trichinellosis in naturally infected cattle was 1.2% (2/163). Trichinella larvae were detected in 1.4% (3/215) of sheep and in 2.1% (1/47) of beef cattle sold at markets. Canine trichinellosis was recorded in 13 Provinces, Autonomous Regions or Municipalities (P/A/M) and the average prevalence of the infection in dogs slaughtered in abattoirs was 16.2% (5654/34,983) ranging from 1.2% to 44.8%, with the highest prevalence located in northeast China. The prevalence in dog meat sold at markets was 3.5% (988/27,898) in 5 P/A. Feline Trichinella infection was reported in 10 P/A/M. The prevalence of Trichinella infection in rats varied from 1.1% (51/459) to 15.1% (50/332). Trichinella larvae were detected in 1.5% (9/587) of house rats ( Rattus norvegicus) as well as in 0.8% (3/369) of wild rats ( Apodemus chevrieri), and the infection was recorded also in other wildlife (foxes, bears, wild boar, weasels, raccoon dogs, muntjak and bamboo rats). Trichinella larvae were detected in 2.6% (4/156) of weasels ( Mustela sibirica), 1.5% (2/135) of shrews ( Tupaia belangeri) and 7.7% (1/13) of moles ( Parascapter leucurus). All Trichinella isolates from domestic pigs were identified as T. spiralis. Some Trichinella isolates from dogs in north-eastern China were identified as T. nativa, which has muscle larvae that are highly resistant to freezing. Twenty-seven outbreaks of human trichinellosis associated with mutton, dog and game meat occurred in China between 1964 and 2004, but the quarantine of Trichinella larvae in such meat is not mandatory in China at present.

Trichinellosis in Argentina: An historical review

In Argentina, Trichinella infection in pigs is endemic. The first report of human trichinellosis in Argentina was from 1898 in Buenos Aires. The number of human cases increased from 908, between 1971 and 1981, to 6919, between 1990 and 2002. In pigs slaughtered in official establishments, the prevalence of Trichinella infection was 0.46% in 1914 and 0.01–0.03% during the period 1990–2004. T. spiralis is typically found in the domestic cycle that includes pigs, humans and rodents. Trichinella spp. from a sylvatic cycle has also caused human outbreaks resulting from the consumption of meat from puma, armadillo and wild boar. European migration to Argentina (principally Spanish and Italian) during the first years of the 20th century brought the tradition of preparing and eating raw sausages. This increased the risk of human exposure to Trichinella. Detection in pigs was initially made at slaughter by compression of muscle tissue (trichinoscopy) and continued this way until 1996, when artificial digestion was adopted for use in preventing human trichinellosis in Argentina. The following report synopsizes the evolution of trichinellosis in Argentina over the past century.

Trichinella pseudospiralis foci in Sweden

In Sweden, the prevalence of Trichinella infection in domestic pigs has greatly decreased since the 1970s, with no reports in the past 4 years. However, infected wild animals continue to be found. The objective of the present study was to identify the species of Trichinella present in animals of Sweden, so as to contribute to the knowledge on the distribution area and hosts useful for the prevention and control of this zoonosis. In the period 1985–2003, Trichinella larvae were detected in the muscles of 81/1800 (4.5%) red foxes ( Vulpes vulpes), 1/6 (16.7%) arctic fox ( Alopex lagopus), 1/7 (14.3%) wolf ( Canis lupus), 10/200 (5.0%) lynxes ( Lynx lynx), 4/8000 (0.05%) wild boars ( Sus scrofa), and 27/66 × 10 6 (0.000041%) domestic pigs. All four Trichinella species previously found in Europe were detected ( Trichinella spiralis, T. nativa, T. britovi and T. pseudospiralis). The non-encapsulated species T. pseudospiralis was detected in three wild boars from Hölö (Stockholm area) and in one lynx from Frösö (Östersund area), suggesting that this species is widespread in Sweden. These findings are consistent with those of a study from Finland, both for the unexpected presence of T. pseudospiralis infection and the presence of the same four Trichinella species, suggesting that this epidemiological situation is present in the entire Scandinavian region. The widespread diffusion of T. pseudospiralis in the Scandinavian region is also important in terms of it potential impact on public health, given that human infection can occur and the difficulties to detect it by the trichinelloscopic examination.

Trichinella papuaein Saltwater Crocodiles (Crocodylus porosus) of Papua New Guinea

<i>Trichinella papuae</i>in Saltwater Crocodiles (<i>Crocodylus porosus</i>) of Papua New Guinea

Hunting Practices Increase the Prevalence of Trichinella Infection in Wolves from European Russia

Hunting Practices Increase the Prevalence of Trichinella Infection in Wolves from European Russia

Epidemiology of swine trichinellosis in China.

Swine trichinellosis has been reported in 26 provinces, autonomous regions or municipalities (P/A/M) of China. The prevalence rate in swine varied from 0.12% to 34.2% in five P/A/M, from 0.01% to 0.0001% in other P/A/M. The seroepidemiological survey of swine trichinellosis was carried out by ELISA in seven P/A/M, the seroprevalence varied from 0.09% to 29.63%. The prevalence of Trichinella infection in pork sold at the market was from 0.29% to 5.6% in four provinces. The transmission of trichinellosis by garbage is the main features of epidemiology of swine trichinellosis in China. Rat is an important reservoir in the domestic cycle of trichinellosis. The prevalence rates of T. spiralis infection in rats were from 1.98% to 15.06% in six provinces or autonomous regions. The treatment prophylaxis with forage contained albendazole has been applied to the control of swine trichinellosis in Nanyang area of Henan province, the prevalence of swine trichinellosis had decreased from 32.2% before prophylaxis to 0.12% after prophylaxis.