Trichinella spiralis in a cougar (Puma concolor) hunted by poachers in Chile / Trichinella spiralis em um puma (Puma concolor) caçado por caçadores furtivos no Chile

Trichinellosis is a zoonosis caused by nematodes of the Trichinella genus, of which 10 species have been described. Species identification when larvae is found is only possible using molecular tools. Meat from pigs and game animals not subjected to veterinary inspection are the main sources of human infections. The hunting of native carnivores is prohibited in Chile due to conservation issues and the fact that those animals favor pest control. The illegal hunting of a cougar (Puma concolor) occurred in September 2020. Herein, the molecular identification of Trichinella larvae, by analyzing nuclear (expansion segment V) and mitochondrial (cytochrome C oxidase subunit I) sequences are described. Both the amplification of the expansion segment V region and the phylogenetic analysis of a segment of a fragment of the cytochrome c-oxidase subunit I sequence confirmed that the larvae belonged to T. spiralis. The case described herein represents the first evidence of illegal hunting of a protected mammal infected with Trichinella in Chile, highlighting the ‘One Health perspective to face this disease in the rural-sylvatic interphase.(AU)

A triquinelose é uma doença causada por nematoides do gênero Trichinella. Dez espécies foram descritas. A identificação das espécies a partir das larvas só foi possível com ferramentas moleculares. O abate doméstico de suínos e o consumo de animais de caça, sem inspeção veterinária, são as principais fontes de infecção humana. A caça de carnívoros nativos é proibida no Chile por questões de conservação e pelo fato de que esses animais favorecem o controle de pragas. A caça ilegal de um puma (Puma concolor) aconteceu em setembro de 2020. No Chile, a identificação molecular de larvas de Trichinella, obtida pelo exame de sequências nucleares (segmento de expansão V) e mitocondriais (citocromo C oxidase subunidade I) são descritas. Tanto a amplificação da região do segmento de expansão V quanto a análise filogenética de um segmento de um fragmento da sequência da subunidade I da Citocromo c-oxidase, confirmaram que as larvas pertenciam a T. spiralis. O caso aqui descrito representa a primeira evidência de caça ilegal de um mamífero protegido infectado com Trichinella no Chile, destacando a perspectiva de “Saúde Única” para enfrentar esta doença na interfase rural-silvestre.(AU)

Synthetic gene as target to assess the sensitivity of PCR to detect Trichinella spp. larvae in meat from a non-endemic region.

Trichinellosis is a zoonotic disease exotic in Brazil but commonly found worldwide including South American countries like Argentina. International trading of swine meat needs an official Trichinella-free diagnosis commonly carried out by pepsin-HCl digestion of diaphragm tissue fragments followed by microscopic examination for the presence or absence of Trichinella larvae. The easiness of this diagnostic method allows it to be performed at slaughtering plants but, in contrast, it lacks sensitivity and does not allow species differentiation, which is fundamental for determining geographical and species distribution of different genotypes. In our study, we aimed to evaluate a highly sensitive diagnostic method based on the polymerase chain reaction (PCR) that would allow us to detect and classify different species of Trichinella. Thus, we designed a synthetic gene and selected five sets of primers targeting specific regions of the Trichinella genome. The synthetic gene was cloned into a plasmid and then used to optimize PCR conditions. Using our PCR, we were able to detect 0.001 pg of the synthetic gene, which corresponded to 0.01 larvae. Then, we collected 175 samples of Suidae (domestic and wild boars) diaphragm fragments that were pooled into groups, digested with pepsin-HCl, and had the DNA extracted for analysis by PCR. The clinical samples evaluated were negative by PCR. Our results indicate that the PCR-based method might be a useful diagnostic method complementary to the pepsin-HCl digestion method currently in use, mostly in non-endemic areas.

Avaliação da presença de Trichinella spiralis em equinos abatidos em Araguari, MG / Evaluation of the presence of Trichinella spiralis in horses slaughtered in Araguari, MG

A larva do nematódeo Trichinella spiralis é responsável por infectar animais como porcos, javalis e cavalos e por causar grave doença em seres humanos. Surtos devido ao consumo da carne de cavalo são mais comuns na Europa, principalmente na França e Itália, onde existe a cultura de ingeri-la crua. Apesar de no Brasil não ter relatos sobre a infecção desse parasita em animais e seres humanos, os abatedouros exportadores para alguns mercados, como Europa e Estados Unidos, são obrigados a pesquisar o parasita. No presente estudo, a presença de larvas de Trichinella spiralis foi avaliada em 14.852 cavalos abatidos entre dezembro de 2014 a julho de 2016 em um frigorífico de Araguari sob inspeção federal. Os animais eram procedentes dos estados de Minas Gerais, Goiás e Bahia. A técnica empregada foi a de digestão artificial, em que se utilizou o músculo masseter, seguindo as legislações da União Europeia: Diretiva 91/497/CEE, Diretiva 77/96/CEE, Regulamento (CE) N° 2075/2005 e suas alterações. A larva não foi encontrada em nenhuma amostra analisada.

Neoplasia asociada a Trichinella spiralis / Triquinella spiralis associated with neoplasia

La patología del cuello y su abordaje quirúrgico es una práctica clínica habitual para el cirujano de cabeza y cuello. El planteamiento de la cirugía será en base al diagnóstico de sospecha, con las pruebas de imagen y citología por punción de la tumoración cervical. En algunos casos el diagnóstico definitivo solo nos lo dará el estudio anatomopatológico de la pieza quirúrgica. Se presenta el caso de una tumoración cervical, de tórpida y rápida evolución, en la cual el agente Trichinella spiralis, pudo tener un papel en la etiología del cuadro.

Neck masses and their surgical approach form part of standard practice for the head and neck surgeon. The approach of the surgery will be based on the diagnosis of suspicion, with imaging and cytology by puncture of the cervical tumor. Sometimes the definitive diagnosis will only be established during surgery or, in particular, after pathological analysis. We present a case of a patient with cervical tumor, showing a rapid and fatal progression. In this patient, triquinella spiralis might play a role in cancer development.

Description of an outbreak of human trichinellosis in an area of Argentina historically regarded as Trichinella-free: the importance of surveillance studies.

Trichinellosis is an important food-borne zoonosis which is not treated as a major public health concern in Argentina. After more than 20 years without reports of infection in an area regarded as Trichinella-free, research studies reported that infection occurred in humans, pigs and game animals, including the recent outbreak of human trichinellosis revealed here. The outbreak, affecting 64 individuals, occurred in July 2010 in the province of Entre Ríos. Epidemiological studies, clinical observations, laboratory analyses and immunoserological specific assays (indirect immunofluorescence, IIF, and ELISA) were performed. Food samples were analyzed by artificial digestion, and Trichinella larvae isolates were identified to the species level by multiplex PCR. The main source of infection, commercially available food, had a parasite load of 1.1 muscle larvae per gram. Larvae were identified as Trichinella spiralis. Patients presented predominantly with oedema, fever and myalgia; and laboratory findings and/or immunoserological tests were positive for trichinellosis. Individuals received outpatient treatment. No deaths or secondary sequelae were recorded. Results suggest that the presence of T. spiralis infection should be suspected in all endemic areas, especially where animal husbandry and official food safety controls are not properly conducted. The lack of the cases reported ought not to be taken as a proof of parasite absence. We highlight the importance of the urgent need to implement interdisciplinary and inter-institutional programs aimed to control infection transmission, to guarantee food safety and to conduct epidemiological surveillance studies.

Determinantes de infestación durante un brote de trichinellosis en el sudoeste de la provincia de Buenos Aires / Determinants of infestation during an outbreak of trichinellosis in southwest Buenos Aires province / Determinantes da infecçâo durante um surto de triquinose no sudoeste da provincia de Buenos Aires

Se estudió la asociación entre infestación, parámetros de laboratorio y signos clínicos en personas expuestas a infestación por Trichinella spiralis durante un brote de trichinellosis en el sudoeste de la provincia de Buenos Aires, Argentina. Asimismo, se investigó el grado de concordancia entre las pruebas inmunoserológicas más comúnmente utilizadas en el diagnóstico de trichinellosis humana. En las personas expuestas, la presencia de síntomas clínicos y los niveles elevados de la enzima creatina fosfoquinasa al día 7 post-exposición se asociaron significativamente con la infestación al día 30 post-exposición. Por el contrario, la eosinofilia (>7%) a los siete días postexposición no se asoció al estado de infestación a los 30 días post-exposición. El mayor grado de concordancia entre pruebas inmunoserológicas se dio entre el par ELISA-Western Blot tanto al día 7 como 30 post-exposición.

The association between infestation, laboratory parameters and clinical signs was investigated in human patients exposed to Trichinella spiralis during an outbreak of human trichinellosis in southwest Buenos Aires province, Argentina. The degree of agreement between immunoserological tests commonly used for diagnosis of human trichinellosis was determined. Among exposed individuals, the presence of clinical symptoms and high concentration of the creatine phosphoquinase enzyme 7 days post-exposure was significantly associated with infestation by day 30 post-exposure. Contrarily, Randazzo V et al. a high level of eosinophils (>7%) 7 days post-exposure was not associated with infestation by day 30 post-exposure. Test agreement was highest between ELISA and Western Blot both by days 7 and 30 post-exposure.

Foi estudada a associagáo entre a infestagáo, parámetros laboratoriais e sinais clínicos em pessoas expostas à infestagáo por Trichinella spiralis durante um surto de triquinose, no sudoeste da provincia de Buenos Aires, Argentina. Também se pesquisou o grau de concordáncia entre os testes imunosorológicos mais comumente utilizados no diagnóstico de triquinose humana. Em pessoas expostas, a presenga de sintomas clínicos e os níveis elevados da enzima creatina fosfoquinase no dia 7 pós-exposigáo foram associados significativamente à infestagáo no dia 30 pós-exposigáo. Em contraste, a eosinofilia (> 7%) aos sete dias pós-exposigáo náo foi associada ao estado de infestagáo aos 30 dias pós-exposigáo. O maior grau de concordáncia entre testes imunoserológicos ocorreu entre o par de ELISA-Western Blot tanto no dia 7 quanto no dia 30 pós-exposigáo.

[Epidemiological study of recorded trichinosis cases in Santa Fe Province, Argentina, 1998-2009]. / Estudio epidemiológico de los casos de triquinelosis registrados en la provincia de Santa Fe, Argentina, 1998-2009.

OBJECTIVE: To characterize recorded trichinosis cases and outbreaks in Santa Fe Province, Argentina, from 1998 to 2009 from epidemiological, clinical, and laboratory viewpoints. METHODS: An analysis was conducted of 1 519 epidemiological records of persons who had signs and symptoms compatible with trichinosis in Santa Fe Province in the period 1998-2009. A descriptive statistical analysis of information in epidemiological records and of clinical and laboratory results, as well as a bifactorial analysis of possible associations with epidemiological and environmental factors were also carried out. RESULTS: Trichinosis symptoms were found in 1 276 cases; 372 met the clinical case definition and 224 samples were positive by indirect immunofluorescence, independent of their clinical case classification. There were 27 outbreaks that involved 1 157 cases identified in eight departments, with greater frequency in the province's center and south. Annual distribution of epidemiologically associated cases was heterogeneous, with greater frequency in the period 2000-2003 and in the months of August to October. Probability of becoming sick was greater with consumption of products from informal sources (OR = 3.69; P = 0.014) and in rural areas (OR = 1.799; P = 0.011). Disease incubation period (median) was 12 days. The risk of becoming sick was 2.06 times greater in persons who ate meat or ate pork by-products than in those who did not. CONCLUSIONS: The greatest number of outbreaks occurred in departments that were more populous and where pork production was greater. Specific actions should be designed for prevention and control of the disease in those departments. Epidemiological risk analysis should be considered in evaluating, managing, and communicating trichinosis health risks.

Estudio epidemiológico de los casos de triquinelosis registrados en la provincia de Santa Fe, Argentina, 1998-2009 / Epidemiological study of recorded trichinosis cases in Santa Fe Province, Argentina, 1998-2009

OBJETIVO: Caracterizar desde los puntos de vista epidemiológico, clínico y de laboratorio los casos y brotes de triquinelosis que se registraron en la provincia de Santa Fe, Argentina, entre 1998 y 2009. MÉTODOS: Se analizaron 1 519 fichas epidemiológicas de personas que presentaron síntomas y signos compatibles con triquinelosis en la provincia de Santa Fe en el período 1998-2009. Se realizó el análisis estadístico descriptivo de la información contenida en las fichas epidemiológicas y los resultados clínicos y de laboratorio; se aplicó el análisis bifactorial para determinar las posibles asociaciones con factores epidemiológicos y ambientales. RESULTADOS: Se encontraron síntomas de triquinelosis en 1 276 casos; 372 cumplían la definición de caso clínico y 224 muestras resultaron positivas por inmunofluorescencia indirecta, independientemente de su clasificación como caso clínico. Se identificaron 27 brotes que involucraron a 1 157 casos en ocho departamentos, con mayor frecuencia en el centro y el sur de la provincia. La distribución anual de los casos asociados epidemiológicamente entre sí fue heterogénea, con una mayor frecuencia en el período 2000-2003 y en los meses de agosto a octubre. Hubo mayor probabilidad de enfermar cuando se consumieron productos de fuentes informales (OR = 3,69; P = 0,014) y en las áreas rurales (OR = 1,799; P = 0,011). El período de incubación de la enfermedad (mediana) fue de 12 días. Las personas que consumieron carne de cerdo o sus derivados tuvieron 2,06 veces más riesgo de enfermar que las que no la consumieron. CONCLUSIONES: El mayor número de brotes ocurrió en los departamentos más poblados y con mayor producción porcina. Se deben diseñar acciones específicas de prevención y control de la enfermedad en esos departamentos. Se debe considerar el análisis epidemiológico de riesgos al evaluar, gestionar y comunicar los riesgos sanitarios de triquinelosis.

OBJECTIVE: To characterize recorded trichinosis cases and outbreaks in Santa Fe Province, Argentina, from 1998 to 2009 from epidemiological, clinical, and laboratory viewpoints. METHODS: An analysis was conducted of 1 519 epidemiological records of persons who had signs and symptoms compatible with trichinosis in Santa Fe Province in the period 1998-2009. A descriptive statistical analysis of information in epidemiological records and of clinical and laboratory results, as well as a bifactorial analysis of possible associations with epidemiological and environmental factors were also carried out. RESULTS: Trichinosis symptoms were found in 1 276 cases; 372 met the clinical case definition and 224 samples were positive by indirect immunofluorescence, independent of their clinical case classification. There were 27 outbreaks that involved 1 157 cases identified in eight departments, with greater frequency in the province's center and south. Annual distribution of epidemiologically associated cases was heterogeneous, with greater frequency in the period 2000-2003 and in the months of August to October. Probability of becoming sick was greater with consumption of products from informal sources (OR = 3.69; P = 0.014) and in rural areas (OR = 1.799; P = 0.011). Disease incubation period (median) was 12 days. The risk of becoming sick was 2.06 times greater in persons who ate meat or ate pork by-products than in those who did not. CONCLUSIONS: The greatest number of outbreaks occurred in departments that were more populous and where pork production was greater. Specific actions should be designed for prevention and control of the disease in those departments. Epidemiological risk analysis should be considered in evaluating, managing, and communicating trichinosis health risks.

Trichinella spiralis: monoclonal antibody against the muscular larvae for the detection of circulating and fecal antigens in experimentally infected rats.

In this work we search for antigens of Trichinella spiralis in sera and stool of rats experimentally infected. The kinetic of antibodies to excretory and secretory (ES) antigens of muscle larvae (ML) was also determined. Wistar rats were infected with 15 ML per gram of body weight and blood samples were collected weekly for 10 weeks. Antibodies were studied using an indirect ELISA. For detection of circulating antigens and coproantigens, a sandwich ELISA was developed with the use of polyclonal rabbit antibodies obtained against the total extract of ML and an IgM monoclonal antibody (Mab) against ES antigens of ML. No reactivity was observed between Mab and the total worm antigens of Angiostrongylus cantonensis, Ascaris suum, Echinococcus granulosus, Fasciola hepatica, Strongyloides stercoralis, Taenia solium, Toxocara canis and Trichuris trichiura. The IgM Mab recognized antigens of 45, 49, and 55 kDa in ES antigens and was unable to bind ES antigens deglycosylated with trifluoromethanesulphonic acid (TFMS) indicating that a glycan structure is present in the epitope recognized by this Mab. The sensitivity of sandwich ELISA was 1 ng/mL. Circulating antigens were detected in all infected rats between 3 and 8 weeks post infection and coproantigens were found during the first two days post infection. Antibodies were detected since the third week post infection through the end of experiment. These results suggested that antigen detection by our sandwich ELISA could be a useful complementary laboratory test for antibody detection.

[Trichinellosis serology in blood-donors from a non-endemic area of Argentina]. / Serología para triquinosis en dadores de sangre en área no endémica de la Argentina.

The aim of the present study was to determine the presence of human trichinellosis in an area of Argentina historically regarded as free of this parasitic disease. This parasitosis was assessed on 150 blood donors by means of immunoserological tests, and their relation with risk alimentary habits by a questionnaire. The questionnaires showed that 98.0% (n=147) of the individuals consumed pork and pork products at a high frequency. The main pork products incorporated to the habitual diet were the stuffed ones. A 80.3% (n=118) of the individuals had acquired such products at butchers, a 38.1% (n=56) at home slaughters and a 34.0% (n=50) at supermarkets. The immunoserological techniques employed were: enzyme immunoanalysis, indirect immunofluorescence and/or immunoelectrotransfer blot assay. Anti-Trichinella antibodies were detected in 8.0% (n=12) of the serum samples by more than one of the methodologies employed, considering these results as confirmatory of trichinellosis. The studies carried out herein demonstrate the existence of human trichinellosis in an area historically regarded as free of this parasitic disease and suggest its relationship with the ingestion of pork or pork products as a risk factor. These results indicate that the lack of reports should not be the only criterion for an area to be considered as Trichinella-free. The awareness of the existence of the parasite in a region will favor the establishment of control and prevention strategies which is of fundamental importance to avoid the spread of the disease.

Serología para triquinosis en dadores de sangre en área no endémica de la Argentina / Trichinellosis serology in blood-donors from a non-endemic area of Argentina

El presente estudio tuvo como objetivo determinar la presencia de triquinosis humana en un área considerada históricamente libre de esta parasitosis en la Argentina. Se evaluó la parasitosis mediante técnicas inmunoserológicas y su relación con los hábitos alimenticios de riesgo mediante un cuestionario realizado a 150 donantes de sangre. Las encuestas revelaron que el 98.0% (n=147) de los individuos consumía carne de cerdo y/o derivados con elevada frecuencia. Los principales productos porcinos incorporados a la alimentación habitual fueron los chacinados. El 80.3% (n=118) de los individuos adquirían los productos en carnicerías, el 38.1% (n=56) en faenas domiciliarias y el 34.0% (n=50) en supermercados. Las técnicas inmunoserológicas utilizadas para el diagnóstico de triquinosis fueron: enzimoinmunoanálisis, inmunofluorescencia indirecta y/o inmunoelectrotransferencia. En el 8.0% (n=12) de los sueros de los individuos se detectaron anticuerpos anti-Trichinella por más de una de las técnicas realizadas, considerándose este resultado diagnóstico confirmatorio de triquinosis. Los estudios realizados demuestran la existencia de triquinosis humana en un área considerada libre de esta parasitosis y sugieren su relación con la ingesta de carne porcina y/o sus subproductos, hábito alimenticio de riesgo. Estos resultados indican que la falta de denuncia de casos de la enfermedad no debe ser el único criterio a tener en cuenta para considerar a una región área libre de triquinosis. El conocimiento de la presencia del parásito en un área determinada favorece la instauración de medidas de control y prevención evitando la diseminación de la parasitosis.

The aim of the present study was to determine the presence of human trichinellosis in an area of Argentina historically regarded as free of this parasitic disease. This parasitosis was assessed on 150 blood donors by means of immunoserological tests, and their relation with risk alimentary habits by a questionnaire. The questionnaires showed that 98.0% (n=147) of the individuals consumed pork and pork products at a high frequency. The main pork products incorporated to the habitual diet were the stuffed ones. A 80.3% (n=118) of the individuals had acquired such products at butchers, a 38.1% (n=56) at home slaughters and a 34.0% (n=50) at supermarkets. The immunoserological techniques employed were: enzyme immunoanalysis, indirect immunofluorescence and/or immunoelectrotransfer blot assay. Anti-Trichinella antibodies were detected in 8.0% (n=12) of the serum samples by more than one of the methodologies employed, considering these results as confirmatory of trichinellosis. The studies carried out herein demonstrate the existence of human trichinellosis in an area historically regarded as free of this parasitic disease and suggest its relationship with the ingestion of pork or pork products as a risk factor. These results indicate that the lack of reports should not be the only criterion for an area to be considered as Trichinella-free. The awareness of the existence of the parasite in a region will favor the establishment of control and prevention strategies which is of fundamental importance to avoid the spread of the disease.

[Human trichinosis. A case simulating polymyositis]. / Triquinosis humana. Un caso que simula polimiositis.

The human trichinosis is a cosmopolitan rare zoonosis in Mexico. It presents clinically, with an infectious toxic pattern. Typical symptomatology includes: fever, diarrhea, facial edema and myalgias, which can resemble other illnesses like typhoid fever, angioneurotic edema, septicemia, rheumatic disease-like vasculitis and dermato-polymyositis. The treatment is based on the use of antiparasites. In this paper a trichinosis case is described in a woman, 29 years old who lives in the metropolitan area, with a clinical pattern that suggest polymyositis. The diagnosis was confirmed through a muscle biopsy. The treatment was albendazole and prednisone with successful results.

Evaluation of three immunoserological techniques in the detection of porcine trichinellosis.

Three immunoserological tests (IST) used for the detection of porcine trichinellosis, immunofluorescence (IF), enzyme-inmunoanalysis (EIA), and Western blot (WB), were compared. Three groups of animals were analyzed: Group 1, animals naturally infected with parasite burdens (PB) of <1 muscle larvae (ML)/g (n=18); Group 2, animals naturally infected with PB of > or =2ML/g (n=23); Group 3, animals raised and home-slaughtered on farms in Argentina (n=59). Animals from Groups 1 and 2 were identified in outbreaks and were analyzed by individual artificial digestion (AD) of > or =30g of muscle. Animals in Group 3 were subjected to AD of 5g of muscle. The detection percentages in sera of swine with the lower PB were 100% for IF, 72% for EIA, and 50% for WB. Eighty-three percent of the animals were serologically positive by two or three techniques. In pigs with the higher PB, the detection percentage was similar for IF and EIA (100% vs. 91%, respectively), and was lower for the WB (61%). Ninety-six percent of the animals were serologically positive by two or three techniques. Group 3 animals had similar detection percentages for the three techniques (IF, 30%; EIA, 29%; WB, 42%). Twenty-five percent of the animals were serologically positive by two or three techniques. Two animals were positive by AD with PB of 0.33 and 2.4ML/g, and were positive for IF and WB, or IF, EIA, and WB. Results indicate that the sensitivity of each technique depends on the PB, and always ranked in sensitivity as IF>EIA>WB. For the lower PB, the decrease in the sensitivity is more pronounced for the EIA. Although the WB has a low sensitivity, the detection of the specific bands for Trichinella spiralis makes it a useful confirmatory tool. Considering that more than 83% of the parasitologically positive animals had 2 or 3 positive serological results using the techniques tested here, for the diagnosis of porcine trichinellosis, pigs positive by two of these serological techniques must be regarded as truly infected pigs.

Mexican immunoparasitology: what is done and has to be done.

In this special issue of Parasite Immunology, the reader will find reviewed some of the hottest topics in immunoparasitology, with emphasis on the most studied parasite species in Mexico. For instance, the immunological conditions that appear favorable for the survival or destruction of the parasite in the intermediate and definitive hosts in cysticercosis, as well as the use of immunodiagnostic tests in epidemiological/intervention studies are discussed in two different articles. The role that alternatively activated macrophages plays in modulating host immunity is also discussed, while in the field of Leishmaniasis, the reader will find reviewed the role that CD8+ T cells play in the host defense during the human infection. The role that antibodies may play as biomarkers of protective or pathological cellular immune events in Toxoplasma gondii infections, as well as the new insights about the regulation of the inflammatory immune response by the cytokine/chemokine network in amebiasis, are topics reviewed. The use that TSL-1 antigens may have in the development of more sensitive and specific diagnosis of human and animal trichinellosis as well as the role that the neuroimmunoendocrine network plays during schistosomiasis are also presented. We hope that our readers will find fascinating and enticing, the first ever Special Issue devoted to Mexican Immunoparasitology.

Contributions to the study of Trichinella spiralis TSL-1 antigens in host immunity.

The observation on different hosts infected with Trichinella spiralis that recognized similar muscle larvae (ML) antigens and the fact that different monoclonal antibodies (mAb) had a similar reactivity to ML components prompted a proposal to define a useful classification system for these antigens. For this purpose, an international workshop provided a platform for the classification of T. spiralis antigens. ML antigens were classified in eight groups -- Trichinella spiralis larvae groups, TSL-1 to TSL-8. TSL-1 antigens are highly immunogenic and a number of important studies have been performed to analyse the role of these antigens in the host-parasite interplay. In this context, we have focused on the analysis of the role of TSL-1 antigens in the induction of innate immune responses with particular emphasis on the activation of mast cells (MC) by an IgE-independent pathway. These studies provided evidence on the role of mediator release from TSL-1-activated MC in the development of Type 2 immune responses. The protective role of TSL-1 in T. spiralis-infected mice has been described. In addition, it has been demonstrated that the use of TSL-1 antigens allows for a more sensitive and specific diagnosis of human and animal trichinellosis.

Application of Giemsa stain for easy detection of Trichinella spiralis muscle larvae.

The application of Giemsa technique to stain compressed diaphragm samples obtained from rodents experimentally infected with Trichinella spiralis is described. Diaphragm samples from rats heavily infected with 20 muscle larvae per gram of body weight (20 ML/gbw) were cut into several pieces and stained with Giemsa; on the other hand, whole diaphragms from slightly infected mice (1 ML/gbw) were also stained with Giemsa. Besides, muscle samples were also stained with Giemsa. Observation at 10 x magnification revealed that both ML and nurse cells (NC) look as bluish structures clearly contrasting with the pinkish color of the non-infected muscle fibers. NC in the diaphragms of mice could be easily observed at naked eye as blue points contrasting with the pink surrounding areas formed by the non-infected muscle fibers. Among NC observed in the diaphragms of rats infected with 20 ML/gbw, 4.4% was multiple infection. These findings were confirmed in sectioned and hematoxylin-eosin stained specimens. This data could be usefulness for a rapid diagnosis of trichinellosis in post-mortem mammals without magnification procedures.

Detection of coproantibodies and faecal immune complexes in human trichinellosis.

Trichinella spiralis is the nematode causative agent of trichinellosis, an intestinal and tissular parasitosis. Even though an early diagnosis during the intestinal phase is essential to limit the infection in humans, to date, there are no available tests to achieve this goal. Based on the immune response generated by the host's intestinal mucosa, the aim of this work was to develop ELISAs to assess the presence of coproantigens (CAgs), coproantibodies (CAbs) and faecal immune complexes in stool samples of 18 individuals belonging to different outbreaks that have arisen in Argentina. By the methodologies developed in this work it was found that anti-muscle larva excretory-secretory products (ML-ESP) CAbs were detected in 89% of the samples analysed regardless of the time p.i. Anti-ML-ESP IgA, IgG, IgE and IgM were detected in 56%, 56%, 28% and 22% of the individuals respectively. Those samples negative for anti-ML-ESP total immunoglobulins proved positive for anti-adult worm-ESP CAbs. No CAgs were detected in any of the samples. The results obtained in this work indicate that the intestinal immune response in human trichinellosis is featured by all the isotypes of specific immunoglobulins. Furthermore, the detection of antibodies in stool samples, in either the free or complexed form, could be applied to confirm early human trichinellosis.

[Trichinellosis: epidemiological, clinical and laboratory aspects. A retrospective study (1994-2003)]. / Triquinosis: aspectos epidemiológicos, clínicos y de laboratorio. Estudio retrospectivo a 10 años (1994-2003).

BACKGROUND: Trichinellosis is a parasitic zoonosis caused by ingestion of infected meat containing cysts of Trichinella spp. OBJECTIVES: To analyze the epidemiological, clinical and laboratory findings of trichinellosis patients in our center and compare the results with those from published series. To analyze the relationship between the clinical symptoms and laboratory findings. MATERIALS AND METHODS: The clinical records of 127 patients were retrospectively analyzed. RESULTS: Epidemiological: 61% were male and mean age was 32 years; 95% were associated with other cases. The food implicated was always pork. Clinical: 45% presented gastrointestinal symptoms and 98% systemic symptoms. Three patients required intensive care unit hospitalization and one died. In 53%, treatment consisted of associated antiparasitic and anti-inflammatory drugs. Laboratory: 59% presented leukocytosis and 72% absolute eosinophilia. Creatine phosphokinase was elevated in 62%, lactic dehydrogenase in 56% and glutamic-oxaloacetic transaminase (GOT) in 30%. Among 52 patients, 65% had positive serology; trichinoscopy of food samples was positive in three outbreaks. The population studied had a mean of 5 signs and/or symptoms. The patient group with more than 5 signs and/or symptoms presented higher white blood cell counts and GOT levels (p < 0.05) CONCLUSIONS: Our results were comparable to those of other series; however, there was a low rate of complications. An association was found between a larger number of signs and symptoms and higher leukocyte counts and GOT levels. The relevance of these findings should be assessed in future studies. There is no agreement as to the best therapeutic option, a fact reflected in the various treatment modalities seen in our study.

[Clinical, serological and parasitological aspects of an outbreak of human trichinellosis in Villa Mercedes, San Luis, Argentina. The acute and chronic phases of the infection]. / Aspectos clínicos, serológicos y parasitológicos de un brote de triquinelosis humana en Villa Mercedes, San Luis, Argentina. Las fases aguda y crónica de la infección.

Clinical and serological features of individuals undergoing the acute (n: 54) and chronic (n: 32) phases of trichinellosis belonging to an outbreak originated by the consumption of pork products of a commercial source, arisen in Argentina, are described. Epidemiological data, signs, symptoms, and laboratory studies were assessed. Parasitological studies were performed in patients and pork products. Results showed that: a) the parasite burden of pork products was 200.0 +/- 18.3 larvae/g; b) muscle larvae were demonstrated in 10 out of the 11 patients studied; c) during the acute phase, fever (94%), eosinophilia (90%), myalgia (85%), headache (81%), facial edema (54%), diarrhoea (52%) and anti-Trichinella antibodies (64%) were observed; d) 15% of the patients had to be hospitalized, 7% having complications; e) during the chronic phase, myalgia (72%), sight abnormalities (22%), gastrointestinal disorders (31%) and the persistence of antibodies (77%) were observed. This study highlights the socioeconomical impact of trichinellosis due to the clinical characteristics of the acute phase and the presence of symptoms in the chronic phase.