Diagnosis of porcine trichinellosis: parasitological and immunoserological tests in pigs from endemic areas of Argentina.

In order to compare the reliability of serological and parasitological techniques for the diagnosis of porcine trichinellosis from endemic areas in Argentina, 116 pigs were studied: 61 animals from two separate outbreaks and 55 from a small abattoir. Direct diagnostic techniques included trichinoscopy and the artificial digestion method. Indirect diagnostic tests used in this study were the enzyme-linked immunosorbent assay (ELISA), employing the excretory-secretory products of muscle larvae (ML) as antigen, and the indirect immunofluorescence assay using as antigen ML in suspension (IIF-susp), cryostat sections of infected rat muscle or of free ML (IIF-slide). The percentage of parasitologically positive pigs was invariably lower than that of serologically positive animals (IIF-slide), even when digestion studies were carried out individually with a greater amount of muscle sample than required by current regulations. Close correlation was found between IIF using as antigen tissue sections and IIF using free ML sections, while IIF-susp proved unsuitable for diagnosis since this assay presented a high percentage of false negative results (20%). The IIF-slide technique proved positive in all parasitologically positive animals. ELISA rendered a lower percentage of positive reactions than IIF-slide, especially when worm burden was low. Since most parasitologically positive animals rendered at least two positive serological tests (two variations of IIF or IIF plus ELISA), those negative by digestion and positive by two serological methods were strongly suspected of having trichinellosis. Upon studying swine from a abattoir it was found that 9% of the pigs were positive when assayed by two serological techniques, but Trichinella spiralis infection could not be parasitologically confirmed. To sum up, serological methods may be used for screening all pigs and positive findings should be tested by the digestion method by analysing a greater quantity of pork than that required by current regulations, above all in areas with reported clinical trichinellosis in humans, to ensure that the pork is safe for human consumption.

Aspectos serológicos, clínicos y epidemiológicos de un brote de triquinosis en Azul, Provincia de Buenos Aires / Serological, clinical and epidemiological aspects of an outbreak of trichinosis in Azul, province of Buenos Aires

Se estudió un brote de triquinosis ocurrido en el sur de la provincia de Buenos Aires, zona endémica para esta zoonosis. Dieciocho personas fueron afectadas por la ingesta de productos elaborados con carne de cerdo (chacinados sin el correspondiente control veterinario. Se describen síntomas y signos de los apcientes, como así también estudios serológicos relacionados con la formación de anticuerpos y la capacidad citotóxica de los sueros. Se analizaron los producto elaborados (chacinados), así como ocho cerdos interdictos de la granja donde se originó el brote. Con el fin de estudiar la cadena de transmisión se capturaron y analizaron ratas de los alrededores del hábitar de los porcinos. Este trabajo demuestra que los principales síntomas y signos fueron: mialgia, edema palpebral, fiebre y cefalea, que el 61// de los pacientes presentó anticuerpos contra el estadio de larva muscular entre los 15-30 días posteriores a la ingesta, que sólo presentaron anticuerpos contra la larva recien nacida a los 40-60 días postinfección cinco de los dieciocho pacientes, que la carga parasitaria en los chacinados fue de 5,3 larvas/g, que dos de los ocho cerdos se diagnosticaron por técnicas serológicas, mientras que por técnicas parasitológicas se detectó sólo uno y que la rata es uno de los principales reservorios en la cadena epidemiológica (AU)

Aspectos serológicos, clínicos y epidemiológicos de un brote de triquinosis en Azul, Provincia de Buenos Aires / Serological, clinical and epidemiological aspects of an outbreak of trichinosis in Azul, province of Buenos Aires

Se estudió un brote de triquinosis ocurrido en el sur de la provincia de Buenos Aires, zona endémica para esta zoonosis. Dieciocho personas fueron afectadas por la ingesta de productos elaborados con carne de cerdo (chacinados sin el correspondiente control veterinario. Se describen síntomas y signos de los apcientes, como así también estudios serológicos relacionados con la formación de anticuerpos y la capacidad citotóxica de los sueros. Se analizaron los producto elaborados (chacinados), así como ocho cerdos interdictos de la granja donde se originó el brote. Con el fin de estudiar la cadena de transmisión se capturaron y analizaron ratas de los alrededores del hábitar de los porcinos. Este trabajo demuestra que los principales síntomas y signos fueron: mialgia, edema palpebral, fiebre y cefalea, que el 61// de los pacientes presentó anticuerpos contra el estadio de larva muscular entre los 15-30 días posteriores a la ingesta, que sólo presentaron anticuerpos contra la larva recien nacida a los 40-60 días postinfección cinco de los dieciocho pacientes, que la carga parasitaria en los chacinados fue de 5,3 larvas/g, que dos de los ocho cerdos se diagnosticaron por técnicas serológicas, mientras que por técnicas parasitológicas se detectó sólo uno y que la rata es uno de los principales reservorios en la cadena epidemiológica

[Serological, clinical, and epidemiological aspects of an outbreak of trichinosis in Azul, province of Buenos Aires]. / Aspectos serológicos, clínicos y epidemiológicos de un brote de triquinosis en Azul, Provincia de Buenos Aires.

An outbreak of human trichinellosis that took place in Southern Buenos Aires Province, an endemic area for this zoonosis, was studied. Eighteen individuals were infected by eating swine sausages lacking veterinary control. Clinical symptoms, as well as serological studies related to antibody production and cytotoxic capacity of the sera are described. Eight interdicted pigs and their products were analysed. In order to determine the transmission network of this zoonosis, wild rats were hunted in the farm where the swine were bred. The clinical symptoms of the infected individuals were: myalgia, edema, fever and cephalea. Sixty-one percent of the patients showed antibodies against muscle larvae 15-20 days after ingestion of the infected meat. Five out of eighteen patients showed anti-newborn larvae antibodies 40-60 days postinfection. The sausage burden was 5.3 muscle larvae/g. Two out of eight swine were diagnosed employing serological techniques, while parasitic techniques detected only one. The rat is an important reservoir in the domestic cycle of this zoonosis.

Aspectos serológicos, clínicos y epidemiológicos de un brote de triquinosis en Azul, Provincia de Buenos Aires. / [Serological, clinical, and epidemiological aspects of an outbreak of trichinosis in Azul, province of Buenos Aires]

An outbreak of human trichinellosis that took place in Southern Buenos Aires Province, an endemic area for this zoonosis, was studied. Eighteen individuals were infected by eating swine sausages lacking veterinary control. Clinical symptoms, as well as serological studies related to antibody production and cytotoxic capacity of the sera are described. Eight interdicted pigs and their products were analysed. In order to determine the transmission network of this zoonosis, wild rats were hunted in the farm where the swine were bred. The clinical symptoms of the infected individuals were: myalgia, edema, fever and cephalea. Sixty-one percent of the patients showed antibodies against muscle larvae 15-20 days after ingestion of the infected meat. Five out of eighteen patients showed anti-newborn larvae antibodies 40-60 days postinfection. The sausage burden was 5.3 muscle larvae/g. Two out of eight swine were diagnosed employing serological techniques, while parasitic techniques detected only one. The rat is an important reservoir in the domestic cycle of this zoonosis.