An Outbreak of Trichinellosis by Consumption of Raw Soft-Shelled Turtle Meat in Korea

Trichinellosis transmission to humans via the consumption of reptile meat is rare worldwide. In Korea, however, 2 such outbreaks, possibly via consumption of soft-shelled turtle meat, have occurred in 2 successive years. In 17 August 2014, 6 patients were admitted to Wonju Severance Christian Hospital complaining of myalgia, fever, and headache. Eosinophilia was the indication of the initial laboratory results, and they were eventually diagnosed as trichinellosis by ELISA. All of the patients worked at the same company and had eaten raw soft-shelled turtle meat at a company dinner 10 days prior to their admission. They were treated with albendazole for 2 weeks, upon which all of their symptoms disappeared. This is the 8th report on human trichinellosis in Korea, and the second implicating raw soft-shelled turtle meat.

The Fifth Outbreak of Trichinosis in Korea

Trichinosis is a food-borne zoonotic disease caused by the nematode, Trichinella spp., and had been reported several times in Korea. Recently, there was an additional outbreak, involving 5 patients, the findings from which are reported herein. On 30 November 2010, 8 persons ate sashimi of the meat of a wild boar. Then, 2-3 weeks later, they complained of myalgia and fever. Unfortunately, muscle biopsy was not performed, but ELISA was performed using their sera. Two people among 8 were positive for Trichinella on the 34th day post-infection (PI), and 3 patients who initially revealed negative ELISA were additionally proved to be positive for trichinosis on the 42nd day PI. Hence, the confirmed patients of trichinosis were 5 in total in the present outbreak. They were treated with albendazole and discharged uneventfully. This was the fifth outbreak of trichinosis in Korea.

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.

Immunization of laboratory animals with ultraviolet-attenuated larvae against homologous challenge infection with Trichinella britovi.

Immunogenicity of Trichinella britovi (Japanese isolate, cord ISS 408) muscle larvae irradiated with 5 mJ/cm2 of short wavelength ultraviolet (UV) was studied using homologous challenge infections. SCID mice vaccinated with UV-attenuated larvae showed no resistance, although its congenic CB-17 mice exhibited remarkable immunity. Following challenge vaccinated Mongolian gerbils, Meriones unguiculatus, did not show significant immunity. Use of these animal models vaccinated with UV-attenuated larvae will contribute to the investigation of immune mechanisms against Trichinella infection and also to the development of a vaccine of trichinellosis.

A clinical study on trichinosis in Changwat Phayao, Thailand.

An epidemic of trichinosis occurred in Northern Thailand. The source meat was a 150 kg hilltribe pig. A clinical investigation was conducted using indirect IgG ELISA as a criteria for diagnosis. 52 suspected cases who had eaten the trichinous pork and developed relevant symptoms were hospitalized. 49 of them gave positive ELISA within 64 days after infection. The most common clinical features were myalgia (100%), fever (93.88%) and facial edema (87.71%). Diarrhea was found in approximately one half of the patients (55.10%). Skin rashes of various types were unexpectedly high (40.82%).

Immunization against experimental trichinosis using T spiralis larvae and hydatid fluid antigens

Immunization of mice against T. spiralis infection using T. spiralis larval glycoproteins as homogenous antigen and crude hydatid fluid as heterogenous antigen showed a marked reduction in larva burden and a significant rise of serum IgE in immunized mice infected with T. spiralis larvae as compared with control group. More reduction was observed with immunization with homogenous T. spiralis larval antigen compared with heterogenous hydatid fluid antigen. The reduction in larval burden with rise of serum IgE begins after the third week of immunization

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

Epidemiology of swine trichinellosis in Yugoslavia.

Intensive epidemiological and seroepidemiological studies of Trichinella spiralis infection in swine have been carried out in the borough of Kladovo, one of the four regions in Yugoslavia where trichinellosis is endemic. A high prevalence (4.7%) of trichinellosis was discovered in three neighboring parishes adjoining the bank of the river Danube. Both geographically and epidemiologically these three parishes constitute a very unique condition that is very vulnerable to T. spiralis infection. Studies of 7,409 swine showed that the ELISA test for the detection of specific antibodies to T. spiralis in swine was highly reliable.

Estandarización y evaluación de un enzimoinmunoensayo para diagnóstico y seroepidemiologia de triquinosis humana / Standardization and evaluation of an immunoenzyme assay for diagnosis and seroepidemiology of human trichinosis

Se estandarizó un enzimoinmunoensayo (EIE) en fase sólida en el que se empleó un antígeno solubre total de T. spiralis y una dilución única de suero, y se evaluó la capacidad del sistema para detectar anticuerpos totales antitriquina con fines diagnósticos y seroepidemiológicos. Las curvas dosis respuesta mostraron que trabajando con una dilución de suero de 1:100 se obtenía una buena diferenciación entre sueros de individuos no infectados y pacientes de triquinosis con baja concentración de anticuerpos circulantes y la respuesta fue lineal entre valores de 0.15 y 0.64 unidades de densidad óptica (DO). El estudio de 720 sueros de población general no infectada reveló una X=0.07 y una S=0.03 unidades de DO. El 98,61% de esta población presentó valores de DO < X + 3S; el 1,25% valores dom DO entre > ou = X + 3S y < X + 4S; y el 0.14% restante valores entre > ou =X + 4S y < X + 5S. Se empleó un valor de DO = X + 5S como nivel diagnóstico para estudiar 4 brotes de triquinosis humana, 80 sueros de pacientes de triquinosis con diferentes títulos en inmunofluorescencia indireta (IFI) y 20 sueros de pacientes de hidatidosis. El EIE propuesto permitió diferenciar en forma confiable y eficiente población infectada de no infectada y tuvo una buena correlación con la IFI. Todos los sueros de pacientes hidatídicos presentaron valores de DO < X + 4S

Relación entre la evolución del ciclo vital de Trichinella spiralis y la detección de respuesta inmune / Relationship between the course of vital cycle of Trichinella spirallis and the detection of immune response

Un lote de ratas albinas Winster de ambos sexos, fue infestado por vía oral con 1.200-1.500 larvas de Trichinella spiralis. Dos animales fueron sangrados a blanco semanalmente procesando sus sueros en forma individual por técnicas de precipitación en tubos capilares, hemaglutinación pasiva, precipitación en medio gelosado y aglutinación, en la búsqueda de anticuerpos específicos a lo largo de 54 semanas, siendo un extracto salino crudo y pequeños fragmentos de larvas, los antígenos empleados. Paralelamente, se hicieron seguimientos de la localización de larvas en músculo estriado y su enquistamiento. La respuesta celular se siguió durante todo el plan de experimentación, por medio de ensayos de blastogénesis de linfocitos de ratas infestadas, mostrando ser muy débil al tiempo de la migración larval. De las pruebas serológicas efectuadas, la precipitación en tubos capilares y aglutinación mostraron ser más precoces en la detección de anticuerpos circulantes, aunque la hemaglutinación es la más sensible. La distinta especificidad de los anticuerpos participantes en estas reacciones tal vez justifiquen esas diferencias. Tanto la respuesta humoral como la celular parecen llegar tardíamente para oponerse a la masiva invasión larval

Trichinosis: A recent outbreak in Northern Thailand.

During April, 1973, and outbreak of trichinosis occurred in Mae Sruay District, Chiang Rai Province, about 900 kilometers north of Bangkok, Thailand. Thirty-one persons were involved, of whom 27 (20 males, and 7 females), ranging in age from 9 to 72 years, were questioned. One adult female died before being brought to hospital. All subjects gave a history of having consumed raw pork in the form of "lahb" and "nahm", favourite dishes of the northern Thai. Beginning the third week after exposure, all developed fever and myalgia. Other less common complaints were diarrhoea and oedema of extremities and palpebral skin. Leucocytosis was revealed in 37% and 55% had eosinophilia exceeding 20%. Nineteen patients had hookworm and Opisthorchis infections. About 63% were skin test positive with Trichinella antigen. Eight patients were admitted to hospital; muscle biopsy was done on one serious case and trichina larvae were detected.