Persistent Taenia solium Cysticercosis In the State of Morelos, Mexico: Human and Porcine Seroprevalence.

Serological tests are needed to estimate the prevalence of Taenia solium cysticercosis in endemic rural areas. The predictive value of serum antibody levels to diagnose porcine cysticercosis and human neurocysticercosis (NC) was herein assessed by ELISA using serum samples from 247 backyard pigs (141 without cysticercosis and 106 with cysticercosis) and 183 human subjects (116 non-NC subjects and 67 NC patients) in central Mexico diagnosed by necropsy and computed tomography, respectively. A sensitivity of 77.3 and 92.5% and a specificity of 88.6 and 100% were found to diagnose porcine and human cysticercosis, respectively. The prevalence of porcine and human cysticercosis in the state of Morelos was estimated by ELISA. Anti-cysticercal antibodies were found in 8.4 and 19.02% of assayed sera from 1,811 humans and 804 pigs, respectively. Marginalization and living in the eastern region were risk factors for humans, whereas free-roaming, medium marginalization levels and living in Sierra de Huautla were risk factors for pigs. These results clearly evidence the persistence of cysticercosis transmission and neurocysticercosis in a region neighboring Mexico City, pointing out the need to apply effective measures already available for its control.

[Evaluation of the impact of a control program against taeniasis-cysticercosis (Taenia solium)]. / Evaluación del impacto de un programa de control de la teniasis-cisticercosis (Taenia solium).

OBJETIVE: The impact of a control program is evaluated to eventually eradicate taeniasis-cysticercosis (Taenia solium) based on education and vaccination of pigs. MATERIALS AND METHODS: The prevalence of porcine cysticercosis was estimated using tongue inspection, ultrasound and determination of antibodies, before and three years after the application in three regions of the state of Guerrero. RESULTS: A significant reduction in the prevalence of porcine cysticercosis of 7 to 0.5% and 3.6 to 0.3% estimated by tongue examination or ultrasound respectively (p<0.01) and a no significant decrease in seroprevalence from 17.7 to 13.3% were observed. CONCLUSIONS: The reduction of the prevalence of taeniasis-cysticercosis establishes the program's effectiveness in preventing infection. The sustained presence of antibodies, compatible with contact of Taenia solium or other related helminths, underlines the importance of maintaining interventions to achieve eradication.

Evaluación del impacto de un programa de control de la teniasis-cisticercosis (Taenia solium) / Evaluation of the impact of a control program against taeniasis-cysticercosis (Taenia solium)

Objetivo. Evaluar el impacto de un programa de control de la teniasis-cisticercosis por Taenia solium con fines de erradicación, basado en educación de la comunidad y vacunación de cerdos. Material y métodos. Se estimó la prevalencia de cisticercosis porcina por medio de la palpación de lengua, ultrasonido y presencia de anticuerpos en suero, antes de iniciar el programa y tres años después, en tres regiones del estado de Guerrero. Resultados. Se observó una reducción significativa en la prevalencia de cisticercosis porcina de 7 a 0.5% y de 3.6 a 0.3%, estimadas por examen de lengua y ultrasonido, respectivamente (p<0.01), y una disminución no significativa de la seroprevalencia de 17.7 a 13.3%. Conclusiones. La reducción de la prevalencia de teniasis-cisticercosis comprueba la efectividad del programa para prevenir la infección. La presencia sostenida de anticuerpos es compatible con continuos contactos con Taenia solium u otros helmintos relacionados, y señala la necesidad de mantener las intervenciones para lograr su erradicación.

Objetive. The impact of a control program is evaluated to eventually eradicate taeniasis-cysticercosis (Taenia solium) based on education and vaccination of pigs. Materials and methods. The prevalence of porcine cysticercosis was estimated using tongue inspection, ultrasound and determination of antibodies, before and three years after the application in three regions of the state of Guerrero. Results. A significant reduction in the prevalence of porcine cysticercosis of 7 to 0.5% and 3.6 to 0.3% estimated by tongue examination or ultrasound respectively (p<0.01) and a no significant decrease in seroprevalence from 17.7 to 13.3% were observed. Conclusions. The reduction of the prevalence of taeniasis-cysticercosis establishes the program's effectiveness in preventing infection. The sustained presence of antibodies, compatible with contact of Taenia solium or other related helminths, underlines the importance of maintaining interventions to achieve eradication.

Effective protection induced by three different versions of the porcine S3Pvac anticysticercosis vaccine against rabbit experimental Taenia pisiformis cysticercosis.

In an effort to develop an effective and affordable oral vaccine against porcine Taenia solium cysticercosis, the S3Pvac anti-cysticercosis vaccine was expressed in papaya calli. Taenia pisiformis experimental rabbit cysticercosis was used as a model to compare the efficacy of the oral vaccine vs. the injectable S3Pvac-synthetic and S3Pvac-phage versions. Oral S3Pvac-papaya significantly reduced the expected number of hepatic lesions and peritoneal cysticerci to a similar extent than the injectable vaccines. This study reports for the first time an effective oral vaccine against T. pisiformis cysticercosis, possibly useful against porcine T. solium cysticercosis.

Bienestar animal en la enseñanza de Medicina Veterinaria y Zootecnia: ¿Por qué y para qué? / Animal Welfare in the Veterinary Medicine and Animal Husbandry Curriculum: What for and why?

Animal welfare is nowadays considered a science and it should be part of the curriculum of Veterinary Schools and Faculties. Present knowledge of anatomy, physiology, neurobiology and the nervous system in particular show that animals and men share many similar organic mechanisms. Observational and behavioural studies prove that animals are conscious of their surroundings and experience anxieties, fear, stress and pain. The link between animal welfare and production is mentioned and it is concluded that veterinarians must know about animal behaviour, it's physiological and neurological basis, with the objective to provide a state of wellbeing for animals which in return will favourably influence production.

Se revisan brevemente las razones del porqué el Bienestar animal actualmente es considerado una ciencia que debe ser incluida en el plan de estudios de las escuelas y facultades de Medicina Veterinaria y Zootecnia. Se menciona que los conocimientos actuales sobre anatomía, fisiología, neurobiología y otros, nos comprueban que el organismo animal y en especial su sistema nervioso central (SNC) tienen muchas similitudes con los del ser humano y que los estudios observacionales y de comportamiento animal demuestran que los animales se dan cuenta, sufren ansiedad, miedo, estrés y dolor. Se subraya la relación que tiene el bienestar de los animales con la producción y se concluye que es necesario que los médicos veterinarios y zootecnistas conozcan el comportamiento de los animales, sus bases fisiológicas y neurológicas a fondo, para procurarles a un estado de bienestar que a su vez repercutirá en el éxito de su producción.

Recombinant S3Pvac-phage anticysticercosis vaccine: Simultaneous protection against cysticercosis and hydatid disease in rural pigs.

This paper provides macroscopic and histological evidence on the statistically significant protective effects of S3Pvac-phage vaccination against porcine cysticercosis and hydatidosis. The study included 391 rustically bred pigs (187 vaccinated and 204 controls). Vaccination significantly reduced the prevalence of cysticercosis by 61.7%. Vaccination also significantly reduced by 56.1% the prevalence of hydatidosis caused by Echinococcus granulosus in pigs. The presence of the vaccine epitopes in both cestodes is probably involved in the cross-protection observed. Increased inflammation was found in 5% of cysticerci recovered from controls, versus 24% from vaccinated pigs (P<0.01). Hydatid cysts were non-inflammatory in either group. Vaccination was effective to prevent one single disease, but it failed to prevent the simultaneous infections with both parasites in a same pig. The widening of the S3Pvac-phage vaccine protective repertoire to include hydatidosis is a convenient feature that should reduce the prevalence of two frequent zoonoses that affect rustic porcine breading with a single action. Thus, the costs of two different vaccination programs would be reduced to a single one with significant reduction in both zoonoses.

Genetic diversity of Taenia solium cysticerci from naturally infected pigs of central Mexico.

This study was designed to explore if each individual case of naturally acquired porcine cysticercosis, living in different geographic rural areas of central Mexico, is caused by one or more different specimens of Taenia solium tapeworm. The genetic variability among cysticerci from the same pig and that from different pigs was assessed by random amplified polymorphic DNA markers (RAPDs), through the percentage of polymorphic loci, the number of effective alleles, the expected heterozygosity and the Shannon index. The parasite population's reproductive structure was estimated through the association index (I(A)), and the degree of genetic differentiation and variation was determined using AMOVA. Using six different random primers, and a total of 181 cysticerci from 14 pigs, 88 different loci were amplified: 85% were polymorphic between pigs and 24% within pigs. The phenogram grouped the cysticerci into eight major clusters, with differences in the genetic distances among all cysticerci from 14 pigs ranging from 0.78 to 1. Most of the cysticerci grouped in accord with their different geographical origin and with their pig of origin. The similarity matrix produced from the phenogram (obtained by UPGMA) and the original similarity matrix yielded a good cophenetic correlation (r=0.82317, P=0.0004), which suggests that the phenogram accurately represents the original genetic similarities between isolates. The combination of I(A) (0.0-0.089) with the genetic diversity index (0.009-0.073) supports the idea that DNA diversity in T. solium cysticerci of naturally infected pigs is within the range expected from a recombination process occurring during sexual reproduction. The small genetic diversity found within the cysticerci of each pig (33.81%), when compared with that between pigs (66.19%), indicates that pigs are rarely infected by different tapeworms. It would then appear that porcine cysticercosis courses with effective concomitant immunity, as occurs in ovine cysticercosis.

Aspectos relevantes del bienestar del cerdo en tránsito / Relevant aspects of swine welfare in transit

Current globalization policies demand animal welfare standards on animal transportation. In spite of international tendencies to commercialize meat cuts while decreasing live animal transit, transport is still one of the major problems in terms of animal welfare, besides carcass and meat by-products' quality. The present review analyzes, in general terms, the different definitions on animal welfare and factors affecting pig welfare in transit. Several case studies are referred to as examples, showing the animal response to stress during transport and its effects on both meat quality and the economic impact. In addition, legal requirements and Mexican regulations for pig transportation are also described. Information in regard to swine stress and welfare in transit, considers a number of factors that alter the animal metabolic homeostasis with subsequent negative effects on pork quality. It is conclude that knowledge on basic animal behavioral and physiological needs during transport, as well as a suitable training of personnel, are necessary for reducing animal welfare problems. Last but not least, some recommendations on handling practices are given in order to improve swine welfare during transit.

En el marco actual de la globalización, hablar de transporte animal conlleva realizar prácticas que mejoren el bienestar animal, aunque existe la tendencia mundial de incrementar el mercado de la carne en cortes, así como disminuir el comercio de animales vivos, el transporte constituye uno de los factores más preocupantes en términos del bienestar animal, además del impacto en la calidad de la canal y los subproductos respectivos. En la presente revisión se analizan, en términos generales, las distintas definiciones de bienestar animal, así como los factores más importantes que alteran el bienestar de los cerdos durante el transporte; se describen los requisitos legales y la normatividad mexicana para el transporte de animales, así como varios estudios de la respuesta fisiológica del animal durante condiciones adversas del transporte, se señalan, además, las repercusiones sobre la calidad de la carne y su impacto económico. La información con respecto al estrés de los cerdos y su bienestar durante el transporte, considera numerosos factores que alteran el equilibrio homeostático animal y que propician efectos negativos sobre calidad de la carne. Se concluye que tanto el conocimiento de la biología de la especie, como un entrenamiento del personal, son necesarios para disminuir los problemas de bienestar. Finalmente, se recomiendan algunas prácticas derivadas de los hallazgos presentados, con el fin de que se mejore el bienestar de los cerdos en tránsito.

Spatial distribution of Taenia solium porcine cysticercosis within a rural area of Mexico.

Cysticercosis is caused by Taenia solium, a parasitic disease that affects humans and rurally bred pigs in developing countries. The cysticercus may localize in the central nervous system of the human, causing neurocysticercosis, the most severe and frequent form of the disease. There appears to be an association between the prevalence of porcine cysticercosis and domestic pigs that wander freely and have access to human feces. In order to assess whether the risk of cysticercosis infection is clustered or widely dispersed in a limited rural area, a spatial analysis of rural porcine cysticercosis was applied to 13 villages of the Sierra de Huautla in Central Mexico. Clustering of cases in specific households would indicate tapeworm carriers in the vicinity, whereas their dispersal would suggest that the ambulatory habits of both humans and pigs contribute to the spread of cysticercosis. A total of 562 pigs were included in this study (August-December 2003). A global positioning system was employed in order to plot the geographic distribution of both cysticercotic pigs and risk factors for infection within the villages. Prevalence of pig tongue cysticercosis varied significantly in sampled villages (p = 0.003), ranging from 0% to 33.3% and averaging 13.3%. Pigs were clustered in households, but no differences in the clustering of cysticercotic and healthy pigs were found. In contrast, the presence of pigs roaming freely and drinking stagnant water correlated significantly with porcine cysticercosis (p = 0.07), as did the absence of latrines (p = 0.0008). High prevalence of porcine cysticercosis proves that transmission is still quite common in rural Mexico. The lack of significant differentiation in the geographical clustering of healthy and cysticercotic pigs weakens the argument that focal factors (e.g., household location of putative tapeworm carriers) play an important role in increasing the risk of cysticercosis transmission in pigs. Instead, it would appear that other wide-ranging biological, physical, and cultural factors determine the geographic spread of the disease. Extensive geographic dispersal of the risk of cysticercosis makes it imperative that control measures be applied indiscriminately to all pigs and humans living in this endemic area.

Inexpensive anti-cysticercosis vaccine: S3Pvac expressed in heat inactivated M13 filamentous phage proves effective against naturally acquired Taenia solium porcine cysticercosis.

In search of reducing vaccine production costs', a recombinant M13 phage version of the anti-cysticercosis tripeptide vaccine (S3Pvac) was developed. The efficacy of S3Pvac-Phage vs. placebo was evaluated in a randomized trial that included 1,047 rural pigs in 16 villages of Central Mexico. Three to five months after vaccination 530 pigs were examined by tongue inspection. At 5-27 months of age, 331 pigs (197 vaccinated/134 controls) were inspected at necropsy. Vaccination reduced 70% the frequency of tongue cysticercosis and, based on necropsy, 54% of muscle-cysticercosis and by 87% the number of cysticerci.

Improvement of the synthetic tri-peptide vaccine (S3Pvac) against porcine Taenia solium cysticercosis in search of a more effective, inexpensive and manageable vaccine.

Vaccination of pigs may curtail Taenia solium transmission by reducing the number of cysticerci, the precursors of adult intestinal tapeworms in humans. Several antigen preparations induce protection against porcine cysticercosis in experimental settings but only one subunit vaccine (S3Pvac) has been tested and proved effective in the field against naturally acquired disease. Besides improving of the vaccine's effectiveness, significant reductions in production costs and in the logistics of its administration are necessary for the feasibility of nationwide control programs. This review highlights the development of several versions of S3Pvac aimed to increase effectiveness, reduce costs and increase feasibility by novel delivery systems and alternative routes of administration.

Recombinant bacteriophage-based multiepitope vaccine against Taenia solium pig cysticercosis.

The aim of this study was to test the capacity of recombinant phages to deliver antigens for vaccination against porcine cysticercosis. Thus, three peptides (KETc1, KETc12, GK1) and a recombinant antigen KETc7, previously proven to induce high levels of protection against pig cysticercosis, were expressed on the surface of the M13 bacteriophage at multiple copies. The pool of these four recombinant phages induced high levels of protection against an experimental murine cysticercosis. The immunogenicity of the phage vaccine preparation was therefore, tested in pigs, the natural host of Taenia solium. Subcutaneous or oral vaccination with these phages induced antigen-specific cellular immune responses in pigs. Preliminary data also points to the protective capacity of this recombinant phage vaccine against pig cysticercosis. The immunogenicity of these recombinant phages, together with the low cost of their production, make them a realistic candidate to be tested in pigs as an anti-cysticercus phage vaccine for field trials. This is the first report describing the application of a filamentous bacteriophage as a vaccine in large animals such as pigs, the only intermediate hosts of T. solium, a parasite of major medical importance in developing countries. The potential application of phages as a modern platform for vaccines for human and animal diseases is discussed.

Th1 and Th2 indices of the immune response in pigs vaccinated against Taenia solium cysticercosis suggest various host immune strategies against the parasite.

Kinetics of the production of serum antibody levels and Th1 (IL-2, IFN-gamma) and Th2 (IL-4, IL-10) cytokines was studied in five pigs vaccinated with a synthetic tri-peptide vaccine (S3Pvac) against Taenia solium, a vaccine that has been shown protects pigs against naturally acquired infection. Healthy pigs of mixed genetic background, similar to those bred in rural villages of Mexico, were vaccinated with S3Pvac or with adjuvant alone, kept in sanitary conditions and bled at different times after vaccination to study the development of their specific immune response. Peripheral blood mononuclear cells (PBMCs) of vaccinated pigs showed a significant increment in the production of Th1 cytokines (IL-2 and IFN-gamma) but not of Th2 cytokines (IL-4 and IL-10) after specific PBLs stimulation with all the individual peptides. A Th1-inclined cytokine profile leading to an exacerbated local inflammation at the early installation stage of the cysticercus may possibly interfere with their successful establishment in the serum antibodies against total cysticercus antigens and against each of the three different peptides comprising S3Pvac were detected 7-51 days after vaccination. Antibodies against GK-1 interfered with the cysticerci development into intestinal tapeworms in prednisolone-treated hamsters. The sub-lethal crippling effect of anti-GK-1 antibodies upon cysticerci indicates to a therapeutic application of S3Pvac in infected pigs having potential epidemiological consequences, as it could aid in decreasing the number of tapeworms expected to develop from the few cysticerci that survive in the vaccinated pigs.

[Taeniasis and detection of antibodies against cysticercus among inhabitants of a rural community in Guerrero State, Mexico]. / Teniosis y detección de anticuerpos anticisticerco en personas de una comunidad rural del estado de Guerrero.

OBJECTIVE: To assess the frequency of Taenia solium carriers and its relationship with human cysticercosis in a Mexican locality. MATERIAL AND METHODS: A cross-sectional study was conducted in 1998, in a locality of Guerrero State, Mexico. Four hundred and three fecal samples were analyzed by enzyme-linked immunosorbent assay (ELISA) to detect Taenia sp coproantigen. Ninety two serum samples were also analyzed for antibodies against cisticerci using the immunoelectrotransfer blot assay (IET). Data were analyzed using descriptive statistics and odds ratios. RESULTS: Five of the 403 fecal samples were positive (1.2%). The adult cestode was recovered in only two people. Three (3.26%) out of the 92 serum samples that were analyzed for anticysticercus antibodies were positive. Seventeen serum samples corresponded to people living with a person positive to the coproantigen test (first group), the remaining 75 were obtained from people without a history of releasing taenia proglottids (second group). In the first group, 2 positive sera were detected (11.8%), while in the second only I was positive (1.3%) (odds ratio = 9.87, 95% confidence interval 0.64 to 295.56, p = 0.08). CONCLUSIONS: The difficulty to obtain the adult parasite in persons positive to coproantigens, may be due to difficult expulsion, a shorter permanence of the parasite in the host, insufficient dosage of treatment, or to lack of specificity of the diagnostic test. Further studies are needed to evaluate these possibilities; a better knowledge of parasite transmission dynamics will allow the implementation of prevention and control measures and a better assessment of diagnostic tests under field conditions. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Teniosis y detección de anticuerpos anticisticerco en personas de una comunidad rural del estado de Guerrero / Taeniosis and detection of antibodies against cysticerci among inhabitants of a rural community in Guerrero State, Mexico

OBJETIVO: Determinar la frecuencia de portadores de Taenia sp. y su relación con el diagnóstico de cisticercos en humanos en una comunidad rural del estado de Guerrero, México. MATERIAL Y MÉTODOS: Para detectar portadores de Taenia sp. se analizaron 403 muestras de heces de personas, por medio de ELISA para coproantígenos de Taenia sp., así como 92 muestras de suero para detectar anticuerpos anticisticerco mediante inmunoelectrotransferencia. El diseño del estudio fue transversal y se llevó a cabo durante 1998. Se hizo estadística descriptiva y se estimó razón de momios. RESULTADOS: De 403 muestras de heces evaluadas, cinco resultaron positivas (1.2 por ciento). Sólo en dos de las cinco personas positivas se obtuvo el cestodo adulto. En 3 (3.26 por ciento) de los 92 sueros se encontraron anticuerpos anticisticerco. Del total de sueros, 17 fueron de las personas con diagnóstico positivo a teniosis por coproantígenos o que cohabitaban con ellos (primer grupo), los restantes 75 provenían de personas en quienes no se detectaron casos en las viviendas (segundo grupo). En el primer grupo se detectaron 2 (11.8 por ciento) sueros positivos, mientras que en el segundo sólo 1 (1.3 por ciento) (RM= 9.87, I.C 0.64-295.56, p= 0.086). CONCLUSIONES: La dificultad para obtener el parásito adulto en las personas positivas a coproantígenos puede deberse a características propias de éste que dificultan su expulsión, a que la permanencia del cestodo en su huésped es menor a la esperada o a que el tratamiento fue insuficiente para obtener el parásito, o bien, a problemas de especificidad de la prueba. Es necesario realizar estudios tendientes a evaluar estas posibilidades, lo cual permitiría conocer mejor la dinámica de transmisión de esta parasitosis, con el fin de establecer medidas de prevención y control, además de poder comparar con mayor veracidad la eficacia de las pruebas diagnósticas en condiciones de campo

New approaches to improve a peptide vaccine against porcine Taenia solium cysticercosis.

Cysticercosis caused by Taenia solium frequently affects human health and rustic porciculture. Cysticerci may localize in the central nervous system of humans causing neurocysticercosis, a major health problem in undeveloped countries. Prevalence and intensity of this disease in pigs and humans are related to social factors (poor personal hygiene, low sanitary conditions, rustic rearing of pigs, open fecalism) and possibly to biological factors such as immunity, genetic background, and gender. The indispensable role of pigs as an obligatory intermediate host in the life cycle offers the possibility of interfering with transmission through vaccination of pigs. An effective vaccine based on three synthetic peptides against pig cysticercosis has been successfully developed and proved effective in experimental and field conditions. The well-defined peptides that constitute the cysticercosis vaccine offer the possibility to explore alternative forms of antigen production and delivery systems that may improve the cost/benefit of this and other vaccines. Encouraging results were obtained in attempts to produce large amounts of these peptides and increased its immunogenicity by expression in recombinant filamentous phage (M13), in transgenic plants (carrots and papaya), and associated to bacterial immunogenic carrier proteins.

[Laboratory animals and official Mexican norms (NOM-062-ZOO-1999)]. / Animales de laboratorio y la Norma Oficial Mexicana (NOM-062-ZOO-1999).

This article concerns animal experimentation and official Mexican norm Nom 0062-Zoo-1999 entitled Technical specifications for the production, care and use of laboratory animals. The history of animal experimentation is briefly resumed. During the nineteenth century, doubts arose as to the right to expose animals to experimental procedures that frequently cause pain and suffering. The first law which protected animals against cruelty was passed in Great Britain in 1876; subsequently, other nations approved similar legislation. During the second part of the twentieth century, opposition to animal experimentation grew. Other groups, mainly scientists and pharmaceutical concerns, defended the right to use animals in research. New knowledge concerning the neurophysiology, cognitive capacity, and the animal faculty to experience pain is briefly mentioned. Guidelines on care and use of animals used in research published in several countries are listed. Finally, the recently published Mexican legislation (Norm) referring to production, care and use of laboratory animals is discussed and its benefits are stressed.

Animales de laboratorio y la Norma Oficial Mexicana (NOM-062-ZOO-1999) / Laboratory animals and official Mexican norms (NOM-062-ZOO-1999)

This article concerns animal experimentation and official Mexican norm Nom 0062-Zoo-1999 entitled Technical specifications for the production, care and use of laboratory animals. The history of animal experimentation is briefly resumed. During the nineteenth century, doubts arose as to the right to expose animals to experimental procedures that frequently cause pain and suffering. The first law which protected animals against cruelty was passed in Great Britain in 1876; subsequently, other nations approved similar legislation. During the second part of the twentieth century, opposition to animal experimentation grew. Other groups, mainly scientists and pharmaceutical concerns, defended the right to use animals in research. New knowledge concerning the neurophysiology, cognitive capacity, and the animal faculty to experience pain is briefly mentioned. Guidelines on care and use of animals used in research published in several countries are listed. Finally, the recently published Mexican legislation (Norm) referring to production, care and use of laboratory animals is discussed and its benefits are stressed.

Cisticercosis por Taenia solium en cerdos de México / Cysticercosis in pigs of Mexico

En el presente estudio se hace una breve revisión de la historia de la cisticercosis porcina, en especial de su situación en México. La frecuencia en México en áreas remotas, donde se crían los cerdos en forma semiconfinada es hasta 13 por ciento. Se describen la epidemiología y la dinámica de transmisión en cerdos y se discuten los procedimientos diagnósticos. No se ha demostrado que la mosca doméstica constituya vector importante en la transmisión de la enfermedad. Se describen la relación entre anticuerpos y número de metacestodos viables. En seres humanos la forma clínica más frecuente y grave es la neurocisticercosis. Las razones de esta alta frecuencia en seres humanos y en cerdos son la falta de higiene, de inspección sanitaria de la carne y de programas educativos para la población. Se discuten y se recomiendan métodos de control, entre ellos programas educativos para sensibilizar a la población, vacunación de los cerdos e irradiación gama de la carne infectada.

Condiciones patológicas más frecuentes en los équidos de trabajo en el campo mexicano / Frequent pathological conditions in workings equids in Mexico

En muchas comunidades pobres en México los burros, mulas y caballos son usados para el trabajo de campo, para transportar cargas pesadas, jalar carretas y para otros quehaceres. La mayoría de estos animales están sobreexplotados, mal alimentados y se encuentran en general en malas condiciones de carne. El programa International Donkey Protection Trust- International League for the Protection of Horses-Universidad Nacional Autónoma de México( IDPT-ILPH-UNAM ) ofrece atención veterinaria gratuita para estos équidos de trabajo, ya que sus dueños no disponen de los medios económicos para pagar a un médico veterinario. Esta nota describe las condiciones patológicas más frecuentes encontradas en estos animales y sus causas probables. Entre ellas, las más importantes son parasitosis intestinal, heridas cutáneas, mala condición corporal, problemas de cascos y malos avíos. Se recomienda la impartición de cursos cortos en centros de adiestramiento para los jóvenes campesinos con el fin de que aprendan cómo cuidar bien a los animales de trabajo, para que éstos puedan rendirles mejores servicios.