Neurocysticercosis is a disease in which larvae of the tapeworm, Taenia solium, infect the central nervous system of humans. Seizures are the most common symptom of NCC, occurring in between 70 % and 90 % of all symptomatic NCC cases. Neurocysticercosis impacts heavily on the quality of life of patients, and further presents a significant drain on the economic resources of endemic countries. Despite its considerable global impact, the molecular and cellular mechanisms underlying seizures in neurocysticercosis remain largely unknown. In this thesis I have explored novel models for neurocysticercosis by combining mouse hippocampal organotypic brain slice cultures with various preparations of a model parasite, Taenia crassiceps. Utilising these models, I first explored, using patch clamp and local field potential electrophysiology, how Taenia larval extracts directly affect neuronal excitability. I report that extracts of Taenia crassiceps resulted in a significant acute excitation of neurons and triggered seizure-like events in brain slices. Further investigation revealed that this excitation was mediated by the activation of glutamate receptors and that, indeed, the larvae of both Taenia crassiceps and Taenia solium contain and produce levels of glutamate sufficient to explain this effect. Chronic exposure of brain slices to intact, living, larvae did not, however, result in any changes in network excitability. Next, I investigate whether Taenia larvae produce acetylcholinesterases, as these enzymes have the potential to affect neuronal signaling by digesting the neurotransmitter acetylcholine. Ellman's assays, in situ acetylcholinesterase activity assays, and patch clamp electrophysiology reveal that both Taenia crassiceps and Taenia solium larvae produce acetylcholinesterases and that the activity of Taenia acetylcholinesterases is sufficient to digest acetylcholine at a concentration that alters neuronal signaling. Finally, I explore the effect that Taenia larval extracts have on the innate immune cells of the brain, as the responses of these cells can also alter neuronal excitability. Through the measurement of brain slice cytokine release using enzyme-linked immunosorbent assays, I discover that Taenia crassiceps extracts have robust antiinflammatory effects, which involve lipid, protein, and glycan elements. This thesis presents novel findings that reveal ways in which Taenia larvae interact with both neuronal and nonneuronal resident brain cells. It further delves into how these interactions could contribute to seizure generation in neurocysticercosis and proposes some potential new therapeutic approaches to treat seizures in neurocysticercosis.

Neurocisticercose (NCC) é uma infecção parasítica freqüente do sistema nervoso central, principalmente em países em desenvolvimento. Os custos elevados dos exames de neuroimagem (Ressonância Magnética e Tomografia Computadorizada), hoje em dia considerados como os métodos mais precisos no diagnóstico da doença, podem ser inviáveis nestas regiões, além disso, há que se considerar os problemas na correta interpretação dos diversos testes imunológicos disponíveis, freqüentemente difíceis e delicados devido o alto número de falso-positivos e/ou falso-negativos. Nós demonstramos neste trabalho que o DNA de Taenia solium está presente no líquido cefalorraquiano (LCR) de pacientes infectados, permitindo o diagnóstico molecular desses pacientes através da metodologia da PCR (Polymerase Chain Reaction). Neste caso em específico, foi possível estabelecer um diagnóstico preciso para 29/30 (96.7 %) pacientes avaliados, com especificidade de 100%. A presença do DNA do parasita no LCR dos pacientes tem implicações consideráveis no diagnóstico desta importante doença. Além disso, ampliamos significativamente o conhecimento sobre o transcriptoma da Tênia solium produzindo as primeiras 2880 ESTs (Expressed Sequence Tags) deste cestódeo. Em nossas análises encontramos, pelo menos sete novos genes, importantes por poderem exercer um papel importante na luta contra a NCC, pois é através deste conhecimento que se torna identificar os aspectos mais consideráveis desta doença, sendo aperfeiçoando as estratégias de prevenção, encontrando novos antígenos para aperfeiçoar o imunodiagnóstico e/ou possibilitando o desenvolvimento de uma vacina que seja eficiente em proteger e imunizar os hospedeiros. / Neurocysticercosis is a frequent parasitic infection of the central nervous system, mainly in developing countries. High costs of magnetic resonance images (nowadays the most accurate method of diagnosis) may be prohibitive in these regions and the interpretation of the multiple immunologic tests available is often difficult. We demonstrate in this work that Taenia solium DNA is present in the cerebrospinal fluid (CSF) of patients and enabled the correct diagnosis of 29/30 patients (96.7 %) with 100\% specificity through the PCR methodology. The presence of parasite DNA in the CSF of patients may have important consequences over the diagnosis of this important disease. Besides, we enlarge significant the knowledge about Taenia´s transcriptome producing the first 2880 ESTs (Expressed Sequence Tags) of Taenia solium cysticerci. We were able to found at least seven new important genes that may be a important role in a battle against neurocysticercosis because through them it is possible identify considerable aspects of this disease, even though establishing other and efficient strategies of prevention, founding new antigens to improve the immunodiagnosis or building a vaccine to protect the hosts that carry on this important parasite.

A cisticercose suína é uma doença causada pela larva de Taenia solium, Linneaus, 1758, denominada Cysticercus cellulosae (cisticerco). A doença está amplamente distribuída pelo mundo, sendo mais freqüente nos países onde o consumo de carne suína é elevado e as condições sanitárias são deficientes, como em grande parte dos países em desenvolvimento. A cisticercose causa prejuízo em criações de suínos, pois, a carne infectada torna-se imprópria para o consumo humano. Para o diagnóstico da cisticercose suína são realizados o exame da língua in vivo e o exame post-mortem (necropsia). O exame da língua é pouco sensível apesar da elevada especificidade, uma vez que a localização do parasita pode não ser disseminada. A análise post-mortem é baseada em sítios de predileção dos cisticercos. Por isso, são analisados em rotina de inspeção sanitária, o coração, a língua, o diafragma e músculos mastigadores (masseteres e pterigóide). No entanto, infecções brandas, com reduzido número de cisticercos instalados nos tecidos, podem não ser diagnosticadas na necrópsia, evidenciando uma sensibilidade baixa. Recentemente, tem sido sugerida a implementação de testes imunológicos, dentre eles o ELISA (Enzyme Linked Immunossorbent Assay), que tem por princípio a pesquisa de anticorpos no soro. Assim, o presente trabalho objetiva a avaliação de antígenos no método de ELISA para o imunodiagnóstico da cisticercose suína. Dessa forma, 7 suínos, desmamados, provenientes de criação tecnificada foram infectados com 200.000 ovos de T. solium. Foram coletadas amostras sangüíneas antes da infecção e a cada 7 dias até o 140º dia pós-infecção e os soros obtidos foram congelados a 20ºC negativos. Os soros foram avaliados através do ELISA utilizando antígeno total (T-Tso) e de escólex (Es-Tso) de C. cellulosae e de líquido vesicular de C. longicollis (LV-Tcra). O exame da língua in vivo apresentou sensibilidade baixa pois, não foi detectada a presença de cisticercos nos 7 animais durante o período da infecção. Mediante o exame post-mortem, constatou-se a cisticercose em todos os animais. Por outro lado, a quantidade de cisticercos por animal foi baixa tendo em vista a alta dose de ovos inoculados. Foram detectados ao todo 238 cisticercos, sendo todos viáveis. Quanto à distribuição, foi observado que a musculatura do membro anterior e do membro posterior apresentaram as maiores quantidades de parasitas com 24,38% (58) e 28,57% (68) respectivamente. Apenas 18,67% (43) dos cisticercos foram encontrados em tecidos indicados para inspeção da carne. Quanto ao ELISA, obteve-se a padronização do teste para os 3 antígenos, que detectou aumento significativo de anticorpos à partir do 21º dia p.i., para os 7 suínos. O maior índice de reatividade foi encontrado para o antígeno LV-Tcra. O teste com antígenos Es-Tso e LV-Tcra apresentaram os melhores resultados, detectando níveis de anticorpos acima do cut-off nos soros dos animais. Na análise dos soros dos animais suspeitos através do ELISA com Es-Tso, 64,3% (9) das amostras apresentaram absorbâncias acima do cut-off, sendo os animais considerados prováveis portadores de cisticercose. Ficou demonstrada a boa sensibilidade do ELISA com os 3 antígenos, sobretudo quando utilizados o Es-Tso, detectando a doença em animais com infecção leve. Ademais, o ELISA com o antígeno Es-Tso apresenta-se como uma importante ferramenta na pesquisa epidemiológica da cisticercose. / Swine cysticercosis is a disease caused by the Taenia solium’s metacestodes, called Cysticercys cellulosae (Cisticerci). This disease is largely spread around the world and is more frequent in countries where swine meat consumption is high and sanitary conditions are poor, as in developing countries. Cysticercosis is harmful to the raising of the swine because infected meat is not proper for human consumption. To diagnose swine cysticercosis one clinically examines the tonge in vivo and also examines post-mortem (necropsy). The tonge exam has little sensitivity in spite of its high specificity as the parasite location cannot be determined. Post-mortem analysis is based on metacestodes’s favorite sites. Therefore, the heart, the tonge, the diaphragm, and the chewing muscles (masseteres and pterigoidis) in the tissue are analyzed in the regular sanitary inspection. However, mild infections, with a minor number of metacestodes in the tissues may not be diagnosed in the necropsy, showing that evidently there is an low sensitivity. Recently there has been suggestions of immunological tests, including the ELISA (Enzyme Linked Immunossorbent Assay) which has as a principle the antibodies research in swine’s serum. Thus, this study’s aim is to evaluate the antigens in the ELISA method for immunodiagnosis of the swine cysticercosis. The experiment used 7 weaned swine for technological rising were orally infected with 200.000 T. solium eggs. At every 7 days, up to the 140º day of infection, 10 mL of blood was collected and the serum was frozen at minus 20ºC. The serum were analyzed through the ELISA and the analyses used 3 antigens: total (T-Tso) and scolex (Es-Tso) of C. cellulosae and C. longicollis’s vesicular fluid (LV-Tcra). The in vivo tongue exam showed low sensitivity because at no time during in the infection the presence of metacestodes could be detected. Through the post-mortem exam one could notice the cysticercosis in all animals. However, the amount of metacestodes per animal was very low, considering the high number of inoculated eggs. As a total 238 metacestodes were detected and all were viable. As for distribution, one observed that the muscles of front and hindquarters showed more parasites with 24,38 % (58) and 28,57% (68), respectively. Only 18,67% (43) of metacestodes were found in tissue appointed for meat inspection. As for the ELISA, the standardization was obtained for 3 antigens, that detected a significant rise of antibodies from the 21th day of infection. It was also observed that the test using the 3 antigens could detected antibodies anti-Cysticercus from the 21th day post-infection. The highest rate of reactivity was found for the antigen LV-Tcra. The immunoenzimatic tests with the Es-Tso and LV-Tcra showed best results, detecting antibodies level over the cut-off in the animals. In the analysis of the suspected animals with ELISA using Es-Tso, 64,3% (9) samples showed high absorbance to the cut-off and the animals considered probably cysticercosis carriers. In conclusion, it was proved that there is good sensitivity in the ELISA, particularly when the antigen Es-Tso is used, detecting cysticercosis in animals with mild infection. Moreover, the ELISA with the Es-Tso show as an important tool for the cysticercosis epidemiological research.

Neurocisticercose (NCC) é uma infecção parasítica freqüente do sistema nervoso central, principalmente em países em desenvolvimento. Os custos elevados dos exames de neuroimagem (Ressonância Magnética e Tomografia Computadorizada), hoje em dia considerados como os métodos mais precisos no diagnóstico da doença, podem ser inviáveis nestas regiões, além disso, há que se considerar os problemas na correta interpretação dos diversos testes imunológicos disponíveis, freqüentemente difíceis e delicados devido o alto número de falso-positivos e/ou falso-negativos. Nós demonstramos neste trabalho que o DNA de Taenia solium está presente no líquido cefalorraquiano (LCR) de pacientes infectados, permitindo o diagnóstico molecular desses pacientes através da metodologia da PCR (Polymerase Chain Reaction). Neste caso em específico, foi possível estabelecer um diagnóstico preciso para 29/30 (96.7 %) pacientes avaliados, com especificidade de 100%. A presença do DNA do parasita no LCR dos pacientes tem implicações consideráveis no diagnóstico desta importante doença. Além disso, ampliamos significativamente o conhecimento sobre o transcriptoma da Tênia solium produzindo as primeiras 2880 ESTs (Expressed Sequence Tags) deste cestódeo. Em nossas análises encontramos, pelo menos sete novos genes, importantes por poderem exercer um papel importante na luta contra a NCC, pois é através deste conhecimento que se torna identificar os aspectos mais consideráveis desta doença, sendo aperfeiçoando as estratégias de prevenção, encontrando novos antígenos para aperfeiçoar o imunodiagnóstico e/ou possibilitando o desenvolvimento de uma vacina que seja eficiente em proteger e imunizar os hospedeiros. / Neurocysticercosis is a frequent parasitic infection of the central nervous system, mainly in developing countries. High costs of magnetic resonance images (nowadays the most accurate method of diagnosis) may be prohibitive in these regions and the interpretation of the multiple immunologic tests available is often difficult. We demonstrate in this work that Taenia solium DNA is present in the cerebrospinal fluid (CSF) of patients and enabled the correct diagnosis of 29/30 patients (96.7 %) with 100\% specificity through the PCR methodology. The presence of parasite DNA in the CSF of patients may have important consequences over the diagnosis of this important disease. Besides, we enlarge significant the knowledge about Taenia´s transcriptome producing the first 2880 ESTs (Expressed Sequence Tags) of Taenia solium cysticerci. We were able to found at least seven new important genes that may be a important role in a battle against neurocysticercosis because through them it is possible identify considerable aspects of this disease, even though establishing other and efficient strategies of prevention, founding new antigens to improve the immunodiagnosis or building a vaccine to protect the hosts that carry on this important parasite.

A cisticercose suína é uma doença causada pela larva de Taenia solium, Linneaus, 1758, denominada Cysticercus cellulosae (cisticerco). A doença está amplamente distribuída pelo mundo, sendo mais freqüente nos países onde o consumo de carne suína é elevado e as condições sanitárias são deficientes, como em grande parte dos países em desenvolvimento. A cisticercose causa prejuízo em criações de suínos, pois, a carne infectada torna-se imprópria para o consumo humano. Para o diagnóstico da cisticercose suína são realizados o exame da língua in vivo e o exame post-mortem (necropsia). O exame da língua é pouco sensível apesar da elevada especificidade, uma vez que a localização do parasita pode não ser disseminada. A análise post-mortem é baseada em sítios de predileção dos cisticercos. Por isso, são analisados em rotina de inspeção sanitária, o coração, a língua, o diafragma e músculos mastigadores (masseteres e pterigóide). No entanto, infecções brandas, com reduzido número de cisticercos instalados nos tecidos, podem não ser diagnosticadas na necrópsia, evidenciando uma sensibilidade baixa. Recentemente, tem sido sugerida a implementação de testes imunológicos, dentre eles o ELISA (Enzyme Linked Immunossorbent Assay), que tem por princípio a pesquisa de anticorpos no soro. Assim, o presente trabalho objetiva a avaliação de antígenos no método de ELISA para o imunodiagnóstico da cisticercose suína. Dessa forma, 7 suínos, desmamados, provenientes de criação tecnificada foram infectados com 200.000 ovos de T. solium. Foram coletadas amostras sangüíneas antes da infecção e a cada 7 dias até o 140º dia pós-infecção e os soros obtidos foram congelados a 20ºC negativos. Os soros foram avaliados através do ELISA utilizando antígeno total (T-Tso) e de escólex (Es-Tso) de C. cellulosae e de líquido vesicular de C. longicollis (LV-Tcra). O exame da língua in vivo apresentou sensibilidade baixa pois, não foi detectada a presença de cisticercos nos 7 animais durante o período da infecção. Mediante o exame post-mortem, constatou-se a cisticercose em todos os animais. Por outro lado, a quantidade de cisticercos por animal foi baixa tendo em vista a alta dose de ovos inoculados. Foram detectados ao todo 238 cisticercos, sendo todos viáveis. Quanto à distribuição, foi observado que a musculatura do membro anterior e do membro posterior apresentaram as maiores quantidades de parasitas com 24,38% (58) e 28,57% (68) respectivamente. Apenas 18,67% (43) dos cisticercos foram encontrados em tecidos indicados para inspeção da carne. Quanto ao ELISA, obteve-se a padronização do teste para os 3 antígenos, que detectou aumento significativo de anticorpos à partir do 21º dia p.i., para os 7 suínos. O maior índice de reatividade foi encontrado para o antígeno LV-Tcra. O teste com antígenos Es-Tso e LV-Tcra apresentaram os melhores resultados, detectando níveis de anticorpos acima do cut-off nos soros dos animais. Na análise dos soros dos animais suspeitos através do ELISA com Es-Tso, 64,3% (9) das amostras apresentaram absorbâncias acima do cut-off, sendo os animais considerados prováveis portadores de cisticercose. Ficou demonstrada a boa sensibilidade do ELISA com os 3 antígenos, sobretudo quando utilizados o Es-Tso, detectando a doença em animais com infecção leve. Ademais, o ELISA com o antígeno Es-Tso apresenta-se como uma importante ferramenta na pesquisa epidemiológica da cisticercose. / Swine cysticercosis is a disease caused by the Taenia solium’s metacestodes, called Cysticercys cellulosae (Cisticerci). This disease is largely spread around the world and is more frequent in countries where swine meat consumption is high and sanitary conditions are poor, as in developing countries. Cysticercosis is harmful to the raising of the swine because infected meat is not proper for human consumption. To diagnose swine cysticercosis one clinically examines the tonge in vivo and also examines post-mortem (necropsy). The tonge exam has little sensitivity in spite of its high specificity as the parasite location cannot be determined. Post-mortem analysis is based on metacestodes’s favorite sites. Therefore, the heart, the tonge, the diaphragm, and the chewing muscles (masseteres and pterigoidis) in the tissue are analyzed in the regular sanitary inspection. However, mild infections, with a minor number of metacestodes in the tissues may not be diagnosed in the necropsy, showing that evidently there is an low sensitivity. Recently there has been suggestions of immunological tests, including the ELISA (Enzyme Linked Immunossorbent Assay) which has as a principle the antibodies research in swine’s serum. Thus, this study’s aim is to evaluate the antigens in the ELISA method for immunodiagnosis of the swine cysticercosis. The experiment used 7 weaned swine for technological rising were orally infected with 200.000 T. solium eggs. At every 7 days, up to the 140º day of infection, 10 mL of blood was collected and the serum was frozen at minus 20ºC. The serum were analyzed through the ELISA and the analyses used 3 antigens: total (T-Tso) and scolex (Es-Tso) of C. cellulosae and C. longicollis’s vesicular fluid (LV-Tcra). The in vivo tongue exam showed low sensitivity because at no time during in the infection the presence of metacestodes could be detected. Through the post-mortem exam one could notice the cysticercosis in all animals. However, the amount of metacestodes per animal was very low, considering the high number of inoculated eggs. As a total 238 metacestodes were detected and all were viable. As for distribution, one observed that the muscles of front and hindquarters showed more parasites with 24,38 % (58) and 28,57% (68), respectively. Only 18,67% (43) of metacestodes were found in tissue appointed for meat inspection. As for the ELISA, the standardization was obtained for 3 antigens, that detected a significant rise of antibodies from the 21th day of infection. It was also observed that the test using the 3 antigens could detected antibodies anti-Cysticercus from the 21th day post-infection. The highest rate of reactivity was found for the antigen LV-Tcra. The immunoenzimatic tests with the Es-Tso and LV-Tcra showed best results, detecting antibodies level over the cut-off in the animals. In the analysis of the suspected animals with ELISA using Es-Tso, 64,3% (9) samples showed high absorbance to the cut-off and the animals considered probably cysticercosis carriers. In conclusion, it was proved that there is good sensitivity in the ELISA, particularly when the antigen Es-Tso is used, detecting cysticercosis in animals with mild infection. Moreover, the ELISA with the Es-Tso show as an important tool for the cysticercosis epidemiological research.

Background: Despite the acknowledged importance of economic assessments for public health interventions at the human-animal-ecosystem interface, there are currently limited economic methodologies for doing so. In this thesis studies were undertaken to ascertain the economic impact of interventions to control trypanosomiasis and taeniasis/cysticercosis in south-east Uganda and northern Lao PDR respectively. Also, in Uganda studies were done to find out if demand of draft cattle would be an important economic driver for spreading trypanosomiasis due to inter-district trade. Method: In Uganda, a one year recall cross-sectional baseline survey and an 18 month longitudinal survey of 660 households was conducted; to determine the benefits and changes due to restricted application of deltamethrin insecticide to only the legs, belly and ears of cattle. During the 18 month study, the households participating in the study were divided into six regimes depending on the type of intervention done in their cattle and these were; diminazine injection only, deworming only, no treatment and those had 25%, 50% and 75% of the total village cattle sprayed. Thus, the first three regimes were those households that had their cattle not sprayed with insecticide at all as opposed to the last three. Additionally, cattle trade data was collected for network and value chain analysis in all markets in Tororo and Namutamba districts from 199 cattle traders. In northern Lao PDR, stochastic modelling was done to determine the burden of neurocysticercosis associated epilepsy and soil transmitted helminthes. A cross-sectional study was carried out in 49 households, focusing on the prevalence of cysticercosis and soil transmitted helminths before and after a twelve month intervention to control a hyperendemic focus of Taenia solium. The village data was then extrapolated to the wider northern Lao PDR population. Results: The Uganda study indicated that the restricted application of deltamethrin in cattle induced change of USD 31 per head of adult bovine per year; this was the change in income that directly occurred due to restricted spraying of cattle with deltamethrin. During the intervention period, the annual difference in income between those households that had their cattle sprayed using restricted application protocol and those that did not was USD 123; and this was significant (t= 7.18, p= < 0.001). Analysis of variance using households that had their cattle receive no treatment as control showed that restricted application of deltamethrin significantly increased household income compared to diminazine aceturate injection and deworming of cattle only. The incremental benefit cost ratio of spraying 0% to 25% of the cattle was found to be the highest (16:1) compared to spraying 25% to 50% (3:1) and 50% to 75% (1:1) of the cattle. Cattle trade network and value chain analysis revealed that the key cattle markets from which trypanosomiasis is likely to spread into Tororo District are Molo, Namutumba and Soroti. Also, it was found that the risk of spread of human African trypanosomiasis from south-east to north-west Uganda is high due to the increased demand for male cattle for draft work. In northern Lao PDR, 5,094 (95% CI: 25.6-28,940) DALYs were estimated to be imposed annually due to Taenia solium associated epilepsy, with 446.4 (95% CI: 2.2- 2,536) DALY imposed per 100,000 person-years. Due to the high benefits to pig production, the net monetary cost per DALY averted for simultaneously controlling T. solium, soil transmitted helminthes and classical swine fever was only USD 14, which fell to USD 11 if the separable cost method were applied. If the intervention did not target pigs, then the cost per DALY averted was USD 44; well below the current standard for ’very cost effective ‘of the 1 year’s per capita GDP. Conclusion: This study provided empirical evidence for evaluating the impact of quantifying the benefits of controlling zoonotic diseases in the livestock sector (Uganda case study) and in both livestock and human health populations (Lao PDR case study); this economic assessment approach can be used for planning future integrated health interventions. The results of this study support the policy of preventing the spread of infection by spraying at least 25% of the cattle using RAP, as well as injecting all cattle in key livestock markets in south east Uganda with diminazine aceturate to prevent HAT. In northern Lao PDR, simultaneous control of T. solium, soil transmitted helminths and classical swine fever is the most cost-effective approach. There are still difficulties in incorporating human and animal parameters into a single analytical framework; consequently there is a need to adapt the approaches undertaken in this study to the analysis of other zoonotic diseases in different settings to improve on their robustness.

Taenia solium is a zoonotic helminth which is thought to be one of the leading causes of acquired epilepsy in the developing world. T. solium cysticercosis infections in pigs and humans and human taeniasis were diagnosed using antigen-capture ELISAs. The parasite was found to be endemic in the study site, with cysticercosis being detected by HP10 Ag-ELISA in 6.6% of human samples (95% C.I. 5.6-7.8%) and 17.2% (95% C.I. 10.2-26.4%) of porcine samples. Human taeniasis was detected by Copro-Ag ELISA in 19.9% (95% C.I. 18.2-21.8%) of faecal samples. The study site was found to be co-endemic with a large selection of other neglected tropical diseases, including soil transmitted helminthiasis, schistosomiasis, strongyloidiasis and amoebiasis. Potential control measures for this parasite have been modeled and the exclusion of infective pork from the food chain through the use of a pre-slaughter test for pig farmers, traders and slaughtermen was found to have the potential to avoid 72.6% (95% C.I. 62.1-80.9%) of infective meals consumed in the area at an incremental cost-effectiveness ratio (ICER) of $0.25 (0.2-0.35). Such a diagnostic tool is currently under development and its performance was evaluated as part of this thesis. The novel, user-friendly lateral flow assay, utilising the HP10 monoclonal antibody, was evaluated using a Bayesian framework and was estimated to perform with a Sensitivity of 82.7% (95% B.C.I. 72.5-91.9%) and Specificity of 87% (95% B.C.I. 80.2-93.4), results which demonstrate the potential utility of this test in epidemiological studies and in control strategies. Free-ranging pig production has been previously demonstrated to be a key risk factor for porcine cysticercosis and is commonly practised in this study region. A study carried out as part of this thesis found that these pigs have a home range of 15,085m2 which is almost 10 times the average area of a homested. This work indicates that pigs can be exposed to infective eggs from any human T. solium carriers within that homerange area, greatly assisting transmission of this parasite. Western Kenya is a severely deprived region where pig production is becoming hugely popular and is seen as a major tool for economic development, yet the data presented in this thesis indicates an area with endemic status for the harmful parasite T. solium, for which effective control strategies are desperately required.

El objetivo del estudio fue determinar la transmisión de anticuerpos maternos de cerdas inmunizadas con el antígeno Tsol18 expresado en la pichia pastoris (vacuna Tsol18 IIL) hacia sus lechones y la persistencia de estos anticuerpos contra la oncósfera de la Taenia solium. Para este trabajo se usaron 50 lechones que fueron divididos en 4 grupos. Los grupos 1, 2 y 3 con 11, 12 y 11 lechones que procedían de cerdas inmunizadas con dos dosis de la vacuna Tsol18 IIL a las 6 y 2 semanas antes del parto. El grupo 4 con 16 lechones que procedían de cerdas no inmunizadas. La inmunización de las crías fue con la misma vacuna que recibió la madre. El grupo 1 fue vacunado da los 8 y 12 semanas, el grupo 2 fue vacunado a los 12 y 16 semanas, el grupo 3 y grupo 4 fueron los controles. Las muestras de sangre fueron tomadas a las 2, 8, 12, 16 y 20 semanas de edad de la cual se obtuvieron los sueros que fueron evaluados con la prueba de ELISA indirecta estandarizada con el antígeno Tsol18. El valor de la densidad óptica (DO) representan los niveles de anti-Tsol18 en el suero de los cerdos, que posteriormente este valor fue expresado en función al porcentaje de positividad para evaluar los niveles de anticuerpos. Al inicio del estudio, Los lechones procedentes de cerdas inmunizadas poseen niveles altos de anticuerpos maternos IgG, cuando pasaron las semanas, estos anticuerpos descendieron debido a los procesos metabólicos normales del animal, se comparó la diferencia en el incremento en los niveles de anticuerpos entre el grupo 1 y 2, obteniendo como resultado que entre la semana 8 y 12 permanecen los anticuerpos maternos, pero en niveles bajos con la capacidad de interferir en el efecto de la vacuna con el antígeno Tsol18. Palabras claves: Taenia solium, Cysticercus cellulosae, Tsol 18 IIL, inmunidad materna, Anticuerpos Maternos, ELISA. / --- The aim of this study was to determine maternal antibodies transmission from Tsol18 immunized with antigen expressed in Pichia pastoris (vaccine Tsol18 IIL) sows to piglets and the persistence of these antibodies in piglets against oncosphere of Taenia solium. To do this study it was necessary to use fifty piglets with two doses of the vaccine Tsol18 IIL at 6 and 2 weeks before birth, which were divided into 4 groups. Group 1, 2 and 3 containing 11, 12 and 11 piglets respectively came from vaccinated sows. Group 4 containing 16 piglets came from unvaccinated sows. The first group was vaccinated at 8 and 12 weeks old, the group 2 at 12 and 16 weeks and group 3 and 4 were control groups. Blood samples were taken at 2, 8, 12, 16 and 20 weeks old. Were obtained serums that were assessed with standardized indirect ELISA with antigen Tsol18The results were expressed according to the percentage of positive individuals, The value of antibody titers were expressed according to the percentage of positive which was obtained from the optical density (OD) of each serum sample between the OD of a standard positive control. At the beginning of the study, piglets from immunized sows had high levels of maternal antibodies Ig G. As the weeks passed, these antibodies were decreasing due to normal metabolic process. comparing the difference in the increase in antibody levels between groups 1 and 2, the result being that between week 8 and 12 remain maternal antibodies, but at low levels, with the ability to interfere with the effect of vaccination with antigen Tsol18. Keywords: Taenia solium, Cysticercus cellulosae, Tsol 18 IIL, maternal immunity, maternal antibodies, ELISA. / Tesis

Neurocysticercosis (NCC) is a parasitic disease caused by the larva of the zoonotic cestode Taenia solium. The objectives of this study were to evaluate the distribution of presenting clinical manifestations of NCC, to evaluate the socio-demographic characteristics of NCC patients, to compare quality of life of individuals diagnosed with NCC with an age and sex matched control population and to estimate the non-monetary burden of NCC in Mexico. In order to accomplish these objectives, a case series of NCC patients was conducted in two neurology referral hospitals in Mexico City, Mexico during 2007-2008. Information on clinical manifestations associated with NCC was obtained via medical chart reviews of NCC patients. Information on socio-demographic characteristics of NCC patients was obtained through the administration of questionnaires. In addition, a cross-sectional study was conducted to compare the quality of life of NCC patients to an age and sex matched control population using the short form 12 v2 (SF-12 v2) survey. Non-monetary burden of NCC in Mexico was estimated using disability adjusted life years (DALYs), incorporating morbidity due to both NCC-associated epilepsy and severe headache and mortality due to NCC-associated epilepsy. NCC patients presented to the neurology referral hospitals with numerous clinical manifestations, with severe headache and epilepsy being the most common. Lack of knowledge of T. solium transmission was common among NCC patients, with 25 percent of patients not knowledgeable about tapeworm infections in humans. Of those that were aware that tapeworm infections do occur, 57 percent were not aware of how the worms were transmitted to humans. The SF-12 v2 general health survey showed that individuals with NCC had a significantly lower score for all eight domains of health evaluated (physical functioning, role physical, bodily pain, vitality, general health, social functioning, role emotional and mental health) compared with the age and sex matched population from the same region (p< 0.05). The mean total number of DALYs lost due to NCC in Mexico was estimated to be 99,866 (95 percent CR: 43,187 –189,182), with a mean of 0.95 (95 percent CR: 0.4–1.8) DALYs lost per thousand persons per year.

Taenia solium is a cestode that has a two-hosts life cycle. The adult tapeworm causes an asymptomatic disease known as taeniasis whereas the larval stage causes a disease called cysticercosis. In humans, the most common localization for the larvae is the central nervous system where it produces the neurological disorder neurocysticerco-sis. Previous works by several research groups around the world have shown that T. so-lium is a potentially eradicable parasite. Control programs have included treatment of human and pig populations with antihelmintics in conjunction with health education and are now considering vaccination of naïve piglets. The potential of a live vector vaccine system to deliver Taenia solium Tsol18, a proven protective antigen, to prevent transmission of cysticercosis was investigated. An attenuated strain of Salmonella enterica serovar Typhimurium χ9402 was used to develop an oral delivery system. Tsol18 gene was cloned downstream from the β-lactamase signal sequence in a multicopy asd + plasmid vector pYA3620 to yield plasmid pYA3620/Tsol18 and then transformed into the vaccine strain. The recombinant atte-nuated salmonella vaccine construct was stable for 50 generations and expressed rTsol18. Immunization of mice either with one or two doses of 109 CFU of the recombi-nant vaccine strain carrying plasmid pYA3620/Tsol18 elicited specific antibody response to Salmonella self antigens and to rTsol18. Moreover, oral immunization of piglets with 1012 CFU of the vaccine construction significantly reduced the numbers of viable cysts after challenged. The development of a quantitative assay to detect specific antibodies against Tsol18 is also presented here. The Falcon assay screening test –enzyme linked immu-noabsorbant assay (FAST-ELISA) format was used to develop a quantitative antibody detection assay. We have cloned, expressed and purified rTsol18. With purified porcine IgGs we constructed a standard curve that can be used to quantify the immune re-sponse. Our Fast-ELISA was able to follow the kinetics of the immune response in vac-cinated pigs from an experimental trial. The data we present here provides the basis for a safe, affordable and easy vaccine delivery system that can be used as an adjunct in control programs.