Resumo: Este artigo avalia as repercussões da pandemia da COVID-19 no cotidiano de trabalho da equipe da Estratégia Saúde da Família (ESF) em diversos municípios do Nordeste brasileiro, na perspectiva dos agentes comunitários de saúde (ACS). Um questionário estruturado foi utilizado para coletar informações sobre a COVID-19, atividades dos ACS e equipes da ESF em 2021. Participaram 1.935 ACS de quatro capitais (Fortaleza - Ceará, João Pessoa - Paraíba, Recife - Pernambuco e Teresina - Piauí) e quatro cidades do interior (Crato, Juazeiro do Norte, Barbalha e Sobral, Ceará). A idade média dos ACS era de 46,25±8,54 anos, sendo a maioria mulheres (82,42%). Muitos (39,92%) estavam infectados com COVID-19, dos quais 70,78% acreditavam ter sido infectados no ambiente de trabalho. Ao todo, 77,82% definiam seu papel como linha de frente no combate à COVID-19, 16,07% relataram receber treinamento para a COVID-19 e 13,74% tinham acesso a equipamentos de proteção suficientes contra a COVID-19. A maioria (90,27%) acredita que suas rotinas de trabalho foram modificadas pela pandemia, fortalecendo o espírito de equipe (41,46%) ou enfraquecendo-o (44,41%). Houve uma redução na promoção da saúde nas escolas (75,66%) e na frequência de visitas domiciliares (60,55%), de grupos específicos na comunidade (93,96%) e outros serviços comunitários locais (66,01%). Nos municípios avaliados, observou-se uma heterogeneidade significativa em relação à resposta à pandemia de COVID-19, possivelmente associada à falta de coordenação do Governo Federal. A pandemia levou a uma reconfiguração dos sistemas locais de saúde, fluxos de trabalho e protocolos de atenção primária para as equipes da ESF. A importância do Sistema Único de Saúde (SUS) e seu potencial de reorganização durante as crises devem ser reconhecidos, preservando-se os avanços alcançados até o momento.

Resumen: Este artículo evalúa las repercusiones de la pandemia de COVID-19 en el trabajo cotidiano del equipo de la Estrategia Salud de la Familia (ESF) en diversos municipios del Nordeste brasileño, desde la perspectiva de los agentes comunitarios de salud (ACS). Se utilizó un cuestionario estructurado para recopilar información sobre COVID-19, actividades de los ACS y equipos de la ESF en el 2021. Participaron 1.935 ACS de cuatro capitales (Fortaleza - Ceará, João Pessoa - Paraíba, Recife - Pernambuco y Teresina - Piauí) y cuatro ciudades del interior (Crato, Juazeiro do Norte, Barbalha y Sobral - Ceará). La edad media de los ACS era de 46,25±8,54 años, y la mayoría eran mujeres (82,42%). Muchos (39,92%) estaban infectados con COVID-19, de los cuales el 70,78% creía haberse contagiado en el entorno laboral. En total, el 77,82% definió su papel como línea de frente en el combate a la COVID-19, el 16,07% informó haber recibido capacitación para la COVID-19 y el 13,74% tuvo acceso a equipos de protección suficiente contra la COVID-19. La mayoría (90,27%) cree que sus rutinas de trabajo se vieron modificadas por la pandemia, fortaleciendo el espíritu de equipo (41,46%) o debilitándolo (44,41%). Hubo una reducción en la promoción de la salud en las escuelas (75,66%) y en la frecuencia de las visitas domiciliarias (60,55%), de grupos específicos en la comunidad (93,96%) y otros servicios comunitarios locales (66,01%). En los municipios analizados, se observó una heterogeneidad significativa con relación a la respuesta a la pandemia de COVID-19, posiblemente asociada a la falta de coordinación del Gobierno Federal. La pandemia condujo a una reconfiguración de los sistemas locales de salud, los flujos de trabajo y los protocolos de atención primaria para los equipos de la ESF. Se debe reconocer la importancia del Sistema Único de Salud y (SUS) su capacidad de reorganización durante las crisis, preservando los avances logrados hasta el momento.

Abstract: This article evaluates the COVID-19 pandemic impacts on the Family Health Strategy (FHS) team’s work routines across a range of northeast Brazilian cities as perceived by community health workers (CHW). Data on COVID-19, CHW activities, and FHS teams were collected in 2021 by a structured questionnaire. A total of 1,935 CHWs from four state capitals (Fortaleza - Ceará State, João Pessoa - Paraíba State, Recife - Pernambuco State, Teresina - Piauí State) and four hinterland cities (Crato, Juazeiro do Norte, Barbalha, Sobral - Ceará State) participated in the study. Most CHWs were women (82.42%), with mean age 46.25±8.54 years. Many (39.92%) were infected with COVID-19, of which 70.78% believed they were infected in the workplace. A total of 77.82% defined their role as frontline in the fight against COVID-19, 16.07% reported receiving training for COVID-19, and 13.74% had access to sufficient protective equipment. Most (90.27%) believed their work routines were modified by the pandemic, either strengthening (41.46%) or weakening (44.41%) the team spirit. Home visits (60.55%), health promotion actions in schools (75.66%) and in specific community groups (93.96%), and other on-site community services (66.01%) showed a reduction in frequency. The sampled cities revealed a significant heterogeneity regarding responses to the COVID-19 pandemic, possibly associated with a lack of coordination by the Federal Government. Regardless of context, the pandemic led to a reconfiguration of local health systems, workflows, and primary care protocols for FHS teams. The importance of the Brazilian Unified National Health System (SUS) and its potential for reorganization during crisis should be acknowledged while preserving the headway made thus far.

Abstract: This article evaluates the COVID-19 pandemic impacts on the Family Health Strategy (FHS) team’s work routines across a range of northeast Brazilian cities as perceived by community health workers (CHW). Data on COVID-19, CHW activities, and FHS teams were collected in 2021 by a structured questionnaire. A total of 1,935 CHWs from four state capitals (Fortaleza - Ceará State, João Pessoa - Paraíba State, Recife - Pernambuco State, Teresina - Piauí State) and four hinterland cities (Crato, Juazeiro do Norte, Barbalha, Sobral - Ceará State) participated in the study. Most CHWs were women (82.42%), with mean age 46.25±8.54 years. Many (39.92%) were infected with COVID-19, of which 70.78% believed they were infected in the workplace. A total of 77.82% defined their role as frontline in the fight against COVID-19, 16.07% reported receiving training for COVID-19, and 13.74% had access to sufficient protective equipment. Most (90.27%) believed their work routines were modified by the pandemic, either strengthening (41.46%) or weakening (44.41%) the team spirit. Home visits (60.55%), health promotion actions in schools (75.66%) and in specific community groups (93.96%), and other on-site community services (66.01%) showed a reduction in frequency. The sampled cities revealed a significant heterogeneity regarding responses to the COVID-19 pandemic, possibly associated with a lack of coordination by the Federal Government. Regardless of context, the pandemic led to a reconfiguration of local health systems, workflows, and primary care protocols for FHS teams. The importance of the Brazilian Unified National Health System (SUS) and its potential for reorganization during crisis should be acknowledged while preserving the headway made thus far.

Resumen: Este artículo evalúa las repercusiones de la pandemia de COVID-19 en el trabajo cotidiano del equipo de la Estrategia Salud de la Familia (ESF) en diversos municipios del Nordeste brasileño, desde la perspectiva de los agentes comunitarios de salud (ACS). Se utilizó un cuestionario estructurado para recopilar información sobre COVID-19, actividades de los ACS y equipos de la ESF en el 2021. Participaron 1.935 ACS de cuatro capitales (Fortaleza - Ceará, João Pessoa - Paraíba, Recife - Pernambuco y Teresina - Piauí) y cuatro ciudades del interior (Crato, Juazeiro do Norte, Barbalha y Sobral - Ceará). La edad media de los ACS era de 46,25±8,54 años, y la mayoría eran mujeres (82,42%). Muchos (39,92%) estaban infectados con COVID-19, de los cuales el 70,78% creía haberse contagiado en el entorno laboral. En total, el 77,82% definió su papel como línea de frente en el combate a la COVID-19, el 16,07% informó haber recibido capacitación para la COVID-19 y el 13,74% tuvo acceso a equipos de protección suficiente contra la COVID-19. La mayoría (90,27%) cree que sus rutinas de trabajo se vieron modificadas por la pandemia, fortaleciendo el espíritu de equipo (41,46%) o debilitándolo (44,41%). Hubo una reducción en la promoción de la salud en las escuelas (75,66%) y en la frecuencia de las visitas domiciliarias (60,55%), de grupos específicos en la comunidad (93,96%) y otros servicios comunitarios locales (66,01%). En los municipios analizados, se observó una heterogeneidad significativa con relación a la respuesta a la pandemia de COVID-19, posiblemente asociada a la falta de coordinación del Gobierno Federal. La pandemia condujo a una reconfiguración de los sistemas locales de salud, los flujos de trabajo y los protocolos de atención primaria para los equipos de la ESF. Se debe reconocer la importancia del Sistema Único de Salud y (SUS) su capacidad de reorganización durante las crisis, preservando los avances logrados hasta el momento.

Resumo: Este artigo avalia as repercussões da pandemia da COVID-19 no cotidiano de trabalho da equipe da Estratégia Saúde da Família (ESF) em diversos municípios do Nordeste brasileiro, na perspectiva dos agentes comunitários de saúde (ACS). Um questionário estruturado foi utilizado para coletar informações sobre a COVID-19, atividades dos ACS e equipes da ESF em 2021. Participaram 1.935 ACS de quatro capitais (Fortaleza - Ceará, João Pessoa - Paraíba, Recife - Pernambuco e Teresina - Piauí) e quatro cidades do interior (Crato, Juazeiro do Norte, Barbalha e Sobral, Ceará). A idade média dos ACS era de 46,25±8,54 anos, sendo a maioria mulheres (82,42%). Muitos (39,92%) estavam infectados com COVID-19, dos quais 70,78% acreditavam ter sido infectados no ambiente de trabalho. Ao todo, 77,82% definiam seu papel como linha de frente no combate à COVID-19, 16,07% relataram receber treinamento para a COVID-19 e 13,74% tinham acesso a equipamentos de proteção suficientes contra a COVID-19. A maioria (90,27%) acredita que suas rotinas de trabalho foram modificadas pela pandemia, fortalecendo o espírito de equipe (41,46%) ou enfraquecendo-o (44,41%). Houve uma redução na promoção da saúde nas escolas (75,66%) e na frequência de visitas domiciliares (60,55%), de grupos específicos na comunidade (93,96%) e outros serviços comunitários locais (66,01%). Nos municípios avaliados, observou-se uma heterogeneidade significativa em relação à resposta à pandemia de COVID-19, possivelmente associada à falta de coordenação do Governo Federal. A pandemia levou a uma reconfiguração dos sistemas locais de saúde, fluxos de trabalho e protocolos de atenção primária para as equipes da ESF. A importância do Sistema Único de Saúde (SUS) e seu potencial de reorganização durante as crises devem ser reconhecidos, preservando-se os avanços alcançados até o momento.

Quando se fala de doenças crônicas e do sistema público de saúde, a escassez de recursos está sempre em pauta. O estudo analisou o referenciamento e o acesso à medicação em indivíduos assistidos pelo serviço público estadual Hiperdia. Trata-se de pesquisa transversal, com 250 indivíduos referenciados para esse nível secundário de atenção à hipertensão e diabetes. Investigaram-se critérios biológicos, acesso aos medicamentos, perfil sociodemográfico e econômico e condição de saúde. O nível de significância estatística foi de 5%. O referenciamento correto foi de 64,0%, embora incorreto para quase metade dos que utilizaram o transporte público municipal. O acesso total à medicação (69,6%) estava associado à menor renda familiar (p < 0,05). A discussão, fundamentada no princípio da justiça distributiva, concluiu pela recomendação de melhor capacitação dos profissionais no referenciamento de serviços assistenciais, com redução do desperdício em transporte público e atenção especializada, além do que, tal investimento deve ser revertido em maior distribuição gratuita de medicamentos.

When speaking of chronic illnesses and the public health system, the lack of resources is on the agenda. The study analyzed the referencing and access to medication in individuals assisted by the State Public Service Hiperdia. It is a transversal study, with 250 individuals referred for this secondary level of attention to hypertension and diabetes. The study investigated biological criteria, access to medicine, socio-demographic and economic profile and health condition. The level of statistical significance was 5%. The correct referencing was 64.0%, although incorrect for nearly half of those that used municipal public transportation. The total access to medicine (69.6%) was associated with the lowest family incomes (p < 0.05). The discussion, based on the principle of distributive justice, was concluded by recommending better training of professionals in referencing assistance services, with a reduction of waste in public transport and specialized attention, because such investment should be reverted to a wider distribution of medicine.

Cuando se habla de enfermedades crónicas y sistema público de salud, la escasez de recursos está en agenda. El estudio analizó la derivación y el acceso a la medicación de individuos asistidos por el servicio público estatal Hiperdia. Se trata de un estudio transversal, con 250 individuos derivados hacia el nivel secundario, para la atención de hipertensión y diabetes. Se investigaron criterios biológicos, acceso a los medicamentos, perfil sociodemográfico y económico y condición de salud. El nivel de significación estadística fuel del 5%. La derivación correcta fue del 64,0%, aunque incorrecto para casi la mitad de los que utilizaron transporte público municipal. El acceso total a la medicación (69,6%) estuvo asociado al menor ingreso familiar (p < 0,05). La discusión, basada en el principio de la justicia distributiva, concluyó recomendando mejor capacitación de los profesionales en la derivación de servicios asistenciales, con reducción del gasto en transporte público y atención especializada, pues tal inversión debe ser traducida en mayor distribución gratuita de medicamentos.

A field survey on schistosomiais was carried out in 1998, in the municipality of Pedro de Toledo, a low endemic area in the state of São Paulo, Brazil. According to the parasitologic Kato-Katz method, the prevalence rate was 1.6%, with an infection intensity of 40.9 eggs per gram of stool. By the immunofluorescence test (IFT) for detection of IgG and IgM antibodies in the serum, IgG-IFT and IgM-IFT, respectively, prevalence indices of 33.2% and 33.5% were observed. To assess the impact of the schistosomiasis control program in the area, parasitologic and serologic data obtained in 1998, analyzed according to the age, sex, and residence zone, were compared to previous data obtained in a epidemiologic study carried out in 1980, when prevalence indices were of 22.8% and 55.5%, respectively by Kato-Katz and IgG-IFT. A significant fall of the prevalence was observed, indicating that the control measures were effective. Nonetheless, residual transmission was observed, demonstrating the need for a joint effort to include new approaches for better understanding the real situation and improving the control of the disease in low endemic areas.

A técnica coproparasitológica de concentração em formol acetato de etila foi empregada para a quantificação de ovos de helmintos. O método quantitativo proposto foi padronizado utilizando-se o sistema comercial Coprotest® e amostras fecais contendo diferentes cargas de ovos de Ascaris lumbricoides. Para a comparação do Coprotest® quantitativo com outros métodos de quantificação de ovos, foi preparada em laboratório uma série de amostras fecais, com carga decrescente de ovos de A. lumbricoides, Trichuris trichiura e Schistosoma mansoni. Discutem-se as vantagens de se empregar um método capaz de detectar maior número de espécies de helmintos, além de protozoários, e que permita, concomitantemente, estimar a intensidade das infecções por geo-helmintos e S. mansoni nas populações. O Coprotest® quantitativo mostrou ser de aplicação viável, fornecendo resultados comparáveis a outros métodos quantitativos já descritos na literatura.

The formol ethyl acetate concentration technique was applied for the quantification of helminth eggs in fecal samples. The proposed quantitative method was standardized through the use of a commercial kit, Coprotest®, and fecal samples with different counts of Ascaris lumbricoides eggs. For the comparison of the quantitative Coprotest® with other methods of egg quantification, a series of fecal samples was prepared in laboratory, with decreasing number of A. lumbricoides, Trichuris trichiura and Schistosoma mansoni eggs. It is discussed the advantages of a method that is able of detecting different helminth and also protozoa species, allowing, in concomitance, to estimate in the populations the intensity of S. mansoni and geohelminth infections. The quantitative Coprotest® showed to be feasible, providing results that were comparable to the other quantitative methods already described in the literature.

Um método imunoenzimático para detecção de anticorpos IgM (ELISA-IgM) contra uma fração do extrato total de vermes de Schistosoma mansoni, solúvel em ácido tricloro acético (fração TCA-solúvel) foi avaliado para fins epidemiológicos, em área de baixa endemicidade para esquistossomose. Amostras de sangue em papel de filtro, coletadas de uma população residente no município de Pedro de Toledo, Estado de São Paulo, foram submetidas ao ELISA-IgM e os resultados, analisados comparativamente aos obtidos pela RIFI-IgM e pelo exame parasitológico de fezes Kato-Katz. Obteve-se 36,8% de positividade pelo ELISA-IgM, 33,5% pela RIFI-IgM e 1,6% pelo Kato-Katz, que indicou uma média geométrica de 40,9 ovos por grama de fezes (opg). A concordância de resultados, quase perfeita (índice Kappa de 0,89), observada entre os dois métodos sorológicos, indica um bom desempenho diagnóstico do teste em avaliação. O ELISA-IgM constitui-se em um método potencialmente útil para fins diagnósticos da esquistossomose, em indivíduos com baixa carga parasitária.

An immunoenzymatic method for the detection of IgM antibodies (IgM-ELISA) against a fraction of Schistosoma mansoni adult worm antigen, soluble in trichloroacetic acid (TCA-soluble fraction), was evaluated for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples on filter paper were collected from a population living in the municipality of Pedro de Toledo, São Paulo State, and submitted to IgM-ELISA. The results were compared to those obtained by the IgM-immunofluorescence test (IgM-IFT) and the Kato-Katz parasitological method. Positive rates of 36.8%, 33.5%, and 1.6% were obtained respectively by the IgM-ELISA, IgM-IFT, and Kato-Katz methods. The geometric mean obtained by the parasitological method was 40.9 eggs per gram of feces (epg). The nearly perfect agreement observed between the two serological tests (Kappa index of 0,89) indicates good diagnostic performance by the evaluated test. IgM-ELISA is a potentially useful method for diagnosis of schistosomiasis in individuals with low worm burden.

Um método imunoenzimático para detecção de anticorpos IgM (ELISA-IgM) contra uma fração do extrato total de vermes de Schistosoma mansoni, solúvel em ácido tricloro acético (fração TCA-solúvel) foi avaliado para fins epidemiológicos, em área de baixa endemicidade para esquistossomose. Amostras de sangue em papel de filtro, coletadas de uma população residente no município de Pedro de Toledo, Estado de São Paulo, foram submetidas ao ELISA-IgM e os resultados, analisados comparativamente aos obtidos pela RIFI-IgM e pelo exame parasitológico de fezes Kato-Katz. Obteve-se 36,8% de positividade pelo ELISA-IgM, 33,5% pela RIFI-IgM e 1,6% pelo Kato-Katz, que indicou uma média geométrica de 40,9 ovos por grama de fezes (opg). A concordância de resultados, quase perfeita (índice Kappa de 0,89), observada entre os dois métodos sorológicos, indica um bom desempenho diagnóstico do teste em avaliação. O ELISA-IgM constitui-se em um método potencialmente útil para fins diagnósticos da esquistossomose, em indivíduos com baixa carga parasitária.

An immunoenzymatic method for the detection of IgM antibodies (IgM-ELISA) against a fraction of Schistosoma mansoni adult worm antigen, soluble in trichloroacetic acid (TCA-soluble fraction), was evaluated for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples on filter paper were collected from a population living in the municipality of Pedro de Toledo, São Paulo State, and submitted to IgM-ELISA. The results were compared to those obtained by the IgM-immunofluorescence test (IgM-IFT) and the Kato-Katz parasitological method. Positive rates of 36.8%, 33.5%, and 1.6% were obtained respectively by the IgM-ELISA, IgM-IFT, and Kato-Katz methods. The geometric mean obtained by the parasitological method was 40.9 eggs per gram of feces (epg). The nearly perfect agreement observed between the two serological tests (Kappa index of 0,89) indicates good diagnostic performance by the evaluated test. IgM-ELISA is a potentially useful method for diagnosis of schistosomiasis in individuals with low worm burden.

The high sensitivity and the ability to diagnose schistosomiasis in a very early phase after infection have indicated the detection of IgM antibodies to Schistosoma mansoni gut antigens by the immunofluorescence test (IgM-IFT) as a useful serological test for epidemiological studies in low endemic areas. When applied in a follow-up study for two years, higher rates of seroconversion from IFT negative to positive were observed during the summer months, suggesting seasonal transmission of schistosomiasis in the rural area of the municipality of Itariri (São Paulo, Brazil). In each survey, blood samples from about 600 schoolchildren were collected on filter paper and submitted to IgM-IFT. When the blood samples were classified for the IgM antibody levels, according to the intensity of fluorescent reaction observed at fluorescence microscopy, and correlated to the egg counts in the Kato-Katz positive patients, no association was observed. This observation might suggest that the intensity of fluorescence observed in the IgM-IFT, as an indicator of IgM antibody levels, could not be an useful seroepidemiological marker for classifying areas of low endemicity according to degrees of infection.

The susceptibility of a fourth generation Ouh strain (Paranapanema Valley, São Paulo, Brazil) of Schistosoma mansoni to oxamniquine (OXA) and praziquantel (PZQ) was studied. Ten groups of 13 female albino mice each were infected with 70 cercariae per animal. These mice were medicated orally on the 50th day after infection. Five groups were given OXA doses of 0, 100, 200, 300 and 400 mg/kg (single doses) and the rest were treated with PZQ doses of 0, 100, 200, and 250 mg/kg/5 days. Each group was sub-divided: 8 animals underwent perfusion after 15 days treatment, 5 mice followed up for oviposition and their feces were tested every 15 days for miracidia hatching. The efficacy of the OXA doses of 100 and 200 mg/kg was 66% and 91.4%, respectively and for the 100 mg/kg PZQ dose it was 90.1%. The follow-up groups with 100 and 200 mg/kg of OXA and PZQ, 100 and 150 mg/kg, showed that they re-established the oviposition after a period of 60 to 75 days of treatment. The ED50 was 69.6mg/kg OXA and 39.4 mg/kg PZQ. The results show the tolerance of the Ouh strain to a dose of 100 mg with both drugs and they appoint the need for a dose review during the follow up of the oviposition and in monitoring phenomena in the field.

O potencial diagnóstico dos anticorpos IgM e IgA contra antígenos do tubo digestivo do Schistosoma mansoni, detectados através da reação de imunofluorescência indireta utilizando-se cortes parafinados de vermes adultos, foi avaliado, comparativamente aos resultados do exame parasitológico de fezes, para fins epidemiológicos em áreas de baixa endemicidade para a esquistossomose. Amostras de sangue em papel de filtro foram coletadas de escolares, residindo em duas localidades diferentes dentro do município de Itariri (São Paulo, Brasil), com características epidemio-lógicas distintas em relação à esquistossomose. Os dados parasitológicos e sorológicos foram comparados aos obtidos com um outro grupo de escolares, residentes em uma área não endêmica para esquistossomose. Os resultados demonstraram a falta de sensibilidade do método parasitológico para detecção de indivíduos com baixa carga parasitária e indicam a potencialidade do método sorológico como importante instrumento a ser incorporado aos programas de controle e de vigilância da esquistossomose, para verificação da real situação da esquistossomose em áreas de baixa endemicidade.

The diagnostic potential of circulating IgM and IgA antibodies against Schistosoma mansoni gut-associated antigens detected by the immunofluorescence test (IFT) on adult worm paraffin sections was evaluated comparatively to the fecal parasitological method, for epidemiological purposes in low endemic areas for schistosomiasis. Blood samples were collected on filter paper from two groups of schoolchildren living in two different localities of the municipality of Itariri (São Paulo, Brazil) with different histories and prevalences of schistosomiasis. The parasitological and serological data were compared to those obtained for another group of schoolchildren from a non-endemic area for schistosomiasis. The results showed poor sensitivity of the parasitological method in detecting individuals with low worm burden and indicate the potential of the serological method as an important tool to be incorporated into schistosomiasis control and vigilance programs for determining the real situation of schistosomiasis in low endemic areas.

A partir de um estudo de caso-controle por pareamento (1:1) foram determinados os fatores de risco para infecção por Schistosoma mansoni. O trabalho foi desenvolvido no município de Pedro de Toledo, São Paulo, Brasil, área onde Biomphalaria tenagophila é o hospedeiro intermediário. Por meio de questionários foram obtidas informações sobre o padrão de contato com águas naturais; percepção da doença e condições sanitárias e socio-econômicas. Os fatores de risco foram estimados individualmente e através de modelo logístico. A maioria dos pesquisados admitiu contatos recentes com águas naturais (90,6% dos casos). O motivo mais freqüente para estes contatos foi nadar, brincar e pescar. O rio representou o principal local de contato com águas naturais. De acordo com a técnica de regressão logística, os principais fatores de risco foram: a) contato com água para nadar, brincar, pescar; b) vadear; c) más condições de higiene. Concluímos que as atividades recreativas são as principais responsáveis pela transmissão da esquistossomose em Pedro de Toledo e alternativas de lazer devem ser oferecidas a esta população.

Risk factors for Schistosoma mansoni infection were identified using a 1:1 matched case-control design. The work was conducted in the municipality of Pedro de Toledo, São Paulo State, Brazil, an area where the snail host is Biomphalaria tenagophila. Information on water contact patterns, knowledge, attitudes and pratices (kap), socioeconomic and sanitary conditions were obtained by mean of questionnaires. The crude odds ratio estimates and the adjusted odds ratio estimates using the logistic regression model are presented. Most of the examined individuals admitted recent water contacts (90.6% of the cases). The most frequent reason for contact was swimming, playing and fishing and the preferential site of contact was the river. According to the logistic regression technique, the main risk factors for infection were: a) water contact through swimming, playing and fishing; b) fording; c) bad hygiene. We concluded that recreational activities are the main reasons for schistosomiasis transmission in Pedro de Toledo and leisure alternatives should be offered to the local population.

The susceptibility of four isolates of Schistosoma mansoni (BH, MAP, MPR-1 and K) to four multiple doses of anti-schistosomal agents (hycanthone, niridazole, oxamniquire, and praziquantel) were evaluated in infected female Swiss albino mice. These schistosomal isolates had been maintained in the laboratory without further drug pressure for 20 to 30 generations. Multiple dosage regimens were used for each drug against each isolate of S. mansoni to generate ED50 (effective dose 50%) values. Results demonstrated that the K isolate is resistant to niridazole, the MPR-1 isolate to oxamniquine, and the MAP isolate to both hycanthone and oxamniquine. The BH isolate was susceptible to all drugs and was used as the reference isolate. All isolates were susceptible to praziquantel. The significance of the difference in response of the MPR-1 and MAP isolates is discussed. These results confirm the resistance of these isolates of S. mansoni of three schistosomicides and demonstrate that the resistance of these isolates are stable over long periods of time without exposure to drugs.

Dentre as regiões do Estado de São Paulo, onde Biomphalaria tenagophila é hospedeira intermediária, o vale do Ribeira é área endêmica da esquistossomose. Nos últimos onze anos a endemia vem sendo intensamente controlada no vale, principalmente, nos municípios de Pedro de Toledo e Itariri. Estudamos a suscetibilidade de B. tenagophila de Itariri à linhagem simpátrica de Schistosoma mansoni, isolada do campo em 1988 e mantida no laboratório em camundongos suiço e B. tenagophila. Estudou-se a 2ª geração do trematódeo. Constituiram-se 3 grupos de 60 moluscos cada, sendo um grupo exposto a um miracídio e outro a 10 e um grupo controle não infectado. Observou-se mortalidade e eliminação de cercárias durante 78 dias. Findo este período, foram seguidos apenas moluscos que liberaram larvas até cessar sua eliminação. Nos moluscos expostos a 1 e 10 miracídios as mortalidades foram de 23% e 31% e os índices de infecção de 8% e 60% respectivamente, assim como a eliminação de cercárias foi de 82 e 104 dias. No controle a mortalidade foi de 22%. Assim, podemos concluir que B. tenagophila apresenta boa adaptação a linhagem simpátrica de S. mansoni

In the São Paulo State, Brazil, where the Biomphalaria tenagophila is the intermediate host, the Ribeira Valley is an important endemic schistosomiasis mansoni area. During last eleven years there has been intense control measures focusing on schistosomiasis. The efforts have been concentrated in the municipalities of Pedro de Toledo and Itariri. We determined the susceptibility of B. tenagophila to sympatric strain of S. mansoni, both recently isolated from Itariri field. In 1988, this strain was isolated and maintained in the experimental model: Swiss mice - sympatric B. tenagophila. The second generation of the worm was evaluated. The snail were divided in the three groups of 60 snails each. One group was exposed to 1 miracidium and other to 10. The third group was the control. The mortality and the shedding of cercariae were checked during 78 days. After that, the positive snails were observed until they ceased to shed cercariae. The exposed molluscs showed mortality rates of 23% and 31% and infection indexes were of 8% and 60% to 1 and 10 miracidia respectively. The mortality was of 22% in the control group. The periods of shedding cercariae in the two groups were 82 and 104 days. We can conclude that B. tenagophila is an effective intermediate host to the sympatric strain of S. mansoni sympatric strain

The schistosomiasis is transmitted by Biomphalaria tenagophila in our study area (Pedro de Toledo, Sao Paulo, Brazil). From 1980 to 1990 epidemiological surveys in a population of 4.000 inhabitants, has shown that: prevalence Kato-Katz (KKT), immunofluorescence (FT) and intradermal (IDT) techniques were 22.8%, 55.5% and 51.8% respectively; intensity of infection was low, 58.5 eggs per gram of faeces (epg); there were no symptomatic cases; prevalences were higher in mates, children and rural zone; index of potential contamination was 57.5% in the age group 5 to 20 years; 2/3 of patients were autochtonous; cases were no-randomly aggregated; transmission was focal and only 0.4% of snails were infected; water contacts through recreation showed the most important odds ratio; knowledge, attitudes and practices were satisfatory. From the epidemiological control findings a control programme was carried out; yearly faeces exams, chemotherapy, molluscocide, health education and sanitation. Thus, the prevalence decreased sharply to 3.3% and intensity of infection to 30.3 epg; the incidence rates ranged between 0.4% and 2.5% annualy; the sanitation became better and the youngsters were the main target in prophylaxis. To improve control, immunodiagnosis has to be conducted and the involvment of the population should be increase. However, we cannot forget that re-infection and the involvment of the population should be increase. However, we cannot forget that re-infection, therapeutic failure, etc, could play a major role in the maintnance this residual prevalence.

The objective of this study is to determine whether various hycanthone resistant strains of schistosomes which have been independently isolated are all affected in the same gene. A strain obtained from a Brazilian patient was compared with a strain of Puerto Rican origin selected in the laboratory. If the mutation conferring resistance involved two different genes, one would expect that the progeny of a cross between the two strains would show complementation, i.e. it would be sensitive to the drug. We have performed such a cross and obtained F1 hybrid worms wich were essentially all resistant, thus suggesting that the mutation conferring resistance in the two strains involves the same gene.