Human lagochilascariasis-A rare helminthic disease.

Lagochilascariasis is a parasitic disease caused by a helminth of the order Ascaroidea, genus Lagochilascaris that comprises 6 species, among which only Lagochilascaris minor Leiper, 1909, is implicated in the human form of the disease. It is remarkable that the majority of cases of human lagochilascariasis in the Americas have been reported in Brazil. The natural definitive hosts of this parasite seem to be wild felines and canines. Lagochilascariasis is mostly a chronic human disease that can persist for several years, in which the parasite burrows into the subcutaneous tissues of the neck, paranasal sinuses, and mastoid. L. minor exhibits remarkable ability to migrate through the tissues of its hosts, destroying even bone tissue. Fatal cases have been described in which the parasite was found in the lungs or central nervous system. Treatment is often palliative, with recurrence of lesions. This paper summarizes the main features of the disease and its etiologic agent, including prevalence, life cycle, clinical course, and treatment.

Study on Chagas disease occurrence in the municipality of Monte Negro, State of Rondônia, Brazilian Amazon / Estudo da ocorrência da doença de Chagas em Monte Negro, Estado de Rondônia, Amazônia Brasileira

INTRODUCTION: Studies on Chagas disease deal with the perspective of its occurrence in the Amazon region, which is directly correlated to the population growth and the spread of the bug biotope. The state of Rondônia has an immense source of vectors (Triatomine) and reservoirs of Trypanosoma cruzi. Environmental changes brought forth by the deforestation in the region may cause vector behavior changes and bring these vectors to a closer contact with humans, increasing the probability of vector infection. METHODS: This study was carried out to check the occurrence of Chagas disease in the municipality of Monte Negro, Rondônia, Brazil, based on a random sampling of the farms and people wherein blood collection from the population and capturing triatomines were done. The blood samples were submitted to serologic tests to detect antibodies of the IgG class against T. cruzi. The triatomines that were collected had their digestive tract checked for the presence of trypanosomatidae with morphology resembling that of the T. cruzi. RESULTS: The population examined was mostly from other states. From the 322 bugs examined on the microscope, 50 percent showed parasites with morphology compatible with T. cruzi. From the serology of 344 random samples of human blood, 1.2 percent was found positive, 6 percent showed inconclusive results, and 92.8 percent were negative. CONCLUSIONS: Monte Negro shows low prevalence of human infection by T. cruzi and none active vector transmission; however, preventive and surveying measures, which are not performed until now, shall be taken due to the abundance of vectors infected by trypanosomatidae.

INTRODUÇÃO: Estudos anteriores sobre doença de Chagas tratam da perspectiva da ocorrência endêmica da parasitose na região Amazônica, que se correlaciona diretamente com o aumento populacional e a invasão do ecótopo pelos triatomíneos. O Estado de Rondônia possui um imenso manancial de vetores e reservatórios de Trypanosoma cruzi. As modificações ambientais ocasionadas pelo desmatamento na região podem gerar mudanças nos hábitos dos vetores, trazendo-os para um contato mais próximo do homem, aumentando as possibilidades de infecção vetorial. MÉTODOS: Este estudo foi realizado para verificar a ocorrência da doença de Chagas em Monte Negro, Rondônia, equivalente à amostragem aleatória das propriedades rurais e de pessoas residentes no município, onde foram realizadas coletas sanguíneas dos moradores e coleta de triatomíneos. As amostras sanguíneas foram submetidas a testes sorológicos para detecção de anticorpos da classe IgG contra T. cruzi e os triatomíneos coletados foram analisados para verificar a presença de tripanosomatídeos em seu trato digestivo. RESULTADOS: A população estudada, randomicamente selecionada, é em sua maioria advinda de outros estados. Dos 322 barbeiros avaliados microscopicamente, 50 por cento apresentavam flagelados com morfologia compatível com Trypanosoma cruzi. A sorologia das 344 amostras de sangue humano coletadas randomicamente apresentou 1,2 por cento de positividade para T. cruzi, 6,1 por cento de resultados inconclusivos e 92,8 por cento negativos. CONCLUSÕES: Monte Negro apresenta baixa prevalência de infecção por T. cruzi em humanos, em torno de 1,2 por cento e sem transmissão vetorial ativa, porém há a necessidade de medidas preventivas de vigilância, não existentes atualmente, devido à abundância do vetor, e a presença de vetores infectados por tripanosomatídeos.

[The national survey of seroprevalence for evaluation of the control of Chagas disease in Brazil (2001-2008)]. / O inquérito nacional de soroprevalência de avaliação do controle da doença de Chagas no Brasil (2001-2008).

A survey for seroprevalence of Chagas disease was held in a representative sample of Brazilian individuals up to 5 years of age in all the rural areas of Brazil, with the single exception of Rio de Janeiro State. Blood on filter paper was collected from 104,954 children and screened in a single laboratory with two serological tests: indirect immunofluorescence and enzyme linked immunoassay. All samples with positive or indetermined results, as well as 10% of all the negative samples were submitted to a quality control reference laboratory, which performed both tests a second time, as well as the western blot assay of TESA (Trypomastigote Excreted Secreted Antigen). All children with confirmed final positive result (n = 104, prevalence = 0.1%) had a follow-up visit and were submitted to a second blood collection, this time a whole blood sample. In addition, blood samples from the respective mothers and familiar members were collected. The infection was confirmed in only 32 (0.03%) of those children. From them, 20 (0.025%) had maternal positive results, suggesting congenital transmission; 11 (0.01%) had non-infected mothers, indicating a possible vectorial transmission; and in one whose mother had died the transmission mechanism could not be elucidated. In further 41 visited children the infection was confirmed only in their mothers, suggesting passive transference of maternal antibodies; in other 18, both child and mother were negative; and in 13 cases both were not localized. The 11 children that acquired the infection presumably through the vector were distributed mainly in the Northeast region of Brazil (States of Piauí, Ceará, Rio Grande do Norte, Paraíba and Alagoas), in addition to one case in Amazonas (North region) and another in Parana (South region). Remarkably, 60% of the 20 cases of probably congenital transmission were from a single State, Rio Grande do Sul, with the remaining cases distributed in other states. This is the first report demonstrating regional geographical differences in the vertical transmission of Chagas disease in Brazil, which probably reflects the predominant Trypanosoma cruzi group IId and IIe (now TcV and TcVI) found in this state. Overall, these results show that the regular and systematic control programs against the transmission of Chagas disease, together with socioeconomic changes observed in Brazil in the last decades, interrupted the vectorial transmission in Brazil, resumed in the few cases found in this national survey. Furthermore they reinforce the need for maintenance of control programs for the consolidation of this major advance in public health.

Study on Chagas disease occurrence in the municipality of Monte Negro, State of Rondônia, Brazilian Amazon.

INTRODUCTION: Studies on Chagas disease deal with the perspective of its occurrence in the Amazon region, which is directly correlated to the population growth and the spread of the bug biotope. The state of Rondônia has an immense source of vectors (Triatomine) and reservoirs of Trypanosoma cruzi. Environmental changes brought forth by the deforestation in the region may cause vector behavior changes and bring these vectors to a closer contact with humans, increasing the probability of vector infection. METHODS: This study was carried out to check the occurrence of Chagas disease in the municipality of Monte Negro, Rondônia, Brazil, based on a random sampling of the farms and people wherein blood collection from the population and capturing triatomines were done. The blood samples were submitted to serologic tests to detect antibodies of the IgG class against T. cruzi. The triatomines that were collected had their digestive tract checked for the presence of trypanosomatidae with morphology resembling that of the T. cruzi. RESULTS: The population examined was mostly from other states. From the 322 bugs examined on the microscope, 50% showed parasites with morphology compatible with T. cruzi. From the serology of 344 random samples of human blood, 1.2% was found positive, 6% showed inconclusive results, and 92.8% were negative. CONCLUSIONS: Monte Negro shows low prevalence of human infection by T. cruzi and none active vector transmission; however, preventive and surveying measures, which are not performed until now, shall be taken due to the abundance of vectors infected by trypanosomatidae.

O inquérito nacional de soroprevalência de avaliação do controle da doença de Chagas no Brasil (2001-2008) / The national survey of seroprevalence for evaluation of the control of Chagas disease in Brazil (2001-2008)

Um inquérito de soroprevalência de doença de Chagas foi realizado em amostra representativa da população com idade até cinco anos de toda a área rural brasileira, exceto o Estado do Rio de Janeiro. Foram estudadas 104.954 crianças, que tiveram amostras de sangue coletadas em papel de filtro e submetidas a testes de screening pelas técnicas de imunofluorescência indireta (IFI) e ELISA em um único laboratório. Todas as amostras com resultados positivos ou indeterminados, juntamente com 10 por cento daquelas com resultados negativos, foram enviadas para um laboratório de referência e aí submetidas a novos testes por IFI e ELISA, além de western blot TESA (Trypomastigote Excreted Secreted Antigen). Para as crianças com resultado final positivo foi agendada uma re-visita para coleta de sangue venoso do próprio participante e das suas mães e familiares. Da avaliação do conjunto de testes resultaram 104 (0,1 por cento) resultados positivos, dos quais apenas 32 (0,03 por cento) foram confirmadas como infectadas. Destas, 20 (0,02 por cento) com positividade materna concomitante (sugerindo transmissão congênita), 11 (0,01 por cento) com positividade apenas na criança (indicativo de provável transmissão vetorial), e uma criança positiva cuja mãe havia falecido. Em 41 situações ocorreu confirmação apenas nas mães, sugerindo transferência passiva de anticorpos maternos; em 18 a positividade não se confirmou nem nas crianças nem nas suas mães; e em 13 não foi possível a localização de ambas. As 11 crianças que adquiriram a infecção por provável via vetorial distribuíram-se predominantemente na região nordeste (Piauí, Ceará, Rio Grande do Norte, Paraíba e Alagoas), acrescidas de um caso no Amazonas e um no Paraná. Dos 20 casos com provável transmissão congênita sobressaiu-se o Rio Grande do Sul, com 60 por cento deles, representando este o primeiro relato de diferenças regionais na transmissão congênita da doença de Chagas no Brasil, possivelmente relacionada à existência de Trypanosoma cruzi grupo IId e IIe, atualmente classificados como TcV e TcVI. Os resultados deste inquérito apontam para a virtual inexistência de transmissão de doença de Chagas por via vetorial no Brasil em anos recentes, resultante da combinação dos programas regulares e sistemáticos de combate á moléstia e de mudanças de natureza socioeconômica observadas no país ao longo das últimas décadas. Por outro lado, reforçam a necessidade de manutenção de um programa de controle que garanta a consolidação deste grande avanço.

A survey for seroprevalence of Chagas disease was held in a representative sample of Brazilian individuals up to 5 years of age in all the rural areas of Brazil, with the single exception of Rio de Janeiro State. Blood on filter paper was collected from 104,954 children and screened in a single laboratory with two serological tests: indirect immunofluorescence and enzyme linked immunoassay. All samples with positive or indetermined results, as well as 10 percent of all the negative samples were submitted to a quality control reference laboratory, which performed both tests a second time, as well as the western blot assay of TESA (Trypomastigote Excreted Secreted Antigen). All children with confirmed final positive result (n = 104, prevalence = 0.1 percent) had a follow-up visit and were submitted to a second blood collection, this time a whole blood sample. In addition, blood samples from the respective mothers and familiar members were collected. The infection was confirmed in only 32 (0.03 percent) of those children. From them, 20 (0.025 percent) had maternal positive results, suggesting congenital transmission; 11 (0.01 percent) had non-infected mothers, indicating a possible vectorial transmission; and in one whose mother had died the transmission mechanism could not be elucidated. In further 41 visited children the infection was confirmed only in their mothers, suggesting passive transference of maternal antibodies; in other 18, both child and mother were negative; and in 13 cases both were not localized. The 11 children that acquired the infection presumably through the vector were distributed mainly in the Northeast region of Brazil (States of Piauí, Ceará, Rio Grande do Norte, Paraíba and Alagoas), in addition to one case in Amazonas (North region) and another in Parana (South region). Remarkably, 60 percent of the 20 cases of probably congenital transmission were from a single State, Rio Grande do Sul, with the remaining cases distributed in other states. This is the first report demonstrating regional geographical differences in the vertical transmission of Chagas disease in Brazil, which probably reflects the predominant Trypanosoma cruzi group IId and IIe (now TcV and TcVI) found in this state. Overall, these results show that the regular and systematic control programs against the transmission of Chagas disease, together with socioeconomic changes observed in Brazil in the last decades, interrupted the vectorial transmission in Brazil, resumed in the few cases found in this national survey. Furthermore they reinforce the need for maintenance of control programs for the consolidation of this major advance in public health.

[Seroprevalence of American trypanosomiasis in adults in an area of the western Brazilian Amazon region]. / Soroprevalência de tripanossomíase americana em adultos de uma área da Amazônia ocidental Brasileira.

From January to March 2001 a seroepidemiological survey for American trypanosomiasis (Chagas disease) was carried out among urban and rural human populations in areas of the Upper Purus basin, in the western Brazilian Amazon region, using serial testing with three different serological techniques. The sample was composed of 1,055 individuals: 844 from urban and 211 from rural areas. Autochthonous infection was identified in nine individuals aged 16 to 72 years: five from urban and four from rural areas. The estimated prevalences of Chagas infection for the urban and rural areas were 0.6% (95% CI: 0.2-1.4) and 1.9% (95% CI: 0.6-4.5) respectively. An apparent clustering trend was noted: seven were born along the Purus river: three lived at the same locality and two of them in the same dwelling.

Soroprevalência de tripanossomíase americana em adultos de uma área da Amazônia ocidental Brasileira / Seroprevalence of American trypanosomiasis in adults in an area of the western Brazilian Amazon region

Foi realizado no período de janeiro a março de 2001 um inquérito soroepidemiológico para tripanossomíase americana (doença de Chagas) em populações humanas, urbana e rural, de áreas da bacia do alto Purus, Amazônia Ocidental Brasileira, através de testagem em série utilizando três técnicas sorológicas. A amostra foi constituída de 1. 055 indivíduos, 844 da área urbana e 211 da área rural. Foi identificada a infecção autóctone em nove indivíduos, cinco da área urbana e quatro da área rural, com idades variando entre 16 e 72 anos. As prevalências estimadas de infecção chagásica foram: 0,6 por cento (IC95 por cento 0,2-1,4) e 1,9 por cento (IC95 por cento 0,6-4,5) para as áreas urbana e rural respectivamente. Observou-se aparente tendência à aglomeração: sete eram naturais do rio Purus, três residiam na mesma localidade, dois habitavam o mesmo domicílio.

From January to March 2001 a seroepidemiological survey for American trypanosomiasis (Chagas disease) was carried out among urban and rural human populations in areas of the Upper Purus basin, in the western Brazilian Amazon region, using serial testing with three different serological techniques. The sample was composed of 1,055 individuals: 844 from urban and 211 from rural areas. Autochthonous infection was identified in nine individuals aged 16 to 72 years: five from urban and four from rural areas. The estimated prevalences of Chagas infection for the urban and rural areas were 0. 6 percent (95 percent CI: 0. 2-1. 4) and 1. 9 percent (95 percent CI: 0. 6-4. 5) respectively. An apparent clustering trend was noted: seven were born along the Purus river: three lived at the same locality and two of them in the same dwelling.

Positividade do xenodiagnóstico de acordo com a faixa etária, o sexo e a forma clínica da Doença de Chagas / Relation between parasitemia detected by xenodiagnosis, age and sex in patients at the chronica phase of Chagas' disease

O xenodiagnóstico foi aplicado em 76 pacientes chagásicos na fase crônica, dos quais eram conhecidos os exames clínico e sorológicos, e nenhum dos pacientes tinha sido submetido a tratamento específico. Em cada xenodignóstico utilizou-se o mínimo de 36 triatomíneos distribuídos eqüitativamente entre as quatro espécies. A positividade do xenodiagnóstico foi de 55,3 pôr cento e mostrou-se independente da faixa etária, do sexo e da forma clínica da doença