Interruption of lymphatic filariasis transmission in Manaus, a former focus of Wuchereria bancrofti in the Western Brazilian Amazon / Interrupción de la transmisión de la filariasis linfática en Manaos, anteriormente un foco de Wuchereria bancrofti en la Amazonia occidental de Brasil / Interrupção da transmissão da filariose linfática em Manaus, anteriormente um foco de Wuchereria bancrofti na parte leste da Amazônia brasileira

ABSTRACT Objective. To confirm the absence of Wuchereria bancrofti autochthonous cases in Manaus, a former focus of lymphatic filariasis in the Western Brazilian Amazon. Methods. A field survey was carried out in 2016 using immunochromatographic rapid tests (ICT card) for the detection of circulating filarial antigens in blood. The sample included a group of 3 000 schoolchildren aged 6 to 10 years enrolled in schools from different urban areas of Manaus (including the former lymphatic filariasis focus in the city) and a group of 709 adolescents and adults, between the ages of 11 and 85 years, born and raised in different areas of Manaus. Results. All of the individuals tested negative for W. bancrofti antigen. Conclusions. Although Manaus was once considered endemic, this focus no longer seems to be active for lymphatic filariasis transmission. The results of this study could support the certification by the World Health Organization of the lymphatic filariasis transmission elimination exercise in Brazil.

RESUMEN Objetivo. Confirmar la ausencia de casos autóctonos de Wuchereria bancrofti en Manaos, anteriormente un foco de filariasis linfática en la Amazonia occidental de Brasil. Métodos. En el 2016 se llevó a cabo una encuesta en el terreno con pruebas rápidas inmunocromatográficas (tiras inmunocromatográficas) para detectar antígenos filáricos circulantes en sangre. La muestra constó de un grupo de 3 000 escolares de 6 a 10 años matriculados en escuelas de diferentes zonas urbanas de Manaos (incluida la zona que anteriormente era el foco de filariasis linfática en la ciudad) y de un grupo de 709 adolescentes y adultos, de edades comprendidas entre 11 y 85 años, nacidos y criados en diferentes áreas de Manaos. Resultados. Todas las personas dieron negativo en la prueba de antígeno de Wuchereria bancrofti. Conclusiones. Aunque hubo un tiempo en que Manaos se consideraba zona endémica, parece que este foco de transmisión de la filariasis linfática ya no está activo. Los resultados de este estudio podrían brindar apoyo a la certificación de la Organización Mundial de la Salud respecto de los esfuerzos realizados en Brasil para eliminar la transmisión de la filariasis linfática.

RESUMO Objetivo. Confirmar a ausência de casos autóctones de Wuchereria bancrofti em Manaus, anteriormente um foco da filariose linfática na parte leste da Amazônia brasileira. Métodos. Uma pesquisa de campo foi realizada em 2016 com o uso de teste rápido por imunocromatografia (cartão ICT) para detecção de antígenos de microfilárias circulantes no sangue. A amostra estudada consistiu de um grupo de 3 000 crianças escolares entre 6 e 10 anos de idade matriculados em escolas de diferentes áreas da zona urbana de Manaus (englobando a área anteriormente com o foco de filariose linfática) e um grupo de 709 adolescentes e adultos entre 11 e 85 anos de idade nascidos e crescidos em diferentes áreas de Manaus. Resultados. Todos os indivíduos pesquisados tiveram teste negativo para o antígeno da W. bancrofti. Conclusões. Apesar de Manaus ter sido anteriormente uma área endêmica, parece que não existe mais foco ativo de transmissão da filariose linfática na cidade. Os resultados deste estudo podem servir para embasar a certificação pela Organização Mundial da Saúde da eliminação da transmissão da filariose linfática no Brasil.

Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region

BACKGROUND The human filarial worm Mansonella ozzardi is highly endemic in the large tributaries of the Amazon River. This infection is still highly neglected and can be falsely negative when microfilariae levels are low. OBJECTIVES This study investigated the frequency of individuals with M. ozzardi in riverine communities in Coari municipality, Brazilian Amazon. METHODS Different diagnostic methods including polymerase chain reaction (PCR), blood polycarbonate membrane filtration (PCMF), Knott's method (Knott), digital thick blood smears (DTBS) and venous thick blood smears (VTBS) were used to compare sensitivity and specificity among the methods. Data were analysed using PCMF and Bayesian latent class models (BLCM) as the gold standard. We used BLCM to calculate the prevalence of mansonelliasis based on the results of five diagnostic methods. FINDINGS The prevalence of mansonelliasis was 35.4% by PCMF and 30.1% by BLCM. PCR and Knott methods both possessed high sensitivity. Sensitivity relative to PCMF was 98.5% [95% confidence interval (CI): 92.0 - 99.7] for PCR and 83.5% (95% CI: 72.9 - 90.5) for Knott. Sensitivity derived by BLCM was 100% (95% CI 93.7 - 100) for PCMF, 100% (95% CI: 93.7 - 100) for PCR and 98.3% (95% CI: 90.6 - 99.9) for Knott. The odds ratio of being diagnosed as microfilaremic increased with age but did not differ between genders. Microfilariae loads were higher in subjects aged 30 - 45 and 45 - 60 years. MAIN CONCLUSIONS PCMF and PCR were the best methods to assess the prevalence of mansonelliasis in our samples. As such, using these methods could lead to higher prevalence of mansonelliasis in this region than the most commonly used method (i.e., thick blood smears).

Wuchereria bancrofti infection in Haitian immigrants and the risk of re-emergence of lymphatic filariasis in the Brazilian Amazon

Abstract INTRODUCTION: Lymphatic filariasis (LF) is a public health problem in Haiti. Thus, the emigration of Haitians to Brazil is worrisome because of the risk for LF re-emergence. METHODS: Blood samples of Haitian immigrants, aged ≥18 years, who emigrated to Manaus (Brazilian Amazon), were examined using thick blood smears, membrane blood filtration, and immunochromatography. RESULTS: Of the 244 immigrants evaluated, 1 (0.4%) tested positive for W. bancrofti; 11.5% reported as having received LF treatment in Haiti. CONCLUSIONS: The re-emergence of LF in Manaus is unlikely, due to its low prevalence and low density of microfilaremia among the assessed Haitian immigrants.

Progression of the load of waterborne and intestinal parasitic diseases in the State of Amazonas

In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil) were Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana (LILACS) and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

Importância do método de gota espessa de sangue no diagnóstico de filárias simpátricas no Amazonas, Brasil / The importance of thick blood film method for sympatric filarial diagnosis in Amazon basin

Esse trabalho relata os métodos de diagnósticos para filárias humanas no sangue, referindo-se a importância do método de gota espessa em relação aos métodos de filtração em membrana de policarbonato e Knott na diferenciação das espécies de microfilárias, principalmente em áreas de ocorrência de mais de uma espécie, como em regiões do Amazonas. Lâminas com microfilárias de Mansonella ozzardi foram montadas e fotografadas pelos diferentes métodos de diagnósticos. O método da gota espessa de sangue é o mais confiável, pois permite visualizar com nitidez o espaço cefálico e caudal, disposição dos núcleos caudais e formato da cauda, que são características morfológicas que diferenciam as espécies de microfilárias sanguíneas que ocorrem no Amazonas.

In this work, the visual diagnostic methods for human filarias in the blood are evaluated. The thick blood film method is more faithful to identify the microfilariae species if compared to policarbonate membrane filtration and Knott methods, especially in areas where more than one species occur, as in Amazon basin. Slides with Mansonella ozzardi microfilariae were mounted and photographed by different diagnosis methods. The thick blood film method is much easier to see the diagnostic morphological characters as cephalic and caudal space, pattern of nucleation of the tail and tail shape that can separate the blood Amazonian microfilariae species.

Mansonella ozzardi in Amazonas, Brazil: prevalence and distribution in the municipality of Coari, in the middle Solimões River

This study investigated some epidemiological aspects of the Mansonella ozzardi in municipality of Coari, Amazonas. Clinical symptoms were correlated with the filarial infection and the parasitic infection rates (PIR) were estimated in simuliid vectors. The general M. ozzardi human prevalence rate was 13.3 percent (231/1733), of which 10.2 percent (109/1069) were from the urban area and 18.4 percent (122/664) from the rural area. The prevalence rates were higher in men (14.5 percent urban and 19.7 percent rural) than in women (6.7 percent urban and 17.2 percent rural) and occurred in most age groups. The indices of microfilaremics were higher in people > 51 years old (26.9 percent urban and 61.5 percent rural). High prevalence rates were observed in retired people (27.1 percent urban area), housewives and farmer (41.6 percent and 25 percent, respectively, in rural area). The main clinical symptoms were joint pains and sensation of leg coldness. Only Cerqueirellum argentiscutum (Simuliidae) transmits M. ozzardi in this municipality (PIR = 5.6 percent urban and 7.1 percent rural). M. ozzardi is a widely distributed parasitic disease in Coari. Thus, temporary residency in the region of people from other localities involved with the local gas exploitation might be a contributing factor in spreading the disease.

Acometimento ocular em pacientes com mansonelose / Ocular manifestations in mansonelliasis

OBJETIVOS: Avaliar as alterações oculares observadas em indivíduos com mansonelose residentes na área rural do município de Coari, AM, na região do médio Amazonas. MÉTODOS: Foi conduzido um estudo de corte transversal envolvendo 543 moradores residentes na área rural do município de Coari, na margem direita do rio Solimões. Todos os indivíduos foram submetidos a exame de gota espessa para pesquisa de microfilária e os indivíduos positivos foram submetidos a exame oftalmológico. Lesões oculares suspeitas foram biopsiadas e enviadas para exame histopatológico. RESULTADOS: Mansonella ozzardi foi encontrada no sangue periférico em 103 (18,9 por cento) indivíduos. Noventa e cinco pacientes com mansonelose foram examinados, observando ceratite puntata em 12 (11,7 por cento) destes, ceratite numular em um indivíduo (1 por cento) e esclerosante em outro (1 por cento). Biópsia de pele foi negativa em todos os indivíduos. Biópsia de conjuntiva e limbo foi realizada em cinco pacientes com mansonelose e biópsia de córnea em outros três pacientes. Duas biópsias de conjuntiva e limbo e uma biópsia de córnea foram enviadas para exame histopatológico, não sendo observadas microfilárias ou alterações sugestivas da presença destas nas peças estudadas. O restante das biópsias foi enviado para pesquisa de DNA do parasita por PCR, não se encontrando microfilária. CONCLUSÕES: Associação entre infecção por Mansonella ozzardi e lesões corneanas sem etiologia aparente foi verificada neste estudo, mas a ausência de achados específicos no exame histopatológico e a não identificação de microfilárias por PCR em lesões suspeitas põem em dúvida a o acometimento corneano na mansonelose. Estudos mais amplos de populações com alta prevalência de M. ozzardi e a realização de outros testes para identificação de microfilárias em tecido ocular são necessários para investigar a patogenicidade da microfilária ao tecido ocular.

PURPOSE: To evaluate eye manifestations in mansonelliasis patients from Coari, AM, rural area on the middle Amazonas River. METHODS: Cross-sectional study consisted of evaluation of 543 subjects from Coari rural area on Solimões River right margin. All subjects were submitted to blood test for microfilaria and the subjects who had a positive test also were submitted to skin biopsies and ophthalmologic examination. Histopathology and PCR research for microfilaria were done on eye biopsies of suspect lesions. RESULTS: Mansonella ozzardi was found in peripheral blood of 103 (18.9 percent) subjects. Ninety-five mansonelliasis patients were examined. Punctate keratitis was observed in 12 of them, nummular keratitis in one subject and sclerosing keratitis in another one. Skin biopsies were negative in all subjects. Conjunctival and limbal biopsies were done in five mansonelliasis patients and corneal biopsy in another three patients. Conjunctival and limbal biopsies of two patients and corneal biopsy of one patient showed no microfilaria or alterations due to its presence on histopathology. PCR showed no evidence of microfilaria in the other biopsies. CONCLUSION: Association between Mansonella ozzardi infection and corneal lesions with no evident etiology was observed in this study, but the lack of conclusive findings on histopathology and PCR make us doubt the corneal involvement in mansonelliasis. Large studies of high mansonelliasis prevalence populations and extensive employment of microfilaria identification tests in ocular tissue are needed to evaluate the microfilaria corneal pathogenicity.

Freqüência de anticorpo anti-Toxocara canis em comunidade do Rio Uatumã, no Estado do Amazonas / Frequency of the antibody anti-Toxocara canis in a community along the Uatumã river, State of Amazonas

Um estudo seccional foi realizado nas Vilas Waimiri e Atroari em Balbina, entre julho e outubro de 2006, com o objetivo de estimar a freqüência de anticorpo antiToxocara canis da classe IgG e avaliar as variáveis epidemiológicas e socioculturais. Foram estudadas 34 famílias e incluídos 100 indivíduos, o que correspondeu a 5 por cento (100/2.000) da população das vilas. A idade variou de zero a 76 anos (M=22,9 Dp=18). Quanto ao gênero, 53 por cento eram femininos e 47 por cento masculino; 52 por cento das amostras foram positivas para Toxocara canis, 44,5 por cento negativas e 3,2 por cento inconclusivas. Observou-se menor número de indivíduos com sorologia negativa na Vila Atroari 29,5 por cento (13/44) em comparação com a Waimiri 46,4 por cento (26/56). Com relação ao contato com cães, dos 55 indivíduos com contato domiciliar 60 por cento (33/55) foram positivos para anticorpo antiToxocara canis Apresentaram sorologia positiva 66,6 por cento (10/15) dos indivíduos que tinham contato domiciliar com filhotes de cão (chi²22,149 p=0,008). A existência de contato domiciliar com cães e filhotes mostrou associação com a presença de anticorpo anti-Toxocara canis na população estudada.

A cross-sectional study was carried out in the Waimiri and Atroari settlements in Balbina, between July and October 2006, with the aims of estimating the frequency of the antibody anti-Toxocara canis of the IgG class and studying the epidemiological and sociocultural variables. Thirty-four families were studied and 100 individuals were included, corresponding to 5 percent (100/2000) of the population of the settlements. The age range was 0-76 years (mean = 22.9; standard deviation = 18). The gender distribution was 53 percent female and 47 percent male. The samples were 52 percent positive for Toxocara canis, 44.5 percent negative and 3.2 percent inconclusive. The number of individuals who tested serologically negative in Atroari (29.5 percent; 13/44) was lower than in Waimiri (46.4 percent; 26/56). In relation to contact with dogs, among the 55 individuals with contact in their homes, 60 percent (33/55) were positive for Ac anti-Toxocara canis and 40 percent (22/55) were negative (chi2= 14.317; p = 0.026). Among the individuals who had contact in their homes with puppies, 66.6 percent (10/15) were serologically positive (chi2= 22.149; p=0.008). The existence of home contact with dogs and puppies showed an association with the presence of Ac anti-Toxocara canis in the study population.

Comparative study of the efficacy and tolerability of Secnidazole suspension (single dose) and Tinidazole suspension (two days dosage) in the treatment of amebiasis in children

Amebiasis caused by Entamoeba histolytica may be considered the most aggressive parasitic disease affecting human intestine, causing acute amoebic colitis and extra-intestinal diseases of high morbidity and mortality. 5-nitroimidazoles are the drugs of choice. In this multicenter, open and randon clinical trial, the efficacy and tolerability of secnidazole suspension in a single oral dose of 1ml/kg was compared with 0.5ml/kg doses of tinidazole suspension given for 2 consecutive days to 303 Entamoeba histolytica-positive children aged 2 to 13. Patients with extra-intestinal complications were excluded from the study. Clinical and parasitological follow-up using the Faus and Kato-Katz method were carried out 7, 14, and 21 days after treatment. Clinical improvement/cure was observed in 93 percent of the patients in the secnidazole group and 91 percent in the tinidaloze group. Parasitological sucess was reported for 77 percent and 63 percent of the secnidazole and tinidazole patients, respectively, showing a significant statistical difference between the two groups (p=0.007). Both drugs were well tolerated, and the adverse effects reported were mild, consisting mainly of digestive disturbances. This comparative study showed that a single oral dose of 1ml/kg of secnidazole produced a significantly higher parasitological cure rate than 2 doses of tinidazole. Secnidazole is a safe and effective drug for the treatment of uncomplicated intestinal amebiasis.

Eficácia de Secnidazol no tratamento de portadores de Entamoeba Histolytica e Giardia Lamblia, avaliado no Instituto de Medicina Tropical do Amazonas -IMT - AM / Efficacy of the Secnidazol in the treatment of the patients with Entomoeba Histolytica and Giardia Lamblia, evaluation in the Instituto de Medicina Tropical do Amazonas - IMIT - AM

Foram avaliados 224 portadores de cistos e/ou trofozoítas de Entamoeba histolytica e 45 de giardia lamblia, diagnosticados através de metodologia de sedimentaçäo espontânea e de flutuaçâo de sulfato de zinco, sendo intituída a terapêutica de dose única de dois gramas de Secnidazol (Secni-plus), independente de peso ou idade. Na primeira avaliaçäo, sétimo dia de controle, 201 (89,7 por cento) pacientes portadores de E. histolytica ewncontravam-se negativos em seus exames coproparasitológicos; os demais pacientes, 23 (10,3 por cento) foram retirados da observaçäo clínica. Quarenta e quatro (97,8 por cento) pacientes portadores de G. lamblia encontravam-se negativos em seus exames coproparasitológicos, e 1 (2,3 por cento) foi retirado da observaçäo clínica. Na segunda avaliaçäo, 14§ dia após o tratamento, 180 (80,4 por cento) pacientes portadores de E. histolytica encontravam-se negativos em seus exames coproparasitológicos, sendo 90,9 por cento o índice de cura clínica dos pacientes inicialmente sintomáticos. Quarenta e um (91,1por cento) pacientes estavam negativos para G. lamblia, sendo 100 por cento o índice de cura clínica dos pacientes inicialmente sintomáticos. Os efeitos secundários adversos foram constatados somente nas primeiras 48 horas, sendo eles sabor metálico residual e náuseas, clinicamente inexpressivos. Concluem os autores que, na observaçäo clínica desenvolvida, Secnidazol (Secni-Plus) é uma terapêutica eficaz no tratamento de pacientes portadores de E. histolytica e Giardia lamblia na posologia de dois gramas, en dose única oral

Ergasilus hypophthalmi n. sp. (Copepoda, Poecilostomatoida, Ergasilidae) from the gill rakers of the Amazonian catfishes, Hypophthalmus edentatus Spix and H. fimbriatus Kner

A fêmea de Ergasilus hypophthalmi sp.n. (Copepoda, Poecilostopmatoida, Erhasilidae) é descrita dos rastros branquiais dos bagres amazônicos, Hypophthalmus edentatus Spix e H. fimbriatus Kner. A nova espécie é morfologicamente semelhante a E. hydrolycus Thatcher e Boeger, 1984, da qual se difere principalmente por ter o segmento torácico II fusionado ao cefalotórax e uma antena relativamente mais curta. Ergasilus hypophthalmi é a terceira espécie de Ergasilidae descrita dos rastros branquiais de peixe