Henry P. F. Willcox

Nova concepção para o método de Baermann-Moraes-Coutinho na pesquisa de larvas de nematódeos

We have adapted the Baermann-Moraes-Coutinhos technique and the results have demonstrated that more economy of material and physical space have been obtained becoming easier to work in the laboratory and in the field. The sensitivity of the adapted technique was somewhat higher for Strongyloides stercoralis (2,8%) when compared with the original technique and 6,5% for sedimentarion methods.We have adapted the Baermann-Moraes-Coutinhos technique and the results have demonstrated that more economy of material and physical space have been obtained becoming easier to work in the laboratory and in the field. The sensitivity of the adapted technique was somewhat higher for Strongyloides stercoralis (2.8%) when compared with the original technique and 6.5% for sedimentation methods.

Evaluation of the xenodiagnosis of chronic Chagas patients infected ten years or over in an area where transmission has been interrupted - Iguatama and Pains, west Minas Gerais State, Brazil

To evaluate the results of xenodiagnosis in chronic Chagas patients infected for ten years or over in an area where transmission has been stemmed as well as the performance of these tests applied one or more times to determine the presence of the parasite in serum-positive patients for Trypanosoma cruzi infection, 570 xenodiagnosis were performed in 246 patients by exposing each patient to 40 Triatoma infestans nymphs of 3rd/4th stage once, twice or three times, at 30 days intervals. The 570 xenodiagnosis showed overall positive results in 50.7% with a peak 78% in patients under 20 years of age, and 60.5% in those over 60. Of the 158 patients who underwent three xenodiagnosis, 51 (32.3%) had three positive tests, 48 (30.3%) had all negative results, and the remainder had alternating positive and negative findings. There was no difference in number of positive results between the 1st, 2nd and 3rd tests; however, the 1st and 2nd trials added up to 53.2% and the sum total of all three trials was 57.7%.

Aspectos epidemiológicos, sociais e sanitários de uma área no Rio Negro, estado do Amazonas, com especial referência às parasitoses intestinais e à infecção chagásica

Um estudo seccional foi realizado na populacao residente em um de cada quatro domicilios habitados na cidade de Barcelos (no norte do Estado do Amazonas, na margem direita do Rio Negro, a 490km de Manaus por via fluvial), visando a avaliar as condicoes sociais, sanitarias e os indicadores especificos para as parasitoses intestinais e para infeccao chagasica. No inquerito, foram aplicados dois questionarios, um domiciliar para avaliar os aspectos sociais e sanitarios, e outro individual, para a avaliacao das condicoes sociais e epidemiologicas da populacao. Uma amostra por conglomerado familiar de 171 domicilios foi estudada. De cada um dos 658 habitantes, foi requisitada uma amostra de fezes para exame parasitologico pelas tecnicas de sedimentacao de Lutz e de Baermann-Moraes-Coutinho, modificado por Willcox & Coura (1989, 1991) e coletada uma amostra de sangue em papel de filtro para a reacao de imunofluorescencia para anticorpos anti-T. cruzi pelo metodo de Fife & Muschel modificado por Camargo (1966) e Souza & Camargo (1966) e Petana & Willcox (1975). O exame de fezes mostrou 69,4% das amostras com um ou mais parasitos. O Ascaris lumbricoides foi predominante, com 51% de positividade, e o Entamoeba histolytica, embora com exame nao especifico, foi positivo em 19,7%. Surpreendentemente, 20,1% das 658 amostras de sangue foram reativas para anticorpos anti-T. cruzi na diluicao de 1:20, e 13,7%, na diluicao de 1:40. Houve forte correlacao entre esses resultados e o nivel de contato da populacao humana com triatomineos silvestres, conhecidos localmente como piolho-da-piacava, e conseguimos isolar por xenodiagnostico uma cepa de T. cruzi de um paciente (no 209-1) com sorologia positiva para infeccao chagasica, natural da area e que havia trabalhado na agricultura, transportando piacava, e que conhecia muito bem o piolho-da-piacava.

Parasitemia em pacientes chagásicos crônicos avaliada pelo indice de triatomíneos infectados no xenodiagnóstico

As part of a pre-treatment study of chronic Chagas infections, the parasitemia of 206 patients (85 men and 121 women, aged 7 to 80 y) from Virgem da Lapa, Minas Gerais State Brazil, was evaluated by three xenodiagnoses per patient during a one year period. Each time, 40 3rd or 4th instar nymphs of Triatoma infestans were applied. The parasitemia was arbitrarily classified as: not detected (when all nymphs were negative), low (when the number of infected nymphs was less than 2%), medium (when it was higher than 2% and up to 7%) and high (when higher than 7%). The parasitemia was not detected in 105 (51%) of the patients, and was considered low in 55 (26.7%), medium in 27 (13.1%) and high in 19 (9.2%). There was no significant differences in levels of parasitemia in relation to sex or age, but the high parasitemia was more frequent among the patients with chagasic cardiomyopathy. Persistent parasitemia (all three xenodiagnoses positive) was observed in 100% of the patients with high parasitemia, in 22.2% with medium and in none with low parasitemia.

The efficiency of Lutz, Kato-Katz and Baermann-Moraes (adapted) techniques association to the diagnosis of intestinal helmints

The association of Lutz/Kato-Katz and Lutz/Baermann-Moraes (adapted) techniques was used to improve better results that ranged from 0.4 to 11 times in the search of eggs of Ascaris lumbricoides, Schistosoma mansoni, Trichiuris trichiura, Taenia sp. and larvae of Strongyloides stercoralis.

Esquistossomose mansoni autóctone e outras parasitoses intestinais em escolares do bairro alto da Boa Vista, da Cidade do Rio de Janeiro

The present situation regarding schistosomiasis mansoni prevalence among primary school children was evaluated in the periphery of Rio de Janeiro city (Alto da Boa Vista). A coproscopic survey was carried out with students of 8 to 15 years oldfrom 3 schools of the area. Among 15 5 examined, 4 positive cases (2,6%) of schistosomiasis were found. On examining 25 relatives of the positive students, 4 other positives cases (16%) were found, all from the same region. The malacological survey carried out revealed a Biomphalaria tenagophila population largely distributed in the irrigation ditches of water-cress gardens surrounding the Fumas River. Seven (7) out of2400 snails collected were positive for Schistosoma mansoni (0,29%). Comparing these results with previous data, it can be observed that schistosomiasis prevalence has been maintained in this area for as long as 15 years. Stool examinations revealed a high prevalence of A. lumbricoides (48,4%). E. nana (23,5%) and T. trichiura (38%).

Serological survey for Chagas' disease in school children in the Rio de Janeiro State, Brazil

Um inquerito sorologico pela reacao de imunofluorescencia indireta para doenca de Chagas, foi realizado, incluindo 13.254 criancas de 168 escolas primarias sorteadas em 20 municipios do Estado do Rio de Janeiro. Os casos positivos pela imunofluorescencia eram confirmados pela reacao de fixacao do complemento e submetidos a exame clinico, investigando-se em seguida suas residencias quanto a existencia ou nao de triatomineos. Somente nos municipios de Mage e Araruama houve um numero significativo de criancas com sorologia positiva. Do total de amostras estudadas somente 143 (1%) foram positivas pela imunofluorescencia e confirmadas pela reacao de fixacao do complemento para doenca de Chagas. Destas, 57 eram de Mage, 58 de Araruama, 4 de Cabo Frio, 3 de Marica, 1 de Saquarema e 1 de Casimiro de Abreu. Nenhuma das criancas examinadas clinicamente apresentava sinais ou sintomas importantes para a doenca de Chagas e nao foram encontrados triatomineos em suas residencias, admitindo-se que tenham sido infectadas acidentalmente ou pela existencia no passado de triatomineos domiciliares. Embora a doenca de Chagas nao pareca um problema importante na regiao estudada, recomendam-se investigacoes em escala mais ampla, principalmente nos municipios de Araruama e Mage para esclarecer os percentuais de positividade soro logica ali encontrados e o mecanismo de transmissao da doenca.