OBJECTIVE: This study aimed to explore the association between asthma and atopy in a cohort of children living in a large urban center in Brazil. Atopy was defined by the presence of allergen-specific IgE in serum or by a positive skin prick test. METHODS: In a sample of 1 445 Brazilian children, the association between the prevalence of asthma, skin prick test positivity, and allergen-specific IgE in serum was investigated. RESULTS: The prevalence of asthma was 22.6%. The presence of serum allergen-specific IgE was frequent in asthmatics and nonasthmatics, and the prevalence of asthma increased only with levels of allergen-specific IgE > 3.5 kilounits/L. The proportion of asthma attributable to atopy was estimated to be 24.5% when atopy was defined by the presence of allergen-specific IgE. With a given level of specific IgE, no association between skin test reactivity and asthma was observed. Skin prick tests were less sensitive than specific IgE for detection of atopy. CONCLUSIONS: Most asthma cases in an urban underprivileged setting in Brazil were not attributable to atopy. This observation has important implications for understanding the risk factors for the asthma epidemic in Latin America

OBJETIVO: Explorar la relación entre el asma y la atopia en una cohorte de niños que viven en un gran centro urbano de Brasil. En este estudio, se considera atopia la detección de IgE sérica específica de algún alérgeno o un resultado positivo a la prueba de punción cutánea. MÉTODOS: Se estudió la relación entre la prevalencia del asma, el resultado positivo a la prueba de punción cutánea y la detección de IgE sérica específica de algún alérgeno en una muestra de 1 445 niños brasileños. RESULTADOS: El asma registró una prevalencia de 22,6%. La presencia de IgE séricas específicas de alérgenos fue frecuente tanto en los asmáticos como en los no asmáticos, y la prevalencia del asma fue mayor solo cuando el valor detectado de la IgE específica del alérgeno era > 3,5 kilounidades/litro. Se calculó que la atopia definida como la detección de IgE específicas de alérgenos es responsable de 24,5% de los casos de asma. No se observó ninguna relación entre la reactividad a la prueba de punción cutánea y el asma en función de los valores de IgE específicas. La prueba de punción cutánea es menos sensible que la detección de IgE específicas en lo que respecta al diagnóstico de atopia. CONCLUSIONES: La mayoría de los casos de asma que se registran en entornos urbanos desfavorecidos de Brasil no son atribuibles a atopia. Esta observación tiene implicaciones importantes en lo que respecta a la comprensión de los factores de riesgo que predisponen a la epidemia de asma en América Latina

The importance of racial factors in the epidemiology and clinical manifestations of onchocercosis in the Afro-Ecuadorian and Chachi indigenous races, two distinct ethnic groups in the hyperendemic area of the Ecuadorian onchocercal focus, were evaluated. No difference in the disease prevalence among the two races was noted, although the Chachi had a significant higher dermal microfilariae intensity. Approximately 72.2% of the Afro-Ecuadorians presented with onchocercal skin lesions, as compared to 56.4% of the Chachi. Pretibial depigmentation, sowdah, scrotal elephantiasis and hydrocele were only documented in the Afro-Ecuadorians. Greater prevalence of palpable nodules was found in the Chachi (51.4% vs. 43.0%). Chachi presented with more nodules in the head (25.6% vs 17.6%) and iliac crest (40.1% vs. 30.3%) regions while the Blacks had more nodules in the sacrococcygeal region (18.2% vs 10.8%). Microfilariae in the anterior chamber was seen more frequently in the Chachi (51.9% vs 34.2%). However, a higher prevalence of chorioretinitis and optic atrophy was seen in the Afro-Ecuadorians (17.6% vs 11.2% and 8.5% vs 0.5% respectively). Several possible causes for these differences are discussed

Se evaluó la importancia de los factores raciales en la epidemiología y las manifestaciones clínicas de la oncocercosis en la raza Negra y la raza indígena Chachi, dos grupos étnicos diferentes del área hiperendémica del foco oncocercótico ecuatoriano. Los Chachi presentaron una significativa mayor densidad de microfilarias en la piel. De los Negros, 72,2% presentaron lesiones oncocercóticas en la piel comparado con 56,4% en los Chachi. Se encontró mayor prevalencia de nódulos palpables en los Chachi (51,4% vs. 43,0%). La presencia de microfilarias en la cámara anterior del ojo fue más frecuente en los Chachi (51,9% vs. 34,2%), pero se evidenció una mayor prevalencia de corioretinitis y atrofia del nervio óptico en los Negros (17,6% vs 11,2% y 8,5% vs. 0,5%, respectivamente)

O efeito macrofilaricida da infiltração local, com uma alta concentração de cloroquina, dentro da cápsula do nódulo oncocercótico sobre o verme adulto de Onchocerca volvulus foi determinado. Seis semanas depois da infiltração, estudos histopatológicos de nódulos simple demonstraram todos os vermes adultos mortos. Em conglomerados de nódulos a ação da cloroquina foi só sobre os vermes adultos do nódulo infiltrado, não acontecendo a difusão da droga aos nódulos adjacentes. A infiltração de cloroquina a nódulos novos ou de recente formação reduz a carga de vermes adultos dos indivíduos parasitados e pode ser uma alternativa para os altos custos das nodulectomias.

The macrofilaricidal effects of local infiltration of high concentrations of chloroquine into the capsule of onchocercal nodules on adult worms of Onchocerca volvulus was determined. Six weeks post infiltration, histological examination of single nodules showed all adult worms to be dead. With nodule conglomerates, there was localized action of chloroquine only on the adult worms in the infiltrated nodule, with no diffusion of the drug to adjacent nodules. Chloroquine infiltration of young, recently formed nodules to reduce the adult worm load of infected individuals may be an alternative method to costly nodulectomy.

DNA obtido do sangue periférico de dois pacientes equatorianos, que apresentavam severa patologia digestiva, foi amplificado pela "polymerase chain reaction" (PCR) utilizando os oligonucleotídoes específicos do Trypanosoma cruzi, derivados de uma seqüência primária de cDNA codificado de 24 kDa proteína excretória/secretória. Os resultados positivos da PCR junto com os achados clínicos confirmam que os dois pacientes tinham uma patologia digestiva de origem chagásica. Esta patologia poderia ser mais freqüente que a descrita previamente nas regiões endêmicas chagásicas das cidades dos Andes.

DNA extracted from peripheral blood of two Ecuadorian patients showing severe digestive pathology was amplified by the polymerase chain reaction using a Trypanosoma cruzi specific oligonucleotide primers derived from the primary sequence of a cDNA encoding for a 24 kDa excretory/secretory protein. The positive PCR results together with the clinical findings confirmed that both patients had a digestive pathology due to Chagas' disease. This pathology could be more frequent than previously described in the chagasic endemic regions of Andean countries.

Two well-defined synthetic peptides TcD and PEP2 were used in a sero-epidemiological study for the detection of Trypanosoma cruzi infections in an indigenous group in the Amazon region of Ecuador. Of the 18 communities studied along the Río Napo, province of Napo, 15 (83.3%) were found to be positive for T. cruzi infection. Of the 1,011 individuals examined 61 (6.03%) resulted positive. A prevalence of infection of 4.8% was found in children aged 1-5 years. The prevalence of infection increased with age, with adults 50 years or older showing a maximum prevalence of 18.8%. Autochthonous transmission of T. cruzi is present among this isolated indigenous population

The prevalence of onchocerciasis infection was determined in communities on 7 rivers located in the northern area of the cantón San Lorenzo, province of Esmeraldas. Diagnosis of the infection was obtained by skin biopsies and recombinant-antigen based-serology. No evidence of infection was detected in 9 communities studied along the Río Mataje, which forms the frontier between Ecuador and Colombia, nor in 10 adjacent communities located on 5 interior rivers. Evidence for Onchocerca volvulus infection was found in 4 communities on the Río Tululví with the following prevalence: La Boca (3.5% by biopsy and 3.9% by serology), Guayabal (9.1% by both biopsy and serology), La Ceiva (51.5% by biopsy and 53% by serology), and Salidero (4% by biopsy and 7.7% by serology). A few individuals in these communities were seropositive for O. volvulus in the absence of detectable dermal microfilariae: these might harbor very light or prepatent infections. No clinical disease attributable to onchocerciasis was found. The infected communities will be included in the ivermectin-based National Control Program for the disease, with no evidence of the infection having extended north of the Ecuadorian-colombian border

Trends in prevalence rates of onchocercal ocular lesions were examined over the period 1980 to 1990 using data from two cross-sectional surveys. There was evidence for increasing prevalence of anterior chamber microfilariae, iridocyclitis, optic atrophy, and chorioretinopathy. Large increases in prevalence, in particular, were seen for posterior segment lesions: optic atrophy increased from 2.7% to 6.4% and chorioretinopathy from 8.8% to 35.6%. Greatest increases in these lesions were seen in the Chachi which was attributed to the large increases in prevalence of microfilariae in the anterior chamber particularly in those aged 30 years or greater. The study findings suggest that ocular onchocerciasis is evolving in parallel with the well documented parasitological changes.

O método de imunofluorescência direta (DIFMA), com anticorpos monoclonais gênero- específicos para Leishmania, foi avaliado na rotina diagnostica da leishmaniose cutânea no Equador. O método foi comparado com técnicas diagnosticas de rotina: o esfregaço, a cultura e o exame histopatolôgico. As amostras para o diagnóstico foram obtidas de um total de 90 lesões cutâneas ativas, de doentes das ãreas do Equador, endêmicas para leishmaniose cutânea. O DIFMA foi positivo em todas as lesões, com resultados significativamente superior aos métodos diagnósticos de rotina, isolado ou em combinação. A sensibilidade do DFIMA não diminui em lesões crônicas. O método mostra-se muito útil no diagnóstico de leishmaniose cutânea, pela sua sensibilidade, rapidez e facilidade de execução.

A direct immunofluorescent antibody (DIFMA) test using a Leishmania genus- specific monoclonal antibody was evaluated in the routine diagnosis of cutaneous leishmaniasis (CL) in Ecuador. This test was compared with the standard diagnostic techniques of scrapings, culture and histology. Diagnostic samples were taken from a total of 90 active dermal ulcers from patients from areas of Ecuador known to be endemic for cutaneous leishmaniasis. DIFMA was positive in all lesions. It was shown to be significantly superior to standard diagnostic methods either alone or in combination. The sensitivity of DIFMA did not diminish with chronicity of lesions. This test proved to be extremely useful in the routine diagnosis of CL because it is highly sensitive, is easy to use and produces rapid results.

A prevalência de infecções com helmintos Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale e Strongyloides stercoralis foi examinada em 632 pessoas em diferentes comunidades na Região de Esmeraldas no Equador. Estas comunidades foram divididas em dois grupos conforme a área na qual residem, o que reflete diferentes circunstâncias sócio- econômicas. Intentou-se correlacionar os tiposde infecção com a raça e os grupos sanguíneos ABO. Nestes grupos raciais estão incluídos negros, ameríndios Chachi, e mestiços. Notou-se a prevalência de infecções nas áreas sócio-econômicasmais baixas. Não se encontrou nenhuma relação com a infecção helmíntica e raça ou grupo sanguíneo depois de controlar-se o status sócio- econômico.

Prevalence of infection with the intestinal helminths, Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale and Strongyloides stercoralis was examinedin 632 residents of communities in Esmeraldas province of Ecuador. These communities were divided into two groups according to area of habitation which reflected different socioeconomic circumstances. Attempts were made to correlate infection status with race and ABO blood group phenotype. The racial groups included blacks, Chachi amerindians, and mixed-race mestizos. Greater prevalences of infection were seen in the area oflower socioeconomic status. No racial or blood group associations with helminth infection were seen controlling for socioeconomic status.