Water-contact patterns and risk factors for Schistosoma mansoni infection in a rural village of Northeast Brazil

Schistosomiasis mansoni in the Serrano village, municipality of Cururupu, state of Maranhão, Brazil, is a widely spread disease. The PECE (Program for the Control of Schistosomiasis), undertaken since 1979 has reduced the prevalence of S. mansoni infection and the hepatosplenic form of the disease. Nevertheless piped water is available in 84% of the households, prevalence remains above 20%. In order to identify other risk factors responsible for the persistence of high prevalence levels, a cross-sectional survey was carried out in a systematic sample of 294 people of varying ages. Socioeconomic, environmental and demographic variables, and water contact patterns were investigated. Fecal samples were collected and analyzed by the Kato-Katz technique. Prevalence of S. mansoni infection was 24.1%, higher among males (35.5%) and between 10-19 years of age (36.6%). The risk factors identified in the univariable analysis were water contacts for vegetable extraction (Risk Ratio - RR = 2.92), crossing streams (RR = 2.55), bathing (RR = 2.35), fishing (RR = 2.19), hunting (RR = 2.17), cattle breeding (RR = 2.04), manioc culture (RR = 1.90) and leisure (RR = 1.56). After controlling for confounding variables by proportional hazards model the risks remained higher for males, vegetable extraction, bathing in rivers and water contact in rivers or in periodically inundated parts of riverine woodland (swamplands)

Dimensionamento do Sistema Híbrido para Alimentação de Energia Elétrica da Escola Rural de Nangade (Cabo Delgado)

Os combustíveis fósseis, como o carvão, o petróleo e o gás, constituem fontes de energia que em breve se esgotarão e que são demasiado caras para serem desperdiçadas pelas centrais elétricas na produção de electricidade. Para além desse facto, existem outros argumentos (sobretudo económicos) que inviabilizam a utilização destas fontes de energia em algumas regiões, abrindo caminho a fontes de energia alternativas (e.g. solar, eólica, biomassa, mini-hídricas, geotérmicas, etc) e preferencialmente com contornos locais. No caso particular de Moçambique, tem-se verificado um interesse crescente por parte do governo e de várias ONGs na promoção do uso de energias alternativas para as zonas onde a energia convencional não chega e não chegará, devido aos custos muito elevados que esse processo acarretaria. Esta dissertação apresenta um estudo aprofundado do dimensionamento dum sistema híbrido de geração de energia elétrica envolvendo gerador FV e grupo eletrogéneo de emergência para a Escola Rural da Nangade, situada no Distrito de Nangade, na Província do Cabo Delgado. São também descritos os diversos componentes e as tecnologias associadas a um sistema deste género, com a inclusão de sistemas inteligentes de controlo de energia com a utilização de inversores bidireccionais (inversores de bateria e carregadores) para sistemas isolados. Os resultados são apresentados de forma a facilitar a aplicação e montagem deste tipo de sistemas in loco. Espera-se que esta dissertação possa servir de base no futuro próximo, para a implementação deste tipo de sistemas para permitir a melhoria da qualidade de ensino através de melhores infraestruturas, democratizando desta forma o acesso à educação para as crianças das zonas rurais das várias províncias de Moçambique. Como as energias renováveis são parte integrante do Sistema Elétrico Nacional, apresenta-se resumidamente, no anexo 17, o “Plano de Desenvolvimento na Área de Energia de Moçambique”.

Culture-dependent characterization of cyanobacterial diversity in the intertidal zones of the Portuguese coast: A polyphasic study

Cyanobacteria are important primary producers, and many are able to fix atmospheric nitrogen playing a key role in the marine environment. However, not much is known about the diversity of cyanobacteria in Portuguese marine waters. This paper describes the diversity of 60 strains isolated from benthic habitats in 9 sites (intertidal zones) on the Portuguese South and West coasts. The strains were characterized by a morphological study (light and electron microscopy) and by a molecular characterization (partial 16S rRNA, nifH, nifK, mcyA, mcyE/ndaF, sxtI genes). The morphological analyses revealed 35 morphotypes (15 genera and 16 species) belonging to 4 cyanobacterial Orders/Subsections. The dominant groups among the isolates were the Oscillatoriales. There is a broad congruence between morphological and molecular assignments. The 16S rRNA gene sequences of 9 strains have less than 97% similarity compared to the sequences in the databases, revealing novel cyanobacterial diversity. Phylogenetic analysis, based on partial 16S rRNA gene sequences showed at least 12 clusters. One-third of the isolates are potential N2-fixers, as they exhibit heterocysts or the presence of nif genes was demonstrated by PCR. Additionally, no conventional freshwater toxins genes were detected by PCR screening.

Serologic survey for hantavirus infections among wild animals in rural areas of São Paulo State, Brazil

A serosurvey was conducted in wild animals captured close to two areas where hantavirus cardiopulmonary syndrome (HCPS) occurred in São Paulo State, Brazil. Serum samples from a total of 43 mammals were tested for antibodies reactive with Sin Nombre (SN) hantavirus using a strip immunoblot assay. RNAs from the blood clots of the positive samples were submitted to reverse transcriptase-polymerase chain reaction (RT-PCR). Two rodents of the genus Oligoryzomys were positive for hantavirus antibodies. These animals were captured in the Iguape region and represented 16.7% (2/12) of the sera from rodents and 100.0% (2/2) of the Oligoryzomys captured in that area. RT-PCR failed to amplify any viral cDNA. These results are in agreement with other data that suggest that members of this genus are important reservoirs of hantaviruses in Brazil.

Frequency of serum anti-cysticercus antibodies in the population of a rural Brazilian community (Cássia dos Coqueiros, SP) determined by ELISA and immunoblotting using Taenia crassiceps antigens

Considering the impact of cysticercosis on public health, especially the neurologic form of the disease, neurocysticercosis (NC), we studied the frequency of positivity of anti-Taenia solium cysticercus antibodies in serum samples from 1,863 inhabitants of Cássia dos Coqueiros, SP, a municipal district located 80 km from Ribeirão Preto, an area considered endemic for cysticercosis. The 1,863 samples were tested by enzyme linked immunosorbent assay (ELISA) using an antigenic extract from Taenia crassiceps vesicular fluid (Tcra). The reactive and inconclusive ELISA samples were tested by immunoblotting. Of the 459 samples submitted to immunoblotting, 40 were strongly immunoreactive to the immunodominant 18 and 14 kD peptides. Considering the use of immunoblotting as confirmatory due to its high specificity, the anti-cysticercus serum prevalence in this population was 2.1%.

Seroprevalence of Helicobacter pylori infection in chronic chagasic patients, and in the rural and urban population from Uberlândia, Minas Gerais, Brazil

As patients with chronic Chagas disease exhibit morphological and functional changes of the stomach (hypomotility and hypochlorhydria), malnutrition, immunological deficiency and high prevalence of peptic disease associated to Helicobater pylori infection, the purpose of this study was to evaluate if the prevalence of H. pylori infection in chronic chagasic is higher than in non-chagasic individuals in the urban and rural population from Uberlândia, MG, Brazil. Serological determination of IgG antibodies to H. pylori was performed using a second-generation ELISA. Thus, 598 people were evaluated: 128 chagasic (CG), 222 non-chagasic living in urban area (U-NCG) and 248 non-chagasic living in rural area (R-NCG). Regarding the age range from 21 to 50 years, the prevalence of H. pylori infection in the CG (85.1%) was significantly higher than in the U-NCG (56.3%, p < 0.01) and the R-NCG (67.4%, p < 0.05). In the patients over 50 years, the prevalence in the CG (86.4%) was similar to the U-NCG (78.8%) and R-NCG (86.1%). Similar results were also found between the U-NCG and R-NCG for all age ranges, with prevalence rates of 29.1% and 35.3% for the age range from 5 to 13 years, and 47.2% and 40% for that from 14 to 20 years, respectively. We conclude that chagasic patients showed a higher seroprevalence of H. pylori infection than non-chagasic individuals, in the age range from 21 to 50 years, and that the prevalence of this infection was similar in the studied urban and rural non-chagasic population.

Cultura tradicional e meio rural

pp. 99-119

Prevalence of human papillomavirus infection in rural villages of the Bolivian Amazon

Cervical cancer constitutes a major health problem in developing countries like Bolivia. The roles of certain genotypes of human papillomaviruses (HPVs) in the pathogenesis of cervical cancer is well established. The prevalence of HPV infection among sexually active women varies greatly. Information regarding HPV infection in Bolivia is very much scarce, specially in regions like the Amazonian lowland. We studied 135 healthy women living in four rural localities of the Bolivian Amazon. Presence of HPV in DNA extracted from cervical swabs was analyzed using a reverse line hybridization assay. The estimated overall HPV infection prevalence among the studied rural localities was 5.9% (ranging from 0-16.6%). These values were unexpectedly low considering Bolivia has a high incidence of cervical cancer. The fact that Amazonian people seem to be less exposed to HPV, makes it likely that some other risk factors including host lifestyle behaviors and genetic background may be involved in the development of cervical cancer in this population.

Intestinal parasites and commensals among individuals from a landless camping in the rural area of Uberlândia, Minas Gerais, Brazil

We evaluated the occurrence of intestinal parasites and commensals among children and adults from a landless camping in the rural area of Uberlândia, State of Minas Gerais, Brazil, from October to November 2001. Stool samples from 78 individuals were examined by both the Baermann-Moraes and Lutz methods. Fifty-one (65.4%; CI 54.8 - 76.0) individuals were found to be infected, 23 (45.1%) children and 28 (54.9%) adults, of whom 34 (66.7%) were mono-infected, 9 (17.6%) bi-infected, and 8 (15.7%) poly-infected. In conclusion, the high prevalence of intestinal parasites and commensals suggests that parasitological exams should be periodically carried out in addition to the sanitation education and health special care in this population.

Impact of antihelminthic treatment on infection by Ascaris lumbricoides, Trichuris trichiura and hookworms in Covas, a rural community of Pernambuco, Brazil

This work aims to evaluate the impact of drug treatment on infection by Ascaris lumbricoides (Al), Trichuris trichiura (Tt) and hookworms (Hook) in a rural community from the sugar-cane zone of Pernambuco, Brazil. Four parasitological surveys were carried out from March 2001 to March 2002. Individual diagnosis was based on eight slides (four by the Kato-Katz method and four by the Hoffman method) per survey. Infected subjects were assigned to two groups for treatment with either albendazole (n = 62) or mebendazole (n = 57). Prevalence of infection fell significantly (p < 0.05) one month after treatment: Al (from 47.7% to 6.6%); Tt (from 45.7% to 31.8%) and Hook (from 47.7% to 24.5%). One year after treatment, infections by Tt and Hook remained significantly below pre-control levels. A substantial decrease in single-infection cases and multiple infections was found. Egg-negative rate was significant for Al (94.0%), Hook (68.3%) but not for Tt (45.5%), and did not differ significantly between subjects treated with mebendazole or albendazole. Egg counts fell significantly in the individuals remaining positive for Tt. It is recommended that antihelminthic treatment should be selective and given at yearly intervals preferably with albendazole, due to its cost-effectiveness.

Adolescents and School Asthma Knowledge and Attitudes

Introduction: bronchial asthma is a chronic disease that affects a high percentage of adolescents, with a significant restriction of daily activities, and is a cause of school absenteeism. The relationships between adolescents and asthma disease in school were assessed, with a view to improving knowledge about the asthmatic adolescent. Methods: a survey was conducted in the Lisbon metropolitan area, covering urban (Lisbon) and rural (Lourinh˜a ) zones and including 1879 students and 81 teachers from the 7th to 9th high school years. The study groups were asthmatic students, their peers, and teachers. A self-administered questionnaire was applied to collect information. The results were compared with a reference group of 91 asthmatic students attending our Department of Immunoallergy-Hospital Dona Estefânia. Cotinine urinary measurements were made in a sample of asthmatics and a control group. Results: the prevalence of current asthma among students was 10%. Estimates of asthma annual burden among 7th to 9th year students from Lisbon and Lourinh˜a high schools included 4,307 days missed from school, 4,148 medical consultations and a minimum of 351 hospital emergency care and 80 hospital admissions. Exposure to passive smoking was not significantly different between asthmatic students and theirs peers. Cotinine urinary measurements did not discriminate between exposed and non-exposed individuals. Cigarette smoking was almost as common among adolescent asthmatics (5.4%) as it was in non-asthmatic subjects (6.7%). However, 55% of asthmatics mentioned active and passive smoking as an asthma exacerbating factor. Asthmatic students, theirs peers and teachers showed a deficient knowledge about asthma (mean group scores: 17.6; 14.2 and 17.7 of a possible 30), particularly in the areas related to asthma recognition and its management. Asthmatics attending our Allergy Department had the highest scores. All groups showed tolerance in the sense of a positive and understanding attitude toward a person with asthma. However, traditional beliefs about asthma disease (dependence, inferiority...) were confirmed. A positive correlation between knowledge levels and tolerance attitudes was found. Conclusion: in view of the dimension of the asthma problem in adolescence and its social and economic impact, it is justifiable to assess the need for the implementation of asthma education programs in schools in order to improve asthma management by the adolescents and their schools.

Intestinal parasitoses and environmental factors in a rural population of Argentina, 2002-2003

We evaluate the prevalence of intestinal parasites in 504 people and the degree of association between environmental variables and parasites found in population, soil and water in a rural area of Argentina during 2002-2003. A structured survey was used to evaluate the environmental variables and fecal-human, soil and water samples were analyzed. The prevalence of parasites was 45.4%. Most prevalent protozoa were Blastocystis hominis (27.2%) and Giardia lamblia (6.9%), while the most prevalent helminth was Ascaris lumbricoides (3.8%). The analyzed environmental variables showing association (p < 0.05) with presence of parasites in population were: cardboard-tin or wooden house, dirt floor, home or communal water pump, faucet outside the house or public faucet and cesspool or latrine. Parasite forms were found in 82.3% of the soil samples and in 84.2% of the water samples. In both samples we found parasites that were also found in people. In this study we have found deficient sanitary conditions associated with presence of parasites in population and we have evidenced that contaminated soil and water were the source of these parasites.

Environmental contamination by Toxocara spp. Eggs in a rural settlement in Brazil

In order to study the environmental contamination by Toxocara spp. eggs in a rural community from the Pontal do Paranapanema region, São Paulo State, Brazil, soil samples from 31 out of 121 plots were collected in eight different places on each house. The samples were submitted to flotation technique in sodium nitrate (d = 1.20g/cm³). Eggs of Toxocara spp. were recovered in nine (29.03%) out of the 31 plots. At least one dog was registered in 27 of the 31 plots examined (87.1%) and at least one cat in 17 (54.84%). The number of pets per plot ranged from one to six (mean of 2.3) for dogs and one to 14 (mean of 1.29) for cats. In 16 plots (51.61%), the presence of both dogs and cats was observed. There was no relation between the presence of pets in the plots and soil contamination (p > 0.05). However, the environmental contamination by Toxocara spp. eggs associated to the poor conditions of the inhabitants may be an important risk factor for the human population to ocular or visceral larva migrans.