Morphobiological aspects of Rhodnius brethesi Matta, 1919 (Hemiptera:Reduviidae) from the Upper and Middle Negro River, Amazon region of Brazil: I - scanning electron microscopy

The occurrence of autochthonous cases of Chagas disease in the Amazon region of Brazil over recent decades has motivated an intensification of studies in this area. Different species of triatomines have been identified, and ten of these have be proven to be carriers of the parasite Trypanosoma cruzi or " cruzi-like " parasites. Studies conducted in the municipalities of Santa Isabel do Rio Negro and Barcelos, located on the Upper and Middle of the Negro River, microregion of Negro River, state of Amazonas have confirmed not only that Rhodnius brethesi is present in the palm tree Leopoldinia piassaba, but also that this insect was recognized by palm fiber collectors. A morphological study of eyes, inter-ocular and inter-ocellar regions, antennae, buccula, labrum, rostrum, stridulatory sulcus and feet, including the apex of the tibia, spongy fossette and ctenidium was conducted by scanning electron microscopy. The buccula and the stridulatory sulcus presented notable differences in specimens of different genera and also of different species. These data make it possible to suggest that the details presented in these structures can be included as diagnostic characteristics to be used in new dichotomous keys, thereby contributing towards studies of taxonomy and systematics and furnishing backing for comparative analysis of specimens collected from different localities.

Urban malaria in the Brazilian Western Amazon Region I: high prevalence of asymptomatic carriers in an urban riverside district is associated with a high level of clinical malaria

Cross sectional studies on malaria prevalence was performed in 2001, 2002, and 2004 in Vila Candelária, an urban riverside area of Porto Velho, Rondônia, in the Brazilian Western Amazon, followed by longitudinal surveys on malaria incidence. Vila Candelária is a working class district, provided with electricity, water supply, and basic sanitation. Previous preliminary surveys indicated high malaria incidence in this community. At the end of year 2000 regular diagnostic and treatment measures for malaria were introduced, with active search of febrile cases among residents. Despite of both rapid treatment of cases and relative good sanitary and housing conditions, the malaria incidence persisted at high levels during the following years with an annual parasite index of 150 to 300/1000 inhabitants. Parasite surveys in 2001, 2002, and 2004 achieved through microscopy and polymerase chain reaction to diagnose malaria showed a constant high prevalence of asymptomatic carriers for both Plasmodium falciparum and P. vivax parasites. It was concluded that asymptomatic carriers represent an important reservoirs of parasites and that the carriers might contribute to maintaining the high level of transmission. Comparing our findings to similar geo-demographic situations found in other important urban communities of the Brazilian Amazon, we propose that asymptomatic carriers could explain malaria's outbreaks like the one recently observed in Manaus.

Vector bionomics and malaria transmission in the Upper Orinoco River, Southern Venezuela

A longitudinal epidemiological and entomological study was carried out in Ocamo, Upper Orinoco River, between January 1994 and February 1995 to understand the dynamics of malaria transmission in this area. Malaria transmission occurs throughout the year with a peak in June at the beginning of the rainy season. The Annual Parasite Index was 1,279 per 1,000 populations at risk. Plasmodium falciparum infections accounted for 64% of all infections, P. vivax for 28%, and P. malariae for 4%. Mixed P. falciparum/P. vivax infections were diagnosed in 15 people representing 4% of total cases. Children under 10 years accounted for 58% of the cases; the risk for malaria in this age group was 77% higher than for those in the greater than 50 years age group. Anopheles darlingi was the predominant anopheline species landing on humans indoors with a biting peak between midnight and dawn. A significant positive correlation was found between malaria monthly incidence and mean number of An. darlingi caught. There was not a significant relationship between mean number of An. darlingi and rainfall or between incidence and rainfall. A total of 7295 anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite (CS) protein. Only An. darlingi (55) was positive for CS proteins of P. falciparum (0.42%), P. malariae (0.25%), and P. vivax-247 (0.1%). The overall estimated entomological inoculation rate was 129 positive bites/person/year. The present study was the first longitudinal entomological and epidemiological study conducted in this area and set up the basic ground for subsequent intervention with insecticide-treated nets.

Prevalence and level of antibodies to the circumsporozoite protein of human malaria parasites in five states of the Amazon region of Brazil

The aim of this study was to determine the prevalence of malaria infection and antibodies against the repetitive epitopes of the circumsporozoite (CS) proteins of Plasmodium falciparum, P. malariae, P. vivax VK210, P. vivax VK247, and P. vivax-like in individuals living in the states of Rondônia, Pará, Mato Grosso, Amazonas, and Acre. Active malaria transmission was occurring in all studied sites, except in Acre. P. falciparum was the predominant species in Pará and Rondônia and P. vivax in Mato Grosso. Infection by P. malariae was low but this Plasmodium species was detected in Rondônia (3.5%), Mato Grosso (2.5%), and Pará (0.8%). High prevalence and levels of serological reactivity against the CS repeat peptides of P. falciparum were detected in Rondônia (93%) and Pará (85%). Sera containing antibodies against the CS repeat of P. malariae occurred more frequently in Rondônia (79%), Pará (76%), and Amazonas (68%). Antibodies against the repeat epitope of the standard CS protein of P. vivax VK210, P. vivax VK247, and P. vivax-like were more frequent in Rondônia, Pará, and Mato Grosso. The high frequency of reactions to P. malariae in most of the areas suggests that the infection by this Plasmodium species has been underestimated in Brazil.

Anopheles darlingi bionomics and transmission of Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae in Amerindian villages of the Upper-Maroni Amazonian forest, French Guiana

French Guiana is one of the areas in South America most affected by malaria and where the disease has become a serious public health problem. In spite of this situation, little recent entomological data are available from the main localities where the disease occurs, even though they are crucial for development of an effective vector control strategy. A longitudinal entomological survey was carried out from March 2000-February 2002 in three Amerindian villages, namely Twenké, Taluène and Cayodé, located in the Amazonian forest of the Upper-Maroni area, to assess anopheline mosquitoes and malaria transmission dynamics. Anopheles darlingi (Diptera: Culicidae) was the most abundant mosquito species caught during the study. This efficient American malaria vector was active the entire year, but showed an evident peak of abundance during the main rainfall season, from April-June, with an average human biting rate of 255.5 bites per person per night. Parity rates were homogeneous all year, indicating no significant seasonal variability in female survival rates. Estimated vectorial capacity indices were higher during the rainy season, even though the risk of transmission was present throughout the year (VCI > 1). A total of 14 An. darlingi were found infected with Plasmodium falciparum, Plasmodium vivax or Plasmodium malariae. The annual circumsporozoite indices were 0.15, 0.14 and 0.05, and the entomological inoculation rates were 22.8, 27.4 and 14.4 infected bites per person per year in Twenké, Taluène and Cayodé, respectively. An. darlingiwas endo-exophagic and rather exophilic in these localities. The species was collected throughout the night but was more aggressive between 21:30-03:30 h and after 05:30 h. Parity rates were homogeneous during the entire night. Impregnated hammock and/or bed nets, coupled with the use of mosquito repellents, as well as the early treatment of malarial cases, appear to be the most suitable tools for fighting malaria in these Amerindian villages since the spraying of residual insecticides is inefficient because of vector biology and the housing structure.

The level of ascorbate peroxidase is enhanced in benznidazole-resistant populations of Trypanosoma cruzi and its expression is modulated by stress generated by hydrogen peroxide

Ascorbate peroxidases (APX) are class I heme-containing enzymes that convert hydrogen peroxide into water molecules. The gene encoding APX has been characterized in 11 strains of Trypanosoma cruzi that are sensitive or resistant to benznidazole (BZ). Bioinformatic analysis revealed the presence of two complete copies of the T. cruzi APX (TcAPX) gene in the genome of the parasite, while karyotype analysis showed that the gene was present in the 2.000-kb chromosome of all of the strains analyzed. The sequence of TcAPX exhibited greater levels of similarity to those of orthologous enzymes from Leishmania spp than to APXs from the higher plant Arabidopsis thaliana. Northern blot and real-time reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed no significant differences in TcAPX mRNA levels between the T. cruzi strains analyzed. On the other hand, Western blots showed that the expression levels of TcAPX protein were, respectively, two and three-fold higher in T. cruzi populations with in vitro induced (17 LER) and in vivo selected (BZR) resistance to BZ, in comparison with their corresponding susceptible counterparts. Moreover, the two BZ-resistant populations exhibited higher tolerances to exogenous hydrogen peroxide than their susceptible counterparts and showed TcAPX levels that increased in a dose-dependent manner following exposure to 100 and 200 µM hydrogen peroxide.

Helicobacter pylori vacA and cagA genotypes in patients from northeastern Brazil with upper gastrointestinal diseases

Helicobacter pylori causes chronic gastric inflammation and significantly increases the risk of duodenal and gastric ulcer disease and distal gastric carcinoma. In this study, we evaluated the Helicobacter pylori vacA and cagA genotypes in patients from a Brazilian region where there is a high prevalence of gastric cancer. Polymerase chain reaction (PCR) was used to investigate vacA mosaicism and cagA status in the gastric mucosa of 134 H. pylori-positive patients, including 76 with gastritis: 28 with peptic ulcer disease and 30 with gastric cancer. The s1m1 variant was the predominant vacA genotype observed, whereas the s1 allele was more frequently observed in patients with more severe diseases associated with H. pylori infection [p = 0.03, odds ratio (OR) = 5.72, 95% confidence interval (CI) = 1.15-38.60]. Furthermore, all of the s1 alleles were s1b. Mixed vacA m1/m2 strains were found more frequently in patients with gastric cancer and a cagA-positive status was significantly associated with gastric cancer (p = 0.016, OR = 10.36, 95% CI = 1.35-217.31). Patients with gastric cancer (21/21, 100%, p = 0.006) or peptic ulcers (20/21, 95%, p = 0.02) were more frequently colonised by more virulent H. pylori strains compared to gastritis patients (41/61, 67.2%). In conclusion, in the northeastern of Brazil, which is one of the regions with the highest prevalence of gastric cancer in the country, infection with the most virulent H. pylori strains, carrying the cagA gene and s1m1 vacA alleles, predominates and is correlated with more severe H. pylori-associated diseases.

Characterisation of Culex quinquefasciatus (Diptera: Culicidae) larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

Viral aetiology of common colds of outpatient children at primary care level and the use of antibiotics

Although antibiotics are ineffective against viral respiratory infections, studies have shown high rates of prescriptions worldwide. We conducted a study in Brazil to determine the viral aetiologies of common colds in children and to describe the use of antibiotics for these patients. Children up to 12 years with common colds were enrolled from March 2008-February 2009 at a primary care level facility and followed by regular telephone calls and medical consultations. A nasopharyngeal wash was obtained at enrollment and studied by direct fluorescence assay and polymerase chain reaction for nine different types of virus. A sample of 134 patients was obtained, median age 2.9 years (0.1-11.2 y). Respiratory viruses were detected in 73.9% (99/134) with a coinfection rate of 30.3% (30/99). Rhinovirus was the most frequent virus (53/134; 39.6%), followed by influenza (33/134; 24.6%) and respiratory syncytial virus (8/134; 13.4%). Antibiotic prescription rate was 39.6% (53/134) and 69.8% (37/53) were considered inappropriate. Patients with influenza infection received antibiotics inappropriately in a greater proportion of cases when compared to respiratory syncytial virus and rhinovirus infections (p = 0.016). The rate of inappropriate use of antibiotics was very high and patients with influenza virus infection were prescribed antibiotics inappropriately in a greater proportion of cases.

Analysis of the process of translation of knowledge regarding early childhood at the undergraduate level

Objective To analyze innovative contents on Early Child Development Promotion. Method This action-research involves nine faculties from four Higher Education Institutions at inner-state of São Paulo, Brazil.Data were collected by syllabi analyses (2009-2011), interviews and focus group. We have adopted an ECDP underpinning from international consensus, thus evaluating KT Results We have found relevant incorporation between teaching and extension in Nursing (87,5%) and Psychology (75%) undergraduate courses, while Pedagogy was restricted to teaching. Conclusion This KT evaluation has evinced innovative potential of extension, regardless teaching and research, for a better Early Childhood.


Correlation between the infestation level of Sitophilus zeamais Motschulsky, 1855 (Coleoptera, Curculionidae) and the quality factors of stored corn, Zea mays L. (Poaceae)

This experiment was carried out in order to evaluate the effect of Sitophilus zeamais on physical, physiological and sanitary quality of stored corn. Samples of 500 g of the hybrid OC-705, in three replicates, were conditioned in glasses covered with a screened lid, and kept in chamber at 25±2ºC, 70±5% RH and 12 h of photophase, for 150 days. The infestation levels were 0, 5, 15 and 50 adults/replicate, for the storage periods of 30, 60, 90, 120 and 150 days. The moisture content, classification, weight loss, germination and internal infestation were evaluated monthly. Significant inverse correlations were verified between the number of insects and both the germination and the weight loss; also between the internal infestation and the germination and the standard type. The presence of S. zeamais showed a positive correlation with the weight loss, what means that the internal and external infestations contribute to the reduction of physiological and physical quality of corn seeds. The mean dry matter loss was 0,36%/day, corresponding to a consumption of 0,0001%/insect/month. As the result of those damages, the product suffered reduction of the commercial grade in 30 days, with significant loss in all quality factors.