Epidemiological Characteristics of Schistosoma mansoni Infection in Rural and Urban Endemic Areas of Minas Gerais, Brazil

To compare the epidemiological profile and socioeconomic factors associated to the infection by Schistosoma mansoni in a rural and an urban endemic area a cross-sectional study was performed in Água Branca de Minas (rural area) and Bela Fama (urban area), both situated in the State of Minas Gerais, Brazil. Two hundred and eighty eight individuals were surveyed in the rural area and 787 in the urban area. Water contact and socioeconomic questionnaires were used to identify risk factors for the infection. The prevalences of 38.8% and 9.7% and the geometric mean of eggs per gram of faeces of 117.8 and 62.3 were found in the rural and urban areas, respectively. By multivariate statistical analysis age groups over nine years old and previous specific treatment were associated with the infection in rural area. In urban area age over nine years old, low quality housing, weekly fishing and swimming were associated after adjustment by logistic regression

Inter-specific and developmental differences on the array of antennal chemoreceptors in four species of triatominae (Hemiptera: Reduviidae)

The aim of the work was to investigate the pattern of chemoreceptor sensilla in adults and fifth stage nymphs of Rhodnius prolixus, R. neglectus, Triatoma infestans and T. sordida in order to study differences and similarities between genera and species. Three types of sensilla were analyzed by light microscopy: thin-walled trichoidea, thick-walled trichoidea and basiconica. The number of sensilla of each three types were counted. The length of the antennal segments were also used as a variable for the analysis. The statistical analysis showed that the number of these antennal chemoreceptors had significant differences between species and between adults and nymphs of each species. Discriminant analysis separates incompletely the fifth stage nymphs of the four species and showed similarity between them. Discriminant analysis performed with 12 variables of the antennae, allowed a complete separation of the adults of the four species.

Seroepidemiological markers of enterically transmitted viral hepatitis A and E in individuals living in a community located in the North Area of Rio de Janeiro, RJ, Brazil

We investigated the seroprevalence of hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in subjects living in the community of Manguinhos, Rio de Janeiro, Brazil, and assisted at the Health Unit of Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz. After formal consent, individuals were submitted to an interview using a standardized questionnaire. Anti-HAV and anti-HEV antibodies were detected by ELISA. Statistical analysis was carried out using the Epi-Info 6.04b software, to investigate possible associations between serological markers and risk factors. Results were regarded as significant when p value < 0.05. Although a high prevalence of anti-HAV was observed (87%), almost 50% of subjects under the age of 10 were susceptible to HAV infection, an unexpected rate in endemic areas. This fact could be attributed to improvements in environmental sanitation, occurring in this area in the last years. The increasing proportion of susceptible people may result in outbreaks of HAV infection, since the virus still circulates in this area, as verified by the detection of anti-HAV IgM in some individuals. No statistical association was met between HAV infection and the risk factors here assessed. The anti-HEV IgG prevalence found in this population was 2.4%, consistent with the one found in non-endemic areas.

In vitro chloroquine resistance modulation study on fresh isolates of Brazilian Plasmodium falciparum: intrinsic antimalarial activity of phenothiazine drugs

Phenothiazine drugs - fluphenazine, chlorpromazine, methotrimeprazine and trifluoperazine - were evaluated as modulating agents against Brazilian chloroquine-resistant fresh isolates of Plasmodium falciparum. Aiming to simulate therapeutic schedules, chloroquine was employed at the concentration used for sensitive falciparum malaria treatment and anti-psychotic therapeutic concentrations of the phenothiazine drugs were adopted in two-fold serial dilutions. The in vitro microtechnique for drug susceptibility was employed. Unlike earlier reported data, the phenothiazine modulating effect was not observed. However, all the drugs demonstrated intrinsic antiplasmodial activity in concentrations lower than those described in the literature. In addition, IC50 estimates have been shown to be inferior to the usual anti-psychotic therapeutic concentrations. Statistical analysis also suggested an increase in the parasitaemia rate or, even, a predominant antiparasitic effect of phenothiazine over chloroquine when used in combination.

Morphometric study of Schistosoma mansoni adult worms recovered from undernourished infected mice

Some unfavourable effects of malnutrition of the host on Schistosoma mansoni worm biology and structure have been reported based upon brigthfield microscopy. This paper aims to study by morphometric techniques, some morphological parameters in male and female adult worms recovered from undernourished albino mice in comparison with parasites recovered from well-fed infected mice. Undernourished animals were fed a multideficient and essentially low protein diet (RBD diet) and compared to well-fed control mice fed with the commercial diet NUVILAB. Seventy-five days post-infection with 80 cercarie (BL strain) animals were sacrificed. All adult worms were fixed in 10% formalin and stained with carmine chloride. One hundred male and 60 female specimens from each group (undernourished and control) were examined using an image system analysis Leica Quantimet 500C and the Sigma Scan Measurement System. The following morphometrical parameters were studied: body length and width, oral and ventral suckers, number and area of testicular lobes, length and width of ovary and uterine egg. For statistical analysis, the Student's t test for unpaired samples was applied. Significant differences (p < 0.05) were detected in body length and width, in parameters of suckers, uterine egg width, ovary length and area of testicular lobes, with lower values for specimens from undernourished mice. The nutritional status of the host has negative influence on S. mansoni adult worms, probably through unavailability of essential nutrients to the parasites.

Phlebotomine sand flies in Porteirinha, an area of American visceral leishmaniasis transmission in the State of Minas Gerais, Brazil

A study of the phlebotomine sand fly fauna was carried out in an endemic area of American visceral leishmaniasis (AVL) in the municipality of Porteirinha, in the Brazilian state of Minas Gerais. Captures were performed with CDC light traps in 7 districts, 5 days per month, during 2 consecutive years (January 2000 to December 2001). A total of 3240 sand flies were captured and identified. Sixteen species were found, among which 15 belonged to the genus Lutzomyia and one to the genus Brumptomyia. Lutzomyia longipalpis, a proven vector of AVL, was the predominant species (71.85%) throughout the time period. The interference of climatic factors (temperature, humidity, and rainfall) over the populational dynamics of the sand flies was determined. Statistical analysis of the data showed a significant correlation among the number of phlebotomine sand flies collected, rainfall, and humidity, whereas the effect of temperature was negligible, in that particular region. The amount of collected phlebotomine, the number of human cases, and the prevalence of canine AVL in the districts of Porteirinha are discussed.

Association of human leukocyte antigen DQ1 and dengue fever in a white Southern Brazilian population

Dengue is an infectious disease of viral etiology transmitted by the mosquitoes Aedes aegypti, A. albopictus, and A. scutellaris. It can develop either as a benign form or as a severe hemorrhagic form. Previous work showed an association of the hemorrhagic form with human leukocyte antigens (HLA), suggesting a role of genetic factors in disease susceptibility. Nevertheless, data on HLA association with the classical form of the disease is scarce in literature. Sixty-four patients and 667 normal individuals, living in the state of Paraná, Southern Brazil, were used as test and control group, respectively. The patients developed the disease during a virus 1 dengue outbreak either in Maringá city in 1995 (47) or in Paranavaí city in 1999 (17). The diagnostic was confirmed through serology and/or viral culture. HLA class I and II typing was performed by the classical microlynfocitotoxicity test using monoclonal antisera and fluorobeads. Qui-square statistical analysis confirmed a positive association with HLA-DQ1 (76.6% vs 57.7%; p = 0.005243; pc = 0.026215). HLA-DR1 also presented an increased frequency in the test group, not statistically significant after p correction though (32.8% vs 15.9%; p = 0.005729; pc = 0.080206). In conclusion, genetic factors may play a role on the susceptibility to the classical dengue, virus 1, in the Brazilian population. Further independent studies should be performed in the Brazilian population to confirm these preliminary data.

Evaluation of respiratory model employing conventional NIH mice to access the immunity induced by cellular and acellular pertussis vaccines

The increasing number of pertussis cases reported on the last twenty years and the existence of new acellular vaccines reinforce the need of research for experimental models to assure the quality of available pertussis vaccines. In this study, allotments of whole-cell and acellular pertussis vaccines were tested through the Intranasal Challenge Model (INM) using conventional NIH mice. The results have been compared to those achieved by the "Gold standard" Intracerebral Challenge Model (ICM). In contrast to ICM, INM results did not show intralaboratorial variations. Statistical analysis by Anova and Ancova tests revealed that the INM presented reproducibility and allowed identification and separation of different products, including three-component and four-component accellular pertussis vaccines. INM revealed differences between pertussis vaccines. INM provides lower distress to the mice allowing the reduction of mice number including the possibility of using conventional mice (less expensive) under non-aseptic environment. Thus, INM may be used as an alternative method of verifying the consistence of allotment production, including acellular pertussis vaccines.

Association of Lutzomyia longipalpis (Diptera: Psychodidae) population density with climate variables in Montes Claros, an area of American visceral leishmaniasis transmission in the state of Minas Gerais, Brazil

In the present paper, we evaluate the relationship between climate variables and population density of Lutzomyia longipalpis in Montes Claros, an area of active transmission of American visceral leishmaniasis (AVL) in Brazil. Entomological captures were performed in 10 selected districts of the city, between September 2002-August 2003. A total of 773 specimens of L. longipalpiswere captured in the period and the population density could be associated with local climate variables (cumulative rainfall, average temperature and relative humidity) through a mathematical linear model with a determination coefficient (Rsqr) of 0.752. Although based on an oversimplified statistical analysis, as far as the vector is concerned, this approach showed to be potentially useful as a starting point to guide control measures for AVL in Montes Claros.

Correlation of biological serum markers with the degree of hepatic fibrosis and necroinflammatory activity in hepatitis C and schistosomiasis patients

Liver biopsy is the gold-standard method to stage fibrosis; however, it is an invasive procedure and is potentially dangerous. The main objective of this study was to evaluate biological markers, such as cytokines IL-13, IFN-γ, TNF-α and TGF-β, platelets, bilirubins (Bil), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), total proteins, γ-glutamil transferase (γ-GT) and alkaline phosphatase (AP), that could be used to predict the severity of hepatic fibrosis in schistosomiasis and hepatitis C (HC) as isolated diseases or co-infections. The following patient groups were selected: HC (n = 39), HC/hepatosplenic schistosomiasis (HSS) (n = 19), HSS (n = 22) and a control group (n = 13). ANOVA and ROC curves were used for statistical analysis. P < 0.05 was considered significant. With HC patients we showed that TNF-α (p = 0.020) and AP (p = 0.005) could differentiate mild and severe fibrosis. With regard to necroinflammatory activity, AST (p = 0.002), γ-GT (p = 0.034) and AP (p = 0.001) were the best markers to differentiate mild and severe activity. In HC + HSS patients, total Bil (p = 0.008) was capable of differentiating between mild and severe fibrosis. In conclusion, our study was able to suggest biological markers that are non-invasive candidates to evaluate fibrosis and necroinflammatory activity in HC and HC + HSS.

HLA-A*01 allele: a risk factor for dengue haemorrhagic fever in Brazil's population

Severe forms of dengue, such as dengue haemorrhagic fever (DHF) and dengue shock syndrome, are examples of a complex pathogenic mechanism in which the virus, environment and host immune response interact. The influence of the host's genetic predisposition to susceptibility or resistance to infectious diseases has been evidenced in several studies. The association of the human leukocyte antigen gene (HLA) class I alleles with DHF susceptibility or resistance has been reported in ethnically and geographically distinct populations. Due to these ethnic and viral strain differences, associations occur in each population, independently with a specific allele, which most likely explains the associations of several alleles with DHF. As the potential role of HLA alleles in the progression of DHF in Brazilian patients remains unknown, we then identified HLA-A alleles in 67 patients with dengue fever and 42 with DHF from Rio de Janeiro, Brazil, selected from 2002-2008 by the sequence-based typing technique. Statistical analysis revealed an association between the HLA-A*01 allele and DHF [odds ratio (OR) = 2.7, p = 0.01], while analysis of the HLA-A*31 allele (OR = 0.5, p = 0.11) suggested a potential protective role in DHF that should be further investigated. This study provides evidence that HLA class I alleles might be important risk factors for DHF in Brazilian patients.

Use of health services by residents at a seniors-only living facility

The objective of the study was to compare the use of medical and dental services by seniors residing at a seniors-only living facility and in the general community. It was a quantitative study, among 50 residents of the living facility and 173 in the general community. The data were collected between November 2011 and February 2012 through a questionnaire, and subjected to statistical analysis. Performance of clinical exams and satisfaction with health services was greater among seniors living in the general community; however, physical therapy treatment was more common among those living in the facility. The use of medical and dental services showed a statistically significant difference. The seniors in both groups need oral health monitoring and those living in the facility also require coverage by the Family Health Strategy. The presence of professionals with the right profile to adequately serve residents and the network of available services are determining factors for the success of this new housing policy.

Effectiveness of heparin versus 0.9% saline solution in maintaining the permeability of central venous catheters: a systematic review

Abstract OBJECTIVE Determining which is the most effective solution (heparin flush compared to 0.9% saline flush) for reducing the risk of occlusions in central venous catheters (CVC) in adults. METHOD The systematic review followed the principles proposed by the Cochrane Handbook; critical analysis, extraction and synthesis of data were performed by two independent researchers; statistical analysis was performed using the RevMan program 5.2.8. RESULTS Eight randomized controlled trials and one cohort study were included and the results of the meta-analysis showed no difference (RR=0.68, 95% CI=0.41-1.10; p=0.12). Analysis by subgroups showed that there was no difference in fully deployed CVC (RR=1.09, CI 95%=0.53-2.22;p=0.82); Multi-Lumen CVC showed beneficial effects in the heparin group (RR=0.53, CI 95%=0.29-0.95; p=0.03); in Double-Lumen CVC for hemodialysis (RR=1.18, CI 95%=0.08-17.82;p=0.90) and Peripherally inserted CVC (RR=0.14, CI 95%=0.01-2.60; p=0.19) also showed no difference. CONCLUSION Saline solution is sufficient for maintaining patency of the central venous catheter, preventing the risks associated with heparin administration.

Elytra colour polymorphism and randomness of matings in Chauliognathus fallax Germar 1824 from southern Brazil (Coleoptera, Cantharidae)

Beetles of the species Chauliognathus fallax Germar 1824 are polymorphic for elytron colouration with six morphs distinguished on the basis of black pigmentation on a yellow background. We investigated samples of C. fallax taken in eight consecutive weeks aiming to determine the frequency of the morphs which were grouped, for statistical analysis, into three classes according to elytra pigmentation as well as the possible occurrence of assortative mating. Our results showed a variation in the frequency of the classes throughout the season, both in males and females, with the maximum frequency of each class at the fourth and fifth week. The three classes (A, B, C) showed the same pattern of variation, and class B was always the more frequent. To test randomness of matings two approaches were taken: in the first, we compared the frequency of each class in copulating and non-copulating insects. In the second, the frequency of each class in the whole sample was taken as the probability of occurrence of the respective class; then, using the criterion of the probability of independent events we calculated the expected proportion of copulating insects for each pair of events. Both methods gave non-significant differences, suggesting that the matings were random.

Exposure of a single host (Chrysomya megacephala) (Calliphoridae) to different quantities of female parasitoids (Nasonia vitripennis) (Pteromalidae)

The aim of this study was to verify the duration of the development period, number of parasitoids produced per pupa, parasitism rate and sex ratio of Nasonia vitripennis (Hymenoptera, Pteromalidae), when they were exposed to a single host: Chrysomya megacephala (Diptera, Calliphoridae). One pupa was exposed in glass tubes to different numbers of female parasitoids (1, 3, 5, 7, 9 and 11) during 48 h. Twenty replications/treatment were used, under controlled conditions (T= 27 °C day/ 25 °C night, 60 ± 10% RH). Statistical analysis of the data was made using the ANOVA test and the "a posteriori" comparisons were made using the Tukey-HSD test (both tests with a significance level of 5%). The duration of the development period was longer in treatments where a higher density of females per host was used. When five females per host were used, the mean number of parasitoids that emerged per pupa was higher. The data showed a tendency to a decrease in the amount of parasitoids emerged per host, especially of female, when used high quantities of female per host. Higher parasitism rates were observed in the 3:1 and 5:1 treatments and an increase in the percentage of unviable pupae was observed, probably due to an increase of female densities in the treatments, possibly a consequence of superparasitism.