HTLV-I/II and blood donors: determinants associated with seropositivity in a low risk population

OBJECTIVE: Blood donors in Brazil have been routinely screened for HTLV-I/II since 1993. A study was performed to estimate the prevalence of HTLV-I/II infection in a low risk population and to better understand determinants associated with seropositivity. METHODS: HTLV-I/II seropositive (n=135), indeterminate (n=167) and seronegative blood donors (n=116) were enrolled in an open prevalence prospective cohort study. A cross-sectional epidemiological study of positive, indeterminate and seronegative HTLV-I/II subjects was conducted to assess behavioral and environmental risk factors for seropositivity. HTLV-I/II serological status was confirmed using enzyme-linked immunosorbent assay (EIA) and Western blot (WB). RESULTS: The three groups were not homogeneous. HTLV-I/II seropositivity was associated to past blood transfusion and years of schooling, a marker of socioeconomic status, and use of non-intravenous illegal drugs. CONCLUSIONS: The study results reinforce the importance of continuous monitoring and improvement of blood donor selection process.

Association between Schistosomiasis mansoni and hepatitis C: systematic review

OBJECTIVE: To perform a systematic review of the prevalence of the HCV/ S. mansoni co-infection and associated factors in Schistosoma mansoni -infected populations. METHODS: The bibliographic search was carried out using the Medline, Lilacs, SciELO, Cochrane Library and Ibecs databases. The criteria for the studies' selection and the extraction data were based on systematic review methods. Forty five studies were found, with nine being excluded in a first screening. Thirteen articles were used for data extraction. RESULTS: The HCV infection rates in schistosomiasis populations range from 1% in Ethiopia to 50% in Egypt. Several studies had poorly defined methodologies, even in areas characterized by an association between hepatitis C and schistosomiasis, such as Brazil and Egypt, which meant conclusions were inconsistent. HCV infection rates in schistosomotic populations were heterogeneous and risk factors for acquiring the virus varied widely. CONCLUSIONS: Despite the limitations, this review may help to identify regions with higher rates of hepatitis C and schistosomiasis association. However, more studies are necessary for the development of public health policies on prevention and control of both diseases.

HIV risk practices by female sex workers according to workplace

OBJECTIVE To investigate differences in HIV infection- related risk practices by Female Sex Workers according to workplace and the effects of homophily on estimating HIV prevalence. METHODS Data from 2,523 women, recruited using Respondent-Driven Sampling, were used for the study carried out in 10 Brazilian cities in 2008-2009. The study included female sex workers aged 18 and over. The questionnaire was completed by the subjects and included questions on characteristics of professional activity, sexual practices, use of drugs, HIV testing, and access to health services. HIV quick tests were conducted. The participants were classified in two groups according to place of work: on the street or indoor venues, like nightclubs and saunas. To compare variable distributions by place of work, we used Chi-square homogeneity tests, taking into consideration unequal selection probabilities as well as the structure of dependence between observations. We tested the effect of homophily by workplace on estimated HIV prevalence. RESULTS The highest HIV risk practices were associated with: working on the streets, lower socioeconomic status, low regular smear test coverage, higher levels of crack use and higher levels of syphilis serological scars as well as higher prevalence of HIV infection. The effect of homophily was higher among sex workers in indoor venues. However, it did not affect the estimated prevalence of HIV, even after using a post-stratification by workplace procedure. CONCLUSIONS The findings suggest that strategies should focus on extending access to, and utilization of, health services. Prevention policies should be specifically aimed at street workers. Regarding the application of Respondent-Driven Sampling, the sample should be sufficient to estimate transition probabilities, as the network develops more quickly among sex workers in indoor venues.

Evaluation of maternal and neonatal hospital care: quality index of completeness

OBJECTIVE Develop an index to evaluate the maternal and neonatal hospital care of the Brazilian Unified Health System.METHODS This descriptive cross-sectional study of national scope was based on the structure-process-outcome framework proposed by Donabedian and on comprehensive health care. Data from the Hospital Information System and the National Registry of Health Establishments were used. The maternal and neonatal network of Brazilian Unified Health System consisted of 3,400 hospitals that performed at least 12 deliveries in 2009 or whose number of deliveries represented 10.0% or more of the total admissions in 2009. Relevance and reliability were defined as criteria for the selection of variables. Simple and composite indicators and the index of completeness were constructed and evaluated, and the distribution of maternal and neonatal hospital care was assessed in different regions of the country.RESULTS A total of 40 variables were selected, from which 27 single indicators, five composite indicators, and the index of completeness of care were built. Composite indicators were constructed by grouping simple indicators and included the following variables: hospital size, level of complexity, delivery care practice, recommended hospital practice, and epidemiological practice. The index of completeness of care grouped the five variables and classified them in ascending order, thereby yielding five levels of completeness of maternal and neonatal hospital care: very low, low, intermediate, high, and very high. The hospital network was predominantly of small size and low complexity, with inadequate child delivery care and poor development of recommended and epidemiological practices. The index showed that more than 80.0% hospitals had a low index of completeness of care and that most qualified heath care services were concentrated in the more developed regions of the country.CONCLUSIONS The index of completeness proved to be of great value for monitoring the maternal and neonatal hospital care of Brazilian Unified Health System and indicated that the quality of health care was unsatisfactory. However, its application does not replace specific evaluations.

Resistance of Aedes aegypti to temephos and adaptive disadvantages

OBJECTIVE To evaluate the resistance of Aedes aegypti to temephos Fersol 1G (temephos 1% w/w) associated with the adaptive disadvantage of insect populations in the absence of selection pressure. METHODS A diagnostic dose of 0.28 mg a.i./L and doses between 0.28 mg a.i./L and 1.40 mg a.i./L were used. Vector populations collected between 2007 and 2008 in the city of Campina Grande, state of Paraíba, were evaluated. To evaluate competition in the absence of selection pressure, insect populations with initial frequencies of 20.0%, 40.0%, 60.0%, and 80.0% resistant individuals were produced and subjected to the diagnostic dose for two months. Evaluation of the development of aquatic and adult stages allowed comparison of the life cycles in susceptible and resistant populations and construction of fertility life tables. RESULTS No mortality was observed in Ae. aegypti populations subjected to the diagnostic dose of 0.28 mg a.i./L. The decreased mortality observed in populations containing 20.0%, 40.0%, 60.0%, and 80.0% resistant insects indicates that temephos resistance is unstable in the absence of selection pressure. A comparison of the life cycles indicated differences in the duration and viability of the larval phase, but no differences were observed in embryo development, sex ratio, adult longevity, and number of eggs per female. CONCLUSIONS The fertility life table results indicated that some populations had reproductive disadvantages compared with the susceptible population in the absence of selection pressure, indicating the presence of a fitness cost in populations resistant to temephos.

Handling random errors and biases in methods used for short-term dietary assessment

Epidemiological studies have shown the effect of diet on the incidence of chronic diseases; however, proper planning, designing, and statistical modeling are necessary to obtain precise and accurate food consumption data. Evaluation methods used for short-term assessment of food consumption of a population, such as tracking of food intake over 24h or food diaries, can be affected by random errors or biases inherent to the method. Statistical modeling is used to handle random errors, whereas proper designing and sampling are essential for controlling biases. The present study aimed to analyze potential biases and random errors and determine how they affect the results. We also aimed to identify ways to prevent them and/or to use statistical approaches in epidemiological studies involving dietary assessments.

Gender in the allocation of organs in kidney transplants: meta-analysis

OBJECTIVE To analyze whether gender influence survival results of kidney transplant grafts and patients.METHODS Systematic review with meta-analysis of cohort studies available on Medline (PubMed), LILACS, CENTRAL, and Embase databases, including manual searching and in the grey literature. The selection of studies and the collection of data were conducted twice by independent reviewers, and disagreements were settled by a third reviewer. Graft and patient survival rates were evaluated as effectiveness measurements. Meta-analysis was conducted with the Review Manager® 5.2 software, through the application of a random effects model. Recipient, donor, and donor-recipient gender comparisons were evaluated.RESULTS : Twenty-nine studies involving 765,753 patients were included. Regarding graft survival, those from male donors were observed to have longer survival rates as compared to the ones from female donors, only regarding a 10-year follow-up period. Comparison between recipient genders was not found to have significant differences on any evaluated follow-up periods. In the evaluation between donor-recipient genders, male donor-male recipient transplants were favored in a statistically significant way. No statistically significant differences were observed in regards to patient survival for gender comparisons in all follow-up periods evaluated.CONCLUSIONS The quantitative analysis of the studies suggests that donor or recipient genders, when evaluated isolatedly, do not influence patient or graft survival rates. However, the combination between donor-recipient genders may be a determining factor for graft survival.

Factors associated with exclusive breastfeeding in the first six months of life in Brazil: a systematic review

ABSTRACT OBJECTIVE To identify factors associated with exclusive breastfeeding in the first six months of life in Brazil. METHODS Systematic review of epidemiological studies conducted in Brazil with exclusive breastfeeding as outcome. Medline and LILACS databases were used. After the selection of articles, a hierarchical theoretical model was proposed according to the proximity of the variable to the outcome. RESULTS Of the 67 articles identified, we selected 20 cross-sectional studies and seven cohort studies, conducted between 1998 and 2010, comprising 77,866 children. We identified 36 factors associated with exclusive breastfeeding, being more often associated the distal factors: place of residence, maternal age and education, and the proximal factors: maternal labor, age of the child, use of a pacifier, and financing of primary health care. CONCLUSIONS The theoretical model developed may contribute to future research, and factors associated with exclusive breastfeeding may subsidize public policies on health and nutrition.

Methods and challenges for the health impact assessment of vaccination programs in Latin America

ABSTRACT OBJECTIVE To describe methods and challenges faced in the health impact assessment of vaccination programs, focusing on the pneumococcal conjugate and rotavirus vaccines in Latin America and the Caribbean. METHODS For this narrative review, we searched for the terms "rotavirus", "pneumococcal", "conjugate vaccine", "vaccination", "program", and "impact" in the databases Medline and LILACS. The search was extended to the grey literature in Google Scholar. No limits were defined for publication year. Original articles on the health impact assessment of pneumococcal and rotavirus vaccination programs in Latin America and the Caribbean in English, Spanish or Portuguese were included. RESULTS We identified 207 articles. After removing duplicates and assessing eligibility, we reviewed 33 studies, 25 focusing on rotavirus and eight on pneumococcal vaccination programs. The most frequent studies were ecological, with time series analysis or comparing pre- and post-vaccination periods. The main data sources were: health information systems; population-, sentinel- or laboratory-based surveillance systems; statistics reports; and medical records from one or few health care services. Few studies used primary data. Hospitalization and death were the main outcomes assessed. CONCLUSIONS Over the last years, a significant number of health impact assessments of pneumococcal and rotavirus vaccination programs have been conducted in Latin America and the Caribbean. These studies were carried out few years after the programs were implemented, meet the basic methodological requirements and suggest positive health impact. Future assessments should consider methodological issues and challenges arisen in these first studies conducted in the region.

Epidemiological survey of Trypanosoma cruzi infection in North-Eastern Brazil using different diagnostic methods

A survey of the prevalence of Trypanosoma cruzi infection was carried out in Oitis, a small community in the State of Piaui, Brazil. Two hundred and sixty five individuals were screened by microscopic examination, hémoculture, indirect immunofluorescence (IFA), enzyme-linked immunosorbent assay (ELISA), and competitive enzyme-linked immunosorbent assay (C-ELISA) using the monoclonal antibody TCF87 against to a 25kd T. cruzi antigen. Seropositivity was 14.3% by the IFA test, 14.7% by ELISA, and 13.2% by C-ELISA. The C-ELISA using the TCF87 monoclonal antibody seems to be applicable in serodiagnosis of Chagas' disease.

Evaluation of different methods for Plasmodia detection, in well defined population groups in an endemic area of Brazil

In Brazil, more than 500,000 new cases of malaria were notified in 1992. Plasmodium falciparum and P.vivax are the responsible species for 99.3% of the cases. For adequate treatment, precoce diagnosis is necessary. In this work, we present the results of the traditional Plasmodia detection method, thick blood film (TBF), and the results of alternative methods: Immunofluorescence assay (IFA) with polyclonal antibody and Quantitative Buffy Coat method (QBC)® in a well defined population groups. The analysis were done in relation to the presence or absence of malaria clinical symptoms. Also different classes of immunoglobulins anti-P.falciparum were quantified for the global analysis of the results, mainly in the discrepant results. We concluded that alternative methods are more sensitive than TBF and that the association of epidemiological, clinical and laboratory findings is necessary to define the presence of malaria.

Domestic Rhodnius ecuadoriensis (Hemiptera, Reduviidae) infestation in Northern Peru: a comparative trial of detection methods during a six-month follow-up

Two passive methods in the assessment of intradomiciliary infestation by Rhodnius ecuadoriensis were tested: (i) the Gomes Nuñez sensor box (GN), (ii) sheets of white typing paper and (iii) one active timed manual method. The study was carried out in the Alto Chicama River Valley, Province of Gran Chimú, Department of La Libertad. The study design consisted of an initial searching of triatomines inside of the domestic environment by the manual capture active procedure (man/hour) covering all the studied houses. Then, matched pairs of GN boxes and paper sheets were simultaneously installed in the bedrooms of 207 households distributed in 19 localities. A comparative prospective trial of these passive detection devices were monitored at 2, 4 and, finally 6 months follow-up. Parasitological Trypanosoma rangeli and/or T. cruzi infections were investigated in two houses with high level of infestation by R. ecuadoriensis. 16.9% of the 207 households investigated by an initial active manual method were infested with R. ecuadoriensis. The proportion of infested houses fluctuated from 6.2 to 55.5% amongst the 19 localities investigated. T. rangeli natural infection was detected in R. ecuadoriensis specimens collected in two households. Parasite rates in the bugs ranged from 16.6 to 21.7% respectively. The most striking fact was an average rate of salivary gland infection ranging from 7.4 to 8.3%. At the end of the sixth month period, a cumulative incidence of 31.4% of positive GN boxes against 15.9% for paper sheets was recorded. All three methods combined detected domestic infestation in 129 (62.3%) of the 207 houses studied in the 19 localities. The range of houses infested varies from 6.7% to 92.9%. In areas with low bug density infestation rates, the methodology experienced in our studies, seems to be the best choice for investigations on domestic R. ecuadoriensis populations.

Analysis of the clonal relationship among clinical isolates of Salmonella enterica serovar Infantis by different typing methods

Salmonella Infantis has been the second most common serovar in Argentina in the last two years, being isolated mostly from paediatric hospitalised patients. In order to determine the clonal relationship among Salmonella Infantis strains, we examined 15 isolates from paediatric patient faeces in Argentina (12 geographically related and 3 geographically non-related) by using antimicrobial susceptibility, plasmid profiling, repetitive extragenic palindromic (REP) PCR, enterobacterial repetitive intergenic consensus (ERIC) PCR, and low-frequency restriction analysis of chromosomal DNA by pulsed field gel electrophoresis (PFGE). Four Spanish strains were included as controls of clonal diversity in molecular techniques. Antibiotype and plasmid profile was not useful as epidemiological tools. PFGE and REP-PCR were able to discriminate between Argentinean and Spanish isolates of Salmonella Infantis allowing to detect genetically related strains in three different cities. This finding indicates that a possible spread of a clone of this serovar in the North-eastern Region of Argentina has taken place in 1998.

Pulmonary tuberculosis: relationship between sputum bacilloscopy and radiological lesions

OBJECTIVES: To determine the frequency of radiological manifestations of chest tuberculosis among the tuberculosis outpatients at the Santa Casa de Misericórdia de São Paulo Hospital, and to correlate these radiological findings with the sputum bacilloscopy. SAMPLE AND METHODS: A review was made of the medical record cards and chest X-rays of all patients attended between January 1996 and December 1998. Patients with a diagnosis of tuberculosis who presented intrathoracic manifestations of the disease and negative anti-HIV serology were selected. RESULTS: The selection included 153 patients, with an average age of 37.5 years, who were predominantly male (60.8%) and white (56.9%). Pulmonary lesions were present in 121 (79.9%) and extrapulmonary lesions in 32 (20.1%). Parenchymal-infiltrate lesions appeared in 56 patients (36.6%), cavity lesions in 55 (36.0%), pleural effusion in 28 (18.3%), isolated nodules in 6 (3.9%), mediastinal enlargement in 4 (2.6%) and miliary pattern in 4 (2.6%). Cavities were present in 45.5% of the patients with pulmonary lesions, generally in association with the parenchymal-infiltrate lesions. Parenchymal infiltrate was present in 86.8% of the patients with pulmonary lesions. There was significant presence of alcohol-acid resistant bacillus in the sputum of patients with cavities (76.4%), in comparison with those without cavities (50%) (p = 0.003). CONCLUSIONS: Parenchymal-infiltrate lesions are the most frequent radiological manifestation of pulmonary tuberculosis, and they are generally associated with cavities. There is a relationship between the presence of acid fast bacilli in sputum and pulmonary cavity lesions.