Prevalence and monthly distribution of head lice using two diagnostic procedures in several age groups in Uberlândia, State of Minas Gerais, Southeastern Brazil

Some epidemiological characteristics of head lice, Pediculus capitis, were studied using two procedures: cut hair analysis and head inspection. Higher prevalence rates were observed in the middle and at the end of the school terms. Both procedures indicated that children were the main reservoir for this type of pediculosis in Uberlândia.

Susceptibility of Aedes aegypti (L) to the insect growth regulators diflubenzuron and methoprene in Uberlândia, State of Minas Gerais

Aedes aegypti (L) (Diptera: Culicidae) was reared in several concentrations of diflubenzuron and methoprene under laboratory conditions in Uberlândia, State of Minas Gerais, southeastern Brazil. Characteristics such as LC50 and LC95, the susceptibility of immature stages of different ages to these insect growth regulators and their residual effects were studied. The LC50 and LC95 of diflubenzuron and methoprene were 5.19 and 12.24 ppb; 19.95 and 72.08 ppb, respectively. While diflubenzuron caused great mortality in all larval instars, methoprene was more effective when the mosquito was exposed from the start of the fourth larval instar onwards. Commercial concentrations of these two insect growth regulators close to LC95 presented greater residual activity than did their respective technical formulations. The parameters were compared with those obtained elsewhere. The characteristics investigated here indicate that these insect growth regulators are effective alternatives for controlling the dengue vector in the Uberlândia region.

Clinical, epidemiological and laboratory aspects of patients with American cutaneous leishmaniasis in the State of Pernambuco

The diagnosis for American cutaneous leishmaniasis is based on an association of clinical, epidemiological and laboratory characteristics. The present study identified the circulating species of Leishmania in the State of Pernambuco, described its clinical-epidemiological characteristics and diagnosed the disease. Nineteen patients presenting active lesions who had been diagnosed through clinical evaluation and laboratory tests were selected. The tests included direct investigation, in vitro culturing, Montenegro skin test, indirect immunofluorescence and polymerase chain reaction. The Montenegro Skin Test showed positive results in 89% of the patients; indirect immunofluorescence, in 79%; direct investigation, in 58%; and polymerase chain reaction in 75%. Seven Leishmania (Viannia) braziliensis samples were isolated from these patients and were characterized by means of specific monoclonal antibodies. These data confirm that a combination of different diagnosis techniques is needed in order to obtain efficient results and that, so far, Leishmania (Viannia) braziliensis is the only species responsible for American cutaneous leishmaniasis infection in Pernambuco. Thus, it is essential to identify the parasite species involved in cases of human disease in an endemic area in order to determine the clinical and epidemiological characteristics, especially with regard to diagnosis, therapy development and disease prognosis.

Seroprevalence and risk factors for canine visceral leishmaniasis in the endemic area of Dias D'Ávila, State of Bahia, Brazil

INTRODUCTION: Visceral leishmaniasis (VL) is an important zoonosis in relation to public health systems. Dogs are the main domestic reservoir. This study aimed to investigate occurrences of canine VL in Dias D'Ávila, State of Bahia, Brazil. METHODS: The prevalence was evaluated by means of clinical and laboratory tests on a population of 312 domestic dogs from 23 localities in this municipality, using indirect immunofluorescence and immunoenzymatic assays. RESULTS: Among the animals examined, 3.2% and 6.7% showed signs of VL, confirmed by indirect immunofluorescence and immunoenzymatic assays, respectively, with a distribution of 29.9% (24 dogs) in the rural zone and 4.9% (288 dogs) in the urban zone (p = 0.001). The clinical evaluation on seropositive dogs showed both asymptomatic animals (2.4%) and symptomatic animals (47.6%), along with other abnormalities (e.g. normocytic and normochromic anemia, with leukocytosis and thrombocytopenia). Observations relating to phenotypic characteristics (e.g. sex, age, breed and hair) did not present statistical significance, although high seropositivity among male, short-haired and mixed-breed dogs was observed. CONCLUSIONS: The findings showed that VL was a predominantly rural zoonosis and that close contact between poultry and domestic dogs significantly increased the risk of canine infection in this region.

Seroprevalence of hepatitis B virus infection and associated factors among prison inmates in state of Mato Grosso do Sul, Brazil

INTRODUCTION: This study aimed to estimate the prevalence of HBV infection and associated factors among prison inmates in Campo Grande, MS. METHODS: A total of 408 individuals were interviewed regarding sociodemographic characteristics, associated factors and HBV vaccination using a standardized questionnaire. Blood samples were collected from all participants and serological markers for HBV were detected by enzyme-linked immunosorbent assay. Hepatitis B surface antigen (HBsAg) and/or antibodies against hepatitis B core antigen (anti-HBc) positive samples were tested for HBV-DNA by polymerase chain reaction. RESULTS: The overall prevalence of HBV infection was 17.9% (95%CI: 14.4-22.0). The HBsAg carrier rate was 0.5%; 56 (13.7%) individuals had been infected and developed natural immunity and 15 (3.7%) were positive for anti-HBc only. Ninety eight (24%) prisoners had only anti-HBs, suggesting that they had low vaccine coverage. An occult HBV infection rate of 0% was verified among anti-HBc-positive individuals. Multivariate analysis of associated factors showed that age > 35 years-old, low schooling level and illicit drug use are significantly associated with HBV infection. CONCLUSIONS: Analysis of the data showed HBV infection prevalence similar or slightly lower than that reported in other of Brazilian prisons. Independent predictors of HBV infection in this population include older age, low schooling level and illicit drug use.

Comparison of Bothropoides jararaca bites with and without envenoming treated at the Vital Brazil Hospital of the Butantan Institute, State of São Paulo, Brazil

INTRODUCTION: This study analyses the cases of all bites (including dry bites) caused by Bothropoides jararaca attended at the Vital Brazil Hospital of the Butantan Institute, State of São Paulo, Brazil. METHODS: A retrospective study was conducted of patients bitten by Bothropoides jararaca (n=792) from January 1990 to December 2004. The characteristics of the snake specimen, data related to the accident and clinical manifestations on admission were obtained from patient medical records. RESULTS: The majority of the cases in this study were caused by female and juvenile snakes. No stomach contents were found in 93.4% of the snake specimens after dissection. No statistical difference was observed between the occurrence of dry bites and the maturity or sex of the snake. The median SVL of snakes in mild and moderate cases was 40.5cm and in severe cases, SVL increased to 99cm. Necrosis was more common in the digits of the feet and hands (4.8%) compared to the other body regions (1.8%). A significant difference was verified between severity and a time interval greater than six hours from the bite to hospital admission. A significant association was verified between gingival bleeding and abnormal blood coagulability. In accidents caused by adult snakes, necrosis was more frequent (7.2%) compared to accidents caused by juvenile snakes (1%). CONCLUSIONS: In this work, the association between certain epidemiological data and the evolution of biological parameters in the clinical course of Bothrops sensu latu accidents were highlighted, contributing to the improvement of snake bite assistance.

Aedes aegypti and Aedes albopictus (Diptera: Culicidae): coexistence and susceptibility to temephos, in municipalities with occurrence of dengue and differentiated characteristics of urbanization

INTRODUCTION: The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paraná and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS: The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion). Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS: Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paraná. CONCLUSIONS: All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paraná and Santa Catarina) presented survival when exposed to the organophosphate temephos.

Mother-to-child transmission of HIV infection in Manaus, State of Amazonas, Brazil

INTRODUCTION: Reduction in the vertical transmission of HIV is possible when prophylactic measures are implemented. Our objective was to determine demographic characteristics of HIV-infected pregnant women and the rate of mother-to-child transmission of HIV in Manaus, Amazonas, Brazil. METHODS: A descriptive study was conducted using notification, and investigating data from the Notifiable Diseases Data System in the Brazilian State of Amazonas, between 2007 and 2009. RESULTS: During the study period, notification was received of 509 HIV-positive pregnant women. The vertical transmission was 9.9% (95% CI: 7.2-12.6%). The mean age of women was 27 years (SD: 5.7), and the majority (54.8%) had not completed elementary school (eighth grade). Diagnosis of HIV seropositivity was made prior to pregnancy in 115 (22.6%) women, during prenatal care in 302 (59.3%), during delivery in 70 (13.8%), and following delivery in 22 (4.3%). Four hundred four of these women (79.4%) had had prenatal care, with 79.4% of patients receiving antiretroviral during pregnancy and 61.9% of the newborn infants receiving prophylaxis. In the final multivariate logistic regression model, living in urban area [OR = 0.7 (95% CI: 0.35-0.89)] and having had prenatal care [OR = 0.1 (95% CI: 0.04-0.24)] remained as protective factors against vertical HIV transmission in this population. CONCLUSIONS: The relevance of adequate compliance with the measures already established as being effective in guaranteeing a reduction in HIV transmission within the maternal and infant population should be emphasized.

Assessment of integration of the leprosy program into primary health care in Aracaju, state of Sergipe, Brazil

INTRODUCTION: The aim of this study was to assess the epidemiological and operational characteristics of the Leprosy Program before and after its integration into the Primary healthcare Services of the municipality of Aracaju-Sergipe, Brazil. METHODS: Data were drawn from the national database. The study periods were divided into preintegration (1996-2000) and postintegration (2001-2007). Annual rates of epidemiological detection were calculated. Frequency data on clinico-epidemiological variables of cases detected and treated for the two periods were compared using the Chi-squared (χ2) test adopting a 5% level of significance. RESULTS: Rates of detection overall, and in subjects younger than 15 years, were greater for the postintegration period and were higher than rates recorded for Brazil as a whole during the same periods. A total of 780 and 1,469 cases were registered during the preintegration and postintegration periods, respectively. Observations for the postintegration period were as follows: I) a higher proportion of cases with disability grade assessed at diagnosis, with increase of 60.9% to 78.8% (p < 0.001), and at end of treatment, from 41.4% to 44.4% (p < 0.023); II) an increase in proportion of cases detected by contact examination, from 2.1% to 4.1% (p < 0.001); and III) a lower level of treatment default with a decrease from 5.64 to 3.35 (p < 0.008). Only 34% of cases registered from 2001 to 2007 were examined. CONCLUSIONS: The shift observed in rates of detection overall, and in subjects younger than 15 years, during the postintegration period indicate an increased level of health care access. The fall in number of patients abandoning treatment indicates greater adherence to treatment. However, previous shortcomings in key actions, pivotal to attaining the outcomes and impact envisaged for the program, persisted in the postintegration period.

Spatio-temporal patterns of tuberculosis incidence in Ribeirão Preto, State of São Paulo, southeast Brazil, and their relationship with social vulnerability: a Bayesian analysis

INTRODUCTION: The purpose of this ecological study was to evaluate the urban spatial and temporal distribution of tuberculosis (TB) in Ribeirão Preto, State of São Paulo, southeast Brazil, between 2006 and 2009 and to evaluate its relationship with factors of social vulnerability such as income and education level. METHODS: We evaluated data from TBWeb, an electronic notification system for TB cases. Measures of social vulnerability were obtained from the SEADE Foundation, and information about the number of inhabitants, education and income of the households were obtained from Brazilian Institute of Geography and Statistics. Statistical analyses were conducted by a Bayesian regression model assuming a Poisson distribution for the observed new cases of TB in each area. A conditional autoregressive structure was used for the spatial covariance structure. RESULTS: The Bayesian model confirmed the spatial heterogeneity of TB distribution in Ribeirão Preto, identifying areas with elevated risk and the effects of social vulnerability on the disease. We demonstrated that the rate of TB was correlated with the measures of income, education and social vulnerability. However, we observed areas with low vulnerability and high education and income, but with high estimated TB rates. CONCLUSIONS: The study identified areas with different risks for TB, given that the public health system deals with the characteristics of each region individually and prioritizes those that present a higher propensity to risk of TB. Complex relationships may exist between TB incidence and a wide range of environmental and intrinsic factors, which need to be studied in future research.

Factors of poor prognosis of visceral leishmaniasis among children under 12 years of age. A retrospective monocentric study in Belo Horizonte, State of Minas Gerais, Brazil, 2001-2005

INTRODUTION: A major concern with the visceral leishmaniasis (VL) is its high lethality rate, even with proper treatment. Low age, prior malnutrition, disease duration prior to diagnosis, severe anemia, fever for more than 60 days, diarrhea and jaundice are known poor prognostic factors. The goals of this study are to describe the clinical and laboratory characteristics of VL among children under 12 years of age and to identify the factors associated with VL poor outcome. METHODS: Two hundred and fifty children under 12 years of age with confirmed VL admitted to Hospital João Paulo II (FHEMIG), Belo Horizonte, Brazil, between January 2001 and December 2005 were evaluated retrospectively. The primary outcome was the poor clinical evolution: sepsis, and/or pneumonia, and/or urinary tract infection, and/or of bleeding (expect epistaxis), and/or severe neutropenia (neutrophil < 500 cells/mm3). Odds ratio (crude and adjusted) and its 95% confidence interval for each variable were calculated. Values less than 0.05 were considered significant. RESULTS: Average age was 3.3 years (3.6 months-11.6 years), 71.2% were younger than 5 years and 47.2% lived in Metropolitan Area of Belo Horizonte. The mean fatality rate was 3.6%. Sixty-six (26.4%) patients presented poor evolution. After a multivariate analysis, age <18 months, abnormal respiratory physical examination on hospital admission, and platelets <85,000/mm3 remained associated with increased chance of poor evolution. CONCLUSIONS: The results suggest that patients aged between 12 and 18 months, with platelet counts bellow 85,000/mm3, and respiratory abnormalities at admission should be considered potentially severe.

Epidemiological profile of Trypanosoma cruzi-infected mothers and live birth conditions in the state of Minas Gerais, Brazil

INTRODUCTION: The aim of this study was to assess the epidemiological characteristics of Trypanosoma cruzi-infected mothers and the live birth conditions of neonates.METHODS:A serological survey with IgG-specific tests was conducted using dried blood samples from newborn infants in the State of Minas Gerais. T. cruzi infection was confirmed in mothers through positive serology in two different tests, and infected mothers were required to have their infants serologically tested after the age of 6 months. The birth conditions of the neonates were obtained from the System of Information on Live Births database.RESULTS:The study included 407 children born to T. cruzi-infected mothers and 407 children born to uninfected mothers. The average age of seropositive mothers was 32 years (CI95% 31.3-32.6), which was greater than the average age of seronegative mothers - 25 years (CI95% 24.8-25.2). The mothers' level of education was higher among uninfected mothers (41% had 8 or more years of education, versus 22% between the infected mothers). Vaginal delivery was more frequent among infected mothers. There was no evidence of inter-group differences with respect to the child's sex, gestational age, birth weight or Appearance, pulse, grimace, activity and respiration (APGAR) scores at 1 and 5 minutes.Conclusions:The level of education and the greater number of previous pregnancies and cases of vaginal delivery reflect the lower socioeconomical conditions of the infected mothers. In the absence of vertical transmission, neonates had similar health status irrespective of the infection status of their mothers.

Molecular and biological characterization of Trypanosoma cruzi strains isolated from children from Jequitinhonha Valley, State of Minas Gerais, Brazil

Introduction The biological diversity of Trypanosoma cruzi strains plays an important role in the clinical and epidemiological features of Chagas disease. Methods Eight T. cruzi strains isolated from children living in a Chagas disease vector-controlled area of Jequitinhonha Valley, State of Minas Gerais, Brazil, were genetically and biologically characterized. Results The characterizations demonstrated that all of the strains belonged to T. cruzi II, and showed high infectivity and a variable mean maximum peak of parasitemia. Six strains displayed low parasitemia, and two displayed moderate parasitemia. Later peaks of parasitemia and a predominance of intermediate and large trypomastigotes in all T. cruzi strains were observed. The mean pre-patent period was relatively short (4.2±0.25 to 13.7±3.08 days), whereas the patent period ranged from 3.3±1.08 to 34.5±3.52 days. Mortality was observed only in animals infected with strain 806 (62.5%). Histopathological analysis of the heart showed that strains 501 and 806 caused inflammation, but fibrosis was observed only in animals infected with strain 806. Conclusions The results indicate the presence of an association between the biological behavior in mice and the genetic characteristics of the parasites. The study also confirmed general data from Brazil where T. cruzi II lineage is the most prevalent in the domiciliary cycle and generally has low virulence, with some strains capable of inducing inflammatory processes and fibrosis.

Evaluation of natural foci of Panstrongylus megistus in a forest fragment in Porto Alegre, State of Rio Grande do Sul, Brazil

Introduction Panstrongylus megistus is commonly found in wild environments of the State of Rio Grande do Sul, Brazil. The aim of this study was to characterize the network of refuges used by triatomine in a forest fragment of Porto Alegre and to identify Trypanosoma cruzi infection, associated hosts and the epidemiological importance of both hosts and triatomines. Methods Techniques including the spool-and-line method and active searching (transects) were used to identify natural foci. Results The food source for each triatomine was determined using the precipitin test, and the infection of marsupials was determined by xenodiagnosis. A total of 33 adults (domestic environment) and 27 nymphs (wild environment) of P. megistus were found in addition to 43 Didelphis albiventris specimens. The infection rates of triatomine adults, triatomine nymphs and opossums with T. cruzi I were 64%, 73% and 69%, respectively. Birds, rodents and opossums were the main resources used by triatomine. Conclusions This work presents the first characterization of a natural focus of P. megistus in Rio Grande do Sul. The natural characteristics of this focus and its implication in the transmission of T. cruzi are discussed.

Factors related to severe dengue during an epidemic in Vitoria, State of Espirito Santo, Brazil, 2011

Introduction The prognosis of dengue depends on early diagnosis and treatment, which can help prevent severe forms whose characteristics were evaluated here. Methods A cross-sectional study was conducted involving dengue cases in Vitória, State of Espírito Santo, Brazil, in 2011. Results Two health regions registered 56.3% of 371 cases of severe dengue. Of these cases, 21.3% presented with dengue hemorrhagic fever. There were associations between dengue hemorrhagic fever with younger ages and a longer time before receiving care. Conclusions There was a greater involvement of dengue hemorrhagic fever in young people. Delay in care, poor urban quality and high endemicity were identified as possible risk factors for dengue severity.