Marília Dalva Turchi

Dengue and Dengue Hemorrhagic Fever among Adults: Clinical Outcomes Related to Viremia, Serotypes, and Antibody Response

BACKGROUND Clinical manifestations of dengue vary in different areas of endemicity and between specific age groups, whereas predictors of outcome have remained controversial. In Brazil, the disease burden predominantly affects adults, with an increasing trend toward progression to dengue hemorrhagic fever (DHF) noted. METHODS A cohort of adults with confirmed cases of dengue was recruited in central Brazil in 2005. Patients were classified according to the severity of their disease. Associations of antibody responses, viremia levels (as determined by real-time polymerase chain reaction [PCR]), and serotypes (as determined by multiplex PCR) with disease severity were evaluated. RESULTS Of the 185 symptomatic patients >14 years of age who had a confirmed case of dengue, 26.5% and 23.2% were classified as having intermediate dengue fever (DF)/DHF (defined as internal hemorrhage, plasma leakage, manifested signs of shock, and/or thrombocytopenia [platelet count, < or =50,000 platelets/mm3]) and DHF, respectively. The onset of intermediate DF/DHF and DHF occurred at a late stage of disease, around the period of defervescence. Patients with DHF had abnormal liver enzyme levels, with a >3-fold increase in aspartate aminotransferase level, compared with the range of values considered to be normal. Overall, 65% of patients presented with secondary infections with dengue virus, with such infection occurring in similar proportions of patients in each of the 3 disease category groups. Dengue virus serotype 3 (DV3) was the predominant serotype, and viremia was detected during and after defervescence among patients with DHF or intermediate DF/DHF. CONCLUSIONS Viremia was detected after defervescence in adult patients classified as having DHF or intermediate DF/DHF. Secondary infection was not a predictor of severe clinical manifestation in adults with infected with the DV3 serotype.

Epidemiological profile of cocaine users on treatment in psychiatrics hospitals, Brazil

OBJECTIVE To describe the epidemiological profile and patterns of cocaine use among hospitalized drug users. METHODS A cross-sectional study was carried out among drug users, aged 18 years or more, hospitalized in one out six selected psychiatric hospitals in the metropolitan area of Greater S o Paulo, whose clinical conditions allowed them to reliably answer to a standardized questionnaire and who agreed to participate. Six psychiatric hospitals who attended spontaneously referred public and private patients from all Greater S o Paulo were selected. Data collection was conducted using structured interviews, individually applied by a trained psychologist. Statistical analysis was performed using Student t-test and Chi-square test at p<0.05. RESULTS There was a predominance of crack use (38.4%) over intravenous drug use (1.6%). Addicts who smoked cocaine had lower education, most were unemployed and had previously lived on the streets, and used higher amounts of drugs. These addicts also had been previously incarcerated more often than addicts who used other routes for drug administration. CONCLUSIONS Drug use is a serious public health problem in Greater S o Paulo, and this is shown by the great amount of hospital admissions due to drug addiction. Crack users have lower socioeconomic status and more often engage in violence and crimes.

Prevalence and risk factors of Hepatitis C virus infection in Brazil, 2005 through 2009: a cross-sectional study

BackgroundHepatitis C chronic liver disease is a major cause of liver transplant in developed countries. This article reports the first nationwide population-based survey conducted to estimate the seroprevalence of HCV antibodies and associated risk factors in the urban population of Brazil.MethodsThe cross sectional study was conducted in all Brazilian macro-regions from 2005 to 2009, as a stratified multistage cluster sample of 19,503 inhabitants aged between 10 and 69 years, representing individuals living in all 26 State capitals and the Federal District. Hepatitis C antibodies were detected by a third-generation enzyme immunoassay. Seropositive individuals were retested by Polymerase Chain Reaction and genotyped. Adjusted prevalence was estimated by macro-regions. Potential risk factors associated with HCV infection were assessed by calculating the crude and adjusted odds ratios, 95% confidence intervals (95% CI) and p values. Population attributable risk was estimated for multiple factors using a case–control approach.ResultsThe overall weighted prevalence of hepatitis C antibodies was 1.38% (95% CI: 1.12%–1.64%). Prevalence of infection increased in older groups but was similar for both sexes. The multivariate model showed the following to be predictors of HCV infection: age, injected drug use (OR = 6.65), sniffed drug use (OR = 2.59), hospitalization (OR = 1.90), groups socially deprived by the lack of sewage disposal (OR = 2.53), and injection with glass syringe (OR = 1.52, with a borderline p value). The genotypes 1 (subtypes 1a, 1b), 2b and 3a were identified. The estimated population attributable risk for the ensemble of risk factors was 40%. Approximately 1.3 million individuals would be expected to be anti-HCV-positive in the country.ConclusionsThe large estimated absolute numbers of infected individuals reveals the burden of the disease in the near future, giving rise to costs for the health care system and society at large. The known risk factors explain less than 50% of the infected cases, limiting the prevention strategies. Our findings regarding risk behaviors associated with HCV infection showed that there is still room for improving strategies for reducing transmission among drug users and nosocomial infection, as well as a need for specific prevention and control strategies targeting individuals living in poverty.

Multilevel analysis of hepatitis A infection in children and adolescents: a household survey in the Northeast and Central-west regions of Brazil

Background The objectives were to estimate the prevalence of hepatitis A among children and adolescents from the Northeast and Midwest regions and the Federal District of Brazil and to identify individual-, household- and area-levels factors associated with hepatitis A infection. Methods This population-based survey was conducted in 2004–2005 and covered individuals aged between 5 and 19 years. A stratified multistage cluster sampling technique with probability proportional to size was used to select 1937 individuals aged between 5 and 19 years living in the Federal capital and in the State capitals of 12 states in the study regions. The sample was stratified according to age (5–9 and 10- to 19-years-old) and capital within each region. Individual- and household-level data were collected by interview at the home of the individual. Variables related to the area were retrieved from census tract data. The outcome was total antibodies to hepatitis A virus detected using commercial EIA. The age distribution of the susceptible population was estimated using a simple catalytic model. The associations between HAV infection and independent variables were assessed using the odds ratio and corrected for the random design effect and sampling weight. Multilevel analysis was performed by GLLAMM using Stata 9.2. Results The prevalence of hepatitis A infection in the 5–9 and 10–19 age-group was 41.5 and 57.4%, respectively for the Northeast, 32.3 and 56.0%, respectively for the Midwest and 33.8 and 65.1% for the Federal District. A trend for the prevalence of HAV infection to increase according to age was detected in all sites. By the age of 5, 31.5% of the children had already been infected with HAV in the Northeast region compared with 20.0% in the other sites. By the age of 19 years, seropositivity was ∼70% in all areas. The curves of susceptible populations differed from one area to another. Multilevel modeling showed that variables relating to different levels of education were associated with HAV infection in all sites. Conclusion The study sites were classified as areas with intermediate endemicity area for hepatitis A infection. Differences in age trends of infection were detected among settings. This multilevel model allowed for quantification of contextual predictors of hepatitis A infection in urban areas.

Prevalence and risk factors for Hepatitis C and HIV-1 infections among pregnant women in Central Brazil

BackgroundHepatitis C (HCV) and human immunodeficiency virus (HIV) infections are a major burden to public health worldwide. Routine antenatal HIV-1 screening to prevent maternal-infant transmission is universally recommended. Our objectives were to evaluate the prevalence of and potential risk factors for HCV and HIV infection among pregnant women who attended prenatal care under the coverage of public health in Central Brazil.MethodsScreening and counselling for HIV and HCV infections was offered free of charge to all pregnant women attending antenatal clinic (ANC) in the public health system, in Goiania city (~1.1 million inhabitants) during 2004–2005. Initial screening was performed on a dried blood spot collected onto standard filter paper; positive or indeterminate results were confirmed by a second blood sample. HCV infection was defined as a positive or indeterminate sample (EIA test) and confirmed HCV-RNA technique. HIV infection was defined according to standard criteria. Factors associated with HIV and HCV infections were identified with logistic regression. The number needed to screen (NNS) to prevent one case of infant HIV infection was calculated using the Monte Carlo simulation method.ResultsA total of 28,561 pregnant women were screened for HCV and HIV-1 in ANC. Mean maternal age was 23.9 years (SD = 5.6), with 45% of the women experiencing their first pregnancy. Prevalence of HCV infection was 0.15% (95% CI 0.11%–0.20%), and the risk increased with age (p < 0.01). The prevalence of anti-HIV infection was 0.09% (95% CI 0.06%–0.14%). Black women had a 4.9-fold (95% CI 1.42–16.95) greater risk of HIV-1 infection compared to non-black women. NNS to prevent one case of infant HIV infection ranged from 4,141 to 13,928.ConclusionThe prevalence of HIV and HCV infections were low among pregnant women, with high acceptability rates in the opt-in strategy in primary care. Older maternal age was a risk factor for HCV and antenatal HCV testing does not fulfill the requirements for screening recommendation. The finding of higher risk of HIV-1 infection among black women despite being in consonance with the HIV-1 ethnic pattern in some American regions cannot be ruled out to be a surrogate marker of socio-economic condition.

Genetic diversity and HIV-1 incidence estimation among cocaine users in Sao Paulo Brazil.

Summary: We describe HIV‐1 incidence and the prevalence of genetic subtypes among cocaine users in São Paulo, Brazil. A cross‐sectional HIV‐1 survey was carried out among 839 current cocaine users attending seven drug treatment units in the São Paulo metropolitan area from 1997 to 1998. HIV‐1 subtyping was performed among 41 positive individuals using the heteroduplex mobility assay and DNA sequencing. Participants were mainly male (95.7%) with a history of previous imprisonment (54%), and the mean age was 26.9 years (SD = 7.2). The majority (64.4%) were current crack cocaine users, and 82.1% of the total participants were noninjectors. HIV‐1 seroprevalence was 4.9% (95% confidence interval [CI], 3.6%‐6.6%), and the incidence (estimated by the sensitive/less‐sensitive immunoassay testing strategy) was 0.71% per year (95% CI, 0.07‐3.03). HIV‐1 subtype B was predominant (90.3%), followed by subtype F. There was no statistically significant association between HIV‐1 subtype and specific route of drug administration. Our incidence data show evidence of recent HIV‐1 transmission among cocaine users, mainly among noninjectors. Detection of recently infected HIV‐1 cases linked to genetic diversity analysis may provide baseline information for public health interventions in this sentinel group.

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil

A population-based survey to provide information on the prevalence of hepatitis viral infection and the pattern of risk factors was carried out in the urban population of all Brazilian state capitals and the Federal District, between 2005 and 2009. This paper describes the design and methodology of the study which involved a population aged 5 to 19 for hepatitis A and 10 to 69 for hepatitis B and C. Interviews and blood samples were obtained through household visits. The sample was selected using stratified multi-stage cluster sampling and was drawn with equal probability from each domain of study (region and age-group). Nationwide, 19,280 households and ~31,000 residents were selected. The study is large enough to detect prevalence of viral infection around 0.1% and risk factor assessments within each region. The methodology seems to be a viable way of differentiating between distinct epidemiological patterns of hepatitis A, B and C. These data will be of value for the evaluation of vaccination policies and for the design of control program strategies.

Anti-HBc testing for blood donations in areas with intermediate hepatitis B endemicity

En otros estudios se ha evaluado el menor riesgo de infecciones transmitidas por transfusion sanguinea que acarrea el tamizaje de anticuerpos contra los antigenos nucleares de la hepatitis B (anti-HBc), sumado a la prueba detectora de antigenos de superficie (HbsAg). No obstante, la mayoria de estos estudios se basaron en datos procedentes de zonas con baja endemicidad por hepatitis B o de bancos de sangre de paises desarrollados, donde la mayoria de la sangre proviene de personas que han donado previamente. A fin de examinar los pros y los contras del tamizaje de anticuerpos anti-HBc en el Brasil, los autores describen los antecedentes y la interpretacion de las pruebas de tamizaje para prevenir la hepatitis postransfusion. Tambien presentan los datos sobre el tamizaje de la hepatitis B en todas las regiones del Brasil. No hay pruebas suficientes para suspender el tamizaje de los anticuerpos anti-HBc en el pais. Debe darse alta prioridad a comparar el costo-efectividad de un marcador basado en la biologia molecular con el de la actual prueba detectora de anticuerpos anti-HBc aplicada comunmente, a fin de mejorar las medidas de tamizaje que garantizan la inocuidad de la sangre.

Evaluation of a Commercial Real-Time PCR Kit for Detection of Dengue Virus in Samples Collected during an Outbreak in Goiania, Central Brazil, in 2005

ABSTRACT In the past 2 decades, dengue has reemerged in Brazil as a significant public health problem. Clinicians demand a diagnostic test with high sensitivity that is applicable during the early symptomatic phase. We aimed to test two distinct molecular methods on samples from suspected dengue cases during an outbreak in Central Brazil. Acute-phase serum specimens from 254 patients suspected of having dengue were collected during 2005 in the city of Goiânia, Central Brazil. Samples were blindly evaluated by real-time and multiplex PCR in addition to routine immunoglobulin M serology and virus culture. Overall, acute dengue was confirmed by serology, multiplex PCR, or virus isolation for 80% of patients (203/254). Another four patients presented real-time PCR-positive results as the unique marker of dengue. Higher real-time PCR positivity levels and viral loads were observed in the early symptomatic phase of disease (≤5 days) than after this period. Multiplex and real-time PCR assays presented a high kappa agreement (0.85). According to multiplex PCR, 60 samples harbored dengue virus type 3 (DEN-3), 4 samples harbored DEN-2, and 1 sample displayed a pattern compatible with a double infection with DEN-2 and -3. The dengue virus real-time kit was found to be practical and adjustable for high throughput, to display the best performance in the early symptomatic phase of dengue cases, and to be valuable for confirming dengue diagnosis in a timely manner.

Prevalence of Chlamydia trachomatis in asymptomatic Brazilian military conscripts

Background: Few data are available on the prevalence and risk factors for Chlamydia trachomatis infection among young men in Brazil. Objectives: To assess prevalence and risk factors for C. trachomatis infection in male military conscripts. Methods: In 2000, 627 young men recruited for military service in Goiania, Goiás, Brazil, were enrolled in this cross-sectional study. Participants completed a demographic and sexual risk behavior questionnaire, and urine samples were screened for C. trachomatis by polymerase chain reaction. Results: The prevalence of chlamydial infection among asymptomatic conscripts was 5.0% (95% confidence interval [CI], 3.3–7.3). In multivariate analysis, failure to use condoms (odds ratio [OR]adjusted 5.3; 95% confidence interval [CI], 1.2–23.4; P = 0.028) and having more than 2 sexual partners in the last 2 months (ORadjusted 2.6; 95% CI, 1.1–6.9; P = 0.049) were significantly associated with positivity for C. trachomatis. Conclusions: A substantial number of asymptomatic young male military recruits were infected with C. trachomatis, and risk factors for this infection were related to sexual behavior. Further research is required to determine if routine screening may be considered as a strategy to reduce prevalence among this population.