Efficient Identification of HIV Serodiscordant Couples by Existing HIV Testing Programs in South Brazil.

ObjectiveTo examine the feasibility of identifying HIV negative at risk individuals in HIV serodiscordant couples, during voluntary HIV testing in South Brazil.MethodsWe surveyed HIV testers at 4 public testing sites in Rio Grande do Sul. We obtained information on risk behaviors and sexual partnerships. HIV testing and testing for recent infection were performed; HIV prevalence and risk behaviors were assessed among subjects who reported having a steady partner who was HIV positive (serodiscordant group) and compared with the general testing population.ResultsAmong 3100 patients, 490 (15.8%) reported being in a steady relationship with an HIV positive partner. New HIV infections were diagnosed in 23% of the serodiscordant group (vs. 13% in the general population, p = 0.01); among newly positive subjects, recent HIV infections were more frequent (23/86, 26.7%) among testers with positive partners than among the general testing group (52/334; 15.6%; p = 0.016). Less than half of the serodiscordant testers reported having used a condom during the last sexual intercourse with their HIV-positive partner. Participants with inconsistent condom use with steady partner were four times more likely to test positive for HIV compared to those who reported always using condoms with the steady partner (OR: 4.2; 95% CI: 2.3 to 7.5).ConclusionIt is highly feasible to identify large numbers of HIV susceptible individuals who are in HIV serodiscordant relationships in South Brazil testing sites. Condom use within HIV serodiscordant couples is low in this setting, suggesting urgent need for biomedical prevention strategies to reduce HIV transmission

Group B Streptococcus detection in pregnant women via culture and PCR methods

INTRODUCTION: Group B Streptococcus (GBS), a source of neonatal infection, colonizes the gastrointestinal and genitourinary tracts of pregnant women. Routine screening for maternal GBS in late pregnancy and consequent intrapartum antibiotic prophylaxis have reduced the incidence of early-onset GBS neonatal infection. The aim of this study was to evaluate the performance of PCR, compared to culture (gold standard), in GBS colonization screening of pregnant women, and to establish the prevalence of GBS colonization among this population. METHODS: Vaginal introitus and perianal samples were collected from 204 pregnant women, between the 35th and 37th weeks of pregnancy, at the Obstetrics and Gynecology Unit of the University of Caxias do Sul General Hospital between June 2008 and September 2009. All samples were cultured after enrichment in a selective medium and then assayed by culture and PCR methods. RESULTS: The culture and PCR methods yielded detection rates of vaginal/perianal GBS colonization of 22.5% and 26%, respectively (sensitivity 100%; specificity 95.6%; positive and negative predictive values 86.8% and 100%, respectively). A higher prevalence of GBS colonization was detected in the combined vaginal and perianal samples by both culture and PCR assay analyses. CONCLUSIONS: PCR is a faster and more efficient method for GBS screening, allowing for optimal identification of women who should receive intrapartum antibiotic prophylaxis to prevent newborn infection

PCR colorimetric dot-blot assay and clinical pretest probability for diagnosis of Pulmonary Tuberculosis in Smear-Negative patients

<p>Abstract</p> <p>Background</p> <p>Smear-negative pulmonary tuberculosis (SNPTB) accounts for 30% of Pulmonary Tuberculosis (PTB) cases reported annually in developing nations. Polymerase chain reaction (PCR) may provide an alternative for the rapid detection of <it>Mycobacterium tuberculosis </it>(MTB); however little data are available regarding the clinical utility of PCR in SNPTB, in a setting with a high burden of TB/HIV co-infection.</p> <p>Methods</p> <p>To evaluate the performance of the PCR dot-blot in parallel with pretest probability (Clinical Suspicion) in patients suspected of having SNPTB, a prospective study of 213 individuals with clinical and radiological suspicion of SNPTB was carried out from May 2003 to May 2004, in a TB/HIV reference hospital. Respiratory specialists estimated the pretest probability of active disease into high, intermediate, low categories. Expectorated sputum was examined by direct microscopy (Ziehl-Neelsen staining), culture (Lowenstein Jensen) and PCR dot-blot. Gold standard was based on culture positivity combined with the clinical definition of PTB.</p> <p>Results</p> <p>In smear-negative and HIV subjects, active PTB was diagnosed in 28.4% (43/151) and 42.2% (19/45), respectively. In the high, intermediate and low pretest probability categories active PTB was diagnosed in 67.4% (31/46), 24% (6/25), 7.5% (6/80), respectively. PCR had sensitivity of 65% (CI 95%: 50%–78%) and specificity of 83% (CI 95%: 75%–89%). There was no difference in the sensitivity of PCR in relation to HIV status. PCR sensitivity and specificity among non-previously TB treated and those treated in the past were, respectively: 69%, 43%, 85% and 80%. The high pretest probability, when used as a diagnostic test, had sensitivity of 72% (CI 95%:57%–84%) and specificity of 86% (CI 95%:78%–92%). Using the PCR dot-blot in parallel with high pretest probability as a diagnostic test, sensitivity, specificity, positive and negative predictive values were: 90%, 71%, 75%, and 88%, respectively. Among non-previously TB treated and HIV subjects, this approach had sensitivity, specificity, positive and negative predictive values of 91%, 79%, 81%, 90%, and 90%, 65%, 72%, 88%, respectively.</p> <p>Conclusion</p> <p>PCR dot-blot associated with a high clinical suspicion may provide an important contribution to the diagnosis of SNPTB mainly in patients that have not been previously treated attended at a TB/HIV reference hospital.</p

Método de diagnóstico para detecção de Mycobacterium tuberculosis

Universidade Federal do Rio Grande do SulFundação Estadual de Produção e Pesquisa em Saúde (RS)Ciências BiológicasDepositad

Detecção de Mycobacterium tuberculosis em líquido pleural por PCR in house

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Detecção de Mycobacterium tuberculosis em líquido pleural por PCR in house

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Utilização de GM-PCR e PCR dot-blot colorimétrico na detecção de Mycobacterium tuberculosis em amostras de líquido pleural

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