Quality Control in RT-PCR Viral Load Assays: Evaluation of Analytical Performance for HIV, HBV, and HCV.

Introduction: Quality Control Management (QCM) in clinical laboratories is crucial for ensuring reliable results in analytical measurements, with biological variation being a key factor. The study focuses on assessing the analytical performance of the Reverse Transcription Polymerase Chain Reaction (RT-PCR) system for Human Immunodeficiency Virus (HIV), Hepatitis B (HBV), and Hepatitis C (HCV). Five models proposed between 1999 and 2014 offer different approaches to evaluating analytical quality, with Model 2 based on biological variation and Model 5 considering the current state of the art. The study evaluates the RT-PCR system's analytical performance through Internal Quality Control (IQC) and External Quality Control (EQC). Materials and Methods: The Laboratório Central de Saúde Pública do Estado do Ceará (LACEN-CE) conducted daily IQC using commercial kits, and EQC was performed through proficiency testing rounds. Random error, systematic error, and total error were determined for each analyte. Results: Analytical performance, assessed through CV and random error, met specifications, with HIV and HBV classified as "desirable" and "optimal." EQC results indicated low systematic error, contributing to total errors considered clinically insignificant. Conclusion: The study highlights the challenge of defining analytical specifications without sufficient biological variability data. Model 5 is deemed the most suitable. The analytical performance of the RT-PCR system for HIV, HBV, and HCV at LACEN-CE demonstrated satisfactory, emphasizing the importance of continuous quality control in molecular biology methodologies.

Quantum Biochemistry and MM-PBSA Description of the ZIKV NS2B-NS3 Protease: Insights into the Binding Interactions beyond the Catalytic Triad Pocket.

The Zika virus protease NS2B-NS3 has a binding site formed with the participation of a H51-D75-S135 triad presenting two forms, active and inactive. Studies suggest that the inactive conformation is a good target for the design of inhibitors. In this paper, we evaluated the co-crystallized structures of the protease with the inhibitors benzoic acid (5YOD) and benzimidazole-1-ylmethanol (5H4I). We applied a protocol consisting of two steps: first, classical molecular mechanics energy minimization followed by classical molecular dynamics were performed, obtaining stabilized molecular geometries; second, the optimized/relaxed geometries were used in quantum biochemistry and molecular mechanics/Poisson-Boltzmann surface area (MM-PBSA) calculations to estimate the ligand interactions with each amino acid residue of the binding pocket. We show that the quantum-level results identified essential residues for the stabilization of the 5YOD and 5H4I complexes after classical energy minimization, matching previously published experimental data. The same success, however, was not observed for the MM-PBSA simulations. The application of quantum biochemistry methods seems to be more promising for the design of novel inhibitors acting on NS2B-NS3.

Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases.

We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses' epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

Estudo da Qualidade das Águas Adicionadas de Sais Produzidas no Estado Do Ceará / Study on the Quality of Salt-Added Water Produced In the State of Ceará, Brazil

Avaliar a qualidade da água bruta utilizada comomatéria-prima e água envasada, obtida de indústriasprodutoras de Águas Adicionadas de Sais no Estado doCeará. Material e Métodos: Foram coletadas 270 amostrasamostras, em quinze empresas. Foram realizadas análisesmicrobiológicas de determinação de coliformes totais eEscherichia coli; Enterococcus, Pseudomonas aeruginosa,Clostridium perfringens; bactérias heterotróficas e análisesfísico-químicas de determinação de nitrato, nitrito; clororesidual e pH. Resultados: Verificou-se que a água bruta emonze (73,33%), das quinze empresas, não atendeu aospadrões de potabilidade da água para consumo humano.Com relação à água envasada constatou-se que quatorze(93,33%) empresas, não atenderam aos parâmetrosmicrobiológicos e físico-químicos para água mineral naturale água para consumo humano. Conclusao: A maioria dasamostras analisadas neste estudo nao atenderam aospadrões de potabilidade de água para consumo humano, deacordo com a legislação vigente. Dessa forma, se faznecessária a atualização da legislação sanitária da águaadicionada de sais envasada, visando à prevenção de danosà saúde da população...

To evaluate the quality of raw water used as rawmaterial and bottled water, obtained from “salt-added water”companies in the state of Ceará, Brazil. Material andMethods: A total of 270 samples of fifteen brands werecollected. Microbiological analyses were performed in orderto determine the countings of total coliforms and Escherichiacoli; Enterococcus, Pseudomonas aeruginosa, Clostridiumperfringens; and heterotrophic bactéria. Physicochemicalanalyses were performed to determine the product’s levelsof nitrate, nitrite, residual chlorine, and pH. Results: In eleven(73.33%) of the fifteen brands, the raw water did not meetthe standards for potable water for human consumption.With respect to bottled water, it was found that fourteen(93.33%) brands did not meet the microbiological and physicochemicalparameters for natural mineral water and water forhuman consumption. Conclusion: Most of the samplesanalyzed in this study did not meet the water potabilitystandards for human consumption. Thus, it is necessary toupdate the health legislation on salt-added bottled water, inorder to avoid damages to people’s health...