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OBJECTIVES: The accuracy of malaria rapid diagnostic tests is threatened by Plasmodium falciparum with pfhrp2/3 deletions. This study compares gene deletion prevalence determined by multiplex real time polymerase chain reaction (qPCR) and conventional polymerase chain reaction (cPCR) using existing samples with clonality previously determined by microsatellite genotyping. METHODS: Multiplex qPCR was used to estimate prevalence of pfhrp2/3 deletions in three sets of previously collected patient samples from Eritrea and Peru. The qPCR was validated by multiplex digital polymerase chain reaction. Sample classification was compared with cPCR, and receiver operating characteristic curve analysis was used to determine the optimal ΔCq threshold that aligned the results of the two assays. RESULTS: qPCR classified 75% (637 of 849) of samples as single, and 212 as mixed-pfhrp2/3 genotypes, with a positive association between clonality and proportion of mixed-pfhrp2/3 genotype samples. The sample classification agreement between cPCR and qPCR was 75.1% (95% confidence interval [CI] 68.6-80.7%) and 47.8% (95% CI 38.9-56.9%) for monoclonal and polyclonal infections. The qPCR prevalence estimates of pfhrp2/3 deletions showed almost perfect (κ = 0.804, 95% CI 0.714-0.895) and substantial agreement (κ = 0.717, 95% CI 0.562-0.872) with cPCR for Peru and 2016 Eritrean samples, respectively. For 2019 Eritrean samples, the prevalence of double pfhrp2/3 deletions was approximately two-fold higher using qPCR. The optimal threshold for matching the assay results was ΔCq = 3. CONCLUSIONS: Multiplex qPCR and cPCR produce comparable estimates of gene deletion prevalence when monoclonal infections dominate; however, qPCR provides higher estimates where multi-clonal infections are common.
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Antígenos de Protozoários , Malária Falciparum , Reação em Cadeia da Polimerase Multiplex , Plasmodium falciparum , Proteínas de Protozoários , Plasmodium falciparum/genética , Humanos , Malária Falciparum/epidemiologia , Malária Falciparum/diagnóstico , Malária Falciparum/parasitologia , Proteínas de Protozoários/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Prevalência , Antígenos de Protozoários/genética , Deleção de Genes , Reação em Cadeia da Polimerase em Tempo Real/métodos , Peru/epidemiologia , GenótipoRESUMO
Introducción. Una de las consecuencias psicológicas más frecuentes del COVID-19 es el miedo. Éste podría ocasionar una adherencia terapéutica no óptima y permitir la progresión de la enfermedad en personas con VIH. Objetivo. Evaluar la asociación entre el miedo a contraer COVID-19 y la adherencia al tratamiento antirretroviral en personas con VIH entre la tercera y cuarta ola epidémica de COVID-19 en el Perú. Métodos. Estudio transversal analítico en adultos con VIH del centro especializado Vía Libre enrolados por muestreo no probabilístico. Se empleó la escala Fear of COVID-19 Scale para medir el miedo a contraer COVID-19, y el cuestionario SMAQ para evaluar la adherencia terapéutica. Los resultados se presentaron de forma descriptiva, usando chi cuadrado para el análisis bivariado y modelos lineales generalizados familia Poisson para estimar razones de prevalencia crudas y ajustadas (RPa). Resultados. Entre febrero - julio del 2022, se enrolaron 149 personas con una mediana de edad de 35 años, el 91,3% fueron varones, y el 75,2% con carga viral indetectable. No se halló asociación entre el miedo a contraer COVID-19 y la adherencia terapéutica (RPa: 0,99; IC95%: 0,97 a 1,02). Adicionalmente, encontramos que las personas que presentaban alguna comorbilidad fueron 89% más adherentes que los que no las presentaban (RPa: 1,89; IC95%: 1,52 a 2,35). Conclusión. El miedo a contraer COVID-19 no se asoció a la adherencia al TARGA durante la tercera ola de pandemia en el Perú. Sin embargo, el presentar alguna comorbilidad se asoció a una adherencia terapéutica óptima. Se debe poner énfasis en los posibles factores que afecten la adherencia en personas con VIH durante la pandemia por COVID-19.
Introduction. One of the most frequent psychological consequences of COVID-19 is fear, which could lead to non-optimal therapeutic adherence and, therefore, to the disease progression. Objectives. To evaluate the possible association between the fear of contracting COVID-19 and adherence to antiretroviral therapy in persons with HIV during the period between the third and fourth epidemic wave of COVID-19 in Peru. Methods. Analytical cross-sectional study in adults with HIV from the specialized center "Vía Libre" enrolled by non-probabilistic sampling. The validated "Fear of COVID-19 Scale" was used to measure the fear of getting sick from COVID-19, and the "SMAQ" questionnaire to assess therapeutic adherence. Results were presented descriptively, using chi-square for bivariate analysis and generalized linear models, Poisson family to calculate crude and adjusted prevalence ratios (aPR). Results. Between February and July of 2022, 149 adults with a median age of 35 years were enrolled, 91.3% being male, and 75,2% had undetectable viral load levels. No association was found between fear of contracting COVID-19 and HAART adherence (aPR: 0,99; 95% CI 0,97 to 1,02). Persons with a comorbidity were 89% more adherent than persons withoutcomorbidities (RPa: 1,89; 95% CI 1,52 to 2,35). Conclusion. The fear of contracting COVID-19 was not associated with adherence to HAART during the third wave of COVID-19 pandemic in Peru. However, presenting a comorbidity was associated with optimal HAART adherence. Emphasis should be placed on potential factors affecting medication adherence in people with HIV during the COVID-19 pandemic.
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Resumen Introducción: La confiabilidad de la presión sistólica arterial pulmonar por ecocardiografía transtorácica se encuentra limitada por su variabilidad para definir la hipertensión pulmonar. Objetivo: Conocer la variabilidad en la presión sistólica arterial pulmonar estimada por ecocardiografía en la hipertensión pulmonar. Métodos: En el periodo 2016-2020 se captaron sujetos con hipertensión pulmonar que tuvieron estimada la presión sistólica de la arteria pulmonar por ecocardiografía transtorácica y por cateterismo cardiaco derecho. Se obtuvieron sus variables demográficas. Los datos se analizaron con el estadístico descriptivo de Bland-Altman y el coeficiente de correlación intraclase (intervalo de confianza al 95%). Resultados: Se estudiaron 152 sujetos, edad 60 ± 12 años. Índice de masa corporal 27.64 ± 4.69 kg/m2. La presión sistólica de la arteria pulmonar por ecocardiografía transtorácica 58.99 ± 18.62 vs. cateterismo cardiaco 55.43 ± 16.79. Diferencia media (sesgo) -3.6 (29.1, -36.2) y coeficiente de correlación intraclase 0.717 (0.610, 0.794). Conclusiones: La variabilidad es amplia y el acuerdo es sustancial con la presión sistólica de la arteria pulmonar. Se aconseja estimarla solo como tamizaje de la hipertensión pulmonar.
Abstract Introduction: The reliability of pulmonary arterial systolic pressure by transthoracic echocardiography is limited by its variability to define pulmonary hypertension. Objective: To know the variability of pulmonary arterial systolic pressure estimated by echocardiography in pulmonary hypertension. Their demographic variables were obtained. Methods: From 2016-2020 subjects with pulmonary hypertension were recruited, with pulmonary artery systolic pressure estimated by transthoracic echocardiography and by right heart catheterization. Data were analyzed using the Bland-Altman descriptive statistic and the intraclass correlation coefficient (95% confidence interval). Results: 152 subjects, age 60 ± 12 years, were studied. Body mass index 27.64 ± 4.69 kg/m2. The pulmonary artery systolic pressure estimated by transthoracic echocardiography 58.99 ± 18.62 vs. cardiac catheterization 55.43 ± 16.79 mmHg. Mean difference (bias) -3.6 (29.1, -36.2) and intraclass correlation coefficient 0.717 (0.610, 0.794). Conclusions: Variability is wide, and agreement is substantial for pulmonary artery systolic pressure. It is recommended to estimate only as screening for pulmonary hypertension.
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INTRODUCTION: The reliability of pulmonary arterial systolic pressure by transthoracic echocardiography is limited by its variability to define pulmonary hypertension. OBJECTIVE: To know the variability of pulmonary arterial systolic pressure estimated by echocardiography in pulmonary hypertension. Their demographic variables were obtained. METHODS: From 2016-2020 subjects with pulmonary hypertension were recruited, with pulmonary artery systolic pressure estimated by transthoracic echocardiography and by right heart catheterization. Data were analyzed using the Bland-Altman descriptive statistic and the intraclass correlation coefficient (95% confidence interval). RESULTS: 152 subjects, age 60 ± 12 years, were studied. Body mass index 27.64 ± 4.69 kg/m2. The pulmonary artery systolic pressure estimated by transthoracic echocardiography 58.99 ± 18.62 vs. cardiac catheterization 55.43 ± 16.79 mmHg. Mean difference (bias) -3.6 (29.1, -36.2) and intraclass correlation coefficient 0.717 (0.610, 0.794). CONCLUSIONS: Variability is wide, and agreement is substantial for pulmonary artery systolic pressure. It is recommended to estimate only as screening for pulmonary hypertension.
INTRODUCCIÓN: La confiabilidad de la presión sistólica arterial pulmonar por ecocardiografía transtorácica se encuentra limitada por su variabilidad para definir la hipertensión pulmonar. OBJETIVO: Conocer la variabilidad en la presión sistólica arterial pulmonar estimada por ecocardiografía en la hipertensión pulmonar. MÉTODOS: En el periodo 2016-2020 se captaron sujetos con hipertensión pulmonar que tuvieron estimada la presión sistólica de la arteria pulmonar por ecocardiografía transtorácica y por cateterismo cardiaco derecho. Se obtuvieron sus variables demográficas. Los datos se analizaron con el estadístico descriptivo de Bland-Altman y el coeficiente de correlación intraclase (intervalo de confianza al 95%). RESULTADOS: Se estudiaron 152 sujetos, edad 60 ± 12 años. Índice de masa corporal 27.64 ± 4.69 kg/m2. La presión sistólica de la arteria pulmonar por ecocardiografía transtorácica 58.99 ± 18.62 vs. cateterismo cardiaco 55.43 ± 16.79. Diferencia media (sesgo) 3.6 (29.1, 36.2) y coeficiente de correlación intraclase 0.717 (0.610, 0.794). CONCLUSIONES: La variabilidad es amplia y el acuerdo es sustancial con la presión sistólica de la arteria pulmonar. Se aconseja estimarla solo como tamizaje de la hipertensión pulmonar.
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Hipertensão Pulmonar , Humanos , Pessoa de Meia-Idade , Idoso , Reprodutibilidade dos Testes , Pressão Sanguínea , Ecocardiografia , Cateterismo Cardíaco , Artéria Pulmonar/diagnóstico por imagemRESUMO
Peru was the first country where pfhrp2 and pfhrp3 gene deletions were detected despite the fact that rapid diagnostics tests are not commonly used for confirmatory malaria diagnosis. This context provides a unique scenario to study the dynamics of pfhrp2 and pfhrp3 gene deletions without apparent RDTs selection pressure. In this study we characterized the presence of pfhrp2 and pfhrp3 genes on 325 P. falciparum samples collected in Iquitos and surrounding communities between 2011 and 2018 in order to understand the dynamics of gene deletion prevalence, potential associations with clinical symptomatology and parasite genetic background. P. falciparum presence was confirmed by microscopy and PCR of 18 s rRNA, pfmsp1 and pfmsp2. Gene deletions were assessed by amplification of exon1 and exon2 of pfhrp2 and pfhrp3 using gene specific PCRs. Confirmation of absence of HRP2 expression was assessed by ELISA of HRP2 and pLDH. Genotyping of 254 samples were performed using a panel of seven neutral microsatellite markers. Overall, pfhrp2 and pfhrp3 dual gene deletions were detected in 67% (217/324) parasite samples. Concordance between pfhrp2 deletion and negligible HRP2 protein levels was observed (Cohen's Kappa = 0.842). Prevalence of gene deletions was heterogeneous across study sites (adjusted p < 0.005) but there is an overall tendency towards increase through time in the prevalence of dual pfhrp2/3-deleted parasites between 2011 (14.3%) and 2016 (88.39%) stabilizing around 65% in 2018. Dual deletions increase was associated with dominance of a single new parasite haplotype (H8) which rapidly spread to all study sites during the 8 study years. Interestingly, participants infected with dual pfhrp2/3-deleted parasites had a significantly lower parasitemias than those without gene deletions in this cohort. Our study showed the increase of pfhrp2/3 deletions in the absence of RDTs pressure and a clonal replacement of circulating lines in the Peruvian Amazon basin. These results suggest that other factors linked to the pfhrp2/3 deletion provide a selective advantage over non-deleted strains and highlight the need for additional studies and continuing surveillance.
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Malária Falciparum , Plasmodium falciparum , Humanos , Plasmodium falciparum/genética , Peru/epidemiologia , Histidina/genética , Deleção de Genes , Malária Falciparum/parasitologiaRESUMO
Malaria is a major health problem in Peru despite substantial progress achieved by the ongoing malaria elimination program. This study explored the population genetics of 63 Plasmodium falciparum and 170 P. vivax cases collected in the Peruvian Amazon Basin between 2015 and 2019. Microscopy and PCR were used for malaria detection and positive samples were genotyped at neutral and drug resistance-associated regions. The P. falciparum population exhibited a low nucleotide diversity (π = 0.02) whereas the P. vivax population presented a higher genetic diversity (π = 0.34). All P. falciparum samples (n = 63) carried chloroquine (CQ) resistant mutations on Pfcrt. Most P. falciparum samples (53 out of 54) carried sulfadoxine (SD) resistant mutations on Pfdhfr and Pfdhps. No evidence was found of artemisinin resistance mutations on kelch13. Population structure showed that a single cluster accounted for 93.4% of the P. falciparum samples whereas three clusters were found for P. vivax. Our study shows a low genetic diversity for both species with significant differences in genetic sub-structuring. The high prevalence of CQ-resistance mutations could be a result of indirect selection pressures driven by the P. vivax treatment scheme. These results could be useful for public health authorities to safeguard the progress that Peru has achieved towards malaria elimination.
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Antimaláricos , Artemisininas , Malária Falciparum , Malária Vivax , Malária , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Cloroquina/farmacologia , Cloroquina/uso terapêutico , Resistência a Medicamentos/genética , Humanos , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Vivax/tratamento farmacológico , Malária Vivax/epidemiologia , Nucleotídeos/uso terapêutico , Peru/epidemiologia , Plasmodium falciparum/genética , Plasmodium vivax/genética , Proteínas de Protozoários/genética , Sulfadoxina/uso terapêuticoRESUMO
Malaria elimination efforts in Peru have dramatically reduced the incidence of cases in the Amazon Basin. To achieve the elimination, the detection of asymptomatic and submicroscopic carriers becomes a priority. Therefore, efforts should focus on tests sensitive enough to detect low-density parasitemia, deployable to resource-limited areas and affordable for large screening purposes. In this study, we assessed the performance of the Malachite-Green LAMP (MG-LAMP) using heat-treated DNA extraction (Boil & Spin; B&S MG-LAMP) on 283 whole blood samples collected from 9 different sites in Loreto, Peru and compared its performance to expert and field microscopy. A real-time PCR assay was used to quantify the parasite density. In addition, we explored a modified version of the B&S MG-LAMP for detection of submicroscopic infection in 500 samples and compared the turnaround time and cost of the MG-LAMP with microscopy. Compared to expert microscopy, the genus B&S MG-LAMP had a sensitivity of 99.4% (95%CI: 96.9%- 100%) and specificity of 97.1% (95%CI: 91.9%- 99.4%). The P. vivax specific B&S MG-LAMP had a sensitivity of 99.4% (96.6%- 100%) and specificity of 99.2% (95.5%- 100%) and the P. falciparum assay had a sensitivity of 100% (95%CI: 78.2%- 100%) and specificity of 99.3% (95%CI: 97.3%- 99.8%). The modified genus B&S MG-LAMP assay detected eight submicroscopic malaria cases (1.6%) which the species-specific assays did not identify. The turnaround time of B&S MG-LAMP was faster than expert microscopy with as many as 60 samples being processed per day by field technicians with limited training and utilizing a simple heat-block. The modified B&S MG-LAMP offers a simple and sensitive molecular test of choice for the detection of submicroscopic infections that can be used for mass screening in resources limited facilities in endemic settings nearing elimination and where a deployable test is required.
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Malária Falciparum/diagnóstico , Microscopia/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium falciparum/isolamento & purificação , Corantes de Rosanilina/química , Humanos , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Peru/epidemiologiaRESUMO
Materials play a fundamental role in any branch of civil engineering. From ancient times to the present day, society has required enormous amounts of construction materials, which implies an excessive exploitation of the natural environment. The present research work consisted in the design and development of asphalt mixes with a partial substitution of the natural aggregate (NA) by means of recycled concrete aggregate (RCA). The mix was designed with the Marshall methodology, considering the next percentages of substitution and addition by mass: 90% NA and 10% RCA; 80% NA and 20% RCA; 70% NA and 30% RCA. The mixtures were elaborated and analysed under the international standards and the Mexican regulation of the Communications and Transport Ministry, to determine the best option regarding their performance. The materials were characterized according to the current regulations and later employed in the mixes design. A total of 38 specimens were elaborated for each mixture, determining the optimum asphalt content; after that, mechanical tests were performed to analyse and determine the best results. In the aftermath of the examination of all mixtures, we concluded that the 70%AN/30%RCA is the best alternative option according to its performance and numeric results, complying with the cited regulations, and allowing a lower content of asphalt during the process.
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As demonstrated with the novel coronavirus pandemic, rapid and accurate diagnosis is key to determine the clinical characteristic of a disease and to improve vaccine development. Once the infected person is identified, hematological findings may be used to predict disease outcome and offer the correct treatment. Rapid and accurate diagnosis and clinical parameters are pivotal to track infections during clinical trials and set protection status. This is also applicable for re-emerging diseases like dengue fever, which causes outbreaks in Asia and Latin America every 4 to 5 years. Some areas in the US are also endemic for the transmission of dengue virus (DENV), the causal agent of dengue fever. However, significant number of DENV infections in rural areas are diagnosed solely by clinical and hematological findings because of the lack of availability of ELISA or PCR-based tests or the infrastructure to implement them in the near future. Rapid diagnostic tests (RDT) are a less sensitive, yet they represent a timely way of detecting DENV infections. The purpose of this study was to determine whether there is an association between hematological findings and the probability for an NS1-based DENV RDT to detect the DENV NS1 antigen. We also aimed to describe the hematological parameters that are associated with the diagnosis through each test.
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COVID-19/diagnóstico , COVID-19/epidemiologia , Dengue/diagnóstico , Adolescente , Adulto , Ásia/epidemiologia , Criança , Pré-Escolar , Colômbia/epidemiologia , Dengue/virologia , Vírus da Dengue/isolamento & purificação , Testes Diagnósticos de Rotina/métodos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Masculino , Pandemias , Reação em Cadeia da Polimerase , Kit de Reagentes para Diagnóstico , SARS-CoV-2/isolamento & purificação , Adulto JovemRESUMO
Drinking water contamination is a frequent problem in developing countries and could be associated with bacterial pathogen carriage in feces. We evaluated the association between the risk of drinking water and bacterial carrier status in children younger than 5 years in a cross-sectional study conducted in 199 households from three Peruvian rural communities. Fecal samples from children were screened for pathogenic Aeromonas, Campylobacter, and Vibrio species, as well as for Enterobacteriaceae, including pathogenic Escherichia coli. The drinking water risk was determined using E. coli as an indicator of contamination. Nineteen (9.5%) children were colonized with pathogens and classified as carriers, all without diarrhea symptoms. Of 199 drinking water samples, 38 (19.1%) were classified as very high risk because of high fecal contamination (> 100 E. coli/100 mL). Shared-use water sources, daily washing of containers, and washing using only water were associated with higher prevalence of bacterial carriage, whereas there was no association between households reporting boiling and chlorination of water and carrier status. The prevalence of carriage in children exposed to very high-risk water was 2.82 (95% CI: 1.21-6.59) times the prevalence of those who consumed less contaminated water, adjusted by the water source and daily washing. Our results suggest that household drinking water plays an important role in the generation of carriers with diarrheal pathogens. Our findings also highlight the importance of interventions to ensure the safety of drinking water. Further studies are needed to validate the observed association and determine its significance with respect to diarrhea in the community.