Usefulness of receptor binding domain protein-based serodiagnosis of COVID-19.

Objectives: This study evaluated the performance of recombinant receptor binding domain (RBD) protein-based enzyme-linked immunosorbent assays (RBD-ELISAs) for detecting anti-SARS-CoV-2 immunoglobulin (Ig) G and IgM antibodies. Methods: In this study, 705 sera from SARS-CoV-2-infected individuals and 315 sera from healthy individuals were analyzed. Results: The RBD-ELISA IgG exhibited high specificity (99.1%) and moderate sensitivity (48.0%), with an overall diagnostic accuracy of 73.5%. RBD-ELISA IgM demonstrated specificity at 94.6% and sensitivity at 51.1%, with an accuracy of 72.8%. Both assays displayed improved performance when analyzing samples collected 15-21 days post-symptom onset, achieving sensitivity and accuracy exceeding 88% and 90%, respectively. Combining RBD-ELISA IgG and IgM in parallel analysis enhanced sensitivity to 98.6% and accuracy to 96.2%. Comparing these RBD-ELISAs with commercially available tests, the study found overlapping sensitivity and similar specificity values. Notably, the combined RBD-ELISA IgG and IgM showed superior performance. Cross-reactivity analysis revealed low false-positive rates (4.4% for IgG, 3.7% for IgM), primarily with viral infections. Conclusion: This research underscores the potential of RBD-based ELISAs for COVID-19 diagnosis, especially when assessing samples collected 15-21 days post-symptom onset and utilizing a parallel testing approach. The RBD protein's immunogenicity and specificity make it a valuable tool for serodiagnosis, offering an alternative to polymerase chain reaction-based methods, particularly in resource-limited settings.

Alterations in deglutition in children with congenital Zika virus syndrome.

PURPOSE: To characterize swallowing in children with congenital Zika virus syndrome in comparison to typical children. METHODS: This cross-sectional study enrolled 45 children diagnosed with congenital Zika virus syndrome and 45 others with typical development. Swallowing was evaluated through clinical feeding evaluations Protocolo de Avaliação Clínica da Disfagia Pediátrica and using acoustic swallowing parameters (Doppler sonar). RESULTS: The mean age of children with congenital Zika virus syndrome was 26.69 ± 4.46 months and the mean head circumference was 29.20 ± 1.98 cm. Moderate/severe oropharyngeal dysphagia was found in 32(71.1%) of the children with congenital Zika virus syndrome. Significant differences were found between the groups on clinical evaluation: Children with congenital Zika virus syndrome presented insufficient lip closure 42(93.3%) and altered tonus of the tongue 35(77.8%) and cheeks 34(75.6%). In the children in the comparison group, only 6(13.3%) presented insufficient lip closure and 1(2.2%) had inadequate tongue posture. Changes during swallowing with liquid and spoonable food were not observed in the comparison group. When liquid/food was offered, affected children presented difficulties in sipping movements 14(77.8%) and lip/spoon contact 35(75%). The presence of residual food in the oral cavity after swallowing 38(86.4%) and clinical signs indicative of laryngotracheal penetration/aspiration, such as coughing, gagging and/or labored breathing, were also notable. No differences were found between the groups with regard to the acoustic parameters evaluated instrumentally. CONCLUSION: Children with congenital Zika virus syndrome present alterations in the oral phase of swallowing, as well as clinical signs indicative of pharyngeal phase impairment.

Accuracy of the urine point-of-care circulating cathodic antigen assay for diagnosing Schistosomiasis mansoni infection in Brazil: A multicenter study.

BACKGROUND: The World Health Organization recommends a market-ready, urine-based point-of-care diagnostic test for circulating cathodic antigens (CCA) to determine the prevalence of S. mansoni. This study evaluated the performance of the URINE CCA (SCHISTO) ECO TESTE® (POC-ECO), which is currently available in Brazil. METHODS: Residents from eight sites with different prevalence estimates provided one urine sample for POC-ECO and one stool sample for Kato-Katz (KK) and Helmintex® (HTX) testing as an egg-detecting reference for infection status. RESULTS: None of the study sites had significantly higher POC-ECO accuracy than KK. CONCLUSIONS: POC-ECO is not currently recommended in Brazilian schistosomiasis elimination programs.

Accuracy of the urine point-of-care circulating cathodic antigen assay for diagnosing Schistosomiasis mansoni infection in Brazil: A multicenter study

ABSTRACT Background: The World Health Organization recommends a market-ready, urine-based point-of-care diagnostic test for circulating cathodic antigens (CCA) to determine the prevalence of S. mansoni. This study evaluated the performance of the URINE CCA (SCHISTO) ECO TESTE® (POC-ECO), which is currently available in Brazil. Methods: Residents from eight sites with different prevalence estimates provided one urine sample for POC-ECO and one stool sample for Kato-Katz (KK) and Helmintex® (HTX) testing as an egg-detecting reference for infection status. Results: None of the study sites had significantly higher POC-ECO accuracy than KK. Conclusions: POC-ECO is not currently recommended in Brazilian schistosomiasis elimination programs.

Alterations in deglutition in children with congenital Zika virus syndrome / Alterações na deglutição em crianças com síndrome congênita do vírus Zika

ABSTRACT Purpose To characterize swallowing in children with congenital Zika virus syndrome in comparison to typical children. Methods This cross-sectional study enrolled 45 children diagnosed with congenital Zika virus syndrome and 45 others with typical development. Swallowing was evaluated through clinical feeding evaluations Protocolo de Avaliação Clínica da Disfagia Pediátrica and using acoustic swallowing parameters (Doppler sonar). Results The mean age of children with congenital Zika virus syndrome was 26.69 ± 4.46 months and the mean head circumference was 29.20 ± 1.98 cm. Moderate/severe oropharyngeal dysphagia was found in 32(71.1%) of the children with congenital Zika virus syndrome. Significant differences were found between the groups on clinical evaluation: Children with congenital Zika virus syndrome presented insufficient lip closure 42(93.3%) and altered tonus of the tongue 35(77.8%) and cheeks 34(75.6%). In the children in the comparison group, only 6(13.3%) presented insufficient lip closure and 1(2.2%) had inadequate tongue posture. Changes during swallowing with liquid and spoonable food were not observed in the comparison group. When liquid/food was offered, affected children presented difficulties in sipping movements 14(77.8%) and lip/spoon contact 35(75%). The presence of residual food in the oral cavity after swallowing 38(86.4%) and clinical signs indicative of laryngotracheal penetration/aspiration, such as coughing, gagging and/or labored breathing, were also notable. No differences were found between the groups with regard to the acoustic parameters evaluated instrumentally. Conclusion Children with congenital Zika virus syndrome present alterations in the oral phase of swallowing, as well as clinical signs indicative of pharyngeal phase impairment.

RESUMO Objetivo Caracterizar a deglutição das crianças com síndrome congênita do Zika vírus e comparar com crianças típicas. Método Estudo de delineamento transversal, com 45 crianças diagnosticadas com síndrome congênita do Zika vírus e 45 típicas. A deglutição foi avaliada por meio de avaliações clínicas da alimentação através do Protocolo de Avaliação Clínica da Disfagia Pediátrica e dos parâmetros acústicos da deglutição (sonar Doppler). Resultados A idade média das crianças com síndrome congênita do vírus Zika foi de 26,69 ± 4,46 meses e o perímetro cefálico médio foi de 29,20 ± 1,98 cm. Disfagia orofaríngea de moderada a grave foi observada em 32(71,1%) das crianças com síndrome congênita do Zika vírus, ao contrário do grupo comparação que não revelou alterações na deglutição. Nas crianças com síndrome congênita do Zika vírus foram verificados lábios entreabertos 42(93,3%) e tônus alterado em língua 35(77,8%) e bochechas 34(75,6%). Nas crianças do grupo comparação apenas 6(13,3%) apresentaram fechamento labial insuficiente e 1(2,2%) postura de língua inadequada. Alterações durante a deglutição com líquido e alimento pastoso não foram observadas no grupo comparação. Durante a oferta do alimento ocorreram dificuldades no movimento de sorver 14(77,8%), na captação da colher 35(75%), resíduo em cavidade oral 38(86,4%) e sinais clínicos indicativos de penetração/aspiração laringotraqueal como tosse, engasgo e respiração com esforço. Não foram encontradas diferenças nos parâmetros acústicos da avaliação instrumental. Conclusão as crianças com síndrome congênita do Zika vírus têm alterações nas fases oral e faríngea da deglutição, com sinais clínicos indicativos de penetração/aspiração laringotraqueal quando comparadas a crianças típicas.

SARS-CoV-2 variant of concern P.1 (Gamma) infection in young and middle-aged patients admitted to the intensive care units of a single hospital in Salvador, Northeast Brazil, February 2021.

OBJECTIVES: To evaluate changes in the characteristics of patients with coronavirus disease 2019 (COVID-19) after the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern (VOC) P.1 (Gamma), by comparing the clinical, demographic, and laboratory profiles of patients hospitalized during the first (May to July 2020) and second (December 2020 to February 2021) pandemic waves. METHODS: Data were collected from the records of COVID-19 patients (n = 4164) admitted to a single hospital in Salvador, Northeast Brazil. SARS-CoV-2 genome sequencing was performed on nasopharyngeal swab samples from 12 patients aged <60 years admitted to the intensive care unit (ICU) in February 2021. RESULTS: Between June 2020 and February 2021, the median age of patients admitted to the ICU decreased from 66 to 58 years (P < 0.05). This was accompanied by an increased proportion of patients without comorbidities (15.32% vs 32.20%, P < 0.0001). A significant reduction in the cycle threshold values of SARS-CoV-2 RT-PCR tests was observed in the second wave (P < 0.0001). Sequencing analysis detected lineage Gamma in all 12 ICU patients sampled in February 2021. CONCLUSIONS: The results of this study demonstrated an increased proportion of younger adults without comorbidities with severe disease during the second COVID-19 wave, shortly after the confirmation of local Gamma circulation.

Zika Brazilian Cohorts (ZBC) Consortium: Protocol for an Individual Participant Data Meta-Analysis of Congenital Zika Syndrome after Maternal Exposure during Pregnancy.

Despite great advances in our knowledge of the consequences of Zika virus to human health, many questions remain unanswered, and results are often inconsistent. The small sample size of individual studies has limited inference about the spectrum of congenital Zika manifestations and the prognosis of affected children. The Brazilian Zika Cohorts Consortium addresses these limitations by bringing together and harmonizing epidemiological data from a series of prospective cohort studies of pregnant women with rash and of children with microcephaly and/or other manifestations of congenital Zika. The objective is to estimate the absolute risk of congenital Zika manifestations and to characterize the full spectrum and natural history of the manifestations of congenital Zika in children with and without microcephaly. This protocol describes the assembly of the Consortium and protocol for the Individual Participant Data Meta-analyses (IPD Meta-analyses). The findings will address knowledge gaps and inform public policies related to Zika virus. The large harmonized dataset and joint analyses will facilitate more precise estimates of the absolute risk of congenital Zika manifestations among Zika virus-infected pregnancies and more complete descriptions of its full spectrum, including rare manifestations. It will enable sensitivity analyses using different definitions of exposure and outcomes, and the investigation of the sources of heterogeneity between studies and regions.

Neurological symptoms and signs in HTLV-1 patients with overactive bladder syndrome.

OBJECTIVE: To compare neurological symptoms and signs in HTLV-1 asymptomatic carriers and HTLV-1 patients with overactive bladder (OB) syndrome. METHODS: We studied 102 HTLV-1 positive individuals without HAM/TSP (HTLV-1 associated myelopathy/tropical spastic paraparesis) divided into two groups according to the presence or absence of OB syndrome. Clinical interview, neurological exam and proviral load was performed in all patients. RESULTS AND CONCLUSIONS: Individuals with OB were more commonly female (84.3 vs. 60.8% of asymptomatics, p=0.01). The prevalence of neurological complaints was higher in OB group, especially hand or foot numbness and arm or leg weakness. There was no difference between the groups in neurological strength and reflexes. Weakness complaint remained strongly associated with OB in multivariate logistic regression analysis adjusting for sex and age [adjusted odds ratio and 95%CI 3.59 (1.45-8.88) in arms and 6.68 (2.63-16.93) in legs]. Proviral load was also different between the two groups with higher level on OB individuals.

Neurological symptoms and signs in HTLV-1 patients with overactive bladder syndrome / Sinais e sintomas neurológicos em pacientes com HTLV-1 e síndrome de bexiga hiperativa

OBJECTIVE: To compare neurological symptoms and signs in HTLV-1 asymptomatic carriers and HTLV-1 patients with overactive bladder (OB) syndrome. METHODS: We studied 102 HTLV-1 positive individuals without HAM/TSP (HTLV-1 associated myelopathy/tropical spastic paraparesis) divided into two groups according to the presence or absence of OB syndrome. Clinical interview, neurological exam and proviral load was performed in all patients. RESULTS AND CONCLUSIONS: Individuals with OB were more commonly female (84.3 vs. 60.8% of asymptomatics, p=0.01). The prevalence of neurological complaints was higher in OB group, especially hand or foot numbness and arm or leg weakness. There was no difference between the groups in neurological strength and reflexes. Weakness complaint remained strongly associated with OB in multivariate logistic regression analysis adjusting for sex and age [adjusted odds ratio and 95%CI 3.59 (1.45-8.88) in arms and 6.68 (2.63-16.93) in legs]. Proviral load was also different between the two groups with higher level on OB individuals.

OBJETIVO: Comparar sintomas e sinais neurológicos em pacientes portadores do HTLV-1 assintomáticos e com síndrome de bexiga hiperativa (BH). MÉTODOS: Foram estudados 102 indivíduos com HTLV-1 sem HAM/TSP (mielopatia associada ao HTLV-I/paraparesia espástica tropical), divididos em dois grupos segundo a presença ou ausência de BH. Foram realizados em todos os pacientes entrevista clínica, exame neurológico e carga proviral. RESULTADOS E CONCLUSÕES: Indivíduos com BH foram na maioria do sexo feminino (84,3 vs. 60,8% dos assintomáticos, p=0,01). A prevalência de queixas neurológicas foi maior no grupo BH, especialmente dormências e fraqueza em extremidades. Não houve diferença entre os grupos em relação a achados do exame neurológico. Fraqueza subjetiva permaneceu fortemente associada com BH na regressão logística multivariada ajustada para sexo e idade [OR e IC95% 3,59 (1,45-8,88) nos braços e 6,68 (2,63-16,93) nas pernas]. A carga proviral foi também diferente entre os dois grupos com nível maior em indivíduos com BH.

Avaliação da reação da polimerase em cadeia em tempo real para o diagnóstico e prognóstico em crianças com Leishmaniose visceral / Evaluation of reaction polymerase chain real-time diagnosis and prognosis in children with visceral leishmaniasis

As leishmanioses são causadas por protozoários do gênero Leishmania, sendo a Leishmaniose visceral (LV) a forma mais grave da doença. A Organização Mundial de Saúde estima a existência de 500.000 casos/ano mundialmente, sendo que a maioria desses casos ocorre em crianças com idade inferior a 10 anos. Atualmente não existem métodos disponíveis para avaliar o prognóstico e a probabilidade de falha terapêutica em pacientes com LV. Conduzimos um estudo prospectivo entre crianças com LV admitidas em um hospital pediátrico, para avaliar o valor do PCR quantitativo para o manejo clinico da LV em pacientes não infectados pelo HIV. Cinquenta e três pacientes com LV foram incluídos no estudo, sendo observado 85 por cento de cura (79,2 por cento de cura com 30 dias de tratamento e 5,6 por cento de cura após tratamento prolongado), 9,4 por cento de óbitos e 5,6 por cento de recidivas. No momento do diagnóstico, DNA de Leishmania foi detectado em sangue periférico de 44/53 (83 por cento) pacientes e em 26/29 (89.6 por cento) amostras de medula óssea. Após uma semana de tratamento, os níveis de parasitos (carga parasitária em sangue periférico) diminuíram expressivamente (média de 3.086 ±9.365 parasitos/ml para 333± 636 parasitos/ml). As cargas parasitárias tornaram-se indetectáveis após duas semanas de tratamento em todos os pacientes que atingiram critérios de cura com quatro semanas de tratamento. Uma amostra negativa no 14° dia de tratamento foi preditora de cura satisfatória, com as amostras que permaneceram positivas predizendo recaídas ou resposta clínica insatisfatória.

Validação do teste imunocromatográfico rápido IT-LEISH® para o diagnóstico da leishmaniose visceral humana / Validation of the rapid immunochromatographic test IT-LEISH® for the diagnosis of human visceral leishmaniasis

O teste imunocromatográfico rápido IT-LEISH® (DiaMed IT-LEISH®) foi validado para o diagnóstico da leishmaniose visceral (LV) em quatro áreas endêmicas do Brasil. O desempenho do IT-LEISH® foi comparado ao da reação de imunofluorescência indireta; e ao da reação imunoenzimática, usando-se antígeno solúvel de Leishmania chagasi e recombinante K39 (rK39). O estudo incluiu 332 pacientes com quadro clínico sugestivo de LV: 213 casos de LV confirmados parasitologicamente; e 119 não-casos, com confirmação de outra etiologia. O teste IT-LEISH® apresentou sensibilidade de 93 por cento e especificidade de 97 por cento. As técnicas RIFI (imunofluorescência indireta), ELISA L. chagasi e ELISA rK39 apresentaram sensibilidade de 88 por cento, 92 por cento e 97 por cento e especificidades de 81 por cento, 77 por cento e 84 por cento, respectivamente. Os resultados confirmam a validade do teste IT-LEISH® para o diagnóstico da LV no Brasil...

Avaliação de antígenos recombinantes candidatos para o desenvolvimento de vacina para leptospirose / Evaluation of recombinat anyigens as potential targets for development of leptospirosis vaccine

A Leptospirose , causada espiroqueta patogênica Leptospira interrogans, é a zoonose de maior distribuição mundial ( WHO 1999), atigindo principalmente países tropicais, onde representa um problema importante para saúde pública. Abordagens preventivas, como vacinas eficazes para seres humanos precisam ser desenvolvidas urgentemente. Estratégicas baseadas em antígenos recombinantes oferecem uma alternativa custo-efetiva e têm sido usadas para desenvolver vacinas licenciadas para o uso na prevenção de outras doenças bacterianas. Proteínas recombinantes de Leptospira interrogans têm sido caracterizadas e induzem resposta protetora parcial em modelo experimental de imunização para leptospirose. Com isso, surge a necessidade de avaliação e identificação de antígenos recombinantes candidatos para uma vacina segura e efetiva contra leptospirose. Com o recente sequenciamento do genoma de Leptospira, novas proteínas serão identificadas, tornando-se necessário a avaliação destas proteínas para seleção daquelas que possam representar potenciais alvos para o uso em vacina e métodos diagnósticos. Nesta dissertação, padronizamos e validamos ensaios de antigenicidade, imunogenicidade e localização, para caracterização de proteínas de Leptospira. Além disso, caracterizamos uma nova proteína, LigB, que possui homologia com outras proteínas como intimina e invasina, fatores de virulência de E. coli enteropatogênica e Yersinia pseudotuberculosis, respectivamente. A expressão de LigB está presente em cepa virlenta de L. interrogans e não é detectada em cepa atenuada, demonstrando que sua expressão está correlacionada com a virulência. Além disso, a expressão de Ligb está aumentada durante a infecção do hospedeiro e sua localização parece ser na superficie da membrana externa de bactéria. A caracterização de LigB aponta esta proteína como uma candidata promissora para uso no desenvolvimento de uma vacina eficaz contra leptospirose.