Significant Performance Variation Among PCR Systems in Diagnosing Congenital Toxoplasmosis in São Paulo, Brazil: Analysis of 467 Amniotic Fluid Samples

INTRODUCTION: Performance variation among PCR systems in detecting Toxoplasma gondii has been extensively reported and associated with target genes, primer composition, amplification parameters, treatment during pregnancy, host genetic susceptibility and genotypes of different parasites according to geographical characteristics. PATIENTS: A total of 467 amniotic fluid samples from T. gondii IgM- and IgG-positive Brazilian pregnant women being treated for 1 to 6 weeks at the time of amniocentesis (gestational ages of 14 to 25 weeks). METHODS: One nested-B1-PCR and three one-round amplification systems targeted to rDNA, AF146527 and the B1 gene were employed. RESULTS: Of the 467 samples, 189 (40.47%) were positive for one-round amplifications: 120 (63.49%) for the B1 gene, 24 (12.69%) for AF146527, 45 (23.80%) for both AF146527 and the B1 gene, and none for rDNA. Fifty previously negative one-round PCR samples were chosen by computer-assisted randomization analysis and re-tested (nested-B1-PCR), during which nine additional cases were detected (9/50 or 18%). DISCUSSION: The B1 gene PCR was far more sensitive than the AF146527 PCR, and the rDNA PCR was the least effective even though the rDNA had the most repetitive sequence. Considering that the four amplification systems were equally affected by treatment, that the amplification conditions were optimized for the target genes and that most of the primers have already been reported, it is plausible that the striking differences found among PCR performances could be associated with genetic diversity in patients and/or with different Toxoplasma gondii genotypes occurring in Brazil. CONCLUSION: The use of PCR for the diagnosis of fetal Toxoplasma infections in Brazil should be targeted to the B1 gene when only one gene can be amplified, preferably by nested amplification with primers B22/B23

Potential effect of Zika virus infection on human male fertility?

BACKGROUND: Zika virus (ZIKV) sexual transmission and prolonged viral shedding in semen have been previously reported, suggesting a strong viral affinity for genital tissues. A transient impact of ZIKV on male fertility was shown in animal and human studies. METHODS: Adult male patients with confirmed ZIKV infection diagnosed in the city of Araraquara, Brazil during the epidemic season of 2016 were invited one year after the acute infection to respond to a questionnaire of genital symptoms and to provide a semen sample for molecular ZIKV testing and spermogram analysis, as well as a serum sample for hormonal testing. RESULTS: 101 of 187 tested patients had positive ZIKV RT-PCR in plasma and/or urine samples (54%, 72 women and 29 men). Of 15 adult male participants for whom telephone contact was successful, 14 responded to the questionnaire of genital symptoms and six consented to provide a semen sample at a median of 12 months after the acute infection. We report abnormal spermogram results from patients one year after confirmed ZIKV infection. CONCLUSIONS: Our findings suggest a possible long-term detrimental effect of ZIKV infection on human male fertility that has to be further explored in well-characterized samples from cohort studies conducted in ZIKV-endemic areas

Absence of neutralizing antibodies against the Omicron SARS-CoV-2 variant in convalescent sera from individuals infected with the ancestral SARS-CoV-2 virus or its Gamma variant

Objectives: The aim of the present study was to evaluate if neutralizing antibody responses induced by infection with the SARS-CoV-2 strain that was dominant at the beginning of the pandemic or by the Gamma variant was effective against the Omicron variant. Methods: Convalescent sera from 109 individuals, never exposed to a SARS-CoV-2 vaccine, who had mild or moderate symptoms not requiring hospitalization following either a documented SARS-CoV-2 ancestral strain infection or a Gamma variant infection, were assayed for in vitro neutralizing antibody activity against their original strains and the Omicron variant. Results: Following an infection with the ancestral strain, 56 (93.3%), 45 (77.6%) and 1 (1.7%) serum sample were positive for neutralizing antibodies against the ancestral, Gamma variant, and Omicron variant, respectively. After infection with the Gamma variant, 43 (87.8%) and 2 (4.1%) sera were positive for neutralizing antibodies against the Gamma and Omicron variants, respectively. Conclusions: Neutralizing antibodies generated following mild or moderate infection with the SARS-CoV-2 ancestral strain or the Gamma variant are not protective against the Omicron variant

Parasitemia and antibody response to benznidazole treatment in a cohort of patients with chronic Chagas disease

BackgroundEvaluating the effectiveness of Chagas disease treatment poses challenges due to the lack of biomarkers for disease progression and therapeutic response. In this study, we aimed to assess the clearance of Trypanosoma cruzi (T. cruzi) parasites in a group of benznidazole (BNZ)-treated chronic Chagas disease patients using high-sensitivity quantitative PCR (qPCR) and track T. cruzi antibody levels through a semiquantitative chemiluminescent assay.MethodsA total of 102 T. cruzi seropositive patients with previous PCR-positive results were enrolled in the study. We collected samples 30 days before treatment (T-30d), on the day before initiating BNZ treatment (T0d), and at follow-up visits 60 days (T60d), 6 months (T6M), 12 months (T12M), and 36 months (T36M) after treatment initiation. Treatment efficacy was assessed by testing of serial samples using a target-capture qPCR assay specific to satellite T. cruzi DNA and the ORTHO T. cruzi ELISA Test System for antibody quantitation.ResultsOf the enrolled individuals, 87 completed at least 50% of the treatment course, and 86 had PCR results at follow-up visits T6M, T12M, and T36M. PCR results exhibited fluctuations before and after treatment, but levels were significantly lower post-treatment. Only 15 cases consistently tested PCR-negative across all post-treatment visits. Notably, nearly all participants demonstrated a declining antibody trajectory, with patients who tested PCR-negative at T36M exhibiting an earlier and more pronounced decline compared to PCR-positive cases at the same visit.ConclusionOur study suggests that serial PCR results pose challenges in interpretation. In contrast, serial antibody levels may serve as an ancillary, or even a more reliable indicator of parasite decline following BNZ treatment. Monitoring antibody levels can provide valuable insights into the efficacy of treatment and the persistence of parasites in Chagas disease patients

Evaluation of eleven immunochromatographic assays for SARS-CoV-2 detection: investigating the dengue cross-reaction

COVID-19 disease is spread worldwide and diagnostic techniques have been studied in order to contain the pandemic. Immunochromatographic (IC) assays are feasible and a low-cost alternative especially in low and middle-income countries, which lack structure to perform certain diagnostic techniques. Here we evaluate the sensitivity and specificity of eleven different IC tests in 145 serum samples from confirmed cases of COVID-19 using RT-PCR and 100 negative serum samples from blood donors collected in February 2019. We also evaluated the cross-reactivity with dengue using 20 serum samples from patients with confirmed diagnosis for dengue collected in early 2019 through four different tests. We found high sensitivity (92%), specificity (100%) and an almost perfect agreement (Kappa 0.92) of IC assay, especially when we evaluated IgG and IgM combined after 10 days from the onset of symptoms with RT-PCR. However, we detected cross-reactivity between dengue and COVID-19 mainly with IgM antibodies (5 to 20% of cross-reaction) and demonstrated the need for better studies about diagnostic techniques for these diseases

Importation and early local transmission of COVID-19 in Brazil, 2020

We conducted the genome sequencing and analysis of the first confirmed COVID-19 infections in Brazil. Rapid sequencing coupled with phylogenetic analyses in the context of travel history corroborate multiple independent importations from Italy and local spread during the initial stage of COVID-19 transmission in Brazil

Assessment of knowledge and attitudes about Zika virus infection among women of childbearing age

A infecção pelo Zika vírus (ZIKV) vem sendo correlacionada, desde 2015, a um importante aumento do número de casos de recém-nascidos com microcefalia e outras malformações congênitas. O Brasil foi o primeiro país a notificar um aumento do número de casos de microcefalia, e a associação causal com a infecção por ZIKV foi embasada por estudos que revelaram de presença do ZIKV em lesões neurológicas de recém-nascidos e o efeito deletério do vírus em modelos animais. A doença é transmitida principalmente por via vetorial, mas pode também ocorrer transmissão por via sexual, congênita e através da transfusão de hemoderivados. O presente estudo visou avaliar o grau de conhecimento sobre a infecção pelo ZIKV e suas formas de prevenção entre mulheres em idade fértil (MIF) não gestantes e entre gestantes de 18 a 45 anos residentes no município do estado de São Paulo e Grande São Paulo, atendidas em unidades de atenção primária. Esses dois grupos foram comparados quanto ao conhecimento sobre a infecção e sobre práticas de prevenção. Além disso, exploramos o impacto da epidemia sobre o planejamento reprodutivo nessa população. Foram incluídas 324 mulheres, sendo 260 MIF não gestantes e 64 gestantes, durante o período de dezembro de 2017 a julho de 2018. O perfil sócio demográfico foi semelhante nos dois grupos de participantes. Dentre as 64 gestantes, 34% haviam planejado a gravidez, 33% relataram que vinham tomando precauções para evitar a gravidez e as 33% restantes não tinham planejado nem evitado; 12 (19%) das gestantes relataram ter adiado a gravidez, e dentre essas 3 o fizeram por medo da infecção pelo ZIKV. O conhecimento a respeito da transmissão vetorial e da potencial ocorrência de malformações congênitas devido ao ZIKV foi elevado em ambos os grupos; entretanto, a maioria (85%) das mulheres não sabia sobre a transmissão do ZIKV por via sexual, sem diferenças entre gestantes e MIF não gestantes. Os resultados obtidos mostram que ações de educação e prevenção do ZIKV nessa população são urgentemente necessárias, dado o risco iminente de recorrência da infecção em nosso meio.Since 2015, Zika virus (ZIKV) infection has been associated with a significant increase in the number of newborns with microcephaly and other congenital malformations. Brazil was the first country to report an increase in the number of microcephaly cases, with studies supporting the causal association with ZIKV infection based on the demonstration that ZIKV is present in neurological lesions of fetuses and causes direct damage in animal models. ZIKV transmission occurs mainly through the bite of mosquitos, but transmission through sexual intercourse, congenitally and through contaminated blood products have also been demonstrated. This study aimed to evaluate the degree of knowledge about ZIKV infection and its prevention strategies among non-pregnant women of chilbearing age (WCA) and pregnant women aged 18-45 years old living in São Paulo and followed in primary care units. These groups were compared regarding knowledge about ZIKV infection and prevention attitudes. We also explored if ZIKV had an impact on family planning issues in this population. A total of 324 women were included between December 2017 to July 2018, of which 260 were of non-pregnant WCA and 64 were pregnant. Groups had similar demographic characteristics. Among 64 pregnant women, 34% had planned to get pregnant, 33% reported that they were taking precautions to avoid their pregnancy and the remaining 33% had neither planned nor avoided; 12 (19%) of the pregnant women reported they had postponed pregnancy and 3 of those postponed pregnancy because they were afraid of ZIKV infection. Overall, knowledge about ZIKV vector transmission and the risk of congenital malformations was high in both groups; however, most women (85%) ignored the risk of ZIKV sexual transmission. We failed to find statistically significant differences between groups regarding knowledge of ZIKV sexual transmission. Our results show that education and prevention actions are urgently needed for this population, given the risk of recurrence of ZIKV in our setting

ALTERAÇÕES TRANSCRICIONAIS PRECOCEMENTE ENVOLVIDAS NA PROGRESSÃO DE PACIENTES PARA DOENÇA ARTICULAR CRÔNICA PÓS-CHIKUNGUNYA

Introdução/Objetivo: Infecções pelo vírus Chikungunya (CHIKV) podem frequentemente resultar no desenvolvimento de Doença Articular Inflamatória Crônica pós-Chikungunya (pCHIKV-CIJD). Essa condição gera impactos na qualidade de vida dos pacientes e nos gastos com a saúde pública. Neste estudo, visamos identificar mecanismos moleculares precocemente envolvidos na evolução para pCHIKV-CIJD. Método: Pacientes em fase aguda de chikungunya foram incluidos em uma coorte prospectiva e tiveram o seguimento de 90 dias. Aqueles pacientes que permaneceram com sinais clínicos de artrite e exame de imagem alterado foram considerados pCHIKV-CIJD. O RNA foi obtido do sangue total dos pacientes e foi realizado o sequenciamento de RNA total e small RNA. Foram realizadas análises de genes e microRNAs diferencialmente expressos, enriquencimento de vias, análise de módulos de coexpressão e interactoma. Resultados: Comparando os pacientes que evoluíram para pCHIKV-CIJD com aqueles que não evoluíram, nós identificamos assinaturas moleculares precocemente associadas a cronificação nas fases aguda e subaguda da doença. Essas moléculas foram principalmente associadas a alterações na regulação da resposta imune. Dentre elas, o gene LIFR, que codifica para um receptor celular envolvido em um aumento de transcrição de IL-6, encontra-se sub-expresso em pacientes pCHIKV-CIJD. LIFR foi previamente validado como um alvo de miR-98-5p, que encontra-se superexpresso nesses pacientes. Pacientes que evoluíram para doença crônica também apresentaram redução dos níveis de transcritos de importantes mediadores imunológicos como interleucinas e seus receptores, como IL-6 e IL-6R; genes associados ao recrutamento de células imunes e resposta adaptativa, como CCR2; e genes que codificam diferentes subunidades do complexo proteossoma. Além disso, esses pacientes apresentaram redução dos níveis de MMP8, LFT e DDIT4. Esses genes já foram descritos como alterados em outros tipos de artrite como osteoartrite e artrite reumatóide e parecem também ser relevantes para o desenvolvimento de pCHIKV-CIJD. Conclusão: Juntos, nossos achados adicionam conhecimento acerca dos mecanismos moleculares precocemente envolvidos na cronificação e destacam potenciais alvos para novos estudos. Entender esses mecanismos é crucial para o desenvolvimento de terapias efetivas e intervenções para os pacientes acometidos, podendo mitigar os efeitos da doença e reduzir os impactos causados

Clinical, laboratory and follow-up information of the 169 CHIKF-confirmed volunteers.

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