ALVINA CLARA FELIX
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina
LIM/52 - Laboratório de Virologia, Hospital das Clínicas, Faculdade de Medicina
LIM/52 - Laboratório de Virologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
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- Dengue Virus Serotype 2 Intrahost Diversity in Patients with Different Clinical Outcomes(2021) TORRES, Maria Celeste; MENDONCA, Marcos Cesar Lima de; RODRIGUES, Cintia Damasceno dos Santos; FONSECA, Vagner; RIBEIRO, Mario Sergio; BRANDAO, Ana Paula; CUNHA, Rivaldo Venancio da; DIAS, Ana Isabel; BOAS, Lucy Santos Vilas; FELIX, Alvina Clara; PEREIRA, Maira Alves; PINTO, Luzia Maria de Oliveira; SAKUNTABHAI, Anavaj; FILIPPIS, Ana Maria Bispo deIntrahost genetic diversity is thought to facilitate arbovirus adaptation to changing environments and hosts, and it might also be linked to viral pathogenesis. Dengue virus serotype 2 (DENV-2) has circulated in Brazil since 1990 and is associated with severe disease and explosive outbreaks. Intending to shed light on the viral determinants for severe dengue pathogenesis, we sought to analyze the DENV-2 intrahost genetic diversity in 68 patient cases clinically classified as dengue fever (n = 31), dengue with warning signs (n = 19), and severe dengue (n = 18). Unlike previous DENV intrahost diversity studies whose approaches employed PCR, here we performed viral whole-genome deep sequencing from clinical samples with an amplicon-free approach, representing the real intrahost diversity scenario. Striking differences were detected in the viral population structure between the three clinical categories, which appear to be driven mainly by different infection times and selection pressures, rather than being linked with the clinical outcome itself. Diversity in the NS2B gene, however, showed to be constrained, irrespective of clinical outcome and infection time. Finally, 385 non-synonymous intrahost single-nucleotide variants located along the viral polyprotein, plus variants located in the untranslated regions, were consistently identified among the samples. Of them, 124 were exclusively or highly detected among cases with warning signs and among severe cases. However, there was no variant that by itself appeared to characterize the cases of greater severity, either due to its low intrahost frequency or the conservative effect on amino acid substitution. Although further studies are necessary to determine their real effect on viral proteins, this heightens the possibility of epistatic interactions. The present analysis represents an initial effort to correlate DENV-2 genetic diversity to its pathogenic potential and thus contribute to understanding the virus's dynamics within its human host.
- Performance of at-home self-collected saliva and nasal-oropharyngeal swabs in the surveillance of COVID-19(2021) BRAZ-SILVA, Paulo H.; MAMANA, Ana C.; ROMANO, Camila M.; FELIX, Alvina C.; V, Anderson de Paula; FEREIRA, Noeli E.; BUSS, Lewis F.; TOZETTO-MENDOZA, Tania R.; V, Rafael A. Caixeta; LEAL, Fabio E.; GRESPAN, Regina M. Z.; BIZARIO, Joao C. S.; FERRAZ, Andrea B. C.; SAPKOTA, Dipak; GIANNECCHINI, Simone; TO, Kelvin K.; DOGLIO, Alain; MENDES-CORREA, Maria C.Background: SARS-CoV-2 quickly spreads in the worldwide population, imposing social restrictions to control the infection, being the massive testing another essential strategy to break the chain of transmission. Aim: To compare the performance of at-home self-collected samples - saliva and combined nasal-oropharyngeal swabs (NOP) - for SARS-CoV-2 detection in a telemedicine platform for COVID-19 surveillance. Material and methods: We analyzed 201 patients who met the criteria of suspected COVID-19. NOP sampling was combined (nostrils and oropharynx) and saliva collected using a cotton pad device. Detection of SARS-COV-2 was performed by using the Altona RealStar (R) SARS-CoV-2 RT-PCR Kit 1.0. Results: There was an overall significant agreement (kappa coefficient value of 0.58) between saliva and NOP. Considering results in either sample, 70 patients positive for SARS-CoV-2 were identified, with 52/70 being positive in NOP and 55/70 in saliva. This corresponds to sensitivities of 74.2% (95% CI; 63.7% to 83.1%) for NOP and 78.6% (95% CI; 67.6% to 86.6%) for saliva. Conclusion: Our data show the feasibility of using at-home self-collected samples (especially saliva), as an adequate alternative for SARS-CoV-2 detection. This new approach of testing can be useful to develop strategies for COVID-19 surveillance and for guiding public health decisions.
- Zika virus infection among symptomatic patients from two healthcare centers in Sao Paulo State, Brazil: prevalence, clinical characteristics, viral detection in body fluids and serodynamics(2019) TOZETTO-MENDOZA, Tania Regina; AVELINO-SILVA, Vivian Iida; FONSECA, Silvia; CLARO, Ingra Morales; PAULA, Anderson Vicente de; LEVIN, Anna Sara; SABINO, Ester Cerdeira; MENDES-CORREA, Maria Cassia; FIGUEIREDO, Walter Manso; FELIX, Alvina Clara; SOUZA, Nathalia C. Santiago; COSTA, Angela Aparecida; INENAMI, Maria; SILVA, Rosangela M. Gasparetto da; LEVI, Jose Eduardo; ROMANO, Camila Malta; PARANHOS-BACCALA, Glaucia; SEGURADO, Aluisio Cotrim; MAYAUD, PhilippeZika virus (ZIKV) clinical presentation and frequency/duration of shedding need further clarification. Symptomatic ZIKV-infected individuals identified in two hospitals in Sao Paulo State, Brazil, were investigated regarding clinical characteristics, shedding in body fluids, and serodynamics. Ninety-four of 235 symptomatic patients (Site A: 58%; Site B: 16%) had Real-Time PCR-confirmed ZIKV infection; fever, headache and gastrointestinal symptoms were less frequent, and rash was more frequent compared to ZIKV-negative patients. Real-Time PCR in serum had worse performance compared to plasma, while urine had the highest sensitivity. Shedding in genital fluids and saliva was rare. IgM positivity was the highest <14 days after the symptoms onset (86%), decreasing >28 days (24%); IgG positivity increased >14 days (96%) remaining positive in 94% of patients >28 days. ZIKV prevalence varied importantly in two neighboring cities during the same transmission season. Urine Real-Time PCR can improve diagnostic sensitivity; serum testing is less useful. Accurate serological tests are needed to improve diagnosis and surveillance.