Dengue Fever Surveillance in Mato Grosso do Sul: Insights from Genomic Analysis and Implications for Public Health Strategies.

Since its discovery in early 1916, dengue fever, a common vector-borne illness in Brazil, has resulted in extensive urban outbreaks and poses a serious threat to the public's health. Understanding the dynamics of Dengue Virus (DENV) serotypes circulating in different regions of Brazil is essential for implementing effective disease control and prevention measures. In response to this urgent need, we conducted an on-site training program in genomic surveillance in collaboration with the Central Laboratory of Health and the Secretary of Health of the Mato Grosso do Sul state. This initiative resulted in the generation of 177 DENV genome sequences collected between May 2021 and May 2022, a period during which over 11,391 dengue fever cases were reported in the state. Through this approach, we were able to identify the co-circulation of two different dengue serotypes (DENV1 and DENV2) as well as the existence of diverse viral lineages within each genotype, suggesting that multiple introduction events of different viral strains occurred in the region. By integrating epidemiological data, our findings unveiled temporal fluctuations in the relative abundance of different serotypes throughout various epidemic seasons, highlighting the complex and changing dynamics of DENV transmission throughout time. These findings demonstrate the value of ongoing surveillance activities in tracking viral transmission patterns, monitoring viral evolution, and informing public health actions.

Hepatitis B Virus Infection among Japanese Immigrants and Descendants: The Need to Strengthen Preventive and Control Measures.

This cross-sectional study aimed to investigate the prevalence and risk factors of Hepatitis B virus infection among Japanese immigrants and their descendants from São Paulo (SP), and to verify the occurrence of occult hepatitis B and coinfection with HCV, Delta, and HTLV. All samples (n = 2.127) were tested for HBV serological markers by electrochemiluminescence. HBsAg and/or total anti-HBc positive samples were tested for HBV DNA by real-time PCR, and genotyped by sequencing using the Sanger methodology. The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9-14.9%), and 22 (1.1%) were HBsAg positive. A high rate of susceptibility to HBV infection was found (67.4%; CI 95%: 65.4-69.4%). In contrast, only 19.2% (CI 95%: 17.6-20.9%) presented a serological profile analogous to that elicited by Hepatitis B vaccination. HBV isolates (n = 8) were classified as genotypes HBV/B1 (62.5%), HBV/C2 (12.5%), HBV/F1b (12.5%), and HBV/A1 (12.5%). Hepatitis B vaccination strategies and educational measures to control this infection should be considered.

Dinâmica temporal, subtipos e caracteristicas epidemiológicas da infecção pelo hiv-1, Brasil Central / Dinamic temporal, subtypes and epidemiological characteristics of hiv1 infection, Central Brazil

O objetivo deste estudo foi identificar os principais subtipos de HIV-1 circulantes no Mato Grosso do Sul (MS), Brasil Central. Métodos: Trata-se de um estudo transversal de séries temporais com dados de laboratório e relato de doença, analisados por período de diagnóstico e variáveis sociodemográficas e clínicas. Resultados: Subtipo B HIV-1 predominou quando os períodos foram analisados (85,4% vs 85,3%). Além disso, foi detectado um aumento na frequência do subtipo C do HIV-1, mas nenhuma diferença significativa foi observada entre os dois períodos. Após análise univariada, a faixa etária entre 25 e 45 anos (p = 0,004) e o gênero masculino (p = 0,04) mostraram-se associados ao subtipo B HIV-1. Os achados relacionados à resistência do HIV-1 à ARV mostraram que 30,6% dos pacientes diagnosticados com AIDS entre 1985 e 2012, submetidos a testes de genotipagem (212), eram resistentes a mais de três classes de ARVs (MDR). Conclusões: Estudos sobre a diversidade genética, bem como o perfil de mutações de resistência no HIV-1, são ferramentas importantes para a reconstrução histórica de epidemias regionais, vigilância epidemiológica local e diretrizes de tratamento.

The objective of this study was to identify the major subtypes of HIV-1 circulating in Mato Grosso do Sul (MS), Central Brazil. Methods:This is a cross-sectional study of time series with data from laboratory and disease report, analyzed by period of diagnosis and sociodemographic and clinical variables. Results: Subtype B HIV-1 predominated when periods were analyzed (85.4% vs 85.3%). In addition, an increase in the frequency of HIV-1 subtype C was detected, but no significant difference was seen between the two periods. After univariate analysis, the age range between 25 and 45 years (p = 0.004) and the masculine gender (p = 0.04) were found to be associated with subtype B HIV-1. The findings related to the resistance of HIV-1 to ARV showed that 30.6% of the investigated patients diagnosed AIDS between 1985 and 2012 who underwent genotyping tests (212) were resistant to more than three ARV classes (MDR). Conclusions: Studies on the genetic diversity, as well as the profile of resistance mutations in HIV-1, are important tools for both the historical reconstruction of regional epidemics and local epidemiological surveillance and treatment guidelines.