Prognostic factors of COVID-19 severity and mortality in the Yucatecan ethnic of México contrast with other populations.

Introduction: Previous studies that identified the prognostic factors for the severity of the new coronavirus disease 2019 (COVID-19) in different populations have generated controversial conclusions. The lack of a standard definition of COVID-19 severity and the differences between clinical diagnoses might make it difficult to provide optimum care according to the characteristics of each population.

Methodology: We investigated the factors that impacted the severe outcome or death from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients treated at the Mexican Institute of Social Security in Yucatán, México in 2020.

Low Activation of CD8 T Cells in response to Viral Peptides in Mexican Patients with Severe Dengue.

It is acknowledged that antiviral immune response contributes to dengue immunopathogenesis. To identify immunological markers that distinguish dengue fever (DF) and dengue hemorrhagic fever (DHF), 113 patients with confirmed dengue infection were analyzed at 6 or 7 days after fever onset. Peripheral blood mononuclear cells (PBMC) were isolated, lymphocyte subsets and activation biomarkers were identified by flow cytometry, and differentiation of T helper (Th) lymphocytes was achieved by the relative expression analysis of (Th1), (Th2), (Th17), and (T regulatory) transcription factors quantified by real-time PCR.

Antiviral and immunomodulatory effects of polyphenols on macrophages infected with dengue virus serotypes 2 and 3 enhanced or not with antibodies.

There is a lack of specific antiviral therapy against dengue virus (DENV) in current use. Therefore, a great proportion of dengue cases progress to severe clinical forms due to a complex interplay between virus and host immune response. It has been hypothesized that heterotypic non-neutralizing antibodies enhance DENV infection in phagocytic cells, and this induces an inflammatory response that is involved in the pathogenesis of severe dengue.

Serum levels of IFN-β are associated with days of evolution but not with severity of dengue.

The serum levels of beta interferon (IFN-β) were evaluated in clinical samples taken in the acute phase of dengue fever for 107 patients during the 2011 dengue outbreak in Yucatán, México. Dengue diagnoses were confirmed by NS1 or IgM/IgG serology in all patients. Average serum IFN-β levels in patients with dengue fever without warning signs (n = 53) were 140 pg/ml, and 105 pg/ml for patients with warning signs (n = 54).

[Population genetics of dengue virus and transmission of dengue fever].

The endemic behavior of dengue fever in Mexico during the past five years is of major concern to every sector related with public health and the effort to control the transmission has been focused on vector control. However, regardless of the effectiveness of the intervention measures it is important to know which elements determine dengue transmission. With regard to the molecular basis for dengue transmission, a great deal of progress has been made due to the introduction of genomic and bioinformatic approaches.

[Prevalence of neutralizing antibodies to dengue virus serotypes in university students from Tabasco, Mexico].

Objective: Determine the seroprevalence of neutralizing antibodies to dengue virus in students from the state university of Tabasco, Mexico.

Material And Methods: A transversal study was conducted of serum collected from students between September and November, 2005. The sera were screened for anti-dengue IgG and those that had evidence of dengue antibodies were analyzed by a plaque reduction neutralization test.