The Dengue (DENV) and zika (ZIKV) virus infections are currently a public health concern. At present, there is no treatment or a safe and effective vaccine for these viruses. Hence, the development ...of new strategies as host-directed therapy is required. In this sense, Metformin (MET), an FDA-approved drug used for the treatment of type 2 diabetes, has shown an anti-DENV effect in vitro by activating AMPK and reducing HMGCR activity. In this study, MET treatment was evaluated during in vitro and in vivo ZIKV infection and compared to MET treatment during DENV infection. Our results demonstrated that MET has a broad in vitro antiviral spectrum. MET inhibited ZIKV infection in different cell lines, but it was most effective in inhibiting DENV and yellow fever virus (YFV) infection in Huh-7 cells. However, the drug failed to protect against ZIKV infection when AG129 immunodeficient mice were used as in vivo model. Interestingly, MET increased DENV-infected male mice's survival time, reducing the severe signs of the disease. Together, these findings indicate that, although MET was an effective antiviral agent to inhibit in vitro and in vivo DENV infection, it could only inhibit in vitro ZIKV infection.
The epidemic potential of Chikungunya virus (CHIKV) was recently made evident by its introduction and rapid expansion in the Caribbean and the Americas. We sought to gain a detailed understanding of ...the dynamics of the epidemic in Mexico, the country with the highest number of confirmed CHIKV cases in the Americas, and to characterise viral evolution at the population and intra-host level. Analysis of the spatiotemporal distribution of 2,739 diagnosed cases in Mexico from December 2014 to December 2015 showed a rapid nationwide expansion of the epidemic with focalisation in the South West of the country. We sequenced the envelope glycoprotein 1 gene (E1) from 25 patients using the Illumina MiSeq platform and report synonymous and non-synonymous consensus mutations. Bayesian phylogenetic analysis using 249 Asian lineage E1 sequences gave updated estimates of nucleotide substitution rates for E1 and time to most recent common ancestor of major lineages. The analysis indicates phylogenetically-related emergent Latin American clusters in South Western Mexico, Nicaragua and Honduras and transmission of American strains in the Pacific islands. Detailed analysis showed that intra-host changes in E1 mainly occurred in two variable regions (E1:189-220 and E1:349-358) in domains II and III, respectively, in residues involved in inter and intra-envelope spike interactions. At the population level, this study sheds light on the introduction and evolutionary dynamics of CHIKV in the Americas. At the intra-host level, this study identifies mutational hotspots of the E1 protein with implications for understanding the relationship between the CHIKV quasispecies, viral fitness and pathogenesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
There is limited information on the antibody responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in subjects from developing countries with populations having a high ...incidence of co-morbidities. Here, we analysed the immunogenicity of homologous schemes using the ChAdOx1-S, Sputnik V, or BNT162b2 vaccines and the effect of a booster dose with ChAdOx1-S in middle-aged adults who were seropositive or seronegative to the SARS-CoV-2 spike protein before vaccination. The study was conducted post-vaccination with a follow-up of 4 months for antibody titre using enzyme-linked immunosorbent assay (ELISA) and pseudovirus (PV) neutralization assays (PNAs). All three vaccines elicited a superior IgG anti-receptor-binding domain (RBD) and neutralization response against the Alpha and Delta variants when administered to individuals with a previous infection by SARS-CoV-2. The booster dose spiked the neutralization activity among individuals with and without a prior SARS-CoV-2 infection. The ChAdOx1-S vaccine induced weaker antibody responses in infection-naive subjects. A follow-up of 4 months post-vaccination showed a drop in antibody titre, with about 20% of the infection-naive and 100% of SARS-CoV-2 pre-exposed participants with detectable neutralization capacity against Alpha pseudovirus (Alpha-PV) and Delta PV (Delta-PV). Our observations support the use of different vaccines in a country with high seroprevalence at the vaccination time.
During the first year of the SARS-CoV-2 pandemic in Mexico, more than two million people were infected. In this study, we analyzed full genome sequences from 27 February 2020 to 28 February 2021 to ...characterize the geographical and temporal distribution of SARS-CoV-2 lineages and identify the most common circulating lineages during this period. We defined six different geographical regions with particular dynamics of lineage circulation. The Northeast and Northwest regions were the ones that exhibited the highest lineage diversity, while the Central south and South/Southeast regions presented less diversity with predominance of a certain lineage. Additionally, by late February 2021, lineage B.1.1.519 represented more than 89% of all circulating lineages in the country.
With the arrival of chikungunya (CHIKV) and zika (ZIKV) viruses in Mexico, there was a decrease in diagnosed dengue virus (DENV) cases. During the first years of cocirculation (2015-2017), the ...algorithms established by epidemiological surveillance systems and the installed capacity limited us to one diagnostic test per sample, so there was an underestimation of cases until September 2017, when a multiplex algorithm was implemented. Therefore, the objective of this study was determine the impact of the introduction of CHIKV and ZIKV on the incidence of diagnosed DENV in endemic areas of Mexico, when performing the rediagnosis, using the multiplex algorithm, in samples from the first three years of co-circulation of these arboviruses.
For this, 1038 samples received by the Central Laboratory of Epidemiology between 2015 and 2017 were selected for this work. Viruses were identified by multiplex RT-qPCR, and the χ2 test was used to compare categorical variables. With the new multiplex algorithm, we identified 2.4 times the rate of arbovirosis as originally reported, evidencing an underestimation of the incidence of the three viruses. Even so, significantly less dengue was observed than in previous years. The high incidence rates of chikungunya and Zika coincided with periods of dengue decline. The endemic channel showed that the cases caused by DENV rose again after the circulation of CHIKV and ZIKV decreased. In addition, 23 cases of coinfection were identified, with combinations between all viruses.
The results obtained in this study show for the first time the real impact on the detected incidence of dengue after the introduction of CHIKV and ZIKV in Mexico, the degree of underestimation of these arboviruses in the country, as well as the co-infections between these viruses, whose importance clinical and epidemiological are still unknown.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Zika virus (ZIKV) is a mosquito-borne pathogen discovered in the late 40's in Uganda during a surveillance program for yellow fever. By 2014 the virus reached Eastern Island in the Americas, and two ...years later, the virus spread to almost all countries and territories of the Americas. The mosquito Aedes aegypti has been identified as the main vector of the disease, and several researchers have also studied the vector competence of Culex quinquefasciatus in virus transmission. The aim of the present study was to evaluate the vector competence of Ae. aegypti and Cx. quinquefasciatus in order to understand their roles in the transmission of ZIKV in Guadalajara, Jalisco, Mexico. In blood feeding laboratry experiments, we found that Ae. aegypti mosquitoes showed to be a competent vector able to transmit ZIKV in this area. On the other hand, we found that F0 Cx. quinquefasciatus mosquitoes are refractory to ZIKV infection, dissemination and transmission.
Abdominal obesity is highly prevalent in Mexico and has a poor prognosis in terms of the severity of coronavirus disease (COVID-19) and low levels of antibodies induced by infection and vaccination. ...We evaluated the humoral immune response induced by COVID-19 and five different vaccination schedules in Mexican individuals with abdominal obesity and the effects of other variables. This prospective longitudinal cohort study included 2084 samples from 389 participants. The levels of anti-S1/S2 and anti-RBD IgG antibodies were measured at various time points after vaccination. A high prevalence of hospitalization and oxygen use was observed in individuals with abdominal obesity (AO) who had COVID-19 before vaccination; however, they also had high levels of anti-S1/S2 and anti-RBD-neutralizing IgG antibodies. The same was true for vaccination-induced antibody levels. However, their longevity was low. Interestingly, we did not observe significant differences in vaccine reactogenicity between abdominally obese and abdominally non-obese groups. Finally, individuals with a higher body mass index, older age, and previous COVID-19 had higher levels of antibodies induced by COVID-19 and vaccination. Therefore, it is important to evaluate other immunological and inflammatory factors to better understand the pathogenesis of COVID-19 in the presence of risk factors and to propose effective vaccination schedules for vulnerable populations.
This review provides a comprehensive summary of evidence to explore the role and value of differential diagnosis in the management of Acute Respiratory Infections (ARIs) through point-of-care (POC) ...rapid testing in a post-pandemic scenario, paying particular attention to coronavirus disease 2019 (COVID-19), influenza, and respiratory syncytial virus (RSV). The document builds on a review of literature and policies and a process of validation and feedback by a group of seven experts from Latin America (LATAM). Evidence was collected to understand scientific and policy perspectives on the differential diagnosis of ARIs and POC rapid testing, with a focus on seven countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Mexico, and Peru. The evidence indicates that POC rapid testing can serve to improve ARI case management, epidemiological surveillance, research and innovation, and evidence-based decision-making. With multiple types of rapid tests available for POC, decisions regarding which tests to use require the consideration of the testing purpose, available resources, and test characteristics regarding accuracy, accessibility, affordability, and results turnaround time. Based on the understanding of the current situation, this document provides a set of recommendations for the implementation of POC rapid testing in LATAM, supporting decision-making and guiding efforts by a broad range of stakeholders.
SARS-CoV-2 is the causal agent of COVID-19; the first report of SARS-CoV-2 infection was in December 2019 in Wuhan, China. This virus has since caused the largest pandemic in history, and the number ...of deaths and infections has been significant. Nevertheless, the development of vaccines has helped to reduce both deaths and infections. Comorbidities such as diabetes, hypertension, heart and lung diseases, and obesity have been identified as additional risk factors for infection and the progression of COVID-19. Additionally, latent toxoplasmosis has been reported to be a risk factor for acquiring COVID-19 in some studies, but other studies have suggested a negative association between these two infections. Furthermore, in patients after vaccination or with COVID-19 and coinfection, an increase in the lethality and mortality of toxoplasmosis has been observed. Therefore, the objective of the current study is to determine the association of toxoplasmosis with COVID-19 in patients diagnosed with COVID-19. Serum samples from 384 patients previously diagnosed with COVID-19 using IgG antibodies against the S1/S2 antigens of SARS-CoV-2 were collected. Subsequently, anti
IgG and IgM antibodies were analyzed with ELISA. Statistical analysis was performed using SPSS Version 20.0 frequencies, percentages, 2 × 2 tables, and the Pearson correlation coefficient. IgG and IgM anti
antibodies were positive in 105/384 (27.34%) and (26/191) 13.6% of patients, respectively. The positivity for both infections was higher in patients aged >40 years old. Subjects who were overweight or obese were mainly positive for both IgG antibodies against S1/S2 SARS-CoV-2 and
antibodies. In conclusion, the coinfection rate was 21.7%. The prevalence of S1/S2 SARS-CoV-2 was 308/384 (80.2%), and the percentage of
antibodies was 27.34%.
COVID-19 forced us to investigate risk factors to provide the best medical attention, especially in vulnerable groups, such as pregnant patients. Studies in other populations have analyzed blood ...groups in relation to infection, complications, and death. The present study aimed to analyze the association of blood groups with the risk of infection and complications in pregnant women and newborns from the Mexican-Mestizo population. We studied 1906 individuals. Quantitative variables were analyzed through the Student's
-test. Categorical variables were analyzed through Pearson's chi-square test, and logistic regression was used to analyze the association between categorical variables and outcomes. No significant association was observed between blood groups and infection risk. Individuals with the AB blood type are at higher risk for developing severe disease, although blood groups do not seem to be involved in the risk of SARS-CoV-2 infection. However, the AB blood group could be considered a risk factor for developing severe COVID-19 in the Mexican population.
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