The Burden and Risk Factors Associated with Infectious Diseases among Refugees in a Camp for Migrants in Porto Alegre: A Cross-Sectional Survey.

Refugees usually face a disproportionate burden of infectious diseases. Recently, Brazil has experienced an influx of refugees which demands the need for scaling up public health efforts to address the challenges. The research sought to study the burden and risk factors associated with infectious diseases among refugees received in the city of Porto Alegre. This was a cross-sectional study of 261 newly arrived refugees. The study sample was predominantly composed of Venezuelans (50.6%) and Haitians (44%), male (146: 56.7%), single (30.7%), with an average age of 33.38 (± 7.30) years. The average schooling was 10.42 (± 2.09) years. Diseases with the highest prevalence were influenza, whooping cough, diphtheria, and tuberculosis. There was significant association between the country of origin and presence of symptoms for infectious and contagious diseases, which warrants targeted interventions for reducing the incidence of these diseases among refugees in Brazil.

Biological, social, and healthcare factors for death due to influenza A(H1N1) during the 2009 epidemic in Brazil.

OBJECTIVE: To identify risk factors for death from influenza A(H1N1), including the effectiveness of the vaccine against influenza A(H1N1) concerning mortality. METHODS: A case-control of incident cases of influenza A(H1N1) reported in the epidemiological information systems of the states of São Paulo, Paraná, Pará, Amazonas, and Rio Grande do Sul was conducted. RESULTS: 305 participants were included, 70 of them cases and 235 controls, distributed as follows: Amazonas, 9 cases/10 controls; Pará, 22 cases/77 controls, São Paulo, 19 cases/49 controls; Paraná, 10 cases/54 controls; Rio Grande do Sul, 10 cases/45 controls. These participants had a mean age of 30 years, with 33 years among cases and 25 years among controls. There was a predominance of females both among the cases and controls. Biological (age), pre-existing diseases (congestive heart failure, respiratory disease, and diabetes mellitus), and care factors (ICU admission) associated with death from influenza A(H1N1) were identified. CONCLUSION: The risk factors identified in this investigation not only allowed subsidizing the elaboration of clinical conducts but also indicate important aspects for facing "new" influenza epidemics that are likely to occur in our country.

Insights into the association of H1N1 seasonality with the COVID-19 pandemic in Brazil: an ecological time series analysis.

During the COVID-19 pandemic, H1N1 seasonality disappeared worldwide. In Brazil, information on how coronavirus impacted this seasonality is scarce. In this study, we aimed to verify whether COVID-19 pandemic was associated with changes in the seasonality of H1N1, modeling the time series of H1N1 between pre-pandemic (2018 and 2019), pandemic (2020 and 2021) and post-pandemic (2022 and 2023) periods. For this purpose, we superimposed on this time series cases of COVID-19 from 2020 to 2023. Our findings highlighted that H1N1 exhibited a consistent seasonal pattern in the pre-pandemic period, with peaks mainly in months with the highest rainfall. However, this seasonality disappeared during the pandemic, with a significant decrease in the number of cases, in contrast with the predicted seasonality of H1N1 for the same period. In addition, the seasonal pattern of H1N1 in the post-pandemic showed a return to that observed in the pre-pandemic period, especially in 2023. We observed that the COVID-19 pandemic was consistently associated with changes in H1N1 seasonality in Brazil, underscoring the relative importance of monitoring patterns of respiratory syndromes to enhance our understanding of how coronavirus is associated with changes in seasonal diseases.

Evaluation of the design of the influenza-like illness sentinel surveillance system in Brazil.

The influenza-like illness (ILI) sentinel surveillance operates in Brazil to identify respiratory viruses of public health relevance circulating in the country and was first implemented in 2000. Recently, the COVID-19 pandemic reinforced the importance of early detection of the circulation of new viruses in Brazil. Therefore, an analysis of the design of the ILI sentinel surveillance is timely. To this end, we simulated a sentinel surveillance network, identifying the municipalities that would be part of the network according to the criteria defined in the design of the ILI sentinel surveillance and, based on data from tested cases of severe acute respiratory illness (SARI) from 2014 to 2019, we drew samples for each sentinel municipality per epidemiological week. The draw was performed 1,000 times, obtaining the median and 95% quantile interval (95%QI) of virus positivity by Federative Unit and epidemiological week. According to the ILI sentinel surveillance design criteria, sentinel units would be in 64 municipalities, distributed mainly in capitals and their metropolitan areas, recommending 690 weekly samples. The design showed good sensitivity (91.65% considering the 95%QI) for qualitatively detecting respiratory viruses, even those with low circulation. However, there was important uncertainty in the quantitative estimate of positivity, reaching at least 20% in 11.34% of estimates. The results presented here aim to assist in evaluating and updating the ILI sentinel surveillance design. Strategies to reduce uncertainty in positivity estimates need to be evaluated, as does the need for greater spatial coverage.

Genomic diversity and evolutionary dynamics of Influenza A viruses in Colombian swine: implications for one health surveillance and control.

Influenza A viruses (IAV) impose significant respiratory disease burdens in both swine and humans worldwide, with frequent human-to-swine transmission driving viral evolution in pigs and highlighting the risk at the animal-human interface. Therefore, a comprehensive One Health approach (interconnection among human, animal, and environmental health) is needed for IAV prevention, control, and response. Animal influenza genomic surveillance remains limited in many Latin American countries, including Colombia. To address this gap, we genetically characterized 170 swine specimens from Colombia (2011-2017). Whole genome sequencing revealed a predominance of pandemic-like H1N1 lineage, with a minority belonging to H3N2 and H1N2 human seasonal-like lineage and H1N1 early classical swine lineages. Significantly, we have identified reassortant and recombinant viruses (H3N2, H1N1) not previously reported in Colombia. This suggests a broad genotypic viral diversity, likely resulting from reassortment between classical endemic viruses and new introductions established in Colombia's swine population (e.g. the 2009 H1N1 pandemic). Our study highlights the importance of a One Health approach in disease control, particularly in an ecosystem where humans are a main source of IAV to swine populations, and emphasizes the need for continued surveillance and enhanced biosecurity measures. The co-circulation of multiple subtypes in regions with high swine density facilitates viral exchange, underscoring the importance of monitoring viral evolution to inform vaccine selection and public health policies locally and globally.

Niños hospitalizados con influenza en un hospital pediátrico de Argentina durante 2019-2022: ¿qué ha cambiado luego de la pandemia por COVID-19? / Children with influenza admitted at a children's hospital in Argentina in the 2019­2022 period: What has changed after the COVID-19 pandemic?

Introducción. Durante 2020 y 2021, la circulación de los virus influenza se mantuvo por debajo de lo esperado en todo el mundo. En Argentina, en el año 2022 observamos una circulación ininterrumpida de influenza todo el año. Nuestros objetivos fueron describir los patrones de circulación y las características clínicas de niños internados con influenza. Población y métodos. Estudio retrospectivo, analítico, observacional. Se incluyeron todos los niños internados en un centro pediátrico con detección del virus influenza durante los años 2019-2022. Resultados. Se internaron 138 pacientes en 4 años; en 2019 se observó una tasa del 4,5/1000 egresos hospitalarios mientras que en 2022, fue del 15,1/1000. En 2020 y 2021 no hubo casos. En el 2019 la mayoría de los casos ocurrieron en invierno, la causa de la internación fue la infección respiratoria aguda baja (IRAB) en el 79 % y se detectó influenza A en el 92 % de los casos. En el 2022, la mayoría de los casos ocurrieron en primavera, el 62 % presentó IRAB y en el 56 % se detectó influenza A. Ambos períodos tuvieron similares frecuencias de vacunación y de comorbilidades. Conclusiones. En el 2022 se registraron más internaciones por influenza, lo que podría corresponder a que se realizaron métodos diagnósticos moleculares, que son más sensibles, y se observó un cambio en la estacionalidad con más casos en primavera. En 2019 predominó influenza A en infecciones del tracto respiratorio inferior, mientras que en el 2022 influenza A y B fueron similares, y hubo más formas extrapulmonares.

Introduction. During 2020 and 2021, the circulation of influenza virus remained below expectations worldwide. In Argentina, in 2022, we observed an uninterrupted circulation of influenza all year round. Our objectives were to describe the circulation patterns and clinical characteristics of hospitalized children with influenza. Population and methods. Retrospective, analytical, observational study. All children with influenza virus admitted to a children's hospital during the 2019­2022 period were included. Results. A total of 138 patients were admitted over 4 years; in 2019, the rate of hospital discharges was 4.5/1000, compared to 15.1/1000 in 2022. No cases were recorded in 2020 and 2021. In 2019, most cases were observed in the winter; in 79%, the cause was acute lower respiratory tract infection (ALRTI); influenza A was detected in 92%. In 2022, most cases occurred in the spring; 62% developed ALRTI; and influenza A was detected in 56%. Similar rates of vaccination and comorbidities were observed in both periods. Conclusions. In 2022, more hospitalizations due to influenza were recorded, which may have correlated with the use of more sensitive molecular diagnostic testing and a change in seasonality, with more cases observed in the spring. In 2019, influenza A predominated in lower respiratory tract infections, while in 2022, cases of influenza A and B were similar, with more extra-pulmonary forms.

Coinfections and comorbidities observed in COVID-19 during the influenza season in the pediatric patient.

OBJECTIVE: To evaluate if the comorbidity and coinfections presented by SARS-CoV-2 infection vs. COVID-19 impact our Mexican children. METHOD: Prospective and observational study that included the 2020-2021 peak influenza season. All patients with a diagnosis of infection by SARS-CoV-2 vs. COVID-19 who were admitted to the Hospital Infantil de Mexico were analyzed. Real-time RT-PCR for SARS-CoV-2 was performed in all patients, determining E, RdRp and RP genes and protein N, as well as RT-PCR for detection of respiratory viruses. RESULTS: The inclusion criteria were met by 163 patients. The group with the highest risk of becoming ill was adolescents (40.4%), followed by schoolchildren and preschoolers (21.4% and 19.6% of the cases, respectively). There were three cases with viral coinfection: two (1.2%) with parvovirus B-19 and one (0.6%) with herpes type I; another two (1.2%) showed bacterial coinfection. The main comorbidity were obesity, acute lymphoblastic leukemia and arterial hypertension. Regarding mortality, we only had four cases (2.4%). CONCLUSIONS: Obesity, cancer, hypertension, heart disease and diabetes are comorbidity present in our patients, as referred to in literature, but not coinfections. In our study, we did not have any associated mortality related to comorbidity.

OBJETIVO: Evaluar el impacto de la comorbilidad y de las coinfecciones presentadas por la infección por SARS-CoV-2 vs. COVID-19 en niños mexicanos. MÉTODO: Estudio prospectivo y observacional que comprendió la temporada alta de influenza 2020-2021, analizando todos los pacientes con diagnóstico de infección vs. enfermedad por SARS-CoV-2 vs. COVID-19 que ingresaron al Hospital Infantil de México. Se realizó en todos RT-PCR en tiempo real para SARS-CoV-2, determinando gen E, gen RdRp, gen RP y proteína N, y RT-PCR multiplex para detección de virus respiratorios. RESULTADOS: Los criterios de inclusión los cumplieron 163 pacientes. El grupo con mayor riesgo de enfermar fueron los adolescentes (40.4%), seguidos de los escolares y preescolares (21.4% y 19.6% de los casos, respectivamente). Hubo tres casos con coinfección viral: dos (1.2%) con parvovirus B-19 y uno (0.6%) con herpes tipo I; hubo otros dos (1.2%) con coinfección bacteriana. La principal comorbilidad correspondió a obesidad, leucemia linfoblástica aguda e hipertensión arterial. En cuanto a mortalidad, solo hubo cuatro casos (2.4%). CONCLUSIONES: Obesidad, cáncer, hipertensión, cardiopatías y diabetes constituyen la comorbilidad en nuestros pacientes, como se refiere en la literatura, no así las coinfecciones. En nuestro estudio no hubo casos de mortalidad relacionada con la comorbilidad.

Effect of a Structured Multilevel Telehealth Service on Hospital Admissions and Mortality During COVID-19 in a Resource-Limited Region in Brazil: Retrospective Cohort Study.

BACKGROUND: The COVID-19 pandemic represented a great stimulus for the adoption of telehealth and many initiatives in this field have emerged worldwide. However, despite this massive growth, data addressing the effectiveness of telehealth with respect to clinical outcomes remain scarce. OBJECTIVE: The aim of this study was to evaluate the impact of the adoption of a structured multilevel telehealth service on hospital admissions during the acute illness course and the mortality of adult patients with flu syndrome in the context of the COVID-19 pandemic. METHODS: A retrospective cohort study was performed in two Brazilian cities where a public COVID-19 telehealth service (TeleCOVID-MG) was deployed. TeleCOVID-MG was a structured multilevel telehealth service, including (1) first response and risk stratification through a chatbot software or phone call center, (2) teleconsultations with nurses and medical doctors, and (3) a telemonitoring system. For this analysis, we included data of adult patients registered in the Flu Syndrome notification databases who were diagnosed with flu syndrome between June 1, 2020, and May 31, 2021. The exposed group comprised patients with flu syndrome who used TeleCOVID-MG at least once during the illness course and the control group comprised patients who did not use this telehealth service during the respiratory illness course. Sociodemographic characteristics, comorbidities, and clinical outcomes data were extracted from the Brazilian official databases for flu syndrome, Severe Acute Respiratory Syndrome (due to any respiratory virus), and mortality. Models for the clinical outcomes were estimated by logistic regression. RESULTS: The final study population comprised 82,182 adult patients with a valid registry in the Flu Syndrome notification system. When compared to patients who did not use the service (n=67,689, 82.4%), patients supported by TeleCOVID-MG (n=14,493, 17.6%) had a lower chance of hospitalization during the acute respiratory illness course, even after adjusting for sociodemographic characteristics and underlying medical conditions (odds ratio [OR] 0.82, 95% CI 0.71-0.94; P=.005). No difference in mortality was observed between groups (OR 0.99, 95% CI 0.86-1.12; P=.83). CONCLUSIONS: A telehealth service applied on a large scale in a limited-resource region to tackle COVID-19 was related to reduced hospitalizations without increasing the mortality rate. Quality health care using inexpensive and readily available telehealth and digital health tools may be delivered in areas with limited resources and should be considered as a potential and valuable health care strategy. The success of a telehealth initiative relies on a partnership between the involved stakeholders to define the roles and responsibilities; set an alignment between the different modalities and levels of health care; and address the usual drawbacks related to the implementation process, such as infrastructure and accessibility issues.

Low antiviral resistance in Influenza A and B viruses isolated in Mexico from 2010 to 2023.

The most widely used class of antivirals available for Influenza treatment are the neuraminidase inhibitors (NAI) Oseltamivir and Zanamivir. However, amino acid (AA) substitutions in the neuraminidase may cause reduced inhibition or high antiviral resistance. In Mexico, the current state of knowledge about NAI susceptibility is scarce, in this study we report the results of 14 years of Influenza surveillance by phenotypic and genotypic methods. A total of 255 isolates were assessed with the NAI assay, including Influenza A(H1N1)pdm09, A(H3N2) and Influenza B (IBV). Furthermore, 827 sequences contained in the GISAID platform were analyzed in search of relevant mutations.Overall, five isolates showed highly reduced inhibition or reduced inhibition to Oseltamivir, and two showed reduced inhibition to Zanamivir in the NAI assays. Additionally, five A(H1N1)pdm09 sequences from the GISAID possessed AA substitutions associated to reduced inhibition to Oseltamivir and none to Zanamivir. Oseltamivir resistant A(H1N1)pdm09 harbored the H275Y mutation. No genetic mutations were identified in Influenza A(H3N2) and IBV. Overall, these results show that in Mexico the rate of NAI resistance is low (0.6%), but it is essential to continue the Influenza surveillance in order to understand the drug susceptibility of circulating strains.

Influenza A, influenza B, and SARS-COV-2 circulation patterns in midwest Brazil during the 2022-2023 period.

Until 2022, the COVID-19 pandemic caused by the SARS-CoV-2, had profoundly impacted the world. Consequently, Brazil, including the state of Goiás, was also significantly affected. Furthermore, in the second half of 2022, the state of Goiás experienced an unusual rise in influenza cases, despite it being an off-season period for influenza viruses in this region. As SARS-CoV-2 and Influenza infection have similar clinical manifestations, surveillance strategies are crucial for public health. Understanding how SARS-CoV-2 and Influenza viruses co-circulate is important for surveillance and monitoring of these patterns of respiratory infections. In this context, this investigation monitored Influenza A and B cases from symptomatic individuals diagnosed as negative for COVID-19. Between September 2022 and May 2023, among the 779 samples tested, 126 (16.2%) were positive for Influenza A, whereas 93 samples (11.9%) were positive for Influenza B. In this period, the peak Influenza infection cases did not coincide with the peak of SARS-CoV-2 infections, suggesting a seasonal shift in viral circulation patterns.

Outcomes of SARS-CoV-2 and Seasonal Viruses Among 2 Million Adults Hospitalized for Severe Acute Respiratory Infection During the COVID-19 Pandemic in Brazil.

BACKGROUND: The outbreak of the COVID-19 pandemic has had a profound impact on the circulation of seasonal respiratory viruses. This study aimed to compare the outcomes of SARS-CoV-2 and seasonal viruses in adults hospitalized with severe acute respiratory infection during the COVID-19 pandemic. METHODS: This population-based cohort study included patients aged >18 years hospitalized for severe acute respiratory infection in Brazil between February 2020 and February 2023. The primary outcome was in-hospital mortality. A competing risk analysis was used to account for competing events. RESULTS: In total, 2 159 171 patients were included in the study. SARS-CoV-2 was the predominant virus (98.7%). Among patients testing positive, the cumulative incidence of in-hospital mortality was 33.1% for SARS-CoV-2, 31.5% for adenovirus, 21.0% for respiratory syncytial virus, 18.7% for influenza, and 18.6% for other viruses. SARS-CoV-2 accounted for 99.3% of the deaths. Older age, male sex, comorbidities, hospitalization in the northern region, and oxygen saturation <95% were the common risk factors for death among all viruses. CONCLUSIONS: In this large cohort study, individuals infected with SARS-CoV-2 or adenovirus had the highest risk of mortality. Irrespective of the virus type, older age, male sex, comorbidities, hospitalization in vulnerable regions, and low oxygen saturation were associated with an increased risk of fatality.

Nota técnica N. 5/2024 - SES/GEVDT: vigilância da síndrome gripal e síndrome respiratória aguda grave / Technical note N. 5/2024 - SES/GEVDT: surveillance of flu syndrome and severe acute respiratory syndrome

Nota técnica com o objetivo de reforçar a importância da adesão às medidas de vigilância, prevenção, controle e tratamento oportuno da Sindrome Gripal (SG) e Síndrome Respiratória Aguda Grave (SRAG)

Technic note with the aim of reinforcing the importance of adherence to surveillance, prevention, control and timely treatment measures for Flu Syndrome (GS) and Severe Acute Respiratory Syndrome (SARS)

Estimating averted illnesses from influenza vaccination for children and pregnant women - El Salvador, Panama, and Peru, 2011-2018.

BACKGROUND: Estimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011-2018 among two influenza vaccine target populations: children aged 6-23 months and pregnant women. METHODS: We derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries' vaccine coverage was achieved using four different vaccine deployment strategies. RESULTS: Among children aged 6-23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March-June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women). DISCUSSION: Influenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign.

Prevalence of immunization against influenza in elderly Brazilians: National Health Survey, 2019.

OBJECTIVE: The aim of this study was to estimate the prevalence of influenza immunization in elderly people in Brazil in 2019. METHODS: This is a population-based cross-sectional study. The Brazilian individuals (≥60 years) who participated in the 2019 National Health Survey were included. The survey was conducted in permanent households in Brazil from August 2019 to March 2020. The prevalences of influenza vaccination and their respective confidence intervals (95%CI) were estimated according to sociodemographic characteristics and the diagnosis of chronic diseases. RESULTS: The prevalence of influenza vaccination was 72.4% (95%CI 71.5-73.2), with statistically significant differences observed between genders (p=0.001), age groups (p=0.001), and those living with a spouse/partner (p=0.002). Significant differences were found in groups with arterial hypertension (75.2%, p<0.001), diabetes (77.2%, p<0.001), and arthritis or rheumatism (75.5%, p<0.001). CONCLUSION: A global prevalence of influenza vaccination of 72.4% was estimated among elderly people in Brazil.

Resurgence of human respiratory syncytial virus during COVID-19 pandemic in Southern Brazil.

Respiratory Syncytial Virus (RSV) is an important cause of respiratory infection in humans. Severe cases are common in children ≤2 years old, immunocompromised individuals, and the elderly. In 2020, RSV infection reduced in Rio Grande do Sul (RS), southern Brazil; however, in 2021 resurgence of RSV was observed. This study analyzed epidemiological and genetic features of RSV infection cases reported in 2021 in RS. Nasopharyngeal samples collected from individuals with respiratory infection negative for SARS-CoV-2, Influenza A and B viruses were assessed for the presence of RSV by real time RT-qPCR. RSV-A and RSV-B genomic sequencing and phylogenetic reconstructions were performed for genotyping and clade characterization. Among 21,035 respiratory samples analyzed, 2,947 were positive for RSV, 947 of which were hospitalized patients. Positive cases were detected year-round, with the highest number in June-July (winter). Children <1 year comprised 56.28% (n = 533) of the hospitalized patients infected with RSV, whereas 14.46% (n = 137) were individuals >60 years. Of a total of 361 deaths, 14.68% (n = 53) were RSV positive, mostly patients >60 years old (73.58%, n = 39). Chronic kidney disease, cardiopathy, Down syndrome and neurological diseases were associated with RSV infection. RSV-A was identified in 58.5% (n = 117/200) of the patients, and RSV-B in 41.5% (n = 83/200). Of 95 RSV genomes recovered from SARI cases, 66 were RSV-A GA.2.3.5 genotype, while 29 were RSV-B GB.5.0.5a genotype. This study provides epidemiological and molecular data on RSV cases in RS during the COVID-19 pandemic and highlights that investigation of different respiratory viruses is essential for decision-making and disease prevention and control measures.

The weekly P25 of the age of the influenza-like illness shows a higher correlation with COVID-19 mortality than rapid tests and could predict the evolution of COVID-19 pandemics in sentinel surveillance, Piura, Perú, 2021.

GOAL: To describe the dynamics of syndromic surveillance of ILI cases in seasonal and COVID-19 pandemic scenarios. METHODOLOGY: A descriptive study of the epidemiological behavior of ILI in the seasonal and COVID-19 pandemic scenarios. Of a sample of 16,231 cases of ILI from 2013 to 2021, the features of cases from 68 weeks before and during the pandemic were selected and compared; weekly endemic channels were built; data fluctuations on the trend of ILI cases were analyzed; and estimated weekly correlations between weekly P25 age, cases confirmed by rapid tests, and mortality from COVID-19. To analyze clinical-epidemiological and mortality data, Student's t test, Mann-Whitney U, Chi2, Spearman's Ro, polynomial, and multinomial regression with a 95% confidence interval were used. RESULTS: During the COVID-19 pandemic, those most affected with ILI were: adults and the elderly; higher median age; autochthonous cases predominated; a lower proportion of other syndromes; delays in seeking care; and a higher rate of pneumonia attack than in the seasonal period (p< 0.01). Rapid tests (serological and antigenic) confirmed 52.7% as COVID-19. Two ILI pandemic waves were seasonally consistent with confirmed COVID-19 cases and district mortality with robust correlation (p<0.01) before and during the pandemic, especially the ILI weekly P25 age, which has a more robust correlation with mortality than ILI and rapid tests (p<0.01) whose endemic channels describe and could predict the evolution of the pandemic (p<0.01). CONCLUSIONS: The pandemic changed the clinical and epidemiological behavior of ILI, and the weekly P25 of age is a more robust indicator to monitor the COVID-19 pandemic than a rapid test and could predict its evolution.

Novel influenza A viruses in pigs with zoonotic potential, Chile.

Novel H1N2 and H3N2 swine influenza A viruses (IAVs) have recently been identified in Chile. The objective of this study was to evaluate their zoonotic potential. We perform phylogenetic analyses to determine the genetic origin and evolution of these viruses, and a serological analysis to determine the level of cross-protective antibodies in the human population. Eight genotypes were identified, all with pandemic H1N1 2009-like internal genes. H1N1 and H1N2 were the subtypes more commonly detected. Swine H1N2 and H3N2 IAVs had hemagglutinin and neuraminidase lineages genetically divergent from IAVs reported worldwide, including human vaccine strains. These genes originated from human seasonal viruses were introduced into the swine population since the mid-1980s. Serological data indicate that the general population is susceptible to the H3N2 virus and that elderly and young children also lack protective antibodies against the H1N2 strains, suggesting that these viruses could be potential zoonotic threats. Continuous IAV surveillance and monitoring of the swine and human populations is strongly recommended.IMPORTANCEIn the global context, where swine serve as crucial intermediate hosts for influenza A viruses (IAVs), this study addresses the pressing concern of the zoonotic potential of novel reassortant strains. Conducted on a large scale in Chile, it presents a comprehensive account of swine influenza A virus diversity, covering 93.8% of the country's industrialized swine farms. The findings reveal eight distinct swine IAV genotypes, all carrying a complete internal gene cassette of pandemic H1N1 2009 origin, emphasizing potential increased replication and transmission fitness. Genetic divergence of H1N2 and H3N2 IAVs from globally reported strains raises alarms, with evidence suggesting introductions from human seasonal viruses since the mid-1980s. A detailed serological analysis underscores the zoonotic threat, indicating susceptibility in the general population to swine H3N2 and a lack of protective antibodies in vulnerable demographics. These data highlight the importance of continuous surveillance, providing crucial insights for global health organizations.

Impact of influenza vaccination history in the clinical course of older adults hospitalized with COVID-19.

BACKGROUND AND PURPOSE: Some studies have shown that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection; in patients with COVID-19 infection, admission to intensive care is reduced, with less need for mechanical ventilation, shorter hospital stays, and reduced mortality. This study aimed to determine if a history of annual influenza vaccination impacts the clinical course of SARS-CoV-2 infection during hospitalization. METHODS: This was an observational, prospective, cohort study of patients older than 65 admitted to the COVID-19 unit from January to June 2021. The history of influenza vaccination over the last 5 years was assessed in each patient during hospitalization. We measured the length of hospital stay, the need for admission to the intensive care unit (ICU), the patient's oxygen requirements, complications during hospitalization, and outcome (medical discharge or death). Patients with a history of vaccination against SARS-CoV-2 were not included. RESULTS: We analyzed 125 patients, 50.4% (n=63) with history of influenza vaccination and 49.6% (n=62) without a history of influenza vaccination. In-hospital mortality was 44.8%, higher in the unvaccinated (54.8%) population (p=0.008). ICU admission was 27% higher in vaccinated (35%) patients (p=0.05). Patients without a history of influenza vaccination had a higher prevalence of cardiac (8% vs. 5%, p=0.04) and renal complications (29% vs. 13%, p=0.02). Patients with a history of vaccination had a greater need for invasive mechanical ventilation (25.4%, p=0.02). CONCLUSION: In this study, a history of influenza vaccination in older adults with SARS-CoV-2 infection was related to lower in-hospital mortality.