Incidence and prevalence of headache in influenza: A 2010-2021 surveillance-based study.

BACKGROUND AND PURPOSE: Influenza is a common cause of acute respiratory infection, with headache being one of the symptoms included in the European Commission case definition. The prevalence of headache as a symptom of influenza remains unknown. We aimed to describe the incidence and prevalence of headache in patients with influenza. METHODS: All consecutive patients who met the definition criteria of influenza-like illness during the influenza seasons 2010-2011 through 2021-2022 were included. The seasonal cumulative incidence of influenza per 1000 patients at risk and the prevalence of headache as an influenza symptom were calculated, including the 95% confidence intervals (CIs). Subgroup analyses were done based on patients' sex, age group, microbiological confirmation, vaccination status, and influenza type/subtype/lineage. RESULTS: During the study period, 8171 patients were eligible. The incidence of headache in the context of influenza varied between 0.24 cases per 1000 patients (season 2020-2021) and 21.69 cases per 1000 patients (season 2017-2018). The prevalence of headache was 66.1% (95% CI = 65.1%-67.1%), varying between 49.6% (season 2021-2022) and 80.1% (season 2010-2011). The prevalence of headache was higher in women (67.9% vs. 65.7%, p = 0.03) and higher in patients between 15 and 65 years old. Headache was more prevalent in patients infected with B subtypes than A subtypes (68.7% vs. 56.9%, p < 0.001). There were no notable differences regarding vaccination status or microbiological confirmation of the infection. CONCLUSIONS: Headache is a common symptom in patients with influenza, with a prevalence higher than that observed in other viral infections.

Factors associated to the presence of headache in patients with influenza infection and its consequences: a 2010-2020 surveillance-based study.

Headache is a common symptom of influenza infection; however, its causes and consequences remain uncertain. In this manuscript, we analyzed which demographic and clinical factors were associated with the presence of headache during the course of influenza infection and whether patients with headache had a different prognosis, evaluated by need of hospitalization, sick leave or school absenteeism. The influence study (NCT05704335) was an observational study that analyzed data routinely collected from the Health Sentinel Network between 2010 and 2020. During the study period, 7832 cases were considered, among which, 5275 (67.4%) reported headache. The presence of headache was independently associated with myalgia (2.753; 95%CI: 2.456-3.087, P < 0.001), asthenia (OR: 1.958; 95%CI: 1.732-2.214, P < 0.001), shivering (OR: 1.925; 95%CI: 1.718-2.156, P < 0.001), nasopharyngeal erythema (OR: 1.505; 95%CI: 1.293-1.753, P < 0.001), fever (OR: 1.469; 95%CI: 1.159-1.861; P = 0.001), sudden onset of symptoms (OR: 1.380; 95%CI: 1.120-1.702, p = 0.004), female sex (OR: 1.134; 95%CI: 1.023-1.257, P = 0.018), and gastrointestinal symptoms (OR: 1.169; 95%CI: 1.039-1.315; P = 0.01). Patients with headache had a sex and age adjusted lower odds of being referred to the hospital (OR: 0.463; 95%CI: 0.264-0.812, P = 0.007) and a higher odd of having a sick leave and/or school absenteeism (absenteeism (OR: 1.342; 95%CI: 1.190-1.514, P < 0.001). In conclusion, the presence of headache seems associated with symptoms caused by the innate immune response. These findings support a headache pathophysiology linked with the innate immune response. Due to the potential negative consequences and its treatable nature, clinicians should systematically evaluate it and, whenever necessary, treat it too.

InfluenCEF study: Clinical phenotype and duration of headache attributed to influenza infection.

INTRODUCTION: Headache is a frequent symptom of infections. We aimed to characterize the clinical phenotype and duration of headache attributed to influenza infection. METHODS: Prospective cohort study done in 53 primary care centers between January and April 2023. Patients were included if they had a confirmed influenza diagnosis, were older than 15 years and had a new-onset headache. Patients' demographics, prior medical history, headache phenotype and duration, associated symptoms and patients' outcomes were assessed. The International Classification of Headache Disorders criteria for headache attributed to a systemic viral infection, migraine and tension-type headache were assessed. RESULTS: Of the 478 patients 75 fulfilled eligibility criteria. The mean age was 43, 56% were men, and 27% had a prior headache history. The headache phenotype was a bilateral headache (52%), with frontal topography (48%), pressing quality (61%), moderate intensity, rhinorrhea (79%), nasal congestion (76%), and photophobia (59%). All patients fulfilled headache attributed to acute systemic viral infection criteria, 43% fulfilled migraine criteria and 31% tension-type headache criteria. The median duration of the headache was four (Inter-quartile range: two-six) days. CONCLUSION: The clinical phenotype of headache attributed to influenza infection was similar to other infections, with more pronounced cranial autonomic symptoms. The headache was an early symptom and was self-limited within a few days.Trial Registration: The study protocol is registered in ClinicalTrial.gov (NCT05704335).

Community-onset Pseudomonas aeruginosa urinary sepsis in elderly people: Predictive factors, adequacy of empirical therapy and outcomes.

Purpose To know the predictive factors for Pseudomonas aeruginosa (PA) urinary sepsis in hospitalised elderly patients coming from community, the adequacy of empirical antibiotic therapy and its outcomes. Methods Retrospective case-control study conducted between 2007 and 2017. Patients aged 65 years or older with PA urinary sepsis were included as cases. Three age-matched controls, with urinary sepsis caused by other microorganisms, were selected for each case. Predictors for PA urinary sepsis were determined by logistic regression analysis. Adequacy of empirical antibiotic therapy and outcomes were compared between both groups. Results A total of 332 patients, from which 83 were cases, were included. Predictive factors for PA urinary sepsis were as follows: male sex (OR 3.16, 95% CI 1.61-6.10; P < .001), urinary catheter (OR 3.25, 95% CI 1.73-6.11; P < .001) and healthcare-associated infection (OR 5.52, 95% CI 1.76 -17.29; P = .003). Inadequate empirical antimicrobial therapy (IEAT) and length of hospital stay were higher in PA group (42% vs 24%, P = .002; 7.45 ± 4.36 days vs 6.43 ± 3.82 days, P = .045, respectively), but mortality was not different (7.2% vs 8.8%, P = .648). Conclusions Pseudomonas aeruginosa urinary sepsis in elderly people was associated with male sex, urinary catheter and healthcare-associated infection. These infections had a higher rate of IEAT and a longer hospital stay than urinary sepsis caused by other microorganisms.

Prospective cohort study of risk factors for extended-spectrum ß-lactamase-producing Escherichia coli urinary tract infections in elderly patients admitted to hospital.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are currently common in community-onset infections, limiting therapeutic options. In this work we aim to identify the prevalence of and risk factors for ESBL-producing E. coli in elderly patients with urinary tract infections (UTI) admitted to hospital. METHODS: Prospective cohort study on elderly patients with E. coli UTI admitted to a university hospital in Spain, from January 2013 to December 2015. Clinical features, microbiology and outcomes were recorded from the electronic medical records and reviewed by two researchers. Cases were segregated according to ESBL-producing E. coli. Risk factors for ESBL-producing E. coli were analysed by multivariate analysis. RESULTS: The prevalence of ESBL-producing E. coli was 27.4% (85/310). Healthcare-associated UTI was the only risk factor for ESBL-producing E. coli (OR 6.79; 95% CI 3.22-14.31, P < .001) by multivariate analysis. ESBL-producing E. coli was 43.9% in the healthcare-associated UTI group and 8.9% in the community-acquired UTI group (P < .001). Inadequate empirical antibiotic therapy and length of stay in hospital were higher in the ESBL-producing E. coli group than in the non-ESBL-producing E. coli group (62.3% vs 5.3% and 6.60 ± 3.69 days vs 5.61 ± 3.16 days, respectively). Mortality was not significantly different between groups (13% in ESBL-producing E. coli group vs 7.5% in non-ESBL-producing E. coli group, P = .140). SUMMARY: Healthcare-associated UTI was a risk factor for ESBL-producing E. coli in elderly patients with UTI admitted to hospital. Our results might help clinicians in choosing empirical antibiotics in an overall high rate setting of ESBL-producing E. coli.

Molecular (ticks) and serological (humans) study of Crimean-Congo hemorrhagic fever virus in the Iberian Peninsula, 2013-2015.

INTRODUCTION: Crimean-Congo hemorrhagic fever (CCHF) is a viral disease, mainly transmitted through tick bite, of great importance in Public Health. In Spain, Crimean-Congo hemorrhagic fever virus (CCHFV) was detected for the first time in 2010 in Hyalomma lusitanicum ticks collected from deer in Cáceres. The aim of this study was to investigate the presence of CCHFV in ticks from Cáceres, and from other Spanish areas, and to evaluate the presence of antibodies against the virus in individuals exposed to tick bites. METHODS: A total of 2053 ticks (1333 Hyalomma marginatum, 680 H. lusitanicum and 40 Rhipicephalus bursa) were analyzed using molecular biology techniques (PCR) for CCHFV detection. The determination of specific IgG antibodies against CCHFV in 228 serum samples from humans with regular contact with ticks (at risk of acquiring the infection) was performed by indirect immunofluorescence assay. RESULTS: The CCHFV was not amplified in ticks, nor were antibodies against the virus found in the serum samples analyzed. CONCLUSION: The absence of the CCHFV in the ticks studied and the lack of antibodies against the virus in individuals exposed to tick bites would seem to suggest a low risk of acquisition of human infection by CCHFV in Spain.

HIV-2 viral tropism influences CD4+ T cell count regardless of viral load.

BACKGROUND: HIV-2 infection is characterized by low plasma viraemia and slower progression to AIDS in comparison with HIV-1 infection. However, antiretroviral therapy in patients with HIV-2 is less effective and often fails to provide optimal CD4 recovery. METHODS: We examined viral tropism in persons with HIV-2 infection enrolled in the HIV-2 Spanish cohort. Viral tropism was estimated based on V3 sequences obtained from plasma RNA and/or proviral DNA. RESULTS: From a total of 279 individuals with HIV-2 infection recorded in the Spanish national register, 58 V3 sequences belonging to 42 individuals were evaluated. X4 viruses were recognized in 14 patients (33%). Patients with X4 viruses had lower median CD4+ cell counts than patients with R5 viruses [130 (17-210) versus 359 (180-470) cells/mm(3); P = 0.007]. This was true even considering only the subset of 19 patients on antiretroviral therapy [94 (16-147) versus 184 (43-368) cells/mm(3); P = 0.041]. In multivariate analysis, significant differences in CD4+ cell counts between patients with X4 and R5 viruses remained after adjusting for age, gender, antiretroviral therapy and viral load. CONCLUSIONS: The presence of X4-tropic viruses in HIV-2 infection is associated with low CD4+ cell counts, regardless of antiretroviral treatment. Along with CD4+ cell counts, viral tropism testing may assist decisions about when to initiate antiretroviral therapy in HIV-2-infected individuals.

Potential Effects on Elderly People From Nirsevimab Use in Infants.

Nirsevimab therapy has the potential to revolutionize infant respiratory syncytial virus (RSV) prophylaxis. But other populations suffering RSV, such the elderly or those over 60, may also be protected by using this novel antibody in the infant group. It is true that some studies link the use of nirsevimab to a reduction in the virus's ability to spread by lowering the viral load in infants as a result of the drug's long half-life. However, this protective effect may not be very significant because RSV transmission in the elderly typically comes from other elderly people or from school-aged children. Furthermore, RSV may be transmitted at any time of the year and not just during the period of nirsevimab protection due to its existence in human reservoirs. The reasons made here show that, even though nirsevimab treatment in infants may protect the elderly, this benefit would be limited and testimonial. Therefore, immunizing the elderly with currently licensed and developing vaccines should be a priority.

El uso de nirsevimab puede suponer una revolución en la prevención del virus respiratorio sincitial (VRS) en lactantes. Sin embargo, el uso de este nuevo anticuerpo en dicho grupo de edad podría proteger también a otros grupos que conviven con ellos, como por ejemplo las personas de edad avanzada o grupo de personas mayores de 60 años. Si bien es cierto que algunos estudios sugieren una disminución en la propagación del virus con el uso de nirsevimab, al reducir la carga viral en lactantes como consecuencia de la prolongada vida media del fármaco, este efecto protector podría ser de escasa relevancia, ya que la transmisión del VRS en personas de edad avanzada sucede en la mayor parte de los casos desde personas de la misma edad o desde niños en edad escolar. Adicionalmente, la presencia de VRS en reservorios humanos puede permitir que el VRS se transmita en cualquier época del año, no limitándose únicamente al periodo de protección de nirsevimab. Los argumentos aquí expuestos demuestran que, si bien el uso de nirsevimab en lactantes podría tener un efecto protector en las personas de edad avanzada, este solo sería testimonial y limitado. En consecuencia, debe priorizarse la inmunización de los pacientes de edad avanzada con las vacunas actualmente autorizadas y en desarrollo.

Association of viral loads of influenza A (H3N2) with age and care setting on presentation-a prospective study during the 2022-2023 influenza season in Spain.

OBJECTIVES: The aim of this study was to analyze the viral load (VL) using cycle threshold (Ct) in patients infected with influenza A (H3N2). METHODS: This prospective study was conducted during the 2022-2023 influenza season in sentinel, non-sentinel, and hospitalized patients of Castilla y León (Spain). Respiratory samples were obtained from nasopharyngeal swabs and analyzed by quantitative reverse transcription-polymerase chain reaction specific for influenza A (H3N2) to obtain the Ct value. RESULTS: A total of 1047 individuals were enrolled (174 [16.6%] sentinel, 200 [19.1%] non-sentinel, 673 [64.3%] hospitalized). The mean Ct value was lower in infants, young children, and in the elderly, with a sharp increase in the last from 65 years until 90 years. In addition, the lower Ct values were observed in non-sentinel patients and then in hospitalized patients, probably because non-sentinel are outpatients in the acute phase of the influenza infection. CONCLUSIONS: A higher VL (lower Ct value) is related to the extreme ages of life: children and the elderly. Furthermore, a higher VL is related with the care setting, being probably higher in outpatients because they are in the acute phase of the disease and slightly lower in hospitalized patients because they are attended during the post-acute phase.

Impact on the time elapsed since SARS-CoV-2 infection, vaccination history, and number of doses, on protection against reinfection.

SARS-CoV-2 reinfections have been frequent, even among those vaccinated. The aim of this study is to know if hybrid immunity (infection + vaccination) is affected by the moment of vaccination and number of doses received. We conducted a retrospective study in 746 patients with a history of COVID-19 reinfection and recovered the dates of infection and reinfection and vaccination status (date and number of doses). To assess differences in the time to reinfection(tRI) between unvaccinated, vaccinated before 6 months, and later; and comparing one, two or three doses (incomplete, complete and booster regime) we performed the log-rank test of the cumulative incidence calculated as 1 minus the Kaplan-Meier estimator. Also, an adjusted Cox-regression was performed to evaluate the risk of reinfection in all groups. The tRI was significantly higher in those vaccinated vs. non-vaccinated (p < 0.001). However, an early incomplete regime protects similar time than not receiving a vaccine. Vaccination before 6 months after infection showed a lower tRI compared to those vaccinated later with the same regime (adj-p < 0.001). Actually, early vaccination with complete and booster regimes provided lower length of protection compared to vaccinating later with incomplete and complete regime, respectively. Vaccination with complete and booster regimes significantly increases the tRI (adj-p < 0.001). Vaccination increases the time it takes for a person to become reinfected with SARS-CoV-2. Increasing the time from infection to vaccination increases the time in which a person could be reinfected and reduces the risk of reinfection, especially in complete and booster regimes. Those results emphasize the role of vaccines and boosters during the pandemic and can guide strategies on future vaccination policy.

Old and new aspects of influenza. / Nuevos y viejos aspectos de la gripe.

Influenza is a classic infectious disease that, through the continuous variation of the viruses that produce it, imposes new challenges that we must solve as quickly as possible. The COVID-19 pandemic has substantially modified the behavior of influenza and other respiratory viruses, and in the coming years we will have to coexist with a new pathogen that will probably interact with existing pathogens in a way that we cannot yet glimpse. However, knowledge prior to the pandemic allows us to focus on the aspects that must be modified to make influenza an acceptable challenge for the future. In this review, emphasis is placed on the most relevant aspects of epidemiology, disease burden, diagnosis, and vaccine prevention, and how scientific and clinical trends in these aspects flow from the previously known to future challenges.

Adjuvants for COVID-19 Vaccines.

In recent decades, the improvement of traditional vaccines has meant that we have moved from inactivated whole virus vaccines, which provoke a moderate immune response but notable adverse effects, to much more processed vaccines such as protein subunit vaccines, which despite being less immunogenic have better tolerability profiles. This reduction in immunogenicity is detrimental to the prevention of people at risk. For this reason, adjuvants are a good solution to improve the immunogenicity of this type of vaccine, with much better tolerability profiles and a low prevalence of side effects. During the COVID-19 pandemic, vaccination focused on mRNA-type and viral vector vaccines. However, during the years 2022 and 2023, the first protein-based vaccines began to be approved. Adjuvanted vaccines are capable of inducing potent responses, not only humoral but also cellular, in populations whose immune systems are weak or do not respond properly, such as the elderly. Therefore, this type of vaccine should complete the portfolio of existing vaccines, and could help to complete vaccination against COVID-19 worldwide now and over the coming years. In this review we analyze the advantages and disadvantages of adjuvants, as well as their use in current and future vaccines against COVID-19.

Impact of COVID-19 on Adherence to Treatment in Patients with HIV.

In patients with human immunodeficiency virus (HIV), adherence to treatment is affected by the adverse effects of treatment, the presence of additional comorbidities, the complexity of dosage, and family and community support. However, one recent circumstance that was likely to have influenced therapeutic adherence was the COVID-19 pandemic and the applied containment measures. An observational retrospective study of a sample of patients with HIV was conducted to establish the relationship between sociodemographic, clinical, and pharmacological variables and therapeutic adherence before and after the pandemic. Adherence was measured using the validated simplified medication adherence questionnaire (SMAQ) and medication possession rate. A statistical analysis was performed to determine the mean, standard deviation, and median of the quantitative variables and the frequencies of the qualitative variables, and the relationship between the dependent and independent variables was analysed using the chi-squared test and Student's t-test. No statistically significant differences were found between treatment adherence measured before and 22 months after the start of the pandemic. Sex, occupation, treatment regimen, viral load levels, and COVID-19 disease status did not influence adherence during either period. However, the age of patients with HIV had an impact on adherence during both periods (p = 0.008 and p = 0.002, respectively), with the age group under 45 years being less adherent. In addition, experiencing adverse drug reactions (ADRs) was shown to have an impact on adherence before the pandemic (p = 0.006) but not afterwards. The COVID-19 pandemic was not shown to have an impact on the degree of adherence to antiretroviral treatment in patients with HIV. Instead, adherence was influenced by patient age and ADR occurrence; therefore, measures must be taken in this regard. The SMAQ demonstrated sensitivity in assessing adherence.

Lactate/albumin ratio prognostic value for mortality in patients older than 65 years with complicated urinary tract infection.

BACKGROUND: Lactate to albumin ratio (LAR) is an emerging sepsis biomarker that has been tested for mortality in patients with sepsis of different focus. Our goal is to evaluate the prognostic value of LAR in patients admitted to the hospital due to complicated urinary tract infections. METHODS: Prospective observational study of patients older than 65 years diagnosed with UTI. Area under the ROC curve, sensibility, and specificity to predict 30-day mortality were calculated for LAR, qSOFA and SOFA. RESULTS: 341 UTI cases were analyzed. 30-day mortality (20.2% vs. 6.7%, p < 0.001) and longer hospital stay (5 [4-8] vs. 4 [3-7], p 0.018) were associated with LAR ≥ 0.708. LAR has no statistically significant differences compared to qSOFA and SOFA for predicting 30-day mortality (AUROC 0.737 vs. 0.832 and 0.777 respectively, p 0.119 and p 0.496). The sensitivity of LAR was similar to the sensitivity of qSOFA and SOFA (60.8% vs. 84.4% and 82.2, respectively, p 0.746 and 0.837). However, its specificity was lower than the specificity of qSOFA (60.8% vs. 75%, p 0.003), but similar to the specificity of SOFA (60.8% vs. 57.8%, p 0.787). CONCLUSION: LAR has no significant differences with other well-stablished scores in sepsis, such as qSOFA and SOFA, to predict 30-day mortality in patients with complicated UTI.

The Impact of the COVID-19 Pandemic on Influenza Vaccination Attitudes and Actions in Spain's Adult Population.

Seasonal influenza is an acute respiratory infection caused by the influenza virus which constitutes a significant public health issue associated with high morbidity and mortality. The aim of this study was to investigate changes in attitudes, perceptions, and practices regarding influenza vaccination in the Spanish adult population during the COVID-19 pandemic, as well as their vaccination intentions, with special attention paid to those over 65 years old and in high-risk groups. To this end, a cross-sectional study was conducted through 2219 telephone interviews, and the results were compared with results obtained a year earlier. Regarding the reasons for deciding to get vaccinated in the 2022/23 season, a significant increase was observed in vaccine confidence (36.7% vs. 42.8%), social responsibility (32.5% vs. 43.8%), and in awareness of the importance of vaccination due to COVID-19 (21.7% vs. 25.4%). Advanced age (OR 2.8, 95% CI 2.0-3.9), belonging to high-risk groups (OR 2.7, 95% CI 2.0-3.7), and prior vaccination (OR 25.3, 95% CI 19.5-32.7) emerged as significant predictors for the intent to receive the influenza vaccine in the 2022/23 season. Continuously observing shifts in perceptions and behaviors related to influenza immunization is crucial to pinpoint factors that may influence the willingness to receive the vaccine and, in this way, design public health strategies that achieve a greater acceptance of it.

Long-term influenza antibodies profiles in previously vaccinated and non-vaccinated adults.

The aim of this work is to describe the dynamics of influenza antibodies after vaccination in adults. We conducted a case-cohort serological study in the automobile manufacturing plants of the Renault España S.A. group in Valladolid and Palencia (Spain), including 550 workers (66.9%) previously vaccinated against influenza (group V), and 272 (33.1%) never vaccinated (group NV). A pre-vaccination serum sample was collected, another after 30-40 days and another after 6 months. The dynamics of antibodies were analyzed. A lower seroprotection of NV before vaccination was observed, but an antibody response between 2 and 4 times higher than in V was assessed. After 6 months, antibodies declined in both groups until equalize. Antibodies titers decrease with age, and no differences were found among underlying pathologies. Adults never vaccinated against influenza had lower seroprotection than those previously vaccinated, but influenza vaccination produces a more intense serological response in them, acquiring significantly higher antibody titers than those previously vaccinated. The antibodies, although in lower titers, persist and equalize among both groups at least 6 months after vaccination, which allows the individual to be protected during the entire circulation of the influenza virus in the same season.

Development of tropical spastic paraparesis in human T-lymphotropic virus type 1 carriers is influenced by interleukin 28B gene polymorphisms.

Interleukin 28B (IL28B) rs12979860 polymorphisms were examined in 41 individuals with human T-lymphotrophic virus type 1 (HTLV-1). The alleles CT/TT were more frequent in 12 individuals with HTLV-1-associated myelopathy/tropical spastic paraparesis than in 29 asymptomatic carriers (80% vs 20%; P = .03), and median HTLV-1 proviral load was greater in CT/TT than CC carriers (P = .01). Thus, IL28B testing and closer follow-up of HTLV-1 asymptomatic CT/TT carriers is warranted.

Trends in the prevalence and distribution of HTLV-1 and HTLV-2 infections in Spain.

BACKGROUND: Although most HTLV infections in Spain have been found in native intravenous drug users carrying HTLV-2, the large immigration flows from Latin America and Sub-Saharan Africa in recent years may have changed the prevalence and distribution of HTLV-1 and HTLV-2 infections, and hypothetically open the opportunity for introducing HTLV-3 or HTLV-4 in Spain. To assess the current seroprevalence of HTLV infection in Spain a national multicenter, cross-sectional, study was conducted in June 2009. RESULTS: A total of 6,460 consecutive outpatients attending 16 hospitals were examined. Overall, 12% were immigrants, and their main origin was Latin America (4.9%), Africa (3.6%) and other European countries (2.8%). Nine individuals were seroreactive for HTLV antibodies (overall prevalence, 0.14%). Evidence of HTLV-1 infection was confirmed by Western blot in 4 subjects (prevalence 0.06%) while HTLV-2 infection was found in 5 (prevalence 0.08%). Infection with HTLV types 1, 2, 3 and 4 was discarded by Western blot and specific PCR assays in another two specimens initially reactive in the enzyme immunoassay. All but one HTLV-1 cases were Latin-Americans while all persons with HTLV-2 infection were native Spaniards. CONCLUSIONS: The overall prevalence of HTLV infections in Spain remains low, with no evidence of HTLV-3 or HTLV-4 infections so far.

Attitudes, Perceptions and Practices of Influenza Vaccination in the Adult Population: Results of a Cross-Sectional Survey in Spain.

In Spain, the 2021/22 influenza season overlapped with the sixth wave of the 2019 coronavirus disease pandemic (COVID-19). Influenza is a major public health problem associated with high morbidity and mortality. The objectives of this study were to determine the knowledge, perceptions and practices of influenza vaccination in the Spanish population, coinciding with the COVID-19 pandemic, with special attention paid to people over 65 years of age. A cross-sectional study was carried out by conducting 2211 telephone interviews. It was observed that 81.6% of people ≥ 65 years were vaccinated annually or with some frequency compared to 35.5% of those under 65 years (p < 0.001). Fifty percent of Spaniards showed an intention to be vaccinated in the 2021/22 campaign, during the SARS-CoV2 pandemic. In the case of people ≥ 65 years old, this figure was 83% compared to 42% of those under 65 years old (p < 0.001). Significant predictors of intention to be vaccinated were age of 65 years or older (OR 1.8, 95% CI 1.3-2.5), female sex (OR 1.9, 95% CI 1.5-2.4), belonging to risk groups (OR 2.2, 95% CI 1.6-3.1) and having been previously vaccinated (OR 29.7, 95% CI 22.5-39.2). The main reasons for deciding to be vaccinated were the need to be protected against the virus and to be vaccinated annually. On the other hand, lack of recommendation and considering the influenza vaccine as not necessary were the main reasons for not getting vaccinated. In addition, health personnel stood out as the main source of information (32.9%) compared to traditional media (26.9%) and public administration (12.3%). This study aimed to assess and analyse the factors influencing willingness to receive influenza vaccines in the COVID-19 era among Spanish adults, as well as the main information channels and strategies to encourage vaccination.