Impact of the Universal Implementation of Adolescent Hepatitis B Vaccination in Spain

The aim of this study was to analyse the impact of the introduction of universal adolescent HBV vaccination on the incidence of acute hepatitis B virus (HBV) infections. Acute HBV cases reported to the Spanish National Epidemiological Surveillance Network between 2005 and 2021 were included. For regions starting adolescent vaccination in 1991-1993 and in 1994-1996, HBV incidence rates were compared by calculating the incidence rate ratio (IRR) and 95% confidence interval (CI). We also analysed the 2017 Spanish national seroprevalence survey data. The overall acute HBV incidence per 100,000 persons was 1.54 in 2005 and 0.64 in 2021 (p < 0.001). The incidence in 2014-2021 was lower for regions that started adolescent vaccination in 1991-1993 rather than in 1994-1996 (IRR 0.76; 95% CI 0.72-0.83; p < 0.001). In the 20-29 age group, incidence in regions that started adolescent vaccination in 1991-1993 was also lower (IRR 0.87; 95% CI 0.77-0.98; p = 0.02 in 2005-2013 and IRR 0.71; 95% CI 0.56-0·90; p < 0.001 in 2014-2021). Anti-HBc prevalence in the 35-39 age group was lower in the regions that started vaccination earlier, although the difference was not statistically significant (p = 0.09). Acute HBV incidence decreased more in the young adult population in regions that began adolescent vaccination earlier. Maintaining high universal vaccination coverage in the first year of life and in at-risk groups is necessary to achieve HBV elimination by 2030.

Assessment of Knowledge and Attitudes Over Time in Postacute COVID-19 Environments: Protocol for an Epidemiological Study

BACKGROUND

Globally, COVID-19 is in transition from the acute pandemic phase into a postacute phase, and special attention should be paid at this time to COVID-19 control strategies. Understanding public knowledge and attitudes plays a pivotal role in controlling COVID-19's spread and provides information about the public's adherence to preventive and control measures.

OBJECTIVE

This study protocol describes the planning and management of a survey to investigate the persistent or changing trends in knowledge and attitudes regarding COVID-19, vaccination, and nonpharmaceutical preventive measures among COVID-19 cases' household contacts aged 18 years and older, after the acute phase of the pandemic in Catalonia and Navarre in Spain. The secondary objectives include investigating the rate of secondary transmission in households, taking into account the demographic characteristics, clinical manifestations, and preventive measures toward COVID-19.

METHODS

A telephone questionnaire was designed to assess the changing trends in knowledge, preventive measures, and attitudes toward COVID-19 in 3 rounds (after identification as a household contact, 3 months later, and 6 months later). The questionnaire was developed following an extensive literature review and through discussions with a panel of experts who designed and assessed the validity of the questionnaire in terms of relevance, consistency, completeness, and clarity. The questionnaire consists of the following 7 sections: social and demographic characteristics (ie, gender, age, educational level, and workplace), comorbidities and risk factors (according to the recommendations from the COVID-19 vaccination strategy), epidemiological data (ie, exposure time, relationship with index cases, and frequency of use of nonpharmaceutical preventive measures), COVID-19 vaccination status (ie, the number and date of doses received), knowledge and attitudes toward COVID-19 (assessed using a 5-point Likert scale-totally agree, agree, neither agree nor disagree, disagree, and totally disagree), and sources of information (including traditional mass media, social media, and official sources).

RESULTS

A pilot study was performed in May 2022 to evaluate the questionnaire with 22 household contacts. Preliminary findings indicated that the questionnaire was feasible and acceptable in the general population. The average response time was 15 minutes, with greater variations in responses by older participants. After the pilot study, recruitment of participants began and is expected to be completed at the end of the year 2023, after which the final results will be available in 2024.

CONCLUSIONS

Despite the low transmission levels of SARS-CoV-2 and the relaxation of containment measures, the implementation of the survey during the postacute phase will provide valuable insight to assist public health decision-making and control the transmission of SARS-CoV-2 and other respiratory viruses, thereby attenuating the negative effects of COVID-19 at individual and population level.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52114.

Matrix Metalloproteinase-7 and Osteopontin Serum Levels as Biomarkers for Biliary Atresia

OBJECTIVES

Matrix metallopeptidase-7 (MMP-7) and osteopontin (OPN) are important components in the pathophysiology of fibrosis in biliary atresia (BA). There has been much recent interest in MMP-7 serum level in the diagnosis of BA. We aimed to assess the diagnostic accuracy and prognostic value of both MMP-7 and OPN in a Western BA study.

METHODS

Diagnostic value was assessed by comparison of serum MMP-7 and OPN levels in infants with BA and age-matched cholestatic controls. Prognostic value was assessed through subsequent clearance of jaundice (COJ) and need for liver transplantation (LT).

RESULTS

Serum was assessed from 32 BA and 27 controls. Median MMP-7 was higher in BA (96.4 vs 35 ng/mL; P < 0.0001) with an optimal cut-off value of 69 ng/mL. Sensitivity and specificity was 68% and 93%, respectively [negative predictive value (NPV) = 71%]. Similarly, median OPN was higher in BA (1952 vs 1457 ng/mL; P = 0.0001) and an optimal cut-off of 1611 ng/mL. Sensitivity and specificity was 84% and 78%, respectively (NPV = 81%). MMP-7 level correlated positively with Ishak liver fibrosis score (r = 0.27, P = 0.04). Neither MMP-7 (70 vs 100 ng/mL; P = 0.2) nor OPN (1969 vs 1939 ng/mL; P = 0.3) were predictive of COJ, or need for LT (99 vs 79 ng/mL; P = 0.7, and 1981 vs 1899 ng/mL; P = 0.2), respectively.

CONCLUSIONS

MMP-7 and OPN may have contributory value in the diagnosis of BA, but remain far of the "gold standard" role. Much more prospective data are required and collaborative multi-center initiatives should be the next logical steps.

Epidemiology of GII.4 and GII.2 norovirus outbreaks in closed and semi-closed institutions in 2017 and 2018

Norovirus infections are a leading cause of acute gastroenteritis outbreaks worldwide, with genotypes GII.2 and GII.4 being the most prevalent. The aim of this study was to compare the characteristics of GII.2 and GII.4 norovirus outbreaks reported in Catalonia in closed or semi-closed institutions in 2017 and 2018. The epidemiological and clinical characteristics of GII.2 and GII.4 outbreaks were compared using the chi-square test or Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous variables. Odds ratios and their 95% confidence intervals were estimated. 61 outbreaks were reported: GII.4 was the causative agent in 12 outbreaks (30%) and GII.2 in 9 outbreaks (22.5%). GII.2 outbreaks were detected more frequently in schools or summer camps (66.7%) and GII.4 outbreaks in nursing homes (91.7%) (p = 0.01). Ninety-three people were affected in GII.2 outbreaks and 94 in GII.4 outbreaks. The median age was 15 years (range: 1-95 years) in GII.2 outbreaks and 86 years (range: 0-100 years) in GII.4 outbreaks (p < 0.001). Nausea, abdominal pain, and headache were observed more frequently in persons affected by GII.2 outbreaks (p < 0.05). Symptomatic cases presented a higher viral load suggestive of greater transmission capacity, although asymptomatic patients presented relevant loads indicative of transmission capacity.

Surveillance of influenza B severe hospitalized cases during ten seasons in Catalonia. Does the lineage make a difference?

INTRODUCTION

Influenza B viruses circulates in two lineages (B/Victoria and B/Yamagata). Although classically affecting children, recently it has shown high rate of infection and increased hospitalization in the elderly.

OBJECTIVE

To describe and analyze the clinical and epidemiological characteristics of severe hospitalized laboratory confirmed influenza B virus (SHLCI-B) cases in Catalonia associated to mismatch from Influenza B virus strain included in the trivalent influenza vaccine (TIV).

METHODS

SHLCI-B registered by the influenza sentinel surveillance system of Catalonia (PIDIRAC) during ten surveillance seasons from 2010 to 2020. Variables age, comorbidities, vaccination status were recorded. Vaccine effectiveness was estimated as (1-OR) for intensive care unit (ICU) admission. Statistical significance was established at p <0.05.

RESULTS

A total of 1159 SHLCI-B were registered, of these 68.2% (791) corresponded to the 2017-18 season; 21.8% (253) were admitted to ICU and 13.8% (160) were exitus; 62.5% (725) cases occurred in those aged > 64 years; most frequent risk factor was cardiovascular disease (35.1%, 407) followed by chronic pulmonary obstructive disease-COPD (24.6%, 285) and diabetes (24.1%, 279). In 4 seasons, the predominant circulating lineage was B/Victoria, in 2 seasons the B/Yamagata lineage and 4 seasons had no IBV activity. Four seasons presented discordance with the strain included within the TIV. Vaccine effectiveness (VE) to prevent ICU admission was 31% (95% CI: 4-51%; p=0.03); being 29% (95%CI: -3%, 51%) in discordant and 43% (95% CI:-43%, 77%) in concordant seasons. Significant differences were observed in the number of affected aged > 64 years (OR=2.5; 95% CI: 1.9-3.4; p <0.001) and in patients with heart disease (OR = 2.40 95% CI: 1.7-3.4; p <0.001), COPD (OR = 1.6 95% CI: 1.1-2.3; p = 0.01) and diabetes (OR = 1.5 95% CI: 1.1-2.1; p = 0.04) between discordant and concordant seasons.

CONCLUSIONS

The increase in hospitalization rate in people> 64 years of age and those presenting comorbidities in seasons with circulating influenza B virus belonging to a lineage discordant with the strain included in the TIV and the decrease of VE to prevent ICU admissions evidences the vital need to administer the quadrivalent influenza vaccine regardless of the findings of predominant circulation in the previous season. This article is protected by copyright. All rights reserved.

Hepatitis A Outbreak Characteristics: A Comparison of Regions with Different Vaccination Strategies, Spain 2010-2018

We compared the cumulative incidence and characteristics of hepatitis A outbreaks in two groups of Spanish autonomous regions according to whether a universal or risk group vaccination strategy was followed. Outbreaks between 2010 and 2018 were analyzed. The cumulative incidence rate of outbreaks was estimated and compared by estimating the rate ratio (RR). The characteristics of the outbreaks and those of the first cases were compared. Adjusted OR (aOR) were calculated using a multivariate logistic regression model. Outbreak incidence was 16.04 per million persons in regions with universal vaccination and 20.76 in those with risk-group vaccination (RR 0.77; 95%CI 0.62-0.94). Imported outbreaks accounted for 65% in regions with universal vaccination and 28.7% in regions with risk-group vaccination (aOR 3.88; 95%CI 2.13-7.09). Adolescents and young adults aged 15-44 years and men who have sex with men were less frequently the first case of the outbreak in regions with a universal vaccination strategy (aOR 0.54; 95%CI 0.32-0.92 and 0.23; 95%CI 0.07-0.82, respectively). The cumulative incidence rate of outbreaks was lower in regions with universal vaccination. In all regions, independently of the vaccination strategy, activities to vaccinate persons belonging to high-risk groups for infection should be emphasized.

Hospital-acquired influenza infections detected by a surveillance system over six seasons, from 2010/2011 to 2015/2016

Background

In addition to outbreaks of nosocomial influenza, sporadic nosocomial influenza infections also occur but are generally not reported in the literature.

This study aimed to determine the epidemiologic characteristics of cases of nosocomial influenza compared with the remaining severe cases of severe influenza in acute hospitals in Catalonia (Spain) which were identified by surveillance.

Methods

An observational case-case epidemiological study was carried out in patients aged ≥18 years from Catalan 12 hospitals between 2010 and 2016. For each laboratory-confirmed influenza case (nosocomial or not) we collected demographic, virological and clinical characteristics. We defined patients with nosocomial influenza as those admitted to a hospital for a reason other than acute respiratory infection in whom ILI symptoms developed ≥48 h after admission and influenza virus infection was confirmed using RT-PCR. Mixed-effects regression was used to estimate the crude and adjusted OR.

Results

One thousand seven hundred twenty-two hospitalized patients with severe laboratory-confirmed influenza virus infection were included: 96 (5.6%) were classified as nosocomial influenza and more frequently had > 14 days of hospital stay (42.7% vs. 27.7%, P < .001) and higher mortality (18.8% vs. 12.6%, P < .02). The variables associated with nosocomial influenza cases in acute-care hospital settings were chronic renal disease (aOR 2.44 95% CI 1.44–4.15) and immunodeficiency (aOR 1.79 95% CI 1.04–3.06).

Conclusions

Nosocomial infections are a recurring problem associated with high rates of chronic diseases and death. These findings underline the need for adherence to infection control guidelines.

Usefulness of Clinical Definitions of Influenza for Public Health Surveillance Purposes

This study investigated the performance of various case definitions and influenza symptoms in a primary healthcare sentinel surveillance system. A retrospective study of the clinical and epidemiological characteristics of the cases reported by a primary healthcare sentinel surveillance network for eleven years in Catalonia was conducted. Crude and adjusted diagnostic odds ratios (aDORs) and 95% confidence intervals (CIs) of the case definitions and symptoms for all weeks and epidemic weeks were estimated. The most predictive case definition for laboratory-confirmed influenza was the World Health Organization (WHO) case definition for ILI in all weeks (aDOR 2.69; 95% CI 2.42–2.99) and epidemic weeks (aDOR 2.20; 95% CI 1.90–2.54). The symptoms that were significant positive predictors for confirmed influenza were fever, cough, myalgia, headache, malaise, and sudden onset. Fever had the highest aDOR in all weeks (4.03; 95% CI 3.38–4.80) and epidemic weeks (2.78; 95% CI 2.21–3.50). All of the case definitions assessed performed better in patients with comorbidities than in those without. The performance of symptoms varied by age groups, with fever being of high value in older people, and cough being of high value in children. In patients with comorbidities, the performance of fever was the highest (aDOR 5.45; 95% CI 3.43–8.66). No differences in the performance of the case definition or symptoms in influenza cases according to virus type were found.

Mumps: MMR vaccination and genetic diversity of mumps virus, 2007-2011 in Catalonia, Spain

Background

Mumps is a vaccine-preventable disease but outbreaks have been reported in persons vaccinated with two doses of MMR vaccine.

The objective was to describe the demographic features, vaccination effectiveness and genetic mumps virus diversity among laboratory-confirmed cases between 2007 and 2011 in Catalonia.

Methods

Cases and outbreaks of mumps notified to the notifiable diseases system of Catalonia between 2007 and 2011 retrospectively registered were included. Public health care centres provided written immunization records to regional public health staff to determine the vaccination history.

Saliva and serum specimens were collected from suspected cases for laboratory-confirmation using real-time reverse-transcriptase PCR (rtRT-PCR) or serological testing.

Phylogenetic analysis of the complete SH gene (316 nucleotides) and complete coding HN protein (1749 nucleotides) sequences was made.

Categorical variables were compared using the Chi-square or Fisher’s tests and continuous variables using the Student test. Vaccination effectiveness by number of MMR doses was estimated using the screening method.

Results

During the study period, 581 confirmed cases of mumps were notified (incidence rate 1.6 cases/100,000 persons-year), of which 60% were male. Three hundred sixty-four laboratory-confirmed cases were reported, of which 44% were confirmed by rtRT-PCR. Of the 289 laboratory-confirmed cases belonging to vaccination cohorts, 33.5% (97) had received one dose of MMR vaccine and 50% (145) two doses.

Based on phylogenetic analyses of 316-nucleotide and 174-nucleotide SH sequences, the viruses belonging to viral genotypes were: genotype G (126), genotype D (23), genotype H (2), genotype F (2), genotype J (1), while one remained uncharacterized.

Amino acid differences were detected between circulating strains and the Jeryl Lynn vaccine strains, although the majority of amino acid substitutions were genotype-specific.

Fifty-one outbreaks were notified that included 324 confirmed mumps cases. Genotype G was the most frequent genotype detected. The family (35%), secondary schools (25%) and community outbreaks (18%) were the most frequent settings.

Conclusions

Our study shows that genotype G viruses are the most prevalent in Catalonia. Most cases occurred in people who had received two doses of MMR, suggesting inadequate effectiveness of the Jeryl Lynn vaccine strain. The possible factors related are discussed.

Arbovirus surveillance: first dengue virus detection in local Aedes albopictus mosquitoes in Europe, Catalonia, Spain, 2015

Dengue has emerged as the most important viral mosquito-borne disease globally. The current risk of dengue outbreaks in Europe appeared with the introduction of the vector Aedes albopictus mosquito in Mediterranean countries. Considering the increasing frequency of dengue epidemics worldwide and the movement of viraemic hosts, it is expected that new autochthonous cases will occur in the future in Europe. Arbovirus surveillance started in Catalonia in 2015 to monitor imported cases and detect possible local arboviral transmission. During 2015, 131 patients with a recent travel history to endemic countries were tested for dengue virus (DENV) and 65 dengue cases were detected. Twenty-eight patients with a febrile illness were viraemic, as demonstrated by a positive real-time RT-PCR test for DENV in serum samples. Entomological investigations around the viraemic cases led to the detection of DENV in a pool of local Ae. albopictus captured in the residency of one case. The sequence of the DENV envelope gene detected in the mosquito pool was identical to that detected in the patient. Our results show how entomological surveillance conducted around viraemic travellers can be effective for early detection of DENV in mosquitoes and thus might help to prevent possible autochthonous transmission.

Assessment of two complementary influenza surveillance systems: sentinel primary care influenza-like illness versus severe hospitalized laboratory-confirmed influenza using the moving epidemic method

BACKGROUND

Monitoring seasonal influenza epidemics is the corner stone to epidemiological surveillance of acute respiratory virus infections worldwide. This work aims to compare two sentinel surveillance systems within the Daily Acute Respiratory Infection Information System of Catalonia (PIDIRAC), the primary care ILI and Influenza confirmed samples from primary care (PIDIRAC-ILI and PIDIRAC-FLU) and the severe hospitalized laboratory confirmed influenza system (SHLCI), in regard to how they behave in the forecasting of epidemic onset and severity allowing for healthcare preparedness.

METHODS

Epidemiological study carried out during seven influenza seasons (2010-2017) in Catalonia, with data from influenza sentinel surveillance of primary care physicians reporting ILI along with laboratory confirmation of influenza from systematic sampling of ILI cases and 12 hospitals that provided data on severe hospitalized cases with laboratory-confirmed influenza (SHLCI-FLU). Epidemic thresholds for ILI and SHLCI-FLU (overall) as well as influenza A (SHLCI-FLUA) and influenza B (SHLCI-FLUB) incidence rates were assessed by the Moving Epidemics Method.

RESULTS

Epidemic thresholds for primary care sentinel surveillance influenza-like illness (PIDIRAC-ILI) incidence rates ranged from 83.65 to 503.92 per 100.000 h. Paired incidence rate curves for SHLCI -FLU / PIDIRAC-ILI and SHLCI-FLUA/ PIDIRAC-FLUA showed best correlation index' (0.805 and 0.724 respectively). Assessing delay in reaching epidemic level, PIDIRAC-ILI source forecasts an average of 1.6 weeks before the rest of sources paired. Differences are higher when SHLCI cases are paired to PIDIRAC-ILI and PIDIRAC-FLUB although statistical significance was observed only for SHLCI-FLU/PIDIRAC-ILI (p-value Wilcoxon test = 0.039).

CONCLUSIONS

The combined ILI and confirmed influenza from primary care along with the severe hospitalized laboratory confirmed influenza data from PIDIRAC sentinel surveillance system provides timely and accurate syndromic and virological surveillance of influenza from the community level to hospitalization of severe cases.

Seasonal influenza surveillance: Observational study on the 2017-2018 season with predominant B influenza virus circulation

INTRODUCTION

Influenza is a common respiratory infectious disease affecting population worldwide yearly. The aim of this work is to describe the 2017-2018 influenza season and how it affected elderly population in Catalonia despite moderate vaccine coverage among this age group.

METHODS

Influenza surveillance based on a primary care sentinel surveillance, virological indicators systematic sampling of ILI attended and severe influenza confirmed cases (SHLCI) admitted to hospital.Analysis of data by Chi-squared, ANOVA, multiple regression and negative control test or case to case for vaccine effectiveness assessment in primary care and SHLCI respectively.

RESULTS

Moderate-high intensity and early onset season with predominance of influenza B virus (IVB) (63%) followed by an increase of circulation of influenza A virus (IVA). A total of 419 IV from primary care samples. Vaccine effectiveness (VE) in primary care setting was 14% (95%CI: 0-47%). 1306 severe cases (adjusted cumulative incidence 18.54/100,000 inhabitants (95%CI: 17.54-19.55)). The highest proportion of severe cases were in the >64 (65.1%) (aOR 15.70; 95%CI: 12.06-20.46; p < 0.001) followed by 45-64 yo (25.4%) (aOR 6.03; 95%CI: 4.57-7.97). VE in preventing intensive care unit (ICU) admission was 35% (95%CI: 10-54%). Final outcome death while hospitalized occurred in 175 SHLCI cases with a case fatality rate of 13.4%.

CONCLUSIONS

2017-2018 influenza season was an unusual epidemic season with an early onset, great predominance of influenza B (Yamagata strain) virus with a high hospitalization rate of severe cases among elderly stressing the need to upgrade vaccine uptake in this age group.

Risk factors associated with severe outcomes in adult hospitalized patients according to influenza type and subtype

Seasonal influenza is a cause of hospitalization, especially in people with underlying disease or extreme age, and its severity may differ depending on the types and subtypes of circulating viruses. We investigated the factors associated with ICU admission or death in hospitalized patients with severe laboratory-confirmed influenza according to the viral type and subtype. An observational epidemiological study was carried out in patients aged ≥18 years from 12 Catalan hospitals between 2010 and 2016. For each reported case we collected demographic, virological and clinical characteristics. A mixed-effects logistic regression model was used to estimate crude and adjusted ORs. 1726 hospitalized patients were included: 595 (34.5%) were admitted to the ICU and 224 (13.0%) died. Lower ICU admission was associated with age ≥75 years in all influenza types and subtypes and with age 65-74 years for type A. In contrast, the 65-74 and ≥75 years age groups were associated with an increased risk of death in all types and subtypes, especially for type B (aOR 27.42, 95% CI: 4.95-151.93 and 15.96; 95% CI: 3.01-84.68). The comorbidity most closely associated with severe outcomes was immune deficiency, which was associated with death for type B (aOR 9.02, 95% CI: 3.05-26.69) and subtype A(H1N1)pdm09 (aOR 3.16, 95% CI: 1.77-5.66). Older age was a differential factor for ICU admission and death: it was associated with lower ICU admission but a risk factor for death. The comorbidity with the closest association with death was immune deficiency, mainly in influenza type B patients.

Detection of West Nile virus lineage 2 in North-Eastern Spain (Catalonia)

In September 2017, West Nile virus (WNV) lineage 2 was detected in Catalonia (Northern Spain) in northern goshawks by passive surveillance. The phylogenetic analyses showed that it was related to the Central/Southern European strains, evidencing WNV lineage 2 spread to Western Europe. WNV local transmission was later detected in bearded vultures housed at the Wildlife Recovery center where the goshawk was transferred to. Further studies, before the following period of high mosquito activity, indicated that WNV had circulated intensively in poultry and horses but only surrounding of the area where the virus was detected. In other areas of Catalonia, circulation of flaviviruses different to WNV was identified. Public Health investigations failed to detect WNV infection in humans.

Descriptive study of severe hospitalized cases of laboratory-confirmed influenza during five epidemic seasons (2010-2015)

OBJECTIVE

The Plan of Information on Acute Respiratory Infections in Catalonia (PIDIRAC) included the surveillance of severe hospitalized cases of laboratory-confirmed influenza (SHCLCI) in 2009. The objective of this study was to determine the clinical, epidemiological and virological features of SHCLCI recorded in 12 sentinel hospitals during five influenza seasons.

RESULTS

From a sample of SHCLCI recorded during the 5 influenza epidemics seasons from 2010-2011 to 2014-2015, Cases were confirmed by PCR and/or viral isolation in cell cultures from respiratory samples. A total of 1400 SHCLCI were recorded, 33% required ICU admission and 12% died. The median age of cases was 61 years (range 0-101 years); 70.5% were unvaccinated; 80.4% received antiviral treatment (in 79.6 and 24% of cases within 48 h after hospital admission and the onset of symptoms, respectively); influenza virus A [37.9% A (H1N1)pdm09, 29.3% A (H3N2)] was identified in 87.7% of cases. Surveillance of SHCLCI provides an estimate of the severity of seasonal influenza epidemics and the identification and characterization of at-risk groups in order to facilitate preventive measures such as vaccination and early antiviral treatment.

Factors associated with 30-day readmission after hospitalisation for community-acquired pneumonia in older patients: a cross-sectional study in seven Spanish regions

OBJECTIVE

Hospital readmission in patients admitted for community-acquired pneumonia (CAP) is frequent in the elderly and patients with multiple comorbidities, resulting in a clinical and economic burden. The aim of this study was to determine factors associated with 30-day readmission in patients with CAP.

DESIGN

A cross-sectional study.

SETTING

The study was conducted in patients admitted to 20 hospitals in seven Spanish regions during two influenza seasons (2013-2014 and 2014-2015).

PARTICIPANTS

We included patients aged ≥65 years admitted through the emergency department with a diagnosis compatible with CAP. Patients who died during the initial hospitalisation and those hospitalised more than 30 days were excluded. Finally, 1756 CAP cases were included and of these, 200 (11.39%) were readmitted.

MAIN OUTCOME MEASURES

30-day readmission.

RESULTS

Factors associated with 30-day readmission were living with a person aged <15 years (adjusted OR (aOR) 2.10, 95% CI 1.01 to 4.41), >3 hospital visits during the 90 previous days (aOR 1.53, 95% CI 1.01 to 2.34), chronic respiratory failure (aOR 1.74, 95% CI 1.24 to 2.45), heart failure (aOR 1.69, 95% CI 1.21 to 2.35), chronic liver disease (aOR 2.27, 95% CI 1.20 to 4.31) and discharge to home with home healthcare (aOR 5.61, 95% CI 1.70 to 18.50). No associations were found with pneumococcal or seasonal influenza vaccination in any of the three previous seasons.

CONCLUSIONS

This study shows that 11.39% of patients aged ≥65 years initially hospitalised for CAP were readmitted within 30 days after discharge. Rehospitalisation was associated with preventable and non-preventable factors.

Definitive diagnosis in suspected Middle East Respiratory Syndrome Coronavirus cases

We evaluated the microbiological diagnosis in 14 patients with epidemiological and clinical suspicion of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) attended in a non-endemic area between June 2015 and January 2017. While no MERS-CoV was detected, other respiratory viruses were identified in 12 cases and Mycoplasma pneumoniae in 1 case.

Effectiveness of 23-valent pneumococcal polysaccharide vaccination in preventing community-acquired pneumonia hospitalization and severe outcomes in the elderly in Spain

Pneumococcal pneumonia is a serious cause of morbidity and mortality in the elderly, but investigation of the etiological agent of community-acquired pneumonia (CAP) is not possible in most hospitalized patients. The aim of this study was to estimate the effect of pneumococcal polysaccharide vaccination (PPSV23) in preventing CAP hospitalization and reducing the risk of intensive care unit admission (ICU) and fatal outcomes in hospitalized people aged ≥65 years. We made a multicenter case-control study in 20 Spanish hospitals during 2013-2014 and 2014-2015. We selected patients aged ≥65 years hospitalized with a diagnosis of pneumonia and controls matched by sex, age and date of hospitalization. Multivariate analysis was performed using conditional logistic regression to estimate vaccine effectiveness and unconditional logistic regression to evaluate the reduction in the risk of severe and fatal outcomes. 1895 cases and 1895 controls were included; 13.7% of cases and 14.4% of controls had received PPSV23 in the last five years. The effectiveness of PPSV23 in preventing CAP hospitalization was 15.2% (95% CI -3.1-30.3). The benefit of PPSV23 in avoiding ICU admission or death was 28.1% (95% CI -14.3-56.9) in all patients, 30.9% (95% CI -32.2-67.4) in immunocompetent patients and 26.9% (95% CI -38.6-64.8) in immunocompromised patients. In conclusion, PPSV23 showed a modest trend to avoidance of hospitalizations due to CAP and to the prevention of death or ICU admission in elderly patients hospitalized with a diagnosis of CAP.

Costs associated with influenza-related hospitalization in the elderly

Seasonal influenza epidemics remain a considerable burden in adults, especially in those at higher risk of complications. The aim of this study was to determine the costs associated with influenza-related hospitalization in patients aged ≥65 y admitted to 20 hospitals from 7 Spanish regions during the 2013-14 and 2014-15 influenza seasons. Bivariate analysis was used to compare costs in vaccinated and unvaccinated cases. Costs were calculated according to the Spanish National Health System diagnosis-related group tables for influenza and other respiratory system conditions (GRD 89 and GRD 101). A total of 728 confirmed influenza cases were recorded: 52.9% were male, 46.7% were aged 75-84 years, and 49.3% received influenza vaccine ≥15 d prior to hospital admission. Influenza-related mean hospitalization costs (MHC) were € 1,184,808 in unvaccinated and € 1,152,333 in vaccinated cases (2.75% lower). Influenza vaccination showed significant protection against ICU admission (OR 0.35, 95%CI 0.21-0.59; p < 0001); mechanical ventilation (OR 0.56, 95%CI 0.39-0.80; p = 0.002); secondary bacterial pneumonia (OR 0.61, 95%CI 0.39-0.98; p = 0.04) and a higher degree of dependence (OR 0.74, 95%CI 0.55-0.99; p = 0.04). No association was observed for the Charlson comorbidity index or the mean hospital stay. Although influenza vaccination of the elderly may not achieve significant savings in mean hospitalization costs, it may lessen the degree of severity and avoid complications.

Factors associated with 30-day mortality in elderly inpatients with community acquired pneumonia during 2 influenza seasons

Community-acquired pneumonia (CAP) refers to pneumonia unrelated to hospitals or extended-care facilities. The aim of this study was to determine factors associated with 30-day mortality in patients with CAP aged ≥ 65 y admitted to 20 hospitals in 7 Spanish regions during the 2013-14 and 2014-15 influenza seasons. Logistic regression was used to identify factors associated with 30-day mortality. The adjusted model included variables selected by backward elimination with a cut off of < 0.02. A total of 1928 CAP cases were recorded; 60.7% were male, 46.67% were aged 75-84 years, and 30-day mortality was 7.6% (n = 146). Pneumococcal vaccination had a significant protective effect (OR 0.68, 95% CI, 0.48-0.96; p = 0.03) and influenza vaccination in any 3 preceding seasons slight protective effect against CAP (OR 0.72, 95% CI, 0.51-1.02;p = 0.06). Factors significantly associated with 30-day mortality were having a degree of dependence (aOR 3.67, 95% CI, 2.34-5.75; p < 0,001); age ≥ 85 y (OR 3.01, 95% CI, 1.71-5.30; p < 0.001), liver impairment (aOR 2.41, 95% CI, 1.10-5.31; p = 0.03); solid organ neoplasm (aOR 2.24, 95% CI, 1.46-3.45; p < 0.001), impaired cognitive function (aOR 1.93, 95% CI, 1.22-3.05; p = 0.005), and ICU admittance (aOR2.56, 95% CI, 1.27-5.16; p = 0.009); length of stay (aOR 1.56, 95% CI, 1.02 - 2.40; p = 0.04) and cardio-respiratory resuscitation (aOR 7.75, 95% CI, 1.20 - 49.98; p = 0.03). No association was observed for other comorbidities such as chronic pulmonary obstructive disease (COPD) or heart conditions in the adjusted model. Offering both pneumococcal and influenza vaccination to the elderly may improve 30-day mortality in patients with CAP.

Factors associated with pneumococcal polysaccharide vaccination of the elderly in Spain: A cross-sectional study

Vaccination of the elderly is an important factor in limiting the impact of pneumonia in the community. The aim of this study was to investigate the factors associated with pneumococcal polysaccharide vaccination in patients aged ≥ 65 years hospitalized for causes unrelated to pneumonia, acute respiratory disease, or influenza-like illness in Spain. We made a cross-sectional study during 2013-2014. A bivariate analysis was performed comparing vaccinated and unvaccinated patients, taking into account sociodemographic variables and risk medical conditions. A multivariate analysis was performed using multilevel regression models. 921 patients were included; 403 (43.8%) had received the pneumococcal vaccine (394 received the polysaccharide vaccine). Visiting the general practitioner ≥ 3 times during the last year (OR = 1.79; 95% CI 1.25-2.57); having received the influenza vaccination in the 2013-14 season (OR = 2.57; 95% CI 1.72-3.84) or in any of the 3 previous seasons (OR = 11.70; 95% CI 7.42-18.45) were associated with receiving the pneumococcal polysaccharide vaccine. Pneumococcal vaccination coverage of hospitalized elderly people is low. The elderly need to be targeted about pneumococcal vaccination and activities that encourage healthcare workers to proactively propose vaccination might be useful. Educational campaigns aimed at the elderly could also help to increase vaccination coverages and reduce the burden of pneumococcal disease in the community.

Virological surveillance of influenza and other respiratory viruses during six consecutive seasons from 2006 to 2012 in Catalonia, Spain

Most attention is given to seasonal influenza and respiratory syncytial virus outbreaks, but the cumulative burden caused by other respiratory viruses (RV) is not widely considered. The aim of the present study is to describe the circulation of RV in the general population during six consecutive seasons from 2006 to 2012 in Catalonia, Spain. Cell culture, immunofluorescence and PCR-based assays were used for the RV laboratory-confirmation and influenza subtyping. Phylogenetic and molecular characterizations of viral haemagglutinin, partial neuraminidase and matrix 2 proteins were performed from a representative sampling of influenza viruses. A total of 6315 nasopharyngeal samples were collected, of which 64% were laboratory-confirmed, mainly as influenza A viruses and rhinoviruses. Results show the significant burden of viral aetiological agents in acute respiratory infection, particularly in the youngest cases. The study of influenza strains reveals their continuous evolution through either progressive mutations or by segment reassortments. Moreover, the predominant influenza B lineage was different from that included in the recommended vaccine in half of the studied seasons, supporting the formulation and use of a quadrivalent influenza vaccine. Regarding neuraminidase inhibitors resistance, with the exception of the 2007/08 H275Y seasonal A(H1N1) strains, no other circulating influenza strains carrying known resistance genetic markers were found. Moreover, all circulating A(H1N1)pdm09 and A(H3N2) strains finally became genetically resistant to adamantanes. A wide knowledge of the seasonality patterns of the RV in the general population is well-appreciated, but it is a challenge due to the unpredictable circulation of RV, highlighting the value of local and global RV surveillance.

Estimating influenza vaccine effectiveness in Spain using sentinel surveillance data

We aimed to estimate influenza vaccine effectiveness (VE) against laboratory-confirmed influenza during three influenza seasons (2010/11 to 2012/2013) in Spain using surveillance data and to compare the results with data obtained by the cycEVA study, the Spanish component of the Influenza Monitoring Vaccine Effectiveness (I-MOVE) network. We used the test-negative case–control design, with data from the Spanish Influenza Sentinel Surveillance System (SISS) or from the cycEVA study. Cases were laboratory-confirmed influenza patients with the predominant influenza virus of each season, and controls were those testing negative for any influenza virus. We calculated the overall and age-specific adjusted VE. Although the number of patients recorded in the SISS was three times higher than that in the cycEVA study, the quality of information for important variables, i.e. vaccination status and laboratory results, was high in both studies. Overall, the SISS and cycEVA influenza VE estimates were largely similar during the study period. For elderly patients (> 59 years), the SISS estimates were slightly lower than those of cycEVA, and estimates for children (0–14 years) were higher using SISS in two of the three seasons studied. Enhancing the SISS by collecting the date of influenza vaccination and reducing the percentage of patients with incomplete information would optimise the system to provide reliable annual influenza VE estimates to guide influenza vaccination policies.

Knowledge of and attitudes to influenza in unvaccinated primary care physicians and nurses

Primary healthcare workers, especially nurses, are exposed to the vast majority of patients with influenza and play an important role in vaccinating patients. Healthcare workers’ misconceptions about influenza and influenza vaccination have been reported as possible factors associated with lack of vaccination. The objective of this study was to compare the characteristics of unvaccinated physicians and unvaccinated nurses in the 2011–2012 influenza season. We performed an anonymous web survey of Spanish primary healthcare workers in 2012. Information was collected on vaccination and knowledge of and attitudes to the influenza vaccine. Multivariate analysis was performed using unconditional logistic regression. We included 461 unvaccinated physicians and 402 unvaccinated nurses. Compared with unvaccinated nurses, unvaccinated physicians had more frequently received seasonal influenza vaccination in the preceding seasons (aOR 1.58; 95% CI 1.11–2.25), and more frequently believed that vaccination of high risk individuals is effective in reducing complications (aOR 2.53; 95% CI 1.30–4.95) and that influenza can be a serious illness (aOR 1.65; 95% CI 1.17–2.32). In contrast, unvaccinated physicians were less concerned about infecting patients (aOR 0.62; 95% CI 0.40–0.96). Unvaccinated nurses had more misconceptions than physicians about influenza and the influenza vaccine and more doubts about the severity of annual influenza epidemics in patients with high risk conditions and the prevention of complications by means of the influenza vaccination. For unvaccinated physicians, strategies to improve vaccination coverage should stress the importance of physicians as a possible source of infection of their patients. The effectiveness of influenza vaccination of high risk persons should be emphasized in nurses.

Effectiveness of non-pharmaceutical measures in preventing pediatric influenza: a case-control study

BACKGROUND

Hygiene behavior plays a relevant role in infectious disease transmission. The aim of this study was to evaluate non-pharmaceutical interventions (NPI) in preventing pediatric influenza infections.

METHODS

Laboratory confirmed influenza cases occurred during 2009-10 and 2010-11 seasons matched by age and date of consultation. NPI (frequency of hand washing, alcohol-based hand sanitizer use and hand washing after touching contaminated surfaces) during seven days prior to onset of symptoms were obtained from parents of cases and controls.

RESULTS

Cases presented higher prevalence of underlying conditions such as pneumonia [OR = 3.23; 95% CI: 1.38-7.58 p = 0.007], asthma [OR = 2.45; 95% CI: 1.17-5.14 p = 0.02] and having more than 1 risk factor [OR = 1.67; 95% CI: 0.99-2.82 p = 0.05]. Hand washing more than 5 times per day [aOR = 0.62; 95% CI: 0.39-0.99 p = 0.04] was the only statistically significant protective factor. When considering two age groups (pre-school age 0-4 yrs and school age 5-17) yrs , only the school age group showed a negative association for influenza infection for both washing more than 5 times per day [aOR = 0.47; 95% CI: 0.22-0.99 p = 0.04] and hand washing after touching contaminated surfaces [aOR = 0.19; 95% CI: 0.04-0.86 p = 0.03].

CONCLUSION

Frequent hand washing should be recommended to prevent influenza infection in the community setting and in special in the school age group.

Influenza vaccination of primary healthcare physicians may be associated with vaccination in their patients: a vaccination coverage study

Background

To assess the contribution of physician-related factors, especially their influenza vaccine status, in the vaccination coverage of their patients.

Methods

A study of vaccination coverage was carried out in Spain in 2011–12. The dependent variable (vaccination coverage in patients aged ≥65 years) was obtained from regional records. Information was gathered on the vaccination of physicians through an anonymous web survey. We compared the vaccination coverage of patients with the vaccination of their physicians using the Student t test. Associations were determined using a multilevel regression model.

Results

The coverage in patients aged ≥ 65 years was 56.3% and was higher (57.3%) in patients whose physician had been vaccinated than in those whose physician had not (55.2%) (p = 0.008). In the multilevel regression model, vaccination of the physician was associated (p = 0.049) with vaccination of their patients after controlling for the effects of age (p = 0.046), region (p = 0.089), and opinions on the effectiveness of the vaccine (p = 0.013).

Conclusions

Vaccination of physicians together with their opinions on the effectiveness of the vaccine may be a predictor of vaccination coverage in their patients. Further studies are required to confirm this.

Electronic supplementary material

The online version of this article (doi:10.1186/s12875-015-0259-0) contains supplementary material, which is available to authorized users.

Implication of health care personnel in measles transmission

Healthcare personnel (HCP) play an important role in transmission of highly contagious diseases such as measles. Current immunization guidelines in Catalonia include Measles-Mumps-Rubella (MMR) immunization for HCP born after 1967 without evidence of immunity. Despite high vaccination coverage (90%) a high burden of measles cases related to outbreaks have occurred. The aim of this study was to assess the implication of HCP in measles transmission related to healthcare setting. A review of surveillance case data from 2001 to 2013 gathered through the Measles Elimination Program in Catalonia was performed. Twenty six outbreaks involving 797 cases were reported, 52 (6.5%) were HCP aged 21-41 years, 72,5% (38) patient were care personnel (doctors and nurses) and 22,5% (14) other health care related personnel. Forty six 87%) were unvaccinated, 4(10%) had only one dose and 2 had two doses of MMR. In community outbreaks 30 clusters with HCP involved were observed, yet none were identified as index cases. Non-vaccinated HCPs against measles were all under 45 years of age. Vaccination is the only reliable protection against nosocomial spread of measles from HCPs. Assessing vaccination status of HCPs and implementing a 2 dose vaccination in those lacking evidence of immunity is needed in order to set to zero the risk of acquiring and spreading measles in healthcare (HC) settings.

Influenza vaccine effectiveness assessment through sentinel virological data in three post-pandemic seasons

Influenza vaccination aims at reducing the incidence of serious disease, complications and death among those with the most risk of severe influenza disease. Influenza vaccine effectiveness (VE) through sentinel surveillance data from the PIDIRAC program (Daily Acute Respiratory Infection Surveillance of Catalonia) during 2010-2011, 2011-2012, and 2012-2013 influenza seasons, with three different predominant circulating influenza virus (IV) types [A(H1N1)pdm09, A(H3N2) and B, respectively] was assessed. The total number of sentinel samples with known vaccination background collected during the study period was 3173, 14.7% of which had received the corresponding seasonal influenza vaccine. 1117 samples (35.2%) were positive for IV. A retrospective negative case control design was used to assess vaccine effectiveness (VE) for the entire period and for each epidemic influenza season. An overall VE of 58.1% (95% CI:46.8-67) was obtained. Differences in VE according to epidemic season were observed, being highest for the 2012-2013 season with predominance of IV type B (69.7% ;95% CI:51.5-81) and for the 2010-2011 season, with predominance of the A(H1N1)pdm09 influenza virus strain (67.2% ;95%CI:49.5-78.8) and lowest for the 2011-2012 season with A(H3N2) subtype predominance (34.2% ;95%CI:4.5-54.6). Influenza vaccination prevents a substantial number of influenza-associated illnesses. Although vaccines with increased effectiveness are needed and the search for a universal vaccine that is not subject to genetic modifications might increase VE, nowadays only the efforts to increase vaccination rates of high-risk population and healthcare personnel let reduce the burden of influenza and its complications.

Molecular and clinical epidemiology of norovirus outbreaks in Spain during the emergence of GII.4 2012 variant

BACKGROUND

Norovirus (NoV) is the most common cause of acute nonbacterial gastroenteritis outbreaks worldwide, but the impact of NoV infections in Spain remains underestimated.

OBJECTIVES

This study aimed to determine the prevalence and genetic diversity of NoVs causing outbreaks of acute gastroenteritis in Northeastern Spain (Catalonia) during 2010-2012, and to compare clinical features and levels of viral shedding of the most prevalent GII.4 2012 variant with its predecessor.

STUDY DESIGN

NoVs were screened and genotyped in stools from gastroenteritis outbreaks. Genetic diversity over a region covering 50% of VP1, and viral loads were analyzed in stools belonging to GII.4 2009 and 2012 variants.

RESULTS

More than 50% of outbreaks were caused by genotype GII.4, although outbreaks caused by multiple strains, GII.6 and GII.1 were also prevalent. During 2012, GII.4 2012 strains clearly replaced GII.4 2009 strains. The first 2012 strain was detected in February 2011, representing the earliest isolate reported worldwide. Epidemiological features of GII.4 2012 and GII.4 2009 outbreaks were comparable, as well as levels of viral shedding in stools. Finally, analysis of the capsid gene showed a higher amino acid variability and diversification in GII.4 2012, affecting sites located at the P2 domain, but also in the shell domain.

CONCLUSIONS

Clinical features of outbreaks caused by different genotypes circulating in Spain, including outbreaks caused by GII.4 2012 and GII.4 2009 strains, were comparable. Although shed at similar levels than GII.4 2009 strains, GII.4 2012 strains have clearly replaced the previous predominant strain.

Lack of detection of Middle East respiratory syndrome coronavirus in mild and severe respiratory infections in Catalonia, northeastern Spain

Surveillance of Middle East respiratory syndrome coronavirus (MERS-CoV) was conducted to explore the possible introduction and circulation of this novel virus in Catalonia, northeastern Spain. Five hundred and sixty-three samples from mild and severe respiratory infections collected between January 2012 and April 2013 were screened using real-time RT-PCR. All samples were negative, suggesting that MERS-CoV is not circulating silently in Catalonia.

Norovirus: a growing cause of gastroenteritis in catalonia (Spain)?

Infectious acute gastroenteritis (AGE) is a major health problem worldwide. Salmonella is a leading cause of AGE outbreaks, but viruses may be responsible for up to 80% of cases. We compared the frequency and characteristics of AGE out breaks in Catalonia due to norovirus and Salmonella and the changes in these outbreaks from 2000 through 2010. In 2006 through 2010, we also investigated the distribution by season, setting, and implicated food, the incidence rates of cases associated, and the hospitalization rates. Differences in proportions were estimated by Pearson's chi-square test, and the odds ratio (OR) and 95% confidence interval (CI) were calculated. In 2000 through 2010, the number of AGE outbreaks caused by Salmonella decreased and those caused by norovirus significantly increased. From 2006 onward, norovirus was the most common etiology in AGE outbreaks, but in foodborne outbreaks, Salmonella was the more common cause until 2010. The incidence rate per 10(5) inhabitants was greater for norovirus (20.81 versus 3.97, P < 0.001), and the hospitalization rate was lower for norovirus (0.84 versus 4.69, P < 0.001). Salmonella infections occurred more frequently in the warmer months, and norovirus infections were more common in the colder months, both in terms of total outbreaks (OR = 4.50; 95% CI, 2.85 to 7.11; P < 0.001) and foodborne outbreaks (OR = 4.38; 95% CI, 2.42 to 7.95; P < 0.001). Norovirus infections were less common in private homes (OR = 0.08; 95% CI, 0.04 to 0.14; P < 0.001) and more common in nursing homes (P < 0.001) and hospitals or long-term care facilities (OR = 14.09; 95% CI, 3.35 to 59.33; P < 0.001). Foods most frequently implicated in norovirus infection outbreaks were seafood (22% ; OR = 7.89; 95% CI, 2.59 to 24.3; P < 0.001), and those most common in Salmonella infection outbreaks were mayonnaise and similar items (30.2%; OR = 0.05; 95% CI, 0.01 to 0.22; P < 0.001). Foodborne outbreaks in which the vehicle was not identified were more frequent in cases of norovirus infection (OR = 4.59; 95% CI, 2.54 to 8.30; P < 0.001). Our results indicate that norovirus rather than Salmonella is the most common cause of AGE outbreaks in Catalonia. Foodborne AGE outbreaks were more commonly caused by norovirus than by Salmonella only in 2010, the last year of the study.

Epidemiology of two large measles virus outbreaks in Catalonia: what a difference the month of administration of the first dose of vaccine makes

Measles cases in the European Region have been increasing in the last decade; this illustrates the challenge of what we are now encountering in the form of pediatric preventable diseases. In Catalonia, autochthonous measles was declared eliminated in the year 2000 as the result of high measles-mumps-rubella vaccine (MMR) coverage for first and second dose (15 mo and 4 y) since the mid-1990s. From then on, sporadic imported cases and small outbreaks appeared, until in 2006-2007 a large measles outbreak affecting mostly unvaccinated toddlers hit the Barcelona Health Region. Consequently, in January 2008, first dose administration of MMR was lowered from 15 to 12 mo of age. A new honeymoon period went by until the end of 2010, when several importations of cases triggered new sustained transmission of different wild measles virus genotypes, but this time striking young adults. The aim of this study is to show the effect of a change in MMR vaccination schedule policy, and the difference in age incidence and hospitalization rates of affected individuals between both outbreaks.   Epidemiologic data were obtained by case interviews and review of medical records. Samples for virological confirmation and genotyping of cases were collected as established in the Measles Elimination plan guidelines. Incidence rate (IR), rate ratio (RR) and their 95% CI and hospitalization rate (HR) by age group were determined. Statistic z was used for comparing proportions. Total number of confirmed cases was 305 in the 2010 outbreak and 381 in the 2006-2007 outbreak; mean age 20 y (SD 14.8 y; 3 mo to 51 y) vs. 15 mo (SD 13.1 y; 1 mo to 50 y). Highest proportion of cases was set in ≥ 25 y (47%) vs. 24.2% in 2006 (p < 0.001). Differences in IR for ≤ 15 mo (49/100,000 vs. 278.2/100,000; RR: 3,9; 95%CI 2,9-5.4) and in overall HR 29.8% vs. 15.7% were all statistically significant (p < 0.001). The change of the month of age for the administration of the first MMR dose proved successful to protect infants. Yet, given the current epidemiological situation, continued awareness and efforts to reach young adult population, especially those at high risk of infection and transmission such as healthcare workers and travelers, are needed to stop the spread of the virus when importations occur.

[Surveillance of the pandemic influenza (H1N1) 2009 in Catalonia: results and implications]

BACKGROUND

Pandemics require an assessment of its severity. The objective was to determine the characteristics of pandemic influenza in Catalonia.

METHODS

We conducted a surveillance study on the incidence of ILI and severe cases between June 2009 and May 2010. A network of 55 doctors reported influenza-like illness and collected nasopharyngeal swabs. The severity of the pandemic was assessed through severe cases confirmed.We calculated the lethality and incidence rates and mortality. The differences are studied with the relative risk (RR) with confidence intervals (CI) of 95%.

RESULTS

The incidence of ILI was much higher in the 5 to 14 and from 0 to 4 years old (1227.8 and 1048.4, respectively, in the week of maximum incidence). Of positive samples, 52.4% (477/916) were positive for influenza virus and the majority, 456 (95.6%) were the pandemic influenza virus (H1N1) 2009.The incidence of severe cases was 10.3 per 10(5) and was higher in children (14,5) and adults under 65 years (10,2) (p < 0.0001). Overall mortality was 0.7 per 10(5) and was also higher in children and adults under 65 but the differences were not statistically significant. The fatality rate was estimated at 0.03% and was much higher in the 15 to 44 years (0,03%) (RR = 3.1, 95% CI 1.2 to 8.3), 45 to 64 years (0,11%) (RR = 11.9 95% CI 4.3 to 32.7) and over 64 years (0,73%) (RR = 79.6, 95% CI 25.3 to 250.9) compared to group 5 to 14 years (0,01%).

CONCLUSIONS

The incidence of severe hospitalized cases was similar to or lower than that observed in the southern hemisphere. The lower risk of hospitalization in people over 64 years suggests the relative protection of this age group against the pandemic virus.

Hepatitis A outbreaks: the effect of a mass vaccination programme

A Hepatitis A vaccination programme of people belonging to risk groups begun in Catalonia in 1995 and a universal vaccination programme of pre-adolescents 12 years of age with the hepatitis A + B vaccine was added in 1998. The aim of the study was to investigate the characteristics of hepatitis A outbreaks occurring in Catalonia between 1991 and 2007 to determine the associated risk factors and optimize the use of vaccination. Incidence rates of outbreaks, cases and hospitalizations associated with outbreaks and the rate ratios (RR) of person-to-person transmission outbreaks between the periods before and after mass vaccination and their 95% confidence intervals (CI) were calculated. A rate of 2.45 outbreaks per million persons per year was found. The rate of cases affected in these outbreaks was 1.28 per 10(5) persons per year and the rate of hospitalizations was 0.45 per million persons per year. In person-to-person outbreaks, the highest incidence rate (5.26 and 6.33 per million persons per year) of outbreaks according to the age of the index case was in the 5 to 14 year age group in both periods (RR:0.83; 95% CI:0.48-1.43). A significant increase was observed in the 25 to 44 year age group (RR: 0.35; 95% CI 0.14-0.77). Hepatitis A vaccination has made an important impact on burden and characteristics of outbreaks and could provide greater benefits to the community if the vaccine was administrated to children during their first years of life.

Differences in sentinel influenza confirmed incidence rates and clinical presentation of influenza virus: 2008-09 seasonal vs 2009-10 pandemic influenza

The Influenza sentinel surveillance network of Catalonia (PIDIRAC) allows for the study of circulating influenza virus (IV). The aim of this work was to assess differences between two influenza seasons, the 2008-2009 A(H3N2) season and the 2009-2010 season with predominance of pandemic influenza virus circulation. Incidence rate (IR) of confirmed influenza illness were calculated for both periods and age group. Clinical presentation features by age group (0-4,5-14,15-64 and > 64 y.o.) were studied and compared for both seasons. Statistical significance of proportion differences assessed by statistic z and Mantel Hanzel's Woolf test. The level of statistical significance was established at α=0.05. In both seasons studied, the 5-14 y.o. age group presented the highest confirmed influenza IR and highest presentation of cephalalgia as a symptom in the pandemic A(H1N1)2009 season. In conclusion, the significant burden of influenza, both seasonal and pandemic , on children should encourage upgrading vaccination coverage in these age groups and especially for those included in risk groups for whom yearly vaccination is recommended.

[The viral gastroenteritis: a public health problem]

Acute gastroenteritis (AG), which may be caused by bacteria, parasites and enteropathogenic viruses, including rotaviruses, astroviruses, adenoviruses and caliciviruses, is an important health problem. The frequency of rotavirus as a cause of sporadic cases of AG ranges between 17.3% and 37.4%. Although it has been suggested that common exposure is not an important factor in the diffusion of rotavirus, it is difficult to associate apparently sporadic cases, meaning that there are probably outbreaks that go undetected. Astroviruses cause GA with a frequency ranging between 2 and 26%: outbreaks have been described in schools and kindergartens, but also in adults and the elderly. The frequency of identification of adenoviruses 40 and 41 as causes of sporadic AG in non-immunosuppressed children ranges between 0.7% and 31.5%, although there is probably underreporting because the sensitivity of conventional techniques is low. Caliciviruses are separated phylogenetically into two genera: Norovirus and sapovirus. Norovirus is frequently associated with food- and water-borne outbreaks of AG. It is estimated that 40% of cases of AG due to norovirus are foodborne. In Sweden and some regions of the United States, norovirus is the first cause of outbreaks of foodborne diseases. Sapovirus outbreaks due to person-to-person and foodborne transmission affecting both children and adults have recently been reported in countries such as Canada and Japan.

Mumps vaccine effectiveness in highly immunized populations

The aim of the study was to investigate effectiveness of mumps MMR component in communities with high MMR coverage. Outbreak-related cases of mumps born between 1995 and 2005 notified to Navarre and Catalonia public health services during the period 2005-2007 were studied. Vaccine effectiveness (VE) and their 95%CI were calculated using the screening method. Of 47 confirmed, 85.1% immunized with at least one dose (1MMR) and 44.9% with two (2MMR). Estimated VE was 85.4% (95%CI: 67.3-93.4) for 1MMR and 88.5% (95%CI: 78.1-93.9) for 2MMR. High 2MMR coverage, improved confirmation techniques and further VE studies with all confirmed cases are needed to prevent further outbreaks.

Epidemiological and clinical features of norovirus gastroenteritis in outbreaks: a population-based study

Noroviruses are the most frequent cause of acute gastroenteritis in the community. In Catalonia, it is not clear how this type of viral gastroenteritis is evolving, and the objective of this prospective population-based study was to describe the incidence and epidemiological and clinical features of outbreaks of acute gastroenteritis due to norovirus in Catalonia between October 2004 and October 2005. Incidence rates were calculated using the estimated population of Catalonia in 2005. For each outbreak, the mode of transmission, the number of persons affected, demographic variables, clinical presentation, the date and time of onset of symptoms and the duration of symptoms, physician visits and hospitalizations were collected. Sixty viral outbreaks affecting 1791 people were identified, with no distinct seasonality. The mean number of outbreaks per month was 4.6. The global incidence was 24.6 per 100 000 person-years. The incidence was higher in women (25.7 per 100 000 person-years) and in the 5-11 years (52.4 per 100 000 person-years) and > or =65 years (42.4 per 100 000 person-years) age groups. The prevalence of vomiting, abdominal pain and general malaise was higher in children and adolescents, whereas the prevalence of diarrhoea and myalgia was higher in adults. These results suggest that norovirus infection has an important public health impact in Catalonia and that prevention strategies should be designed and implemented.

Utility of clinical-epidemiological profiles in outbreaks of foodborne disease, Catalonia, 2002 through 2006

The objective of this study was to evaluate the use of clinical-epidemiological profiles for classifying non-laboratory-confirmed outbreaks of foodborne disease (FBD) in Catalonia between 2002 and 2006 and for elucidating associations among factors contributing to these outbreaks. A total of 275 nonfamily outbreaks were studied, of which 190 (69.1%) were laboratory confirmed and 85 (30.9%) were not. In 176 (92.6%) of laboratory-confirmed outbreaks and 69 (81.2%) of non-laboratory-confirmed outbreaks, information was obtained on contributing factors (P = 0.009). In 72% of non-laboratory-confirmed outbreaks, the etiology was assigned by using clinical-epidemiological profiles; thus, 93% of outbreaks eventually were associated with an etiology. In laboratory-confirmed outbreaks, poor personal hygiene was positively associated with norovirus (odds ratio [OR], 2.69; 95% confidence interval [CI], 1.47 to 4.89; P = 0.0007) and negatively associated with Salmonella and Campylobacter (OR, 0.54; 95% CI, 0.33 to 0.89; P = 0.01), and an unsafe source was positively associated with Salmonella and Campylobacter (OR, 4.07; 95% CI, 1.72 to 10.09; P = 0.001) and negatively associated with norovirus (OR, 0.14; 95% CI, 0.04 to 0.58; P = 0.001). No differences were found among contributing factors associated with outbreaks with a laboratory-confirmed etiology and those associated with outbreaks with an etiology assigned according to the clinical-epidemiological profiles. Clinical-epidemiological profiles are useful for determining what prevention and control strategies are appropriate to the agents involved in each community and for designing outbreak investigations.

Differential features of foodborne gastroenteritis outbreaks of known and unknown etiology

Foodborne diseases (FBD) are a major cause of disease and death, but their etiologies are not always known. Factors associated with determination of the etiologic agent of FBD outbreaks reported to the Department of Health in Catalonia (Spain) during 2002 to 2005 were studied. For each outbreak, the year, number of persons affected, hospitalization, and availability of samples from patients, food handlers, and foods were collected. The delay between the date of onset of symptoms of the second case and the report to the surveillance unit was calculated. The relationship between explanatory variables and determination of the cause of each outbreak was studied by logistic regression. The causal agent was identified in 242 (73.3%) of 330 outbreaks. Factors associated with determining the etiologic agent of the outbreak in the univariate analysis were availability of samples from cases (odd ratio [OR] of 6.0, 95% confidence interval [CI] of 3.2 to 11.1), hospitalization (OR of 5.1, 95% CI of 2.6 to 11.1), availability of samples from food handlers (OR of 2.7, 95% CI of 1.6 to 4.5), size > or = 10 cases (OR of 2.2, 95% CI of 1.3 to 3.2), availability of samples from food (OR of 1.8, 95% CI of 1.1 to 3.0), and the last year (2005) of the study period (OR of 1.9, 95% CI of 1.0 to 3.6). In the multivariate analysis, hospitalization (adjusted OR of 5.1, 95% CI of 2.4 to 11.2), size > or = 10 cases (adjusted OR of 2.1, 95% CI of 1.2 to 3.7), and the year 2005 (OR of 2.1, 95% CI of 1.1 to 4.0) remained associated. Collection and processing of clinical samples from cases and appropriate laboratory diagnoses of all possible etiologies of FBD, including viruses, are very important. Efforts by physicians and public health services to coordinate and improve their activity in these areas may help provide more accurate knowledge concerning the etiologies of FBD outbreaks and lead to more effective preventive procedures.

Factors influencing the case-fatality rate of Legionnaires' disease

SETTING

The extent of the public health problem posed by Legionnaires' disease (LD) is not always well- appreciated.

OBJECTIVE

To determine the characteristics and factors associated with the case fatality rate (CFR) of LD in Catalonia, Spain.

DESIGN

Confirmed cases of LD reported during 1993-2004 were studied. Age, sex, hospitalisation, the type of diagnostic confirmation test and the personal risk factors for LD of cases were collected. Comparative bivariate and multivariate analyses according to origin (community-acquired or nosocomial) and nature (sporadic or outbreaks) were performed.

RESULTS

Of 1938 cases reported, 164 died (case-fatality rate [CFR] 8.5%). The CFR fell from 35% in 1993 to 5.6% in 2004, and was higher in sporadic than in outbreak-associated cases (10% vs. 4.7%) and in nosocomial than community-acquired cases (31.7% vs. 6.8%). In community-acquired cases, the CFR was associated with age >70 years (OR 3.42, 95%CI 2.02-5.79), cancer (OR 4.58, 95%CI 2.36-8.90) and diagnostic confirmation methods other than Legionella urinary antigen test. The CFR of nosocomial cases was not associated with any of these factors.

CONCLUSIONS

The CFR of LD fell during the study period due to the incorporation of new diagnostic techniques and improved detection of outbreaks.

Economic benefits for the family of inactivated subunit virosomal influenza vaccination of healthy children aged 3-14 years during the annual health examination in private paediatric offices

Taking the results of a prospective cohort study by our group that evaluated the effectiveness of the inactivated subunit virosomal influenza vaccine (Inflexal V), Crucell-Berna) in the prevention of influenza-related diseases and the reduction of its negative economic consequences, the economic costs and benefits for the family of vaccinating a theoretical cohort of 1000 healthy children aged 3-14 years with no risk factors with one dose of vaccine during the yearly health examination were quantiified. The economic analysis was carried out from the family perspective and the time horizon of the study was established at 6 months. In the base case, the net present value was 21,551.62 euros (21.5 euros per vaccinated child), and the benefit-cost ratio was 2.15, meaning that 1.15 euros is saved per euro invested.

Eliminating congenital rubella syndrome in Spain: does massive immigration have any influence?

In this short report we highlight the importance of implementing good immunization programs adapted to the epidemiological situation of rubella and congenital rubella syndrome (CRS), discuss the influence of massive immigration and stress the need to improve surveillance and control by implementing comprehensive national surveillance and promoting awareness among primary healthcare workers and midwives to find out any signs and symptoms compatible with rubella in pregnant women who have recently arrived from countries with high susceptibility to rubella infection.