Nuria Torner

The epidemiology of invasive Streptococcus pneumoniae disease in Catalonia (Spain): A hospital-based study

The aim of this study was to investigate the incidence of invasive pneumococcal disease (IPD) in Catalonia. A hospital-based incidence study of the period 1997-1999 was carried out by reviewing the isolations of Streptococcus pneumoniae obtained from normally sterile sites reported by the hospitals that voluntarily participate in the Microbiological Reporting System of Catalonia (MRSC), and those obtained by active retrospective surveillance of cases recorded by microbiology laboratories of the remaining hospitals. Cases of pneumonia were included only if the blood culture was positive. The age, sex and clinical presentation of each patient were recorded. The global incidence of hospital-based IPD was 10.5 per 100,000 persons-year, and was much higher in subjects <2 years of age (59.6) and in those aged > or = 65 years (27.9). In subjects > or = 65 years, bacteremic pneumococcal pneumonias were more frequent in the months from December to March than they were in children <2 years of age (P<0.0001). The global incidence of IPD (10.5 per 100,000 persons-year) is high in Catalonia, greater than that of meningococcal or Haemophilus influenzae invasive disease. In children <2 years, the incidence is nearly six times higher (59.6 per 100,000 persons-year) with pneumonias (rate of 26.2 per 100,000 persons-year) and non-focal bacteremias (rate of 22.1 per 100,000 persons-year) being especially frequent.

D225G mutation in the hemagglutinin protein found in 3 severe cases of 2009 pandemic influenza A (H1N1) in Spain.

From 27 April to 16 December 2009, we analyzed the hemagglutinin gene sequence of 2009 pandemic influenza A (H1N1) virus in 189 respiratory specimens. We only found the D225G mutation in 3 severe cases. However, it was not found in samples from other cases with or without clinical criteria of severity. The biologic significance of this mutation remains still unclear.

Influenza C virus surveillance during the first influenza A (H1N1) 2009 pandemic wave in Catalonia, Spain

Although particular attention is paid to influenza A and B virus isolates during influenza surveillance, influenza C virus (FLUCV) coexisted during the first influenza A (H1N1) 2009 pandemic wave during the 2009-2010 season. From 27 April 2009 to 9 May 2010, 12 strains of FLUCV were detected in specimens collected from 1713 nonhospitalized patients with upper respiratory tract illness using a molecular method. Half of the patients with FLUCV infection were older than 14 years. The most frequent symptoms were cough and fever, similar to other viral respiratory infections. Phylogenetic analysis of the hemagglutinin-esterase gene revealed that the strains belonged to the C/Kanagawa/1/76-related and C/Sao Paulo/378/82-related lineages, demonstrating their co-circulation in Catalonia. In addition to regular virological surveillance that provides information about the incidence and the exact role of FLUCV in acute viral respiratory infections in the general population, the genetic lineage identification offers additional data for epidemiological purposes.

Using surveillance data to estimate pandemic vaccine effectiveness against laboratory confirmed influenza A(H1N1)2009 infection: two case-control studies, Spain, season 2009-2010

BackgroundPhysicians of the Spanish Influenza Sentinel Surveillance System report and systematically swab patients attended to their practices for influenza-like illness (ILI). Within the surveillance system, some Spanish regions also participated in an observational study aiming at estimating influenza vaccine effectiveness (cycEVA study). During the season 2009-2010, we estimated pandemic influenza vaccine effectiveness using both the influenza surveillance data and the cycEVA study.MethodsWe conducted two case-control studies using the test-negative design, between weeks 48/2009 and 8/2010 of the pandemic season. The surveillance-based study included all swabbed patients in the sentinel surveillance system. The cycEVA study included swabbed patients from seven Spanish regions. Cases were laboratory-confirmed pandemic influenza A(H1N1)2009. Controls were ILI patients testing negative for any type of influenza. Variables collected in both studies included demographic data, vaccination status, laboratory results, chronic conditions, and pregnancy. Additionally, cycEVA questionnaire collected data on previous influenza vaccination, smoking, functional status, hospitalisations, visits to the general practitioners, and obesity. We used logistic regression to calculate adjusted odds ratios (OR), computing pandemic influenza vaccine effectiveness as (1-OR)*100.ResultsWe included 331 cases and 995 controls in the surveillance-based study and 85 cases and 351 controls in the cycEVA study. We detected nine (2.7%) and two (2.4%) vaccine failures in the surveillance-based and cycEVA studies, respectively. Adjusting for variables collected in surveillance database and swabbing month, pandemic influenza vaccine effectiveness was 62% (95% confidence interval (CI): -5; 87). The cycEVA vaccine effectiveness was 64% (95%CI: -225; 96) when adjusting for common variables with the surveillance system and 75% (95%CI: -293; 98) adjusting for all variables collected.ConclusionPoint estimates of the pandemic influenza vaccine effectiveness suggested a protective effect of the pandemic vaccine against laboratory-confirmed influenza A(H1N1)2009 in the season 2009-2010. Both studies were limited by the low vaccine coverage and the late start of the vaccination campaign. Routine influenza surveillance provides reliable estimates and could be used for influenza vaccine effectiveness studies in future seasons taken into account the surveillance system limitations.

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.

The Effectiveness of Influenza Vaccination in Different Groups.

ABSTRACT Annual administration of the seasonal influenza vaccine, especially to persons known to be at elevated risk for developing serious complications, is the focus of current efforts to reduce the impact of influenza. The main factors influencing estimated inactivated influenza vaccine efficacy and effectiveness, the results obtained in different population groups, current vaccination strategies and the possible advantages of new vaccines are discussed. The available evidence suggests that influenza vaccines are less effective in the elderly than in young adults, but vaccination is encouraged by public health institutions due to higher mortality and complications. There is no consensus on universal vaccination of children yet economic studies suggest that yearly paediatric vaccination is cost saving. The benefits of herd immunity generated by paediatric vaccination require further study. Newer vaccines should be more and more-broadly protective, stable, easy to manufacture and administer and highly immunogenic across all population groups.

Non-preventable mumps outbreaks in schoolchildren in Catalonia

Various doses of the combined MMR vaccine containing the Rubini mumps strain were distributed in Catalonia in 1994 and 1995. We studied outbreaks of mumps reported from 1997 to 2002 to determine the possible involvement of this vaccine in the appearance of non-preventable mumps outbreaks. A total of 17 mumps outbreaks were declared in the period 1997–2000, 14 of which were in schoolchildren. In 11, it was determined that children were correctly vaccinated. Of these, 10 were non-preventable outbreaks. 66% of cases investigated had ages which coincided with vaccination in the period 1994–1996, during which the MMR vaccine containing the Rubini mumps strain was administered. In Catalonia, during the period 1997–2000, at least two-thirds of mumps cases in schoolchildren could be explained by vaccination with the combined MMR vaccine containing the Rubini strain, which has also been associated with mumps outbreaks amongst vaccinated people in other countries.

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.

Paediatric complications of varicella requiring hospitalization

Objective To investigate the incidence and clinical characteristics of paediatric complications of varicella requiring hospitalization in Catalonia. Material and methods The ambit of the study was the population under 15 years of age in Catalonia. Demographic data, admission and discharge dates, previous immunosuppressed state, type of complication, treatment given and the evolution were recorded for all cases of varicella requiring hospitalization during 1999. Results Eighty-three cases of varicella, presenting 107 complications, were detected. The majority of the cases (73.5%) were between 1 and 4 years of age, 54.2% were male, and only 2 cases (2.4%) had a previous immunosuppressive disease. The most frequent type of complications were cutaneous (37%), followed by respiratory (21%), neurologic (19%) and haematological (5%). One death occurred (1.2%). Of the bacterial superinfections found with some microorganism isolated (34.6%), the most frequent agents were Streptococcus pyogenes (42%) and Staphylococcus aureus (36.8%). Average hospital stay was 6.33 ± 5.64 days; three cases were admitted to the ICU, with an average stay of 4.33 ± 3.06 days. Conclusions Varicella in children frequently causes severe complications needing hospitalization. These complications, together with those that are attended at ambulatory level in children and complications in adults justify the incorporation of the varicella vaccine to the routine vaccination schedule.

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.