Rosa Cano

Impact of the meningococcal C conjugate vaccine in Spain: an epidemiological and microbiological decision.

The new meningococcal C conjugate vaccine became available in Spain and was included in the infant vaccination schedule in 2000. A catch-up campaign was carried out in children under six years of age. As a consequence, the incidence of meningococcal disease caused by serogroup C has fallen sharply during the last three epidemiological years in Spain. The risk of contracting serogroup C disease in 2002/2003 fell by 58% when compared with the season before the conjugate vaccine was introduced. There was also an important decrease in mortality. Three deaths due to serogroup C occurred in the age groups targeted for vaccination in 2002/2003, compared with 30 deaths in the same age groups in the season before the launch of the vaccine campaign. In the catch-up campaign the vaccine coverage reached values above 92%. For the 2001, 2002 and 2003 routine childhood immunisation programme coverage values ranged from 90% to 95%. During the past three years a total of 111 cases of serogroup C disease have been reported in patients in the vaccine target group. Most of the vaccination failures occurred during the epidemiological year 2002/2003. Eight (53%) vaccine failures occurred in children who had been routinely immunised in infancy, and could be related to a lost of protection with time since vaccination. The isolation of several B:2a:P1.5 strains (ST-11 lineage) is noteworthy. These may have their origin in C:2a:P1.5 strains which, after undergoing genetic recombination at the capsular operon level, express serogroup B. These strains could have relevant epidemic potential.

The epidemiology of invasive meningococcal disease in EU/EEA countries, 2004–2014

BACKGROUND Invasive meningococcal disease (IMD) is a major cause of bacterial meningitis and septicaemia although infection by some serogroups may be prevented through vaccination. We aimed to describe the epidemiology of IMD in EU/EEA countries during 2004-2014 to monitor serogroup- and age-specific trends, and compare country trends by the period of meningococcal C conjugate (MCC) vaccine introduction. METHODS We analysed IMD surveillance data by age, gender, serogroup, country and outcome. We estimated the percentage change in annual notification rate (NR), using linear regression analysis of the log of the annual NR. We grouped countries by the year they introduced MCC vaccination into their routine immunisation programmes. RESULTS The overall NR was 0.9/100 000 population, and decreased 6.6% (95%CI: -8.0%;-5.1%) annually. Infants had the highest NR (16.0/100 000), and there were decreasing trends in all age groups <50years. Serogroup B (SgB) caused 74% of all cases, and the majority of cases in all age groups. There were decreasing trends in SgB and serogroup C (SgC) and an increasing trend in serogroup Y. Countries that introduced MCC vaccination before, and between 2004 and 2014, had decreasing trends in NR of SgC, but not countries without routine MCC vaccination. CONCLUSIONS Our findings support evidence that routine MCC vaccination was the driving force behind the decreasing SgC trend. Vaccinating against SgB in the first year of life could help reduce the burden of IMD due to this serogroup. Changing serogroup-specific NR trends highlight the need for high-quality surveillance data to accurately assess the changing epidemiology of IMD, the effectiveness and impact of implemented vaccines, and the need for future vaccines.

Changes in meningococcal C epidemiology and vaccine effectiveness after vaccine introduction and schedule modification.

PURPOSE Meningococcal C conjugate vaccine was included in December 2000 in the Spanish childhood vaccination at 2, 4 and 6 months of age. In 2006, routine vaccination was modified to two doses at 2 and 4-6 months and a booster dose during the second year of age. Additionally, successive catch-up campaigns were launched to extend protection to older groups. This study provides long-term information about the vaccine effectiveness (VE) and the impact of vaccination in meningococcal C disease epidemiology in Spain. METHODS We assessed surveillance data from season 1996/97 to season 2012/13 to describe changes in incidence and lethality of the disease. The vaccine-effectiveness study covered all cases notified from January 1st of 2001 onwards and evaluated vaccine effectiveness in both routines and in catch-up campaigns. To investigate the decline in protection over time, we compared the vaccine effectiveness within 1 year and more than one year since vaccination. RESULTS The incidence of meningococcal serogroup C disease decreased first in those age-groups targeted for vaccination. But after 2006/07 season the decrease in incidence was generalised. Vaccine effectiveness was high in all vaccination programmes, although 2, 4-6 months (+ booster dose) routine showed higher overall vaccine effectiveness than 2, 4 and 6 months routine (99.3% vs. 90.2%). VE >1 year since vaccination was lower in 2, 4 and 6 months compared to 2 and 4-6 months (+ booster) routine (81.4% vs. 89.1%). For catch-up campaigns, VE increased and loss of VE decreased with the age of administration. Overall VE was 94.83 (CI95%: 93.37, 95.97), 98.82 (CI95%: 97.96, 99.31) and 90.89 (CI95%: 87.79, 93.21) for ≤ 1 and >1 year since vaccination, respectively. CONCLUSIONS The meningococcal C conjugate vaccination programme has been extremely successful in controlling the disease and continues to be evaluated and adapted to the changes in the epidemiology of the disease to ensure long-term vaccine protection.

Meningococcal C conjugate age-dependant long-term loss of effectiveness

INTRODUCTION Although different epidemiological studies have assessed meningococcal C conjugate vaccine effectiveness within 1 and >1 year since vaccination, none of them evaluated long-term effectiveness. In order to assess if epidemiological data correlates with the findings described in seroprevalence studies we evaluated long-term vaccine effectiveness over time, up to 10 years since vaccination. METHODS Cases targeted by vaccination programs and notified to the Spanish Surveillance System between 2001 and 2013 were included in the study. Vaccine effectiveness was estimated using the screening method. Relationship between vaccine effectiveness and time since vaccination was explored using point estimates, simple logistic regression or restricted cubic splines logistic regression model for all and for those vaccinated at <1, 1-11 and at 12-19 years of age. RESULTS From 345 confirmed cases reported in the period and targeted by vaccination programs, 125 (36.23%) were vaccine failures. Proportion of vaccine failures decreased with age of vaccination: 63.97% at <1 year; 36.84% at 1-11 years; and 3.88% at 12-19 years. Using the best model for each group, vaccine effectiveness decreased from 99.12% to 90.85% (%change=-8.3%) for all; from 99.04% to 48.60% (%change=-50.9%) for those vaccinated at <1 years and from 99.45% to 90.18% (%change=-9.3%) for those vaccinated at 1-11 years after 10 years since vaccination. For those vaccinated at 12-19 years no changes were observed in vaccine effectiveness after 10 years (p=0.968). CONCLUSIONS After 10 years, vaccine effectiveness decreased by 50% in those vaccinated at <1 year, while those vaccinated with one dose at 12-19 years showed no changes. Vaccine failures occurred early after vaccination and more frequently in those vaccinated at younger ages. Vaccination at ≥12 years seems to be related to a low number of vaccine failures and a higher and endurable protection over time.

El brote de Ébola: la crisis local no debe impedir ver el grave problema en África occidental

La respuesta rápida, oportuna y dirigida al foco del problema es una de las claves para que una alerta sanitaria pueda controlarse de manera efectiva. En este momento no hay duda de que en esta emergencia las actuaciones no han sido rápidas ni oportunas y que ha habido un fallo en la respuesta internacional1. El 8 de agosto, la Directora de la Organización Mundial de la Salud (OMS), según la evaluación del Comité de Emergencias del Reglamento Sanitario Internacional [RSI(2005)], declaró el brote de Ébola como una Emergencia de Salud Pública de Interés Internacional (ESPII) cuando el brote ya llevaba varios meses de intensa transmisión2.

Non-imported malaria in non-endemic countries: a review of cases in Spain

Spain declared the elimination of malaria in 1964. In non-endemic areas, the overwhelming majority of malaria cases are acquired abroad, and locally acquired infections are rare events. In Spain, malaria is a statutorily notifiable disease. During these fifty years more than ten thousand malaria cases have been reported, and about 0.8% of them did not have a history of recent travel. In this report, it was carried out a review of the ways in which malaria can be transmitted in non-endemic areas and a short description of the Spanish cases, aggregated by their transmission mechanisms. Four cases contracted malaria by mosquito bites; there were two autochthonous cases and two of “airport malaria”. The other 28 cases were: congenital malaria cases, transfusion-transmitted malaria, post-transplant cases, nosocomial transmission and cases in intravenous drug users. In addition, in 1971 there was an outbreak of 54 cases due to exposure to blood or blood products. So, while malaria usually is an imported disease in non-endemic areas, it should not be excluded in the differential diagnosis of persons who have fever of unknown origin, regardless of their travel history.

Decline in rotavirus hospitalizations following the first three years of vaccination in Castile-La Mancha, Spain

Rotavirus is a major burden on the Spanish Healthcare System. Rotarix® and RotaTeq® were simultaneously commercialized in Spain by February, 2007. The objective is to analyze the incidence and seasonality of rotavirus hospitalizations (RH) in Castile-La Mancha (CLM), following the first 3 y of commercialization. A cross-sectional study of the hospital discharge registrys Minimum Basic Data Set (MBDS) in CLM between 2003 and 2009 was performed. We used the Poisson regression model to quantify the percentage of change in the rotavirus incidence rate (IR) for 2007–09 vs. 2003–05, adjusting for age, sex, and province. To analyze changes between epidemic seasons the chi-square test was used. The median IR in 2003–09 was 224.71 per 105 [interquartile range (IQR): 185.24–274.70], which represents 60% of hospital admissions due to infectious acute gastroenteritis. The median rate in 2007–09 decreased [incidence rate ratio (IRR): 0.86, 95% CI: 0.78–0.96], significantly in Toledo (IRR: 0.54, 95% CI: 0.39–0.75). An incipient decline at the beginning of the last cold season was observed, preceded by a significant decrease of 68% in the autumn season of 2009. Despite its limited coverage, the rotavirus vaccine may have contributed to decrease RH in CLM.

Spatial pattern of legionellosis in Spain, 2003-2007

OBJECTIVES To analyze the spatial pattern of legionellosis in Spain for men and women during the period 2003-2007 and to identify spatial clustering of risk. METHODS We identified the spatial pattern of the distribution of legionellosis rates based on calculation of rates by municipality through the direct method. Smoothing of these rates was performed by the Empirical Bayes method for studying the spatial pattern of disease for both sexes. We used Morans index to analyze spatial autocorrelation rates globally. To calculate local rates, the Local Morans Index [known as local indicators of spatial association (LISA)], was used to analyze the clusters of municipalities with the highest risk. RESULTS After smoothing the risk, the highest rates (over 50 per 100,000 inhabitants) were grouped in the eastern Mediterranean coastal areas and the north of the mainland, as well as in the Mediterranean islands. Morans index smoothed rates were 0.15 for men and 0.23 for women. The spatial clusters of statistically significant higher rates calculated by the LISA index were distributed in the north and east for both sexes. CONCLUSIONS These methods of spatial analysis allow patterns of disease distribution to be identified. All the methods used yielded similar results. These techniques are a complementary tool for epidemiological surveillance of infectious diseases.

Patrón espacial de la legionelosis en España, 2003-2007

OBJECTIVES To analyze the spatial pattern of legionellosis in Spain for men and women during the period 2003-2007 and to identify spatial clustering of risk. METHODS We identified the spatial pattern of the distribution of legionellosis rates based on calculation of rates by municipality through the direct method. Smoothing of these rates was performed by the Empirical Bayes method for studying the spatial pattern of disease for both sexes. We used Morańs index to analyze spatial autocorrelation rates globally. To calculate local rates, the Local Morans Index [known as local indicators of spatial association (LISA)], was used to analyze the clusters of municipalities with the highest risk. RESULTS After smoothing the risk, the highest rates (over 50 per 100,000 inhabitants) were grouped in the eastern Mediterranean coastal areas and the north of the mainland, as well as in the Mediterranean islands. Morans index smoothed rates were 0.15 for men and 0.23 for women. The spatial clusters of statistically significant higher rates calculated by the LISA index were distributed in the north and east for both sexes. CONCLUSIONS These methods of spatial analysis allow patterns of disease distribution to be identified. All the methods used yielded similar results. These techniques are a complementary tool for epidemiological surveillance of infectious diseases.

Spread of Ebola virus disease based on the density of roads in West Africa

On March 23rd 2014 the World Health Organization announced that a new Ebola outbreak had appeared in West Africa involving three countries. The objective of this study was to show how a road density index (RDI) could be constructed and a study of its association with Ebola cases during the outbreak. The study was carried out at the district level across the affected countries. RDI was calculated by km2 of territory as a proxy for the mobility of the population. To calculate this index, the number of km of road constructed in each district was estimated and subsequently divided by the area of each district expressed in km2. The accumulated incidence of Ebola was calculated per district. A generalised linear model with a Poisson distribution was used. The RDI varied from 0.12 to 0.84 between the districts. An RDI increase of 0.01 indicates a 3% increase in Ebola infection risk (RR is 1.03; CI 1.03-1.04). The density of the road network can influence the increased incidence of Ebola cases in the affected zone. An exhaustive mapping of the area could help the relevant organisations to manage another outbreak in the future and it could help the distribution of resources in an emergency situation.