[Incidence of whooping cough in the city of Barcelona between 1999 and 2011]. / Evolución de la incidencia de tos ferina en la ciudad de Barcelona entre 1999 y 2011.

INTRODUCTION: The aim of the study was to describe the long-term incidence of whooping cough in a large city. METHODS: Descriptive study of the cases reported in the notifiable disease registry between 1999 and 2011 in Barcelona. RESULTS: An increase in incidence was observed, especially in children and in the year 2011. Children younger than one year still were most affected, with a specific rate of 426.87/100,000 in 2011. CONCLUSION: A new approach in adolescent and adult vaccination is needed to provide more protection to younger children, as well as research to assess a possible shift in the bacteria itself.

Tuberculosis incidence among infected contacts detected through contact tracing of smear-positive patients.

BACKGROUND: The contacts of people with pulmonary tuberculosis (PTB) have a high risk of becoming infected and developing tuberculosis (TB). Our aim was to determine the incidence of TB and its risk factors in a cohort of contacts with latent TB infection (LTBI) detected through contact tracing of smear-positive PTB cases. METHODS AND FINDINGS: We performed a population-based retrospective cohort study including contacts that had LTBI, and were contacts of people with PTB who started treatment between 2008 and 2014. We followed up contacts until they developed TB or until the end date for follow-up (31st December 2016). We used Kaplan-Meier curves to compute incidence at 2 and 5 years, and Cox regression to compute hazard ratios (HR) and their 95% confidence intervals (CI). We analyzed 3097 close contacts of 565 PTB cases. After exclusion of 81 co-prevalent TB cases, 953 contacts had LTBI, of which 14 developed TB. Their risk of developing TB after two and five years was 0.7% (CI: 0.3-1.6) and 1.8% (CI: 1.1-3.1) respectively. Contacts who had not been referred for LTBI treatment had a 1.0% (CI: 0.2-4.0) risk at 5 years. Risk of developing TB at 5 years was 1.2% (CI: 0.5-3.0) among people who completed treatment, and 11.1% (CI: 5.1-23.3) for those who did not. Risk factors for TB were not completing LTBI treatment (HR 9.4, CI: 2.9-30.8) and being female (HR 3.5, CI: 1.1-11-3). CONCLUSIONS: LTBI treatment plays a fundamental role in decreasing the risk of developing TB. It is necessary to achieve a maximum contact tracing coverage and the highest possible compliance with LTBI treatment.

The decline of the incidence of meningococcal disease in Barcelona between 1988 and 2015: the influence of the vaccine against serogroup C. / El declive de la incidencia de enfermedad meningocócica en Barcelona entre 1988 y 2015: la influencia de la vacunación frente al serogrupo C.

INTRODUCTION AND OBJECTIVE: The purpose of this study was to describe the evolution of meningococcal disease (MD) in the city of Barcelona between 1988 and 2015 and to assess the impact of the vaccine against serogroup C. MATERIALS AND METHODOLOGY: The evolution of MD and by serogroup was analysed using the information included in the mandatory notification diseases registry. Incidences of all serogroups between the periods of before and after the implementation of the serogroup C vaccine in 2000 were compared. Vaccination coverage among cases, serogroup among vaccinated cases and mortality and case fatality rates were analysed. RESULTS: MD has evolved from an incidence rate in children aged under 1 of 63.09 cases per 100,000 in 1997-2000 to 15.44 per 100,000 in 2001-2015. All MD serogroups incidences decreased after the implementation of the vaccine, especially for serogroup C among children aged between 1 and 4. Since 2000 vaccine coverage in MD cases by this serogroup was 7.6% while in those affected by serogroup B it was 35.0% (p<.01). Among those vaccinated, 66.4% of cases were serogroup B and 5.2% were C (p<.01). Mortality and case fatality rates were 7.7% and 0.19/100,000 respectively, without significant changes in time regarding case fatality. CONCLUSIONS: Incidence caused by serogroups B and C has decreased after the systematic vaccination against serogroup C. Vaccination against serogroup B could further reduce the impact of this lethal disease which has not decreased during this period.

[Confirmed Dengue, Chikungunya and Zika Cases during the Period 2014 to 2016 in Barcelona, Spain]. / Casos confirmados de Dengue, Chikungunya y Zika en Barcelona capital durante el período de 2014 al 2016.

OBJECTIVE: Arbovirus infections are a group of diseases whose incidence is increasing and that entail an important problem for public health. The aim of this study was to describe detected cases of arbovirosis in Barcelona, and surveillance and control actions performed in order to reduce the risk of transmission. METHODS: Descriptive cross-sectional study of confirmed dengue, chikungunya and Zika cases in Barcelona during 2014-2016 (1st trimester). Suspected cases detected in the city were notified to the Epidemiology Department of the Barcelona Public Health Agency, where an epidemiological survey is undertaken and, if appropriate, Urban Pests Surveillance and Control Department is contacted. They perform an entomological inspection and implement control and monitoring actions. We collected sociodemographical, epidemiological, clinical and entomological variables. RESULTS: In 2014, 50 chikungunya and 20 dengue cases were detected; 25 entomological inspections were carried out in residences and 38 in the street. In 2015, 47 chikungunya, 51 dengue and 2 Zika cases were detected; 27 inspections were carried out in residences and 80 in the street. In 2016, 17 chikungunya, 52 dengue and 48 Zika cases were detected; 50 inspections were carried out in residences and 103 in the street. No autochtonous case was detected. CONCLUSIONS: We observed an increasing incidence of arbovirosis cases during the 3-year study period. There was a progressive intensification of vector surveillance and control actions (inspections, sample collection…).

OBJETIVO: Las infecciones por arbovirus son un grupo de enfermedades cuya incidencia está aumentando y que suponen un problema importante para la salud pública. El objetivo de este estudio fue describir los casos detectados de arbovirosis en la ciudad de Barcelona y las actuaciones de vigilancia y control realizadas para reducir el riesgo de transmisión. METODOS: Estudio descriptivo transversal de casos confirmados de dengue, chikungunya y Zika en Barcelona durante el período de 2014 al 2016. Los casos sospechosos detectados en la ciudad se notificaron al Servicio de Epidemiología de la Agencia de Salud Pública de Barcelona (ASPB), donde se realizó una encuesta epidemiológica y, si procedía, se contactaba con el Servicio de Vigilancia y Control de Plagas Urbanas. Desde allí se realizó la inspección entomológica y se llevaron a cabo acciones de control y seguimiento. Se recogieron variables sociodemográficas, epidemiológicas, clínicas y entomológicas de los casos. RESULTADOS: En 2014 se detectaron 50 casos de virus chikungunya y 20 de dengue, realizándose 25 inspecciones entomológicas en domicilios y 38 en la vía pública. En 2015 se detectaron 47 casos de chikungunya, 51 de dengue y 2 de Zika, realizándose 27 inspecciones entomológicas en domicilios y 80 en vía pública. En 2016 se detectaron 17 casos de chikungunya, 52 de dengue y 48 de Zika, realizándose 50 inspecciones entomológicas en domicilio y 103 en vía pública. No se detectó ningún caso autóctono. CONCLUSIONES: Se observó un aumento creciente de los casos de arbovirosis durante los 3 años de estudio. Se intensificaron progresivamente las actuaciones de vigilancia y control vectorial (inspecciones, muestras recogidas…).

Evolution of acute hepatitis C virus infection in a large European city: Trends and new patterns.

The aims of this study were to describe the evolution of acute hepatitis C virus (HCV) infections since 2004 and to determine its associated factors. Acute HCV infections diagnosed in Barcelona from 2004 to 2015 were included. Incidence ratios (IR) were then estimated for sex and age groups. Cases were grouped between 2004-2005, 2006-2011 and 2012-2015, and their incidence rate ratios (IRR) were calculated. In addition, risk factors for acute HCV infection were identified using multinomial logistic regression for complete, available and multiple imputed data. 204 new HCV cases were identified. Two peaks of higher IR of acute HCV infection in 2005 and 2013 were observed. Men and those aged 35-54 had higher IR. IRR for men was 2.9 times greater than in women (95% confidence intervals (CI): 1.8 ‒ 4.7). Factors related to the period 2012-2015 (versus 2006-2011) were: a) sexual risk factor for transmission versus nosocomial (relative-risk ratio (RRR): 13.0; 95% CI: 2.3 ‒ 72.1), b) higher educated versus lower (RRR: 5.4; 95% CI: 1.6 ‒ 18.7), and c) HIV co-infected versus not HIV-infected (RRR: 53.1; 95% CI: 5.7 ‒ 492.6). This is one of the few studies showing IR and RRRs of acute HCV infections and the first focused on a large city in Spain. Sexual risk for transmission between men, higher educational level and HIV co-infection are important factors for understanding current HCV epidemic. There has been a partial shift in the pattern of the risk factor for transmission from nosocomial to sexual.

Retrospective space-time cluster analysis of whooping cough, re-emergence in Barcelona, Spain, 2000-2011.

A retrospective, space-time study of whooping cough cases reported to the Public Health Agency of Barcelona, Spain between the years 2000 and 2011 is presented. It is based on 633 individual whooping cough cases and the 2006 population census from the Spanish National Statistics Institute, stratified by age and sex at the census tract level. Cluster identification was attempted using space-time scan statistic assuming a Poisson distribution and restricting temporal extent to 7 days and spatial distance to 500 m. Statistical calculations were performed with Stata 11 and SatScan and mapping was performed with ArcGis 10.0. Only clusters showing statistical significance (P <0.05) were mapped. The most likely cluster identified included five census tracts located in three neighbourhoods in central Barcelona during the week from 17 to 23 August 2011. This cluster included five cases compared with the expected level of 0.0021 (relative risk = 2436, P <0.001). In addition, 11 secondary significant space-time clusters were detected with secondary clusters occurring at different times and localizations. Spatial statistics is felt to be useful by complementing epidemiological surveillance systems through visualizing excess in the number of cases in space and time and thus increase the possibility of identifying outbreaks not reported by the surveillance system.