Luis García-Comas

Effectiveness of 23-valent pneumococcal polysaccharide vaccine in adults aged 60 years and over in the Region of Madrid, Spain, 2008–2011

Invasive pneumococcal disease (IPD) is a notifiable disease in the Region of Madrid. The 23-valent pneumococcal polysaccharide vaccine (PPV23) is recommended for children and adults aged two years or over with a high risk of disease, and for all adults aged 60 and over. We describe the evolution of IPD incidence from 2008 to 2011 in people aged 60 years and over and PPV23 vaccine effectiveness (VE). VE is estimated using both the screening method and indirect cohort method. The incidence of IPD varied from 20.0 in 2008 to 15.2 per 100,000 inhabitants in 2011 (RR: 0.8; 95% CI: 0.6–0.9). Adjusted VE estimated with the screening method was 68.2% (95% CI: 56.2–76.9). VE with the Broome method was 44.5% (95% CI: 23.8–59.6) for all PPV23 serotypes, and 64.4% (95% CI: 45.2–76.8) for PPV23 serotypes not included in conjugate vaccines. VE was lower in patients aged 80 years and older (25.5%; 95% CI:-23.2 to 55.0) and those with highrisk medical conditions (31.7%; 95% CI: -2.2 to -54.4). Adjusted VE was 44.5% (95% CI: 19.4-61.8) within 5 years of vaccination and 32.5% (95% CI: -5.6 to 56.9) after 5 years. These results are compatible with current recommendations for PPV23.

Autochthonous Crimean-Congo Hemorrhagic Fever in Spain.

Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed, viral, tickborne disease. In Europe, cases have been reported only in the southeastern part of the continent. We report two autochthonous cases in Spain. The index patient acquired the disease through a tick bite in the province of Ávila - 300 km away from the province of Cáceres, where viral RNA from ticks was amplified in 2010. The second patient was a nurse who became infected while caring for the index patient. Both were infected with the African 3 lineage of this virus. (Funded by Red de Investigación Cooperativa en Enfermedades Tropicales [RICET] and Efficient Response to Highly Dangerous and Emerging Pathogens at EU [European Union] Level [EMERGE].).

Seroprevalence of measles and rubella virus antibodies in the population of the Community of Madrid, 2008–2009

The seroprevalence (SP) of measles and rubella virus antibodies is presented by age groups obtained in the IV Serosurvey of the Region of Madrid (2008-2009). The target population is composed of residents with ages ranging between 2 and 60 years in the Region of Madrid. A two-stage cluster sample is used. The SP of measles virus antibodies is 97.8% (CI 95%: 97.3-98.2). The highest SP is observed in the 2-5 year and 41-60 year age groups. The point estimate does not reach 95% in the 16-20 and 21-30 year age groups. The SP of rubella virus antibodies is 97.2% (CI 95%: 96.5-97.7). The SP is over 95% in all of the age groups. In immigrant women between the ages of 16 and 49, the SP is 95.9% (CI 95%: 93.7-97.4). The identification of groups susceptible to the measles virus in young adults could lead to outbreaks as a result of importing the virus. The circulation of the rubella virus is possible among immigrant women aged between 16 and 49 years, which could lead to the appearance of SRC cases. Epidemiological surveillance will allow the impact on the measles and rubella elimination plan to be determined in the future.

Hepatitis B virus infection and vaccine-induced immunity in Madrid (Spain)

OBJECTIVE To estimate the prevalence of hepatitis B virus (HBV) infection and vaccine-induced immunity in the region of Madrid, and to analyze their evolution over time. METHODS An observational, analytical, cross-sectional study was carried out in the population aged 16-80 years between 2008 and 2009. This was the last of four seroprevalence surveys in the region of Madrid. The prevalence of HBV infection and vaccine-induced immunity was estimated using multivariate logistic models and were compared with the prevalences in the 1989, 1993 and 1999 surveys. RESULTS In the population aged 16-80 years, the prevalence of HBV infection was 11.0% (95% CI: 9.8-12.3) and that of chronic infection was 0.7% (95% CI: 0.5-1.1). The prevalence of vaccine-induced immunity in the population aged 16-20 years was 73.0% (95% CI: 70.0-76.0). Compared with previous surveys, there was a decrease in the prevalence of HBV infection. CONCLUSIONS Based on the prevalence of chronic infection (<1%), Madrid is a region with low HBV endemicity. Preventive strategies against HBV should especially target the immigrant population.

Effectiveness of acellular pertussis vaccine and evolution of pertussis incidence in the community of Madrid from 1998 to 2015

INTRODUCTION Pertussis is a communicable disease that primarily affects infants. Vaccination has led to an important reduction in the incidence of the disease, however, resurgence of the disease has been observed. This study aimed to analyze the incidence of pertussis and assess the vaccination effectiveness (VE) of different schedules of acellular pertussis vaccination in the community of Madrid. METHODS Pertussis cases notified to the Mandatory Disease Reporting System from 1998 to 2015 were analyzed. Five comparison periods were created: 1998-2001 (reference), 2002-2005, 2006-2009, 2010-2012 and 2013-2015. The incidence ratio (IR) between inter-epidemic periods was analyzed using a Poisson regression. VE was calculated using the screening method. Vaccine status data were collected from the vaccine registry. RESULTS In total, 3855 cases were notified. Inter-epidemic periods were observed every 3-4 years. The incidence increased (IR: 5.99, p < 0.05) in the 2013-2015 period, particularly among infants younger than 1 month (IR: 32.41, p < 0.05). Vaccination data were available in 89% of cases. For those receiving the last dose at ≤6-month VE was 89.9% (95% confidence interval (CI): 87.3-92.0) after one year of follow-up, and 85.5% (95% CI: 82.4-88.1) after 11 years of follow-up. For those receiving the last dose at 18-months VE decreased from 98.8% (95% CI: 98.3-99.1) to 85.1% (95% CI: 81.9-87.7) in the same period, and for those receiving the last dose at 4-year VE decreased from 99.6% (95% CI: 99.3-99.7) to 79.3% (95% CI: 74.6-83.1). CONCLUSIONS B. pertussis is circulating in our population, as shown by the epidemic peaks and increased incidence of pertussis in recent years. VE increased with the number of doses and decreased with the follow-up period. The effect of this and other vaccination strategies must be monitored to control the disease.

Effectiveness and impact of a single-dose vaccine against chickenpox in the community of Madrid between 2001 and 2015

ABSTRACT Background: Chickenpox is a contagious airborne disease. Immunization by varicella vaccine is an effective preventive measure. The objective of this study is to evaluate the impact and effectiveness of a single-dose vaccination against chickenpox at 15 months of age. Methods: Observational study based on data from the Epidemiological Surveillance System of the Autonomous Community of Madrid from 2001 to 2015. The years were grouped into 4 periods according to epidemic cycles and vaccination schedule: 2001–06, 2007–10, 2011–13 and 2014–15. The impact was calculated as Relative Risk (RR) between the incidence of chickenpox in children between 15 months and 13 years of age between 2011–13 and 2001–06 through Poisson regression using notifications made to the Diseases of Compulsory Declaration (DCD) system, the Sentinel Physicians Network (SPN) and hospital discharge records noted as Minimum Basic Data Set (MBDS). The vaccine effectiveness (VE) was calculated using the screening method and a 1:2 case-control study paired by age and paediatrician in population from 15 months to 13 years and between 2007 and 2015 using SPN source data. Results: The RR2011–13/2001–06 using data from the DCD was 0.14 (95% CI: 0.14 to 0.15), 0.07 (95% CI: 0.06 to 0.08) from SPN and 0.17 (95% CI: 0.15 to 0.20) from MBDS. A total of 338 cases were included in the VE screening obtaining an overall of 93.1 (90.9 to 94.8). For a case-control study, 120 cases and 247 controls were recruited obtaining a VE of 92.4% (IC 95%: 80.8 to 97.0%). Conclusions: The single-dose vaccination against chickenpox at 15 months of age has high impact and effectiveness.

Effectiveness of different vaccine schedules for heptavalent and 13-valent conjugate vaccines against pneumococcal disease in the Community of Madrid

INTRODUCTION The heptavalent pneumococcal conjugate vaccine (PCV-7) was added to the childhood routine vaccination program in the Community of Madrid in November of 2006 with 3+1 recommended doses and a catch-up for those under 2years old. In June 2010, PCV-7 was replaced by 13-valent vaccine (PCV-13) with 2+1 recommended doses. In July of 2012, the PCV-13 was removed from the funded program and reintroduced again (2+1 recommended doses) in December 2014. In between, children were vaccinated privately with 3+1 recommended doses of PCV-13. The aim of this study was to evaluate the effectiveness of each vaccination schedule used in the Community of Madrid. METHODS We included all cases of invasive pneumococcal disease (IPD) reported between 2007 and 2015 to the Notifiable Diseases Surveillance System. Vaccination information was obtained from the Immunization Registry. Vaccine effectiveness (VE) was estimated using the indirect cohort design for cases with serotype information. RESULTS A total 779 cases were included in the study. Among them 47.6% of the cases were primo-vaccinated with booster, 20% primo-vaccinated, 15.9% incompletely primo-vaccinated and 16.5% not vaccinated. The VE for ≥1 doses of any PCV was 82% (CI 95%: 67.8-89.9%): 91.9% (CI 95%: 76.5-97.2%) for PCV-7 and 77.2% (48.6-89.9%) for PCV-13. VE in those receiving the full 2+1 or 3+1 schedules was 100% for both vaccines. CONCLUSIONS A high number of vaccine failures were reported in children before they had the opportunity to receive the booster dose, especially due to PCV-13-non-PCV-7 serotypes. VE was higher for PCV-7 compared to PCV-13, except for those that received the complete schedule with booster that achieved 100% of VE, which shows the relevance of the vaccines and complying with all doses scheduled.

Diagnóstico serológico de parotiditis epidémica: valor de la titulación de IgG específica

INTRODUCTION The aim of this study was to evaluate a cut-off point of the titration of IgG by ELISA in the diagnosis of mumps. METHODS A study was made of serum samples from 85 mumps cases (confirmed by PCR in saliva) and 2,351 controls of the general population of the Region of Madrid. RESULTS The IgM detection was positive in 21 cases (sensitivity of 24.7%). The best cut-off point corresponded to IgG titres ≥4,900 (sensitivity of 64.7% and specificity of 86.1%). Among 42 patients immunised with at least one dose of measles mumps, rubella vaccine IgM was detected in 4 cases. However, the detection of IgG ≥4,900 was positive in 29 (sensitivity of 69.0%). CONCLUSIONS An IgG result of ≥4.900 was almost 5 times more probable in a patient with mumps than in a non-infected patient. The detection of high titres of IgG against mumps could improve the IgM results in vaccinated people.