Fernando A. Moraga-Llop

Tos ferina en España. Situación epidemiológica y estrategias de prevención y control. Recomendaciones del Grupo de Trabajo de Tos ferina

A large increase of pertussis incidence has been observed in recent years in countries with high vaccination coverage. Outbreaks of pertussis are increasingly being reported. The age presentation has a bipolar distribution: infants younger 6months that have not initiated or completed a vaccination schedule, and adolescents and adults, due to the lost of natural or vaccine immunity over time. These epidemiological changes justify the need to adopt new vaccination strategies in order to protect young infants and to reduce pertussis incidence in all age groups. Adolescents and adults immunization must be a priority. In the first group, strategy is easy to implement, and with a very low additional cost (to replace dT vaccine by dTap one). Adult vaccination may be more difficult to implement; dT vaccine decennial booster should be replaced by dTap. The immunization of household contacts of newborn infants (cocooning) is the strategy that has a most important impact on infant pertussis. Recently, pregnant women vaccination (after 20weeks of gestation) has been recommended in some countries as the most effective way to protect the newborn.

Infecciones por Staphylococcus aureus resistente a meticilina adquirido en la comunidad en niños

INTRODUCTION Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections were first reported in the 1990s. Young, healthy individuals are frequently affected. The incidence of CA-MRSA in Spain is increasing. METHODS All children seen between August 2006 and January 2009 with CA-MRSA infections were included. The S. aureus isolates were studied by conventional techniques, their antibiotic susceptibility by agar disk diffusion, the presence of mecA gene was detected by multiplex polymerase chain reaction (PCR) and the gene encoding the Panton-Valentine leukocidin (PVL) by conventional PCR. CA-MRSA colonization was studied both in patients and their family members. RESULTS CA-MRSA was isolated in 15 samples from 12 patients, aged between 6 days and 14 years. Half of them were not native. Eight patients required hospital admission. The most common clinical presentation was skin and soft tissue infection (92%). Secondary CA-MRSA bacteraemia was present in two patients. All strains were PVL producers and two were resistant to macrolides associated to methicillin resistance and one of them was also resistant to lincosamides. An intra-familial transmission was identified. The clinical outcome was favourable in all patients. CONCLUSION CA-MRSA infections are emerging in Spain. Empirical treatment of skin and soft tissue infections should not be changed, since their incidence is still low. The drainage of CA-MRSA suppurative infections plays an important role in their treatment. Clindamycin or trimethoprim-sulfamethoxazole should be used for mild or moderate skin and soft tissue infections. Controlling the spread of these strains presents a challenge in the community today.

Vaccine Failures in Patients Properly Vaccinated with 13-Valent Pneumococcal Conjugate Vaccine in Catalonia, a Region with Low Vaccination Coverage.

Vaccine failures occurring with 13-valent pneumococcal conjugate vaccine (PCV13) in 3 pediatric hospitals in Barcelona (2012–2013) are described. PCV13 vaccine failure was defined as the occurrence of an invasive pneumococcal infection in children properly vaccinated by PCV13. Among 84 patients with invasive pneumococcal infection, 32 had received at least one dose of PCV13. Seventeen of them had invasive pneumococcal infection produced by a PCV13 serotype. Among those, 9 patients were considered to have a PCV13 vaccine failure. Serotype 3 was isolated in 6 patients, serotype 19A in 2 and serotype 6B in 1.

Nuevas perspectivas de la tos ferina en el siglo XXI . ¿Estamos fracasando en su control?

Tos ferina: «La tos de los 100 días.» A pesar de haberse implantado la vacunación sistemática antiertussis en todo el mundo, con coberturas del 82% en los niños enores de 1 año en 2008, la tos ferina continúa siendo un prolema de salud pública y es una enfermedad endémica en muchos aíses, incluso en aquellos con altas coberturas vacunales. En spaña, donde la tos ferina también es una enfermedad reemerente, las coberturas son muy amplias: en el año 2009, del 95,9% ara las tres primeras dosis del primer año de vida, del 94,1% para a cuarta dosis y del 88,3% para la quinta de los 4-6 años1. La Organización Mundial de la Salud estima que en 2008 hubo lrededor de 16 millones de casos y 195.000 muertes por tos ferina n el mundo, pero más del 95% correspondió a países en desarrollo2. ctualmente, la tos ferina ocupa el quinto lugar como causa de uerte en los niños menores de 5 años por enfermedades preveibles por vacunas, después de las infecciones neumocócicas, el arampión, la gastroenteritis por rotavirus y las infecciones por aemophilus influenzae tipo b, y representa un 11% del total3. La ncidencia de la enfermedad en los países desarrollados ha aumenado en dos grupos de edad: los lactantes y los adolescentes y dultos; es la llamada distribución bipolar en este nuevo patrón pidemiológico de la tos ferina. En los lactantes se asocia a una alta asa de complicaciones y puede ser letal, mientras que en la edad dulta la morbilidad es importante, aunque raras veces lleva a la uerte, pero es un reservorio importante para transmitir la infeción a recién nacidos y lactantes de menos de 6 meses de edad, odavía no inmunizados o sin haber completado la primovacunaión. La tos ferina se presenta a menudo en el adolescente y en el dulto como una tos prolongada, con una prevalencia entre el 12,4 el 26% en los pacientes con tos de más de 2 semanas de duración4. in embargo, en ocasiones adopta un cuadro clínico similar al del aciente pediátrico, con apnea después de la tos, estridor inspiraorio y vómitos postusígenos5.

Enfermedad neumocócica invasiva y síndrome hemolítico urémico

Introduccion Streptococcus pneumoniae es un agente etiologico infrecuente del sindrome hemolitico uremico (SHU) con una mayor gravedad que el SHU clasico. Casos clinicos Presentamos 2 pacientes con pleuroneumonia neumococica que desarrollaron SHU. En un caso la evolucion fue hacia la normalizacion de la funcion renal y en el otro, hacia la insuficiencia renal, que requirio trasplante renal. Conclusion La enfermedad neumococica invasiva puede ser causa de SHU grave. Un alto indice de sospecha es necesario para un diagnostico precoz y un adecuado tratamiento.

Effectiveness of the 13-valent pneumococcal conjugate vaccine in preventing invasive pneumococcal disease in children aged 7-59 months. A matched case-control study

Background The 13-valent pneumococcal conjugate vaccine (PCV13) was licensed based on the results of immunogenicity studies and correlates of protection derived from randomized clinical trials of the 7-valent conjugate pneumococcal vaccine. We assessed the vaccination effectiveness (VE) of the PCV13 in preventing invasive pneumococcal disease (IPD) in children aged 7–59 months in a population with suboptimal vaccination coverage of 55%. Methods The study was carried out in children with IPD admitted to three hospitals in Barcelona (Spain) and controls matched by hospital, age, sex, date of hospitalization and underlying disease. Information on the vaccination status was obtained from written medical records. Conditional logistic regression was made to estimate the adjusted VE and 95% confidence intervals (CI). Results 169 cases and 645 controls were included. The overall VE of ≥1 doses of PCV13 in preventing IPD due to vaccine serotypes was 75.8% (95% CI, 54.1–87.2) and 90% (95% CI, 63.9–97.2) when ≥2 doses before 12 months, two doses on or after 12 months or one dose on or after 24 months, were administered. The VE of ≥1 doses was 89% (95% CI, 42.7–97.9) against serotype 1 and 86.0% (95% CI, 51.2–99.7) against serotype 19A. Serotype 3 showed a non-statistically significant effectiveness (25.9%; 95% CI, -65.3 to 66.8). Conclusions The effectiveness of ≥1 doses of PCV13 in preventing IPD caused by all PCV13 serotypes in children aged 7–59 months was good and, except for serotype 3, the effectiveness of ≥1 doses against the most frequent PCV13 serotypes causing IPD was high when considered individually.

Tos ferina en el lactante. ¿Quién lo contagia?

espanolObjetivo. La reemergencia de la tos ferina tiene una distribucion por edades bipolar: los lactantes menores de 6 meses de edad y los adolescentes y adultos. El objetivo de este estudio es determinar la fuente de infeccion o caso primario y las caracteristicas clinicas, epidemiologicas y microbiologicas de los lactantes hospitalizados por tos ferina. Material y metodos. Estudio observacional prospectivo sobre lactantes (menores de 12 meses de edad) diagnosticados de tos ferina que ingresaron en el Area Pediatrica del Hospital Universitario Vall d’Hebron de Barcelona en el periodo 2005–2008 y sus contactos domiciliarios. La confirmacion se obtuvo por PCR-RT de Bordetella pertussis y B. parapertussis y por cultivo en agar-charcoal de una muestra de aspirado nasofaringeo. Se realizo tambien una inmunoflorescencia para virus respiratorio sincitial, gripe A y B, parainfluenza y adenovirus. Se analizaron las siguientes variables: edad, sexo, distribucion estacional, estado vacunal, manifestaciones clinicas, evolucion, datos microbiologicos y tipo de contacto domiciliario. Resultados. Se incluyo en el estudio a 52 lactantes; 49 pacientes eran menores de 6 meses y 3 tenian entre 6 y 11 meses. El 57,7% no estaba vacunado por ser menores de 2 meses y solo el 3,8% habia recibido tres dosis. La maxima incidencia de casos se observo en primavera y verano (67,3%). Ocho pacientes requirieron ingreso en la UCI y la letalidad fue del 1,9%. La PCR-RT fue positiva en el 96,1% y el cultivo, en el 56% de los casos. Se observo coinfeccion viral en el 26% de los pacientes. Las manifestaciones clinicas mas frecuentes al ingreso fueron crisis de tos, cianosis y vomitos; hubo apneas en el 21% de los enfermos. El estudio de contactos permitio encontrar el caso primario en el 80,4% de los casos (41 pacientes) y la tos ferina se confirmo por estudio microbiologico en el 27,5% (14 casos); el 85,4% (35 casos) de los casos primarios eran adultos (el 44% padres, el 17% tios y el 15% abuelos). Conclusiones. La tos ferina en el lactante puede ser grave, sobre todo en los menores de 4 meses. La PCR-RT es un medio diagnostico de gran sensibilidad. El 87,8% de los lactantes se contagiaron en el nucleo familiar y el 85,4% de los casos primarios eran adultos. Debe recomendarse la vacunacion sistematica de los adolescentes y adultos, con prioridad de los que esten en contacto con lactantes (estrategia del nido), para disminuir la incidencia de tos ferina en este grupo de edad. EnglishObjective. The re-emergence of pertussis has a bipolar age distribution: infants younger than 6 months, and adolescents and adults. The aim of this study was to determine the source of infection in infants hospitalized with pertussis, and describe the epidemiological, clinical and microbiological characteristics. Material and methods. Observational, prospective design. Infants aged Results. Fifty-two infants were included. Forty-nine were aged Conclusions. Pertussis can be a serious disease in infants, especially in those under 4 months of age. RT-PCR is a highly sensitive microbiological test. Of the 51 cases studied, 87.8% were infected in the household and 85.4% of transmitters were adults. Universal vaccination of adolescents and adults must be recommended, particularly those in contact with infants (cocoon strategy).

Enfermedad neumocócica en la era vacunal y emergencia de serotipos. ¿Tendencias temporales y reemplazo de serotipos?

Las infecciones por Streptococcus pneumoniae son la primera causa de muerte por enfermedades inmunoprevenibles en los ninos menores de 5 anos en todo el mundo y causan entre 700.000 y 1 millon de fallecimientos anuales en la infancia, la mitad de la mortalidad en todas las edades (estimaciones de la Organizacion Mundial de la Salud (OMS) en el ano 2005). La complejidad de la prevencion de las infecciones por S. pneumoniae se debe a que hay 91 serotipos, aunque los que originan la mayoria de los casos de enfermedad invasiva pediatrica son 10. Otras bacterias que causan infeccion sistemica, como Neisseria meningitidis y Haemophilus influenzae, tienen respectivamente 13 serogrupos (de ellos unicamente 6 patogenos: A, B, C, W135, X e Y) y 6 serotipos (solo el b causa enfermedad invasiva en el nino sano). La historia de la profilaxis activa antineumococica se inicia hace 1 siglo (1911) con Wright, al disponer de una vacuna de celulas enteras inactivadas por calor, que fue eficaz para reducir la mortalidad por neumonia entre los 6.000 trabajadores de las minas de oro de Sudafrica. La inmunizacion tiene un hito importante en el inicio del milenio actual: en febrero de 2000 la Food and Drug Administration autorizo en Estados Unidos la primera vacuna conjugada, una heptavalente (VNC7v) (Prevnar, Wyeth), de un nuevo grupo, despues de las no conjugadas (vacuna 23-valente). Ocho meses despues, el Advisory Committee on Immunization Practices la recomendo para todos los ninos menores de 2 anos y para los de 24 a 59 meses de edad pertenecientes a grupos con riesgo de presentar enfermedad invasiva, y se incluyo en el calendario de inmunizaciones de 2001. La Agencia Europea de Medicamentos aprobo esta vacuna en febrero de 2001, y 4 meses despues se comercializo en Espana. Por el momento, solo figura en el calendario de la Comunidad de Madrid, desde noviembre de 2006, pero la Asociacion Espanola de Pediatria la incluyo en su calendario de 2003.

Acellular pertussis vaccines for use among infants and young children

Pertussis is still one of the most common vaccine-preventable childhood diseases in developed countries. Infants, particularly those < 6 months, are the most susceptible and those who suffer the greatest disease burden and mortality. In the 1970s, concerns about the reactogenicity of whole-cell vaccines led to a decrease in vaccine coverage and later the re-emergence of the disease in many countries. The advent of acellular vaccines in recent years has constituted an important advance in the acceptance of this immunisation and consequently the control of the disease. The efficacy of acellular pertussis vaccines is ∼ 59 – 93%, similar to whole-cell vaccines, but all available data confirm the substantial improvement in safety of the new vaccines. With the licensure of acellular pertussis vaccines and combined vaccines containing them, pertussis immunisation has become significantly developed. Furthermore, the possibility of continuing to vaccinate adolescents and adults with new diphtheria, tetanus, and pertussis (dTap) vaccines is an important step in achieving control and elimination of the disease.

Programas de vacunación universal contra la hepatitis A en el mundo

Hepatitis A occurs worldwide and has high morbidity. Tens of millions of infections are estimated to occur every year, but many are not reported due to the high percentage of asymptomatic cases. The presence of clinical manifestations is related to age: most cases in children aged < 6 years are asymptomatic and thus represent an important source of infection, while adults usually present symptoms. Hepatitis A is transmitted by the faecal-oral route and its incidence is related to hygiene and access to safe water. In areas of very low endemicity (high income countries), the virus hardly circulates, and the disease mainly occurs in high risk groups, in whom the World Health Organization (WHO) recommends vaccination. In areas of high endemicity (low income countries) most people are infected during childhood, so very few cases of clinical infection occur. In these countries, the WHO does not recommend vaccination. Clinical hepatitis occurs more frequently in areas of low or intermediate endemicity (developing countries) and the WHO recommends universal vaccination programs against hepatitis A in these countries. Recently, in July 2012, the WHO published an update document on hepatitis A vaccines. In the last 15 years, some countries, such as the USA, Israel and some parts of Spain and Italy, have implemented universal vaccination programs against hepatitis A. In this article, we review the different strategies used and the results obtained with each program.