Incorporación de segunda dosis de la vacuna de la varicela al Calendario Nacional de Vacunación de Argentina / Incorporation of the second dose of the varicella vaccine to the national vaccination schedule of Argentina

A partir de 2022, a la dosis de vacuna contra la varicela contemplada a los 15 meses de edad en el Calendario Nacional de Vacunación de Argentina, se suma una segunda dosis al ingreso escolar. En este artículo se repasan los aspectos clave para la implementación de esta práctica de inmunización universal, gratuita y obligatoria. (AU)

Starting in 2022, a second dose of the varicella vaccine will be added to the 15-month-old dose included in Argentina's National Vaccination Schedule at school entry. This article reviews the key aspects for the implementation of this universal, free and mandatory immunization practice. (AU)

Frecuencia de anticuerpos IgG a seis agentes infecciosos en los estudiantes de la carrera de Química Biológica / Frequency of IgG antibodies to six infectious agents in students of the Biological Chemistry degree

Se determinó la frecuencia de anticuerpos IgG para Toxoplasma gondii y los virus de paperas, sarampión, rubéola, varicela y hepatitis B en 90 estudiantes de la carrera de Química Biológica de la Facultad de CCQQ y Farmacia. La mayor frecuencia se encontró para rubéola y sarampión, 98.9% para cada prueba y la menor frecuencia fue para T. gondii con 23.3%. No se encontró asociación significativa entre la positividad y el género, entre la positividad a paperas, sarampión, varicela y el haber sufrido la infección o haber estado en contacto con personas infectadas y entre la positividad a T. gondii y el consumir carne roja y/o comida callejera (p > .05). Únicamente en el caso de la hepatitis B se encontró una asociación significativa entre la positividad y la edad (p = < .001), el hecho de estar vacunado (p < .001) y el ser sexualmente activo (p = .004). Los porcentajes de vacunación en la población en estudio fue alta únicamente para hepatitis B (80%), mientras que para las otras infecciones fue 35.6% para rubéola y sarampión, 22.2% para varicela y 10% para paperas. Más de 82% de los estudiantes presentaron protección a los seis agentes estudiados y se recomienda realizar encuestas sero-epidemiológicas constantes, evaluar los programas de inmunización, identificar los grupos a riesgo y que las personas que no presenten anticuerpos se vacunen.

The frequency of IgG antibodies for Toxoplasma gondii and the mumps, measles, rubella, varicella and hepa-titis B viruses was determined in 90 students of the Biological Chemistry career of the Faculty of CCQQ and Pharmacy. The highest frequency was found for Rubella and Measles, 98.9% each, and the lowest frequency was for T. gondii with 23.3%. No significant difference was found between positivity and gender, between positivity to mumps, measles, chicken pox and having suffered infection or having been in contact with infected persons and between positivity to T. gondii and consuming red meat and / or street food (p > .05). Only in the case of Hepatitis B a significant difference between positivity and age (p = .001), the fact of being vaccinated (p = .001) and being sexually active (p = .004 was found. The percentage of vaccination in the study population was high only for He-patitis B (80%), while for the other infections it was 35.6% for rubella and measles, 22.2% for varicella and 10% for mumps. More than 82% of the students presented protection to the six agents studied and it is recommended to carry out constant sero-epidemiological surveys, to evaluate the immunization programs, to identify the risk groups and that people who do not present antibodies get vaccinated.

Humoral immune response to measles and varicella vaccination in former very low birth weight preterm infants

ABSTRACT Introduction: Immune response to vaccination in infants born prematurely may be lower than in infants born at full-term. Some clinical factors might be associated with humoral immune response. Objectives: The objectives of this study were to compare the immune response to measles and varicella vaccination in infants born prematurely with those born at full-term and to analyze factors associated with measles and varicella antibody levels. Methods: Prospective study including two groups of infants aged 12 months. One group of infants born prematurely with birth-weight <1500 g and who were in follow-up at the outpatient clinic for preterm infants at the institution and other group of infants born at full-term. Infants with malformations, primary immunodeficiency diseases, born to HIV-positive mothers or who had received plasma or immunoglobulin transfusions five months before or three weeks after vaccination were excluded. Plasma antibodies were measured by ELISA and factors associated with antibody levels were assessed by linear regression. Results: Sixty-five premature and 56 full-term infants were included. The percentage of immune individuals after vaccination against measles (100% vs. 100%) and varicella (92.5% vs. 93.2%) were similar in both groups, as well as the antibody levels against measles (2.393 vs. 2.412 UI/mL; p = 0.970) and varicella (0.551 vs. 0.399 UI/mL; p = 0.114). Use of antenatal corticosteroids decreased measles antibody levels whereas breastfeeding for more than six months increased varicella antibody levels. Conclusions: Humoral responses to measles and varicella were similar between infants born prematurely and full-term infants. Measles antibody levels were negatively associated with antenatal corticosteroid use; varicella antibodies were positively associated with prolonged breastfeeding.

PROTECTIVE LEVELS OF VARICELLA-ZOSTER ANTIBODY DID NOT EFFECTIVELY PREVENT CHICKENPOX IN AN X-LINKED AGAMMAGLOBULINEMIA PATIENT / Nível sérico adequado de anticorpo contra o vírus da varicela-zoster não foi suficiente para prevenir a infecção em criança com agamaglobulinemia ligada ao X

SUMMARY We describe the case of an eight-year-old boy with X-linked agammaglobulinemia who developed mild varicella despite regular intravenous immunoglobulin (IVIG) therapy. He maintained protective antibody levels against varicella and the previous batches of IVIG that he received had adequate varicella-specific IgG levels. The case illustrates that IVIG may not prevent VZV infection.

RESUMO Relatamos o caso de uma criança com agamaglobulinemia ligada ao X, sexo masculino, oito anos de idade, que desenvolveu quadro de varicela leve, apesar do tratamento regular com imunoglobulina intravenosa (IVIG). O paciente mantinha níveis adequados de imunoglobulina (IgG) contra varicela, assim como, os últimos lotes de IVIG por ele recebido também apresentavam níveis adequados do anticorpo específico. O caso ilustra que o tratamento regular com IVIG não é suficiente para prevenir a infecção pelo vírus da varicela-zoster.

Seroprevalencia de virus varicela-zoster en niños con cáncer en seis hospitales de Santiago, Chile / Seroprevalence of varicella-zoster virus in children with cancer in six hospitals in Santiago, Chile

Infections with varicella-zoster virus (VVZ) in immunocompromised children imply a high mortality. There is no data about VVZ seroprevalence in children with cancer in our country. Aim: To determine the prevalence of VVZ antibodies in children with cancer who have undergone chemotherapy or have undergone a hematopoietic stem cell transplant. Methodology: collaborative, multicenter study. Serum samples were collected from 281 children with cancer and episodes of febrile neutropenia from 6 hospitals belonging to the public health network in the Metropolitan Region between June 2004 and August 2006. These samples were stored at -70 ° C, and 200 of them were randomly chosen and analyzed to determine VVZ IgG (ELISA). Results: 179 samples from 179 children, 65% male. Ninety eigth/179 (55%) were positive, 72/179 (40%) negative and 9/179 (5%) indeterminate. Stratified by age, seropositive percentage was: 1 to 4 years 32%, 5-9 years 42%, 10-14 years 78%, over 15 years 88%. Conclusion: Forty percent of children treated for cancer are seronegative to VVZ infection, a frequency that decreases with age. These results support the adoption of preventive measures to avoid infection in this population of children at risk of developing a serious and possibly fatal illness.

Las infecciones por virus varicela-zoster (VVZ) en niños inmunocomprometidos presentan una alta morbi-mortalidad. Se desconoce la seroprevalencia de VVZ en niños con cáncer en nuestro medio. Objetivo: Determinar la prevalencia de anticuerpos anti VVZ en niños sometidos a tratamiento por cáncer (quimioterapia o trasplante de precursores hematopoyéticos). Método: Estudio colaborativo, multicéntrico. Se recolectaron muestras de suero de 281 niños con cáncer y episodios de neutropenia febril (NF) en seis hospitales de Santiago, entre junio 2004 y agosto 2006 y almacenadas a -70° Cº. Doscientas muestras fueron seleccionadas al azar para determinación de IgG anti VVZ. Resultados: De las 200 muestras de suero obtenidas se excluyeron 21: 12 por ser muestras de un mismo paciente en diferentes episodios de NF y 9 por falta de información. Se analizaron las muestras de 179 niños, 65% de sexo masculino. Noventa y ocho resultaron positivos (55%), 72 negativos (40%) y 9 indeterminados (5%). Estratificado por edad: 1-4 años (32%), 5-9 años (42%), 10-14 años (78%) y mayores de 15 años (88%). Conclusión: 40% de los niños en tratamiento por cáncer son seronegativos para VVZ, condición que disminuye en pacientes con mayor edad. Estos resultados apoyan la adopción de medidas que eviten la infección en esta población de niños con riesgo de desarrollar una enfermedad grave y eventualmente fatal.

Estudio de un brote de varicela en un pueblo del Uruguay / Varicella outbreak in a village in Uruguay

A varicella outbreak occurred in a Uruguayan village that introduced the varicella vaccine in 1999 with currently high vaccination rates. Aim: To investigate the cause of the outbreak, vaccine effectiveness, and to describe the measures adopted. Material and Methods: Cases that occurred in the kindergarten and schools in the village were investigated. Vaccination cards were examined, history of chickenpox and clinical characteristic of the current episode were obtained and the outcome of the measures was evaluated. An estimate was made of the vaccine's effectiveness. Results: 37 cases of varicella were reported, 14 occurring in previously vaccinated children, in a one total population of 313 children. The global effectiveness of the vaccine was 80 percent, and 100 percent for severe cases. A shift of cases towards older ages was demonstrated; vaccinated children had a trend of less fever and lower number of lesions. Immunization of healthy unvaccinated children, mainly adolescents stopped the outbreak. Comments: The vaccine proved to be highly effectiveness. In an outbreak situation, immunization policies should consider "catch up" vaccination in non-immunized adolescents without a previous history of varicella.

Un brote de varicela acaeció en un pueblo uruguayo que había introducido la vacunación anti-varicela en 1999 y tenía altas coberturas de vacunación. Objetivo: Investigar las causas del brote, la efectividad de la vacunación y evaluar las medidas adoptadas. Material y Métodos: Se investigó los casos ocurridos enjardines de infantes y colegios. Se revisó el carné de vacunación de cada niño además de averiguar por historia previa de varicela, las características clínicas de los casos y el resultado de las medidas adoptadas. Se hizo una estimación de la efectividad de la vacuna. Resultados: Se presentaron 37 casos de varicela, 14 de los cuales habían recibido la vacuna, en una población total de 313 niños. La efectividad global de la vacuna fue de 80 por ciento, y de 100 por ciento para los casos graves. Se constató un desplazamiento de la enfermedad hacia edades mayores; además, los casos en vacunados tuvieron una tendencia a presentar menos fiebre y un número menor de lesiones. La vacunación de aquellos que no habían tenido la varicela y no estaban vacunados antes, detuvo el brote epidémico. Comentarios: Se demostró la efectividad de la vacuna. La política de vacunación debiera evaluar si es necesario proceder a la vacunación "de rescate" en adolescentes no vacunados y que no exhiben el antecedente de haber padecido la varicela.

Immunohistochemical assessment of hormone receptor status of breast carcinoma: interobserver variation of the quick score.

BACKGROUND: Immunohistochemical (IHC) assessment of estrogen receptor (ER) and progesterone receptor (PR) status has become a routine practice to predict the likely outcome of Tamoxifen therapy. AIMS: To assess the interobserver variation in scoring hormone receptor status of breast carcinoma, using the Quick Score. MATERIALS AND METHODS: IHC-stained slides of breast carcinomas reported by the two authors during a 28-month period were included in the study. Both authors independently reassessed all the tumors. Both were blinded to each other's assessment. The Quick score with a 0-8 point scale was used to score the hormone receptor status. Weighted Kappa was calculated to assess the interobserver variation. RESULTS: A total of 210 breast carcinomas were included in this study. There was a substantial to almost perfect agreement between the two observers in scoring the hormone receptor status (kappa values; ER=0.856, PR=0.711). Both ER and PR showed an almost perfect agreement in assessing the intensity of staining (kappa value; ER=0.882, PR=0.840), while the scoring of proportion of cells gave lower Kappa values (kappa value; ER=0.778, PR=0.592). Interobserver agreement was less in scoring hormone receptor status of breast carcinomas after mastectomies compared with excision biopsies, wide local excisions and metastatic deposits in lymph nodes. Suboptimal fixation resulting in background staining has contributed to the variation. CONCLUSION: A substantial to almost perfect interobserver agreement was seen in assigning an overall Quick score. Detection of complete negative and strong expression had a moderate to substantial agreement.

Differentiation of wild-type varicella-zoster strains from India and the Oka vaccine strain using a VZV open reading frame - 62 based PCR-RFLP technique

Since the introduction of varicella vaccination in India, surveillance of circulating VZV strains has gained significance. Differentiating wild-type VZV strains from the Oka vaccine strain can be achieved only by molecular genotyping methods. The development of PCR methods for VZV strain differentiation has been hampered by the fact that the VZV genome is highly conserved. We used VZV ORF 62 PCR-RFLP analysis to identify and differentiate wild-type VZV strains in India from the Oka vaccine strain. Digestion of VZV ORF 62 amplicons with SmaI, enabled accurate strain differentiation; the Oka strain was positive for three SmaI sites, compared to two SmaI sites in the wild-type VZV strains that we tested.

Reliability of information on varicella history in preschool children

OBJECTIVE: To verify how reliable is the information provided by parents about the history of varicella in their children. METHODS: 204 parents of previously healthy children attending two municipal day-care centers of São Paulo city were interviewed between August 2003 and September 2005. A standardized form was filled out with information regarding age, sex, history of varicella and other diseases, drug use and antecedent of immunization, After medical history, physical examination and checking of immunization records, 5 ml of blood were collected for ELISA (in house) varicella test. Exclusion criteria were: age less than 1 year or more than 60 months, previous immunization against chickenpox, presence of co-morbidities or recent use of immunosuppressive drugs. Data were filed in a data bank using the Excel 2003 Microsoft Office Program and stored in a PC computer. The exact Fisher test was employed to calculate sensibility, specificity, positive and negative predictive values of history of varicella informed by children's parents. RESULTS: The age of the children varied from 12 to 54 months (median, 26 months; 49 (24 percent) children had positive history of varicella, 155 (76 percent) a negative or doubtful history. The predictive positive and negative values of the information were 90 percent and 93 percent, respectively (p = 0.0001). CONCLUSIONS: The degree of reliability of information about history of varicella informed by parents of children attending day care centers was high and useful to establish recommendations on varicella blocking immunization in day-care centers.

OBJETIVOS: Verificar o grau de confiabilidade da informação fornecida pelos pais de crianças atendidas em creches sobre o antecedente de varicela. MÉTODOS: Os pais de 204 crianças previamente saudáveis matriculadas em duas creches da cidade de São Paulo foram entrevistados entre Agosto de 2003 e Setembro de 2005 para preenchimento de um questionário padronizado com informações sobre idade, sexo, antecedente de varicela e outras doenças, uso de medicamentos e história vacina. Após anamnese, exame físico e verificação da carteira de vacinação, foram colhidos 5 ml de sangue para realização do teste ELISA (in house) para varicela. Os critérios de exclusão foram: idade < 1 ano ou acima de 60 meses, vacinação prévia contra varicela, presença de comorbidades e uso recente de imunossupressores. Os dados foram registrados num banco de dados do programa Excel 2003 Microsoft Office e armazenados em microcomputador. Utilizou-se o teste exato de Fisher para calcular a sensibilidade, especificidade e valores preditivo positivo e negativo das informações fornecidas pelos pais sobre o antecedente de varicela das crianças. RESULTADOS: A idade das crianças variou entre 12 e 54 meses (mediana, 26 meses); 49 crianças (24 por cento) tinham antecedente positivo para varicela e 155 (76 por cento) negativo ou duvidoso. Os valores preditivo positivo e negativo da informação foram de 90 por cento e 93 por cento, respectivamente (p = 0.0001). CONCLUSÕES: O grau de confiabilidade das informações sobre varicela informadas pelos pais de crianças atendidas em creches foi elevado e útil para estabelecer recomendações para vacinação de bloqueio de surtos de varicela em creches.

Varicella zoster in children attending day care centers

OBJETIVO: Descrever a morbidade associada à varicela nas crianças usuárias de creches. MÉTODOS: Estudo descritivo, realizado através de inquérito com pais ou responsáveis por 664 crianças que contraíram varicela após admissão às creches Municipais de Taubaté, SP. RESULTADOS: A mediana de idade das crianças acometidas por varicela foi de 36 meses (6 meses a 7 anos); 8,4% tiveram a doença antes dos 12 meses. As principais manifestações foram: exantema (100,0%), febre (85,4%), anorexia (39,6%) e cefaléia (15,3%). Quinhentas e dezessete crianças (77,9%) tiveram pelo menos uma avaliação médica, 80,6% receberam algum tipo de medicamento; 73 (11,0%) receberam antiinflamatórios não-hormonais e 52 (7,8%) receberam antibióticos. Trinta e oito crianças (5,7%) tiveram complicações (intervalo de confiança de 95%: 3 – 8%), oito (1,2%) foram hospitalizadas e cinco (0,7%) ficaram com seqüelas. Em comparação com crianças com mais de um ano, as menores de um ano apresentaram risco 3 vezes maior para complicações e hospitalizações. Mais da metade das crianças e dos pais que trabalhavam ficou mais de uma semana afastada de suas atividades. CONCLUSÕES: A varicela acometeu crianças de baixa idade, causou complicações em mais de 5% e deixou seqüelas em 0,7% dos casos. Mais de 10% das crianças foram tratadas com antiinflamatórios não-hormonais, sendo necessário esclarecer a população sobre os riscos do uso desses fármacos. As autoridades de saúde deveriam estar atentas a essa questão e oferecer a vacina às crianças matriculadas em creches.

Three year seroepidemiological study of varicella-zoster virus in São Paulo, Brazil

A serosurvey of varicella has been carried out in children attending the public school network of São Paulo city, Brazil, from 1992 to 1994. This study was performed in order to establish the age related prevalence of antibodies against varicella-zoster virus (VZV) and its age specific transmission dynamics pattern in these children. Among 2500 schools in the city of São Paulo public network, 304 were randomly selected; 7 children of a given age (ranging from 1 to 15 years) were randomly selected in each school, and blood samples were obtained by fingerprick into filter paper. Blood eluates were analyzed for the presence of antibodies to VZV by ELISA. Proportion of seropositivity were calculated for each age group. Samples consisted of 1768 individuals in 1992, 1758 in 1993, and 1817 in 1994, resulting in 5343 eluates. A high proportion of seropositive children from 1 to 3 years of age was observed, ascending until 10 years of age and reaching a plateau around 90 percent afterwards. VZV transmission in this community was similar along the three years of the study. In children attending public schools in the city of São Paulo, contact with VZV occurs in early childhood. If immunization against VZV is considered it should be introduced as soon as possible.

Imunizaçäo ativa na adolescência / Active immunization in adolescence

Objetivos: O artigo visa a oferecer uma atualizaçäo em imunizaçäo ativa na adolescência, em vista das modificaçöes no esquema de vacinaçäo universal, ocorridas nos últimos anos. Métodos: A revisäo bibliográfica abrangeu a literatura especializada nacional e internacional. As recomendaçöes seguem aquelas da Academia Americana de Pediatria e do ACIP - Advisory Comittee on Immunization practices (EUA). Resultados: Desde o início dos anos 90, vacinas novas foram licenciadas (varicela, hepatite A), e vacinas já existentes passaram a ser recomendadas para uso rotineiro (hepatite B), ou como dose de reforço (sarampo/caxumba/rubéola, tuberculose) na adolscência. Este artigo traz uma revisäo sobre estas vacinas e as recomendaçöes atuais quanto a seu uso na adolescência...

Varicela-zoster: nova perspectiva de controle para uma antiga doença / Varicella-zoster: new perspective for control of an old disease

A vacina contra a varicela e altamente imunogênica e protetora, porém, desde o início da década de 70, quando a vacina contendo a cepa Oka foi desenvolvida no Japäo, tem havido muita discussäo sobre o risco da vacinaçäo de crianças promover um aumento do número de casos de zoster ou de varicela em adultos se a imunidade näo for persistente...

Detection of varicella-zoster antibody by immune adherence hemagglutination test.

The immune adherence hemagglutination (IAHA) is a more sensitive and specific test for evaluation of humoral immunity to varicella-zoster virus (VZV) than a conventional complement fixation (CF) test. The equipment, reagents, procedure used in the IAHA are basically the same as those employed in the CF test. After VZ vaccination, seroconversions detected by IAHA test were significantly greater than those by CF test (P less than 0.01, chi 2 test). Moreover, the IAHA titers were higher about 4 times (G.M. 30.9 vs 8.2) and persisted longer than CF titers. Although the IAHA antigen is not a commercial product, the IAHA is sensitive and suitable assay for VZ antibody determination in routine serological laboratory.