Incidência de vírus respiratórios em crianças pré-termo externas submetidas à ventilação mecânica

Os objetivos do estudo foram determinar a incidência de infecção por vírus respiratórios em crianças pré-termo externas submetidas à ventilação mecânica e avaliar os padrões clínico, laboratorial e radiológico das infecções virais entre crianças pré-termo internadas em unidade de cuidados intensivos neonatal (NICU) com insuficiência respiratória aguda de qualquer tipo. Setenta e oito crianças pré-termo externas foram estudadas de Novembro de 2000 a Setembro de 2002. Os recém-nascidos foram classificados em dois grupos: com infecção viral (Grupo I) e sem infecção viral (Grupo II). Vírus respiratórios foram diagnosticados em 23 crianças pré-termo (29,5%); o vírus mais importante foi o sincicial respiratório (VSR) (14,1%), seguido pelo vírus influenza A (10,2%). Rinorréia, sibilância, vômitos e diarréia, pneumonia, atelectasia e infiltrado intersticial foram significativamente mais freqüentes nos recém-nascidos com infecção viral hospitalar. Houve correlação entre infecção viral hospitalar e valores baixos de proteína C-reativa. Dois pacientes com infecção mista do Grupo I faleceram durante a internação. Em conclusão, o VSR foi vírus mais incidente nestes pacientes com infecção nosocomial do trato respiratório inferior. Foi observado que, embora a maioria das infecções respiratórias virais tenham tido uma evolução favorável, alguns pacientes apresentaram quadro clínico grave e prolongado, principalmente quando houve infecção bacteriana ou fúngica concomitante.The objectives of this study were to determine the incidence of infection by respiratory viruses in preterm infants submitted to mechanical ventilation, and to evaluate the clinical, laboratory and radiological patterns of viral infections among hospitalized infants in the neonatal intensive care unit (NICU) with any kind of acute respiratory failure. Seventy-eight preterm infants were studied from November 2000 to September 2002. The newborns were classified into two groups: with viral infection (Group I) and without viral infection (Group II). Respiratory viruses were diagnosed in 23 preterm infants (29.5%); the most frequent was respiratory syncytial virus (RSV) (14.1%), followed by influenza A virus (10.2%). Rhinorrhea, wheezing, vomiting and diarrhea, pneumonia, atelectasis, and interstitial infiltrate were significantly more frequent in newborns with nosocomial viral infection. There was a correlation between nosocomial viral infection and low values of C-reactive protein. Two patients with mixed infection from Group I died during the hospital stay. In conclusion, RSV was the most frequent virus in these patients. It was observed that, although the majority of viral lower respiratory tract infections had a favorable course, some patients presented a serious and prolonged clinical manifestation, especially when there was concomitant bacterial or fungal infection

Occurrence of influenza B/Hong Kong-Like strains in Brazil, during 2002

Through the influenza virus surveillance from January to October 2002, influenza B/Hong Kong-like strains circulating in the Southeast and Centre East regions of Brazil have been demonstrated. This strain is a variant from B/Victoria/02/88 whose since 1991 and until recently have been isolated relatively infrequently and have been limited to South-Eastern Asia. A total of 510 respiratory secretions were collected from patients 0 to 60 years of age, with acute respiratory illness, living in the Southeast and Centre East regions of Brazil, of which 86 (17.13%) were positive for influenza virus. Among them 12 (13.95%) were characterized as B/Hong Kong/330/2001; 3 (3.49%) as B/Hong Kong/1351/2002 a variant from B/Hong Kong/330/2001; 1 (1.16%) as B/Sichuan/379/99; 1 (1.16%) as B/Shizuoka/5/2001, until now. The percentages of cases notified during the surveillance period were 34.88%, 15.12%, 15.12%, 4.65%, 15.12%, 13.95%, in the age groups of 0-4, 5-10, 11-15, 16-20, 21-30, 31-50, respectively. The highest proportion of isolates was observed among children younger than 4 years but serious morbidity and mortality has not been observed among people older than 65 years, although B influenza virus component for vaccination campaign 2002 was B/Sichuan/379/99 strain. This was probably due to the elderly protection acquired against B/Victoria/02/88. In addition, in influenza A/Panama/2007/99-like (H3N2) strains 22 (25.58%) were also detected, but influenza A(H1N1) has not been detected yet.A vigilância do vírus da influenza, no periodo de janeiro a outubro de 2002, detectou a circulação da estirpe B/Hong Kong/330/2001 nas regiões Sudeste e Centro Oeste do país. Esta estirpe é uma variante do vírus da influenza B/Victoria/02/88 a qual teve sua circulação circunscrita no continente asiático por volta de 1991. Variantes da estirpe B/Hong Kong/330/2001 (B/Hong Kong/1351/2002) e da estirpe B/Sichuan/379/99 (B/Shizuoka/5/2001) também foram detectadas. A porcentagem de vírus caracterizados durante a epidemia foi de 34,88%, 15,12%, 15,12%, 4,65%, 15,12%, 13,95%, nas faixas etárias de 0-4, 5-10, 11-15, 16-20, 21-30, 31-50, respectivamente. Observou-se maior incidência da doença entre os indivíduos menores de 4 anos. Atribuiu-se a ausência de notificação nos indivíduos maiores de 60 anos ao contato prévio, desta faixa etária, com o vírus na década de 80. No mesmo período, detectou-se a circulação do vírus da influenza A/Panamá/2007/99-like (H3N2), por outro lado evidenciou-se a ausência da circulação da estirpe A(H1N1) até a presente data

Ensaio imunoenzimático: detecção de anticorpos anti-adenovirus numa população infantil de São Paulo

Com a finalidade de encontrar um ensaio preciso para a detecção de anticorpos anti-adenovírus, o teste ELISA recentemente padronizado foi comparado à imunofluorescência indireta (IFI) e à fixação de complemento (FC). Após testar 58 soros, o ELISA demonstrou maior sensibilidade do que a IFI e a FC, que mostraram sensibilidades relativas de 94% e 63%, respectivamente. A falta de um padrão universal não permitiu alcançar conclusões definitivas quanto à especificidade dos ensaios. Além disso, o ELISA foi utilizado para estabelecer a prevalência de anticorpos anti-adenovírus em 116 crianças entre 1 e 24 meses de idade (média 7.28). Os dados mostraram que os anticorpos maternos desaparecem ao redor dos 5 a 6 meses de idade e que mais de 80% das crianças tinham sido infectadas antes dos 10 meses de idade.In order to define an accurate assay for anti-adenovirus antibody detection, a recently developed ELISA was compared with IFA and CF. On 58 sera, the ELISA was more sensitive than both CF and IFA, which showed relative sensitivities of 63% and 94%, respectively. It was not possible to determine the exact specificity of the tests because of the lack of a gold standard. Furthermore, the ELISA was used to define the prevalence of adenovirus antibodies in 116 infants between 1 and 24 months old (mean 7.28). The data showed that maternal antibodies waned by the age of 5 to 6 months and that more than 80% of the children had been infected by adenoviruses by the age of 10 months

Epidemia de influenza A (H1N1) no Município de Iporanga, SP, Brasil

From June to July 1999 an outbreak of acute respiratory illness occurred in the town of Iporanga. Out of a total of 4,837 inhabitants, 324 cases were notified to the Regional Surveillance Service. Influenza virus was isolated from 57.1% of the collected samples and 100% seroconversion to influenza A (H1N1) was obtained in 20 paired sera tested. The isolates were related to the A/Bayern/07/95 strain (H1N1). The percentages of cases notified during the outbreak were 28.4%, 29.0%, 20.7%, 6.2% and 15.7% in the age groups of 0-4, 5-9, 10-14, 15-19 and older than 20 years, respectively. The highest proportion of positives was observed among children younger than 14 years and no cases were notified in people older than 65 years, none of whom had been recently vaccinated against influenza. These findings suggest a significant vaccine protection against A/Bayern/7/95, the H1 component included in the 1997-98 influenza vaccine for elderly people. This viral strain is antigenically and genetically related to A/Beijing/262/95, the H1 component of the 1999 vaccine. Vaccines containing A/Beijing/262/95 (H1N1) stimulated post-immunization hemagglutination inhibition antibodies equivalent in frequency and titre to both A/Beijing/262/95-like and A/Bayern/7/95-like viruses. Thus, this investigation demonstrates the effectiveness of vaccination against influenza virus in the elderly.Durante os meses de junho e julho de 1999, foram notificados 324 casos de doença respiratória aguda no Município de Iporanga-SP. O isolamento do vírus da influenza do tipo A/Bayern/07/95 (H1N1) e a conversão sorológica para a estirpe viral (H1N1) foram de 57,1% e 100%, respectivamente. A porcentagem de casos com diagnóstico clínico notificados durante a epidemia foi de 28,4%, 29,0%, 20,7%, 6,2% e 15,7%, nas faixas etárias de 0-4, 5-9, 10-14, 15-19 anos e indivíduos acima de 20 anos de idade, respectivamente. Observou-se maior incidência da doença entre os indivíduos menores de 14 anos. Atribui-se a ausência de notificação de casos em indivíduos maiores de 65 anos à campanha de vacinação, na população idosa de Iporanga, que em 1999 atingiu 72,4%. O virus isolado é genética e antigenicamente semelhante à estirpe A/Beijing/262/95 (H1N1), o componente H1 da vacina de 1999. Vacinas contendo a estirpe A/Beijing/262/95 (H1N1) estimularam, após imunização, anticorpos inibidores da hemaglutinação, os quais foram equivalentes em freqüência e título para ambas as estirpes: A/Bayern/07/95 e A/Beijing/262/95

The Dilemma of Influenza Vaccine Recommendations when Applied to the Tropics: The Brazilian Case Examined Under Alternative Scenarios

Since 1999 the World Health Organization issues annually an additional influenza vaccine composition recommendation. This initiative aimed to extend to the Southern Hemisphere (SH) the benefits—previously enjoyed only by the Northern Hemisphere (NH)—of a vaccine recommendation issued as close as possible to the moment just before the onset of the influenza epidemic season. A short time between the issue of the recommendation and vaccine delivery is needed to maximize the chances of correct matching between putative circulating strains and one of the three strains present in the vaccine composition. Here we compare the effectiveness of the SH influenza vaccination adopted in Brazil with hypothetical alternative scenarios defined by different timings of vaccine delivery and/or composition. Scores were based on the temporal overlap between vaccine-induced protection and circulating strains. Viral data were obtained between 1999 and 2007 from constant surveillance and strain characterization in two Brazilian cities: Belém, located at the Equatorial region, and São Paulo, at the limit between the tropical and subtropical regions. Our results show that, among currently feasible options, the best strategy for Brazil would be to adopt the NH composition and timing, as in such case protection would increase from 30% to 65% (p<.01) if past data can be used as a prediction of the future. The influenza season starts in Brazil (and in the equator virtually ends) well before the SH winter, making the current delivery of the SH vaccination in April too late to be effective. Since Brazil encompasses a large area of the Southern Hemisphere, our results point to the possibility of these conclusions being similarly valid for other tropical regions

Enzyme linked immunosorbent assay: determination of anti-adenovirus antibodies in an infant population

In order to define an accurate assay for anti-adenovirus antibody detection, a recently developed ELISA was compared with IFA and CF. On 58 sera, the ELISA was more sensitive than both CF and IFA, which showed relative sensitivities of 63% and 94%, respectively. It was not possible to determine the exact specificity of the tests because of the lack of a gold standard. Furthermore, the ELISA was used to define the prevalence of adenovirus antibodies in 116 infants between 1 and 24 months old (mean 7.28). The data showed that maternal antibodies waned by the age of 5 to 6 months and that more than 80% of the children had been infected by adenoviruses by the age of 10 months

Enterovírus-70 na região metropolitana de São Paulo, Brasil, de 1984 a 1987: aspectos da infecção em períodos epidêmico e endêmico

Results of investigation about Enterovirus-70 (EV-70) as an etiologic agent of epidemic of acute haemorrhagic conjunctivitis (AHC) and neurological disease in the metropolitan area of São Paulo city are presented. During the first three months of 1984, in an epidemic period of AHC, 3 groups with a total of 291 persons were studied. The group A included 90 individuals affected by AHC; the 99 persons belonging to group B did not acquire the AHC but refered familiar contact with the ill individuals; the group C included 102 persons who denied the AHC or any contact with the illness. Neutralization test in BHK-21 cell culture was used for measurement of antibodies in sera. For the detection of the presence of IgM, indirect immunofluorescence assay was utilized. The presence of IgM antibodies was observed in 56.7%, 33.3% and 20.6% of persons belonging to groups A, B and C, respectively. The 10-29 age group was the most affected in the group A. From april 1984, after the end of epidemic period of AHC, until December 1987, three sporadic cases of AHC and 10 cases with acute neurological disease associated with recent infection by EV-70 were observed. Nine of 10 persons with acute neurological symptoms had paralysis of cranial nerves, all of them recovering without sequelae. The circulation of EV-70 in the population during the endemic period was maintained by either asymptomatic, sporadic cases of AHC or neurological diseases.São apresentados os resultados de estudos sobre o comportamento do Enterovírus-70 (EV-70) na região metropolitana de São Paulo desde sua provável introdução no verão de 1984, determinando extensa epidemia de conjuntivite hemorrágica aguda (C.H.A.), até o final de 1987 abrangendo período em que este agravo foi pouco notado. Na fase epidêmica ocorrida no primeiro trimestre de 1984 foram estudados 291 indivíduos divididos em três grupos denominados A, B e C, o primeiro formado por pessoas atingidas pela C.H.A. e os outros dois por indivíduos não atingidos por este agravo mas que, respectivamente, referiam contato domiciliar com casos de C.H.A. e os que não referiam o citado contato. A demonstração de anticorpos se fez pela técnica de imunofluorescência indireta (IFI) para detectar IgM específico para EV-70 e pela prova de neutralização em cultura de células BHK-21. Verificou-se que 56,7%, 33,3% e 20,6% dos indivíduos pertencentes, respectivamente, aos grupos A, B e C apresentavam anticorpos específicos da classe IgM. No grupo A a faixa etária mais atingida foi a de 10 a 29 anos. No período que vai do fim da primeira e única epidemia até o final de 1987, identificaram-se três casos esporádicos de C.H.A. e 10 pacientes com afecção neurológica aguda associada à infecção recente pelo EV-70. Nove, destes 10 casos, apresentaram paralisia de nervos cranianos, todos evoluindo sem seqüelas clinicamente discerníveis. As formas assintomáticas e os casos esporádicos de C.H.A. e de afecções neurológicas mantiveram a circulação do EV-70 no período não epidêmico