Takumi Iguchi

Immunogenicity of WHO-17D and Brazilian 17DD yellow fever vaccines: a randomized trial

OBJECTIVE To compare the immunogenicity of three yellow fever vaccines from WHO-17D and Brazilian 17DD substrains (different seed-lots). METHODS An equivalence trial was carried out involving 1,087 adults in Rio de Janeiro. Vaccines produced by Bio-Manguinhos, Fiocruz (Rio de Janeiro, Brazil) were administered following standardized procedures adapted to allow blocked randomized allocation of participants to coded vaccine types (double-blind). Neutralizing yellow fever antibody titters were compared in pre- and post-immunization serum samples. Equivalence was defined as a difference of no more than five percentage points in seroconversion rates, and ratio between Geometric Mean Titters (GMT) higher than 0.67. RESULTS Seroconversion rates were 98% or higher among subjects previously seronegative, and 90% or more of the total cohort of vaccinees, including those previously seropositive. Differences in seroconversion ranged from -0.05% to -3.02%. The intensity of the immune response was also very similar across vaccines: 14.5 to 18.6 IU/mL. GMT ratios ranged from 0.78 to 0.93. Taking the placebo group into account, the vaccines explained 93% of seroconversion. Viremia was detected in 2.7% of vaccinated subjects from Day 3 to Day 7. CONCLUSIONS The equivalent immunogenicity of yellow fever vaccines from the 17D and 17DD substrains was demonstrated for the first time in placebo-controlled double-blind randomized trial. The study completed the clinical validation process of a new vaccine seed-lot, provided evidence for use of alternative attenuated virus substrains in vaccine production for a major manufacturer, and for the utilization of the 17DD vaccine in other countries.

Intestinal parasite analysis in organic sediments collected from a 16th-century Belgian archeological site

Parasite eggs found in organic remains collected from medieval structures in Raversijde (medieval name: Walraversijde), a village on the northern coast of Belgium, are discussed. The eggs were identified as Ascaris lumbricoides and Trichuris trichiura, both human parasites. Species identification allowed elucidating the origin of the organic sediments and the structures, in this case latrines used by humans. Capillaria sp. and free-living nematode larvae were also found in the latrine. Although neither parasite burden nor prevalence rates could be measured, the abundance of human intestinal parasite eggs indicated a high infection rate in the village residents, reflecting very poor sanitation.

Epidemiologia descritiva do alcoolismo em grupos populacionais do Brasil

A partir de estudos nacionais, publicados entre 1943 e 1985, que fornecem dados sobre o alcoolismo, foram utilizados no presente artigo, especialmente aqueles que tem algum cunho epidemiologico. Seus dados foram reanalisados e utilizados apenas em seus valores absolutos; recalcularam-se as taxas e porcentagens, aglutinando-as em resultados que tivessem as mesmas caracteristicas. Pelos dados analisados, encontramos maior predominância de alcoolismo em adultos jovens, concentrando-se entre 20 e 49 anos de idade, na razao de 10 homens para 1 mulher. No que diz respeito a taxas de prevalencia, verificou-se que em tres estudos em populacoes acima de 15 anos de idade, houve uniformidade para o alcoolismo-doenca, que no sexo masculino variou de 6% a 13%, e no feminino de 0,7% a 1,4%. Em relacao as internacoes, constatamos que o diagnostico de alcoolismo alcanca elevada proporcao nos estabelecimentos psiquiatricos do pais, a qual, somada a esquizofrenia, compreende 50% do total destas internacoes. Foi impossivel generalizar os dados para todo o Brasil, devido a heterogeneidade cultural e economica da populacao, a extensao territorial, aos criterios divergentes de classificacao utilizados pelos diferentes autores, e a escassez de estudos que fornecam taxas de prevalencia.

Assessoria Estatística e o Laboratório de Estatística Aplicada na Ensp-Fiocruz

Baseados na experiencia vivenciada em varias instituicoes e, em particular, numa experiencia em andamento, os autores discutem a questao do assessoramento estatistico a pesquisadores nas areas que compoem as ciencias da vida. Fazendo um breve comentario da evolucao dos metodos e procedimentos estatisticos aplicados as ciencias da vida, justificam a consolidacao da Bioestatistica como area especifica. Discutem as vantagens e desvantagens de varios tipos de estruturas de assessoramento estatistico que, obviamente, podem ser estendidas a outros tipos de assessoramento. Apresentam a proposta de uma experiencia, em andamento, de criacao de um Laboratorio de Estatistica Aplicada na Ensp (Escola Nacional de Saude Publica) e terminam por apresentar algumas recomendacoes.