ABSTRACT
BACKGROUND: In 2015, the number of infants born with microcephaly increased in Paraíba, Brazil, after a suspected Zika virus outbreak. We did a retrospective case-control investigation to assess the association of microcephaly and Zika virus. METHODS: We enrolled cases reported to the national database for microcephaly and born between Aug 1, 2015, and Feb 1, 2016, on the basis of their birth head circumference and total body length. We identified controls from the national birth registry and matched them to cases by location, aiming to enrol a minimum of two controls per case. Mothers of both cases and controls were asked about demographics, exposures, and illnesses and infants were measured at a follow-up visit 1-7 months after birth. We took blood samples from mothers and infants and classified those containing Zika virus IgM and neutralising antibodies as evidence of recent infection. We calculated prevalence of microcephaly and odds ratios (ORs) using a conditional logistic regression model with maximum penalised conditional likelihood, and combined these ORs with exposure probability estimates to determine the attributable risk. FINDINGS: We enrolled 164 of 706 infants with complete information reported with microcephaly at birth, of whom we classified 91 (55%) as having microcephaly on the basis of their birth measurements, 36 (22%) as small, 21 (13%) as disproportionate, and 16 (10%) as not having microcephaly. 43 (26%) of the 164 infants had microcephaly at follow-up for an estimated prevalence of 5·9 per 1000 livebirths. We enrolled 114 control infants matched to the 43 infants classified as having microcephaly at follow-up. Infants with microcephaly at follow-up were more likely than control infants to be younger (OR 0·5, 95% CI 0·4-0·7), have recent Zika virus infection (21·9, 7·0-109·3), or a mother with Zika-like symptoms in the first trimester (6·2, 2·8-15·4). Once Zika virus infection and infant age were controlled for, we found no significant association between microcephaly and maternal demographics, medications, toxins, or other infections. Based on the presence of Zika virus antibodies in infants, we concluded that 35-87% of microcephaly occurring during the time of our investigation in northeast Brazil was attributable to Zika virus. We estimate 2-5 infants per 1000 livebirths in Paraíba had microcephaly attributable to Zika virus. INTERPRETATION: Time of exposure to Zika virus and evidence of infection in the infants were the only risk factors associated with microcephaly. This investigation has improved understanding of the outbreak of microcephaly in northeast Brazil and highlights the need to obtain multiple measurements after birth to establish if an infant has microcephaly and the need for further research to optimise testing criteria for congenital Zika virus infection. FUNDING: Centers for Disease Control and Prevention.
Subject(s)
Microcephaly/epidemiology , Microcephaly/virology , Zika Virus Infection/epidemiology , Brazil/epidemiology , Case-Control Studies , Female , Humans , Infant, Newborn , Male , Prevalence , Retrospective Studies , Time FactorsABSTRACT
OBJETIVO: sumarizar a produção científica publicada na literatura nacional e internacional relacionada ao HIV/Aids na população indígena. MÉTODO: revisão integrativa, realizada em novembro de 2014 nas bibliotecas virtuais LILACS, SCOPUS, PUBMED e BVS, utilizando como estratégia de busca as palavras chave: HIV, HIV infections, Acquired Immunodeficiency Syndrome, Indigenous population e Health of Indigenous, sem considerar período de publicação das obras. RESULTADOS: os artigos que atenderam aos critérios de inclusão originaram dois eixos temáticos: "Aids na população indígena: contextos de vulnerabilidade e risco" e "enfrentamento da Aids e os desafios da saúde indígena". DISCUSSÃO: observou-se a necessidade de implementação de medidas que visem o controle e a prevenção da Aids nas tribos indígenas, como também de ações educativas inerentes aos hábitos tradicionais dessa população. CONCLUSÃO: essas evidências contribuirão para o direcionamento de ações eficazes de prevenção da Aids voltadas à população indígena.
AIM: To summarize the scientific production published in national and international literature related to HIV/AIDS in the indigenous population. METHOD: Integrative review, held in November 2014 in the virtual libraries LILACS, SCOPUS, PubMed and BVS, using these keywords as a search strategy; HIV, HIV infections, Acquired Immunodeficiency Syndrome, Indigenous Population and Health of Indigenous, regardless of the period of publication of these works. RESULTS: The articles that met the inclusion criteria gave rise to two main themes: "AIDS in the indigenous population: contexts of vulnerability and risk" and "The battle against AIDS and the challenges of indigenous health." DISCUSSION: There was a need to implement measures to control and prevent AIDS in indigenous tribes, as well as educational activities inherent to the traditional habits of this population. CONCLUSION: This evidence will contribute to the effective targeting of AIDS prevention actions aimed at the indigenous population.
OBJETIVO: resumir la producción científica publicada en la literatura nacional e internacional relacionada al HIV/SIDA en la población indígena. MÉTODO: revisión integradora, realizada en noviembre de 2014 en las bibliotecas virtuales LILACS, SCOPUS, PUBMED y BVS, utilizando como estrategia de búsqueda las palabras claves: HIV, HIV infections, Acquired Immunodeficiency Syndrome, Indigenous population y Health of Indigenous, sin considerar período de publicación de las obras. RESULTADOS: los artículos que atendieron a los criterios de inclusión originaron dos ejes temáticos: "SIDA en la población indígena: contextos de vulnerabilidad y riesgo" y "enfrentamiento del SIDA y los desafíos de la salud indígena". DISCUSIÓN: se observó la necesidad de la implementación de medidas que señalen un control y la prevención del SIDAa en las tribus indígenas, como también de acciones educativas inherentes a los hábitos tradicionales de esa población. CONCLUSIÓN: esas evidencias contribuirán para el direccionamiento de una acción eficaz de prevención del SIDA direccionadas a la población indígena.
