A Zika virus epidemic emerged in northeast Brazil in 2015 and was followed by a striking increase in congenital microcephaly cases, triggering a declaration of an international public health ...emergency. This is the final report of the first case-control study evaluating the potential causes of microcephaly: congenital Zika virus infection, vaccines, and larvicides. The published preliminary report suggested a strong association between microcephaly and congenital Zika virus infection.
We did a case-control study in eight public maternity hospitals in Recife, Brazil. Cases were neonates born with microcephaly, defined as a head circumference of 2 SD below the mean. Two controls without microcephaly were matched to each case by expected date of delivery and area of residence. We tested the serum of cases and controls and the CSF of cases for detection of Zika virus genomes with quantitative RT-PCR and for detection of IgM antibodies with capture-IgM ELISA. We also tested maternal serum with plaque reduction neutralisation assays for Zika and dengue viruses. We estimated matched crude and adjusted odds ratios with exact conditional logistic regression to determine the association between microcephaly and Zika virus infection.
We screened neonates born between Jan 15 and Nov 30, 2016, and prospectively recruited 91 cases and 173 controls. In 32 (35%) cases, congenital Zika virus infection was confirmed by laboratory tests and no controls had confirmed Zika virus infections. 69 (83%) of 83 cases with known birthweight were small for gestational age, compared with eight (5%) of 173 controls. The overall matched odds ratio was 73·1 (95% CI 13·0–∞) for microcephaly and Zika virus infection after adjustments. Neither vaccination during pregnancy or use of the larvicide pyriproxyfen was associated with microcephaly. Results of laboratory tests for Zika virus and brain imaging results were available for 79 (87%) cases; within these cases, ten were positive for Zika virus and had cerebral abnormalities, 13 were positive for Zika infection but had no cerebral abnormalities, and 11 were negative for Zika virus but had cerebral abnormalities.
The association between microcephaly and congenital Zika virus infection was confirmed. We provide evidence of the absence of an effect of other potential factors, such as exposure to pyriproxyfen or vaccines (tetanus, diphtheria, and acellular pertussis, measles and rubella, or measles, mumps, and rubella) during pregnancy, confirming the findings of an ecological study of pyriproxyfen in Pernambuco and previous studies on the safety of Tdap vaccine administration during pregnancy.
Brazilian Ministry of Health, Pan American Health Organization, and Enhancing Research Activity in Epidemic Situations.
Summary Background The microcephaly epidemic, which started in Brazil in 2015, was declared a Public Health Emergency of International Concern by WHO in 2016. We report the preliminary results of a ...case-control study investigating the association between microcephaly and Zika virus infection during pregnancy. Methods We did this case-control study in eight public hospitals in Recife, Brazil. Cases were neonates with microcephaly. Two controls (neonates without microcephaly), matched by expected date of delivery and area of residence, were selected for each case. Serum samples of cases and controls and cerebrospinal fluid samples of cases were tested for Zika virus-specific IgM and by quantitative RT-PCR. Laboratory-confirmed Zika virus infection during pregnancy was defined as detection of Zika virus-specific IgM or a positive RT-PCR result in neonates. Maternal serum samples were tested by plaque reduction neutralisation assay for Zika virus and dengue virus. We estimated crude odds ratios (ORs) and 95% CIs using a median unbiased estimator for binary data in an unconditional logistic regression model. We estimated ORs separately for cases with and without radiological evidence of brain abnormalities. Findings Between Jan 15, 2016, and May 2, 2016, we prospectively recruited 32 cases and 62 controls. 24 (80%) of 30 mothers of cases had Zika virus infection compared with 39 (64%) of 61 mothers of controls (p=0·12). 13 (41%) of 32 cases and none of 62 controls had laboratory-confirmed Zika virus infection; crude overall OR 55·5 (95% CI 8·6–∞); OR 113·3 (95% CI 14·5–∞) for seven cases with brain abnormalities; and OR 24·7 (95% CI 2·9–∞) for four cases without brain abnormalities. Interpretation Our data suggest that the microcephaly epidemic is a result of congenital Zika virus infection. We await further data from this ongoing study to assess other potential risk factors and to confirm the strength of association in a larger sample size. Funding Brazilian Ministry of Health, Pan American Health Organization, and Enhancing Research Activity in Epidemic Situations.
Para lograr y mantener la validacion de la eliminacion de la transmision maternoinfantil (ETMI) del VIH, la sifilis y el virus de la hepatitis B es necesario contar con el liderazgo de los ...ministerios de salud, realizar analisis rigurosos de los datos, llevar a cabo evaluaciones de los programas y colaborar en multiples niveles.En esta guia de gobernanza se describen las estructuras y los procesos estandarizados que se utilizan para validar la ETMI a nivel nacional, regional y mundial. Esta edicion revisada, que reemplaza la version anterior publicada en junio del 2020, complementa la actualizacion de las Orientaciones mundiales sobre los criterios y procesos para la validacion de la eliminacion de la transmision maternoinfantil del VIH, la sifilis y el virus de la hepatitis B, en las que la OMS establece criterios para la validacion de la triple eliminacion.
La Estrategia de Gestion Integrada para la prevencion y control del dengue en la Region de las Americas (conocida como EGI-dengue) fue elaborada en el 2003 por los paises de la Region y la ...organizacion panamericana de la Salud (OPS). En el 2016, esta estrategia se amplio para el abordaje de otras enfermedades arbovirales (chikunguna y zika), convirtiendose asi en la Estrategia de gestion integrada para la prevencion y el control de las enfermedades arbovirales en las Americas (EGI-Arbovirus). En la actualidad, la EGI-Arbovirus constituye una herramienta solida de trabajo para dar respuesta a las situaciones causadas por estas enfermedades.Una de las principales fortalezas de la EGI-Arbovirus ha sido su sostenibilidad en el tiempo, en parte gracias a los procesos de monitoreo y evaluacion realizado por los paises de la Region y por la OPS. Hasta la fecha de publicacion de esta metodologia, se han llevado a cabo 34 procesos de evaluaciones externas en los Estados Miembros de la Region, algunos de ellos con dos o mas evaluaciones realizadas. Aqui se recopilan la experiencia y la evidencia extraidas de estos procesos, y se brinda de manera clara y sencilla una metodologia para que los equipos responsables de la aplicacion de las EGI-Arbovirus nacionales en cada pais y el Programa Regional de Enfermedades Arbovirales de la OPS realicen los procesos de seguimiento y evaluacion de estas estrategias de manera homogenea.Se pretende que estos procesos de evaluacion de las EGI-Arbovirus nacionales contribuyan a la mejora de la cooperacion tecnica para el fortalecimiento de las capacidades de respuestas en la prevencion y el control de las enfermedades arbovirales en los paises y territorios de las Americas.
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