SummaryBackground 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.
Brazilian Ministry of Health, Pan American Health Organization, and Enhancing Research Activity in Epidemic Situations.
BackgroundInternational fish trade reached an import value of 62.8 billion Euro in 2006, of which 44.6% are covered by the European Union. Species identification is a key problem throughout the life cycle of fishes: from eggs and larvae to adults in fisheries research and control, as well as processed fish products in consumer protection.Methodology/Principal FindingsThis study aims to evaluate the applicability of the three mitochondrial genes 16S rRNA (16S), cytochrome b (cyt b), and cytochrome oxidase subunit I (COI) for the identification of 50 European marine fish species by combining techniques of “DNA barcoding” and microarrays. In a DNA barcoding approach, neighbour Joining (NJ) phylogenetic trees of 369 16S, 212 cyt b, and 447 COI sequences indicated that cyt b and COI are suitable for unambiguous identification, whereas 16S failed to discriminate closely related flatfish and gurnard species. In course of probe design for DNA microarray development, each of the markers yielded a high number of potentially species-specific probes in silico, although many of them were rejected based on microarray hybridisation experiments. None of the markers provided probes to discriminate the sibling flatfish and gurnard species. However, since 16S-probes were less negatively influenced by the “position of label” effect and showed the lowest rejection rate and the highest mean signal intensity, 16S is more suitable for DNA microarray probe design than cty b and COI. The large portion of rejected COI-probes after hybridisation experiments (>90%) renders the DNA barcoding marker as rather unsuitable for this high-throughput technology.Conclusions/SignificanceBased on these data, a DNA microarray containing 64 functional oligonucleotide probes for the identification of 30 out of the 50 fish species investigated was developed. It represents the next step towards an automated and easy-to-handle method to identify fish, ichthyoplankton, and fish products.
BackgroundStarting in August 2015, there was an increase in the number of cases of neonatal microcephaly in Northeast Brazil. These findings were identified as being an epidemic of microcephaly related to Zika virus (ZIKV) infection. The present study aims to analyse the spatial distribution of microcephaly cases in Recife (2015–2016), which is in Northeast Brazil, and its association with the living conditions in this city.MethodsThis was an ecological study that used data from reported cases of microcephaly from the State Health Department of Pernambuco (August 2015 to July 2016). The basic spatial unit of analysis was the 94 districts of Recife. The case definition of microcephaly was: neonates with a head circumference of less than the cut-off point of −2 standard deviations below the mean value from the established Fenton growth curve. As an indicator of the living conditions of the 94 districts, the percentage of heads of households with an income of less than twice the minimum wage was calculated. The districts were classified into four homogeneous strata using the K-means clustering algorithm. We plotted the locations of each microcephaly case over a layer of living conditions.ResultsDuring the study period, 347 microcephaly cases were reported, of which 142 (40.9%) fulfilled the definition of a microcephaly case. Stratification of the 94 districts resulted in the identification of four strata. The highest stratum in relation to the living conditions presented the lowest prevalence rate of microcephaly, and the overall difference between this rate and the rates of the other strata was statistically significant. The results of the Kruskal-Wallis test demonstrated that there was a strong association between a higher prevalence of microcephaly and poor living conditions. After the first 6 months of the study period, there were no microcephaly cases recorded within the population living in the richest socio-economic strata.ConclusionThis study showed that those residing in areas with precarious living conditions had a higher prevalence of microcephaly compared with populations with better living conditions.
The first cases of a new illness involving fever and rash that was deemed to have been caused by Zika virus (ZIKV) infection in Brazil were reported in 2014, and the presence of the virus was confirmed in April 2015. In October 2015, an unusual increase in the number of cases of microcephaly among newborn infants was reported in Brazil; this disorder was apparently linked to ZIKV infection. From the first investigations of microcephaly, and from subsequent studies in Brazil and elsewhere, it is now clear that ZIKV is a cause of a range of neurologic disorders, including the Guillain-Barré syndrome (GBS) in adults and abnormalities in fetuses and newborn infants, including microcephaly.1 Here, we use routinely collected surveillance data and medical records to show how the spread of ZIKV in Brazil was associated with an increase in the incidence of GBS and microcephaly during 2015 and 2016. We also highlight the limitations of routinely collected data, which cannot yet explain, for example, why there were many fewer cases of microcephaly than expected in 2016.To explore the temporal and geographic distribution of ZIKV infection, we used data provided by municipalities and states in each of the five regions of Brazil, as compiled by the Ministry of Health. These data describe the number of suspected and confirmed cases of ZIKV infection and of cases reported as GBS and microcephaly (Sections 1 and 2 in the Supplementary Appendix, available with the full text of this letter at NEJM.org).Disclosure forms provided by the authors are available with the full text of this letter at NEJM.org.
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