Zika Virus Infection and Microcephaly: A Case-Control Study in Brazil.

Sabrina Gabriele Maia Oliveira Rocha,Antônio José Lêdo Alves Da Cunha,Luciano Lima Correia,Lucas Silveira Do Nascimento,Hermano Alexandre Lima Rocha,Jocileide Sales Campos,Álvaro Jorge Madeiro Leite,Anamaria Cavalcante E Silva,Tereza De Jesus Pinheiro Gomes Bandeira

doi:10.5334/aogh.2394

Sabrina Gabriele Maia Oliveira Rocha, Antônio José Lêdo Alves Da Cunha + Show 7 more

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https://doi.org/10.5334/aogh.2394

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Abstract

Background:Brazil presented an alarming number of newborns with microcephaly in the years 2015 and 2016. The investigation of the cases raised the suspicion of the association of these cases with maternal infections by the zika virus. Also, in 2015, there was an epidemic of zika virus infection in Brazil, reinforcing this hypothesis.Objective:The objective of this study was to identify factors associated with the diagnosis of microcephaly in newborns, including zika virus infection.Methods:We conducted a case-control study. The cases were defined as children who received clinical and imaging diagnosis of microcephaly, born after October 2015 in Ceará, Brazil, which recorded the highest number of microcephaly cases in Brazil during the outbreak. The cases were identified in medical records of public and private maternity hospitals and in child development stimulation clinics tracked until June 2017. Epidemiological, clinical, and socioeconomic variables were collected, visiting their homes and confirming data from their medical records. Controls were children without microcephaly identified in the vicinity of the residence of each case. Logistic regression models were used to control confounding.Findings:We evaluated 58 cases and 116 controls. The odds of having a baby with microcephaly was 14 times higher among mothers who had zika virus infection (p < 0.001), after multivariate analysis. Arboviruses infections symptoms, as fever (p = 0.220), skin change (p < 0.001), and joint pain (p = 0.002) also demonstrated an association with microcephaly.Conclusions:Maternal infection zika virus was associated with a diagnosis of microcephaly. Our study contributes to the investigation of the epidemiological factors associated with the diagnosis of microcephaly.

Highlights

Since October 2015, Brazil has had an alarming number of suspected cases of newborns with microcephaly
Among the women who received a diagnosis during pregnancy, there was a predominance of zika virus syndrome in the pregnant women from the cases, while the majority of the mothers of the controls had urinary tract infections or conditions other than zika (p = 0.040)
% or median interquartile median interquartile. The results of this case-control study indicate that infection by zika virus diagnosed by a physician in the first trimester was, independently, the risk factor most strongly associated with microcephaly, with an adjusted odds ratio (OR) of 14.68 and high statistical significance (p < 0.001) despite the small sample size

Summary

Introduction

Since October 2015, Brazil has had an alarming number of suspected cases of newborns with microcephaly. Is defined as a clinical sign of congenital malformation in children presenting occipitofrontal circumference two standard deviations lower than the mean compared to children of the same age, sex, and ethnicity [3] It is a rare condition, with an incidence of 5.9 cases per 10,000 live births in the United States of America [4], and its diagnosis can be confirmed as delayed brain development identified by imaging tests, such as intrauterine ultrasonography (US) or computer tomography (CT) after childbirth. Objective: The objective of this study was to identify factors associated with the diagnosis of microcephaly in newborns, including zika virus infection. Our study contributes to the investigation of the epidemiological factors associated with the diagnosis of microcephaly

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