Zika Virus Infection In Brazil Research Articles

Establishment and cryptic transmission of Zika virus in Brazil and the Americas.

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

Microcephaly Case Fatality Rate Associated with Zika Virus Infection in Brazil: Current Estimates.

Considering the currently confirmed cases of microcephaly and related deaths associated with Zika virus in Brazil, the estimated case fatality rate is 8.3% (95% confidence interval: 7.2-9.6). However, a third of the reported cases remain under investigation. If the confirmation rates of cases and deaths are the same in the future, the estimated case fatality rate will be as high as 10.5% (95% confidence interval: 9.5-11.7).

Zika virus infection during the Olympic Games in Rio: A fear or an actual risk?

The recent outbreak of Zika virus infection in Brazil has aroused considerable media interest due to its association with neurological malformations in children born from mothers infected by the virus and to its association with Guillain–Barré syndrome in adults. This relationship has led to the World Health Organisation declaring the current epidemic as a “Public Health Emergency of International Concern”. Controversy also emerged on the advisability of delaying or changing the location of the Olympic and Paralympic Games, which were held in August at various locations in Brazil. In this article, we review the available evidence on the risk of Zika and dengue virus infection in individuals who travel to endemic countries, especially for multitudinous events.

Infección por virus Zika durante los Juegos Olímpicos de Río: ¿alarma o riesgo real?

The recent outbreak of Zika virus infection in Brazil has aroused considerable media interest due to its association with neurological malformations in children born from mothers infected by the virus and to its association with Guillain-Barre syndrome in adults. This relationship has led to the World Health Organisation declaring the current epidemic as a “Public Health Emergency of International Concern”. Controversy also emerged on the advisability of delaying or changing the location of the Olympic and Paralympic Games, which were held in August at various locations in Brazil. In this article, we review the available evidence on the risk of Zika and dengue virus infection in individuals who travel to endemic countries, especially for multitudinous events.

Zika virus infection in Brazil and human rights obligations.

The February 2016 WHO declaration that congenital Zika virus syndrome constitutes a Public Health Emergency of International Concern reacted to the outbreak of the syndrome in Brazil. Public health emergencies can justify a spectrum of human rights responses, but in Brazil, the emergency exposed prevailing inequities in the national healthcare system. The government's urging to contain the syndrome, which is associated with microcephaly among newborns, is confounded by lack of reproductive health services. Women with low incomes in particular have little access to such health services. The emergency also illuminates the harm of restrictive abortion legislation, and the potential violation of human rights regarding women's health and under the UN Conventions on the Rights of the Child and on the Rights of Persons with Disabilities. Suggestions have been proposed by which the government can remedy the widespread healthcare inequities among the national population that are instructive for other countries where congenital Zika virus syndrome is prevalent.

Congenital Zika Virus Infection

Recent studies have reported an increase in the number of fetuses and neonates with microcephaly whose mothers were infected with the Zika virus (ZIKV) during pregnancy. To our knowledge, most reports to date have focused on select aspects of the maternal or fetal infection and fetal effects. To describe the prenatal evolution and perinatal outcomes of 11 neonates who had developmental abnormalities and neurological damage associated with ZIKV infection in Brazil. We observed 11 infants with congenital ZIKV infection from gestation to 6 months in the state of Paraíba, Brazil. Ten of 11 women included in this study presented with symptoms of ZIKV infection during the first half of pregnancy, and all 11 had laboratory evidence of the infection in several tissues by serology or polymerase chain reaction. Brain damage was confirmed through intrauterine ultrasonography and was complemented by magnetic resonance imaging. Histopathological analysis was performed on the placenta and brain tissue from infants who died. The ZIKV genome was investigated in several tissues and sequenced for further phylogenetic analysis. Description of the major lesions caused by ZIKV congenital infection. Of the 11 infants, 7 (63.6%) were female, and the median (SD) maternal age at delivery was 25 (6) years. Three of 11 neonates died, giving a perinatal mortality rate of 27.3%. The median (SD) cephalic perimeter at birth was 31 (3) cm, a value lower than the limit to consider a microcephaly case. In all patients, neurological impairments were identified, including microcephaly, a reduction in cerebral volume, ventriculomegaly, cerebellar hypoplasia, lissencephaly with hydrocephalus, and fetal akinesia deformation sequence (ie, arthrogryposis). Results of limited testing for other causes of microcephaly, such as genetic disorders and viral and bacterial infections, were negative, and the ZIKV genome was found in both maternal and neonatal tissues (eg, amniotic fluid, cord blood, placenta, and brain). Phylogenetic analyses showed an intrahost virus variation with some polymorphisms in envelope genes associated with different tissues. Combined findings from clinical, laboratory, imaging, and pathological examinations provided a more complete picture of the severe damage and developmental abnormalities caused by ZIKV infection than has been previously reported. The term congenital Zika syndrome is preferable to refer to these cases, as microcephaly is just one of the clinical signs of this congenital malformation disorder.

EP01.08: Intrauterine Zika virus infection in Brazil: main central nervous system findings

EP01.08: Intrauterine Zika virus infection in Brazil: main central nervous system findings

International Perspectives: Microcephaly and Zika Virus Infection in Brazil

The Zika virus was discovered incidentally in Uganda in 1947 and had remained confined to an equatorial zone across Africa and Asia. A great outbreak of Zika virus was described in Micronesia (2007) and in Polynesia (2013–2014). An epidemic Zika virus infection was reported in 2015 in South and Central America and in the Caribbean. In Brazil, the first autochthonus case was reported in May 2015 in the northeastern region of the country and spread quickly to 22 states. Epidemiologic evidence suggests that this outbreak is associated with the increased number of infants born with congenital microcephaly in 2015–2016. Since April 2016, 6,906 cases suspected of microcephaly have been reported to the government. Of these, 4,046 (58.6%) were still in investigation; 1,814 cases were excluded; and 1,046 were confirmed using brain image diagnosis. Initial research on isolating and sequencing the Zika virus in brains and amniotic liquid of fetuses and newborn infants with microcephaly showed that the virus shares 97% to 100% of its genomic identity with lineages isolated in the outbreak in French Polynesia in 2013. Research studies are being conducted, but at the time of this writing, no specific treatment or vaccines are available. People traveling to areas with autochthonus circulation of Zika virus should take measures to protect themselves from mosquito bites, and pregnant women should avoid traveling to endemic areas.

Zika : Global Concern

Zika : Global Concern

Risk of microcephaly after Zika virus infection in Brazil, 2015 to 2016.

ObjectiveTo estimate the risk of microcephaly in babies born to women infected by the Zika virus during pregnancy in Brazil in an epidemic between 2015 and 2016.MethodsWe obtained data on the number of notified and confirmed microcephaly cases in each Brazilian state between November 2015 and October 2016 from the health ministry. For Pernambuco State, one of the hardest hit, weekly data were available from August 2015 to October 2016 for different definitions of microcephaly. The absolute risk of microcephaly was calculated using the average number of live births reported in each state in the corresponding time period between 2012 and 2014 and assuming two infection rates: 10% and 50%. The relative risk was estimated using the reported background frequency of microcephaly in Brazil of 1.98 per 10 000 live births.FindingsThe estimated absolute risk of a notified microcephaly case varied from 0.03 to 17.1% according to geographical area, the definition of microcephaly used and the infection rate. Assuming a 50% infection rate, there was an 18–127 fold higher probability of microcephaly in children born to mothers with infection during pregnancy compared with children born to mothers without infection during pregnancy in Pernambuco State. For a 10% infection rate, the probability was 88–635 folds higher.ConclusionA large variation in the estimated risk of microcephaly was found in Brazil. Research is needed into possible effect modifiers, reliable measures of Zika virus infection and clear endpoints for congenital malformations.

Gearing Up To Fight Zika

When the Pan American Health Organization put out an alert last May about the first confirmed cases of Zika virus infection in Brazil, the news barely registered. After all, compared with other mosquito-borne viruses, such as potentially life-threatening dengue and yellow fever, Zika seemed pretty harmless. Only 20% of people infected with Zika even become ill, and their symptoms tend to be mild—fever, rash, joint pain, and conjunctivitis. But in January, nine months after the organization raised the alarm, doctors in Brazil reported a disturbing trend that coincided with Zika’s spread across the country. Since October 2015, more than 4,000 babies in Brazil had been born with abnormally small heads and brains—a rare condition known as microcephaly. Although further analysis lowered that figure by 462 cases, the sharp rise nonetheless has experts worried that Zika could be to blame. For comparison, Brazil reported just 147 cases of microcephaly in 2014.

Travel Volume to the United States from Countries and U.S. Territories with Local Zika Virus Transmission.

Introduction: Air, land, and sea transportation can facilitate rapid spread of infectious diseases. In May 2015 the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infection in Brazil. As of March 8, 2016, the U.S. Centers for Disease Control and Prevention (CDC) had issued travel notices for 33 countries and 3 U.S. territories with local Zika virus transmission.Methods: Using data from five separate datasets from 2014 and 2015, we estimated the annual number of passenger journeys by air and land border crossings to the United States from the 33 countries and 3 U.S. territories listed in the CDC’s Zika travel notices as of March 8, 2016. We also estimated the annual number of passenger journeys originating in and returning to the United States (primarily on cruises) with visits to seaports in areas with local Zika virus transmission. Because of the adverse pregnancy and birth outcomes that have been associated with Zika virus disease, the number of passenger journeys completed by women of childbearing age and pregnant women was also estimated.Results: An estimated 216.3 million passenger journeys by air, land, and sea are made annually to the United States from areas with local Zika virus transmission (as of March 8). The destination states with the largest numbers of arrivals were Texas (by land) and Florida (by air and sea). An estimated 51.7 million passenger journeys were made by women of childbearing age and an estimated 2.3 million were made by pregnant women.Conclusion: Travel volume analyses provide important information that can be used to effectively target public health interventions as well as direct public health resources and efforts at local, regional, and country-specific levels.

First report of autochthonous transmission of Zika virus in Brazil.

In the early 2015, several cases of patients presenting symptoms of mild fever, rash, conjunctivitis and arthralgia were reported in the northeastern Brazil. Although all patients lived in a dengue endemic area, molecular and serological diagnosis for dengue resulted negative. Chikungunya virus infection was also discarded. Subsequently, Zika virus (ZIKV) was detected by reverse transcription-polymerase chain reaction from the sera of eight patients and the result was confirmed by DNA sequencing. Phylogenetic analysis suggests that the ZIKV identified belongs to the Asian clade. This is the first report of ZIKV infection in Brazil.