INO-A002 Zika Vaccine

Maternal Zika Viremia: a Marker of Adverse Perinatal Outcomes

Don Hackett — Thu, 25 Feb 2021 00:55:20 +0000

Reviewer:

The recent worldwide Zika virus (ZIKV) outbreak confirmed maternal-fetal transmission and its association with adverse perinatal outcomes.

Whether prolonged viremia after ZIKV infection in pregnant women represents a risk factor for maternal-fetal transmission, congenital Zika syndrome, or other adverse outcomes is an ongoing controversy.

The main findings of a recent ZIKV infection cohort study published by the US Centers for Disease Control and Prevention (CDC) on February 23, 2021, are 2-fold.

First, maternal ZIKV infection with prolonged viremia is associated with a 7-fold increased risk for fetal or neonatal adverse outcomes compared with pregnancies without prolonged viremia.

Second, prolonged maternal viremia is associated with a 2-fold increased risk for confirmed congenital infection than infected mothers without prolonged viremia.

The infected group’s sample size limited this study because only patients with a positive ZIKV RT-PCR result at enrollment were included in the analysis and followed up with monthly RT-PCR testing until clearance or delivery.

However, because the measured effect size was high, the sample size was sufficient to identify an association.

However, the limited number of prolonged viremia cases forced these researchers to group all adverse outcomes to analyze with sufficient power. It prevented the evaluation of its association with individual signs or symptoms or new characteristics.

Although ZIKV testing was based on the previous guidelines relevant during the 2015–2016 epidemic with adaptation to local capacities, testing does not follow the more recent CDC guidelines (patients considered as noninfected underwent serologic testing in each trimester rather than nucleic acid testing, as is currently recommended).

However, patients included as noninfected remained negative for IgM and IgG in each trimester and at delivery, limiting the risk for exposure misclassification.

Similarly, women with only positive IgM testing were excluded from the study because some might have had undetected prolonged viremia, which would have led to exposure misclassification and an underestimation of the consequences of prolonged viremia.

Information about the sensitivity and specificity of neonatal testing remains limited, and several studies have shown the progressive disappearance of ZIKV RNA in the maternal-fetal compartments.

Although the identification of IgM in fetal or neonatal blood was used to avoid congenital ZIKV false negatives, these researchers cannot exclude an outcome misclassification because ZIKV could have infected some neonates with negative results without viremia and immunity against ZIKV detectable at birth.

This risk is likely low given that >80% of fetuses or neonates from infected pregnant women underwent testing in >3 different samples (including blood, urine, placenta, cerebrospinal, and amniotic fluid) (19), and all neonates from non-infected pregnant women underwent serologic testing at birth.

Undetected congenital infections in the two reference groups might result in overestimation of the effect of prolonged viremia overallNeonates from noninfected mothers who underwent postnatal transfontanellar ultrasound (as well as by computed tomography and magnetic resonance imaging, if available) only in the case of an abnormal prenatal ultrasound or symptoms at birth, in contrast to those from infected mothers who underwent routine postnatal imaging.

Moreover, when they are asymptomatic, some neonates from noninfected mothers might have undetected cerebral anomalies at birth, resulting in an overestimation of the consequences of prolonged Zika viremia.

All neonates from noninfected mothers underwent multiple prenatal ultrasound assessments (enhanced by 2 supplementary examinations with neurosonograms during the epidemic), reducing the risk for undetected cerebral anomalies.

Negative and positive predictive values of prolonged maternal viremia for congenital infections and adverse outcomes related to ZIKV seem to be moderate because fetal and neonatal adverse outcomes and congenital infections also occur in pregnant women without identified prolonged viremia.

One explanation could be that prolonged viremia might reflect viral replication in the placenta without further involvement for the fetus.

Some of our cases with prolonged maternal viremia (6/15) did not exhibit congenital infections, suggesting that prolonged maternal viremia might also reflect persistent viral replication in other reservoirs than the fetus or the placenta.

The study of Rodo et al. and a CDC report also described fetuses without congenital infection or adverse outcomes from mothers with prolonged viremia.

These researchers stated, ‘Our results also indicate that noninfected women exhibited a 5.1% risk for fetal neurologic anomalies and 1.2% risk for fetal loss, reflecting that other etiologies for adverse perinatal outcomes remain present even in the context of a ZIKV epidemic.

In conclusion, prolonged maternal ZIKV viremia could be a marker for an increased risk for maternal–fetal transmission and subsequent adverse perinatal outcomes.

Even if prolonged maternal viremia is not consistently present in congenital infection, it might reflect active viral replication in the fetal–placental compartment. It should lead to an enhanced prenatal and neonatal follow-up.

Acknowledgments: This study involved personnel at Centre Hospitalier de l’Ouest Guyanais and Institut Pasteur of French Guiana. The corresponding author attests that all listed authors meet authorship criteria. No others meeting the criteria have been omitted. This manuscript is an honest, accurate, and transparent account of the study being reported, and no important aspects of the study have been omitted.

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Zika congenital infections were confirmed in fetuses and neonates from mothers with prolonged viremia

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Prolonged Maternal Zika Viremia as a Marker of Adverse Perinatal Outcomes

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These Genes Reduce Placenta's Protection From the Zika Virus

Don Hackett — Thu, 29 Oct 2020 18:54:47 +0000

Reviewer:

Robert Carlson, MD

Danielle Reiter, RN

Genetic factors that reduce the placenta's capacity to protect a fetus from the Zika virus are described by Brazilian researchers in an article published in PLOS Neglected Tropical Diseases.

According to these researchers, the findings help explain why only some infants whose mothers are infected by the Zika virus (ZIKV) during pregnancy are born with some kind of anomaly.

Since the 2015 epidemic at least 3,500 babies have suffered from Congenital Zika Syndrome (CZA), which includes microcephaly, brain calcifications, and auditory and visual deficits, according to statistics available from the Brazilian Health Ministry.

However, these cases are believed to correspond to between 5% and 10% of all the fetuses exposed to Zika in the first trimester, the riskiest period of pregnancy.

“We observed differences in the expression of two classes of genes in the placenta of the affected babies. One is associated with the placenta’s capacity to invade and attach to the wall of the uterus. The other has to do with the production of certain molecules known as chemokines, which attract maternal immune cells to combat the virus in the placental barrier,” said Sergio Verjovski, a professor in the University of São Paulo’s Chemistry Institute (IQ-USP) and principal investigator for the study, in a press release issued on October 26, 2020.

The discovery was only possible thanks to a cellular reprogramming technique that enabled the researchers to recreate in the laboratory the cells that make up the so-called primitive placenta, which gives the fetus support in the first trimester.

Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected.

They analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared them by RNA-Seq the trophoblasts from CZS-affected and non-affected twins.

Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected.

Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors, and IFN in the trophoblasts, either before or after ZIKVBR infection.

Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR.

Overall, the results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses’ tissues.

ZikaNews publishes research-based news.

Sub Title:

Genetic factors can make a women’s placenta less capable of protecting a fetus from Zika infection

References:

Study reveals genetic factors that can make placenta less capable of protecting fetus from zika

Differential gene expression elicited by ZIKV infection in trophoblasts from congenital Zika syndrome discordant twins

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Zika Virus Can Spread Vaginally

Don Hackett — Mon, 25 May 2020 14:26:27 +0000

Reviewer:

Holly Lutmer PharmD

Danielle Reiter, RN

The Zika virus is capable of replicating and spreading infectious particles within the outermost cells lining the vaginal tract, according to new research.

This study’s findings provide the first molecular-level insights into how the Zika virus can move from person to person through sexual contact.

While the Zika virus is primarily spread by mosquitoes, researchers have been aware of its potential for sexual transmission based on cases in which people became infected after having sex with a partner who had visited a Zika-affected area.

Previous studies have also found Zika particles present in semen and vaginal fluid from infected individuals.

Having a more detailed understanding of how Zika infiltrates the body through sexual contact could help scientists identify new ways to prevent or treat Zika infections.

This new study examined how Zika particles behaved in cultures of human vaginal epithelial cells and identified the virus's likely entry point as a protein on the surface of the cells called tyrosine-protein kinase receptor UFO, which is encoded by the AXL gene.

"The outcome of this research highlights how local replication of Zika in the vaginal epithelium plays an important role in mediating sexual transmission and subsequent systemic infection in the human host," said lead study author James Mungin Jr., a doctoral candidate at Meharry Medical College, located in Nashville, Tennessee.

"Additionally, our research findings confirming that the receptor UFO (AXL) promotes viral entry can be very instrumental in developing drugs and antibody-based therapies that target and block this receptor, therefore eliminating the pathology caused by this virus."

Mungin and colleagues found that Zika virus particles were able to successfully enter vaginal epithelial cells through the UFO receptor, replicate their RNA genome and steadily release infectious viral particles inside the cells.

The research team plans to further study the factors that contribute to Zika replication for insights on how those factors might be interrupted.

Like Zika, many other viruses in the flavivirus family are spread by insects. However, research on those other viruses, such as dengue and yellow fever, does not always translate well to Zika because they are not sexually transmitted.

"Interestingly, sexual transmission among flaviviruses is in fact unique in nature," said Mungin.

"As of now, Hepatitis C and Zika virus have been identified as the [only] two flaviviruses known to establish infection via sexual contact with an infected partner."

Zika spread rapidly around the world during a major 2015-2016 outbreak, causing about 42,000 infections in the United States and its territories, reported the US Centers for Disease Control and Prevention (CDC).

While the number of cases has since dropped precipitously, the virus is still considered a health threat in many places around the world.

The Zika virus pandemic in the Americas and Caribbean was known to cause over 1 million cases and there were reports in which the virus was found to cause severe, life-threatening complications among patients with associated comorbidities.

Furthermore, infants born to mothers infected with Zika have a high risk of birth defects.

According to the CDC, using condoms can prevent sexual transmission of Zika.

In 2018 and 2019, no local mosquito-borne Zika virus transmission has been reported in the continental USA.

If you are traveling outside of the continental United States, see Zika Travel Information to learn about your destination, says the CDC.

ZikaNews publishes international Zika virus news.

Sub Title:

Zika virus particles were able to successfully enter vaginal epithelial cells through the UFO receptor

References:

Scientists uncover how Zika virus can spread through sexual contact

Human Vaginal Epithelial Cells are Susceptible to the Zika Virus

CDC: Zika Virus

Zika is an Under-Recognized Clinical Entity

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A Small Molecule May Block Zika Virus Infections

Don Hackett — Sun, 20 Oct 2019 13:22:39 +0000

Reviewer:

Danielle Reiter, RN

A recent study found a new small molecule has the ability to block Zika virus infection in human cells (in vitro) and in mice (in vivo).

This molecule, 6-deoxyglucose-diphyllin (DGP), is a broad-spectrum antiviral that potentially blocks infection by Zika viruses.

And, DGP may also inhibit human infections by other flaviviruses.

This study published in EbioMedicine in September 2019, reported the DGP molecule targets the cellular endosomal acidification, preventing the entry of the virus into the cell, consequentially inhibiting infection.

Cellular and virological experiments showed that DGP blocked Zika at a pre-fusion step or during fusion, which prevented the delivery of viral contents into the cytosol of the target cell.

Furthermore, mechanistic studies revealed that DGP prevented the acidification of endosomal/lysosomal compartments in target cells, thus inhibiting ZIKV fusion with cellular membranes and infection.

And finally, DGP effectively prevented Zika virus-induced death in mice during this limited study.

The study of ZIKV infection in animal models has been possible due to the availability of mice strains that are susceptible to infection.

Because of its effectiveness against Zika virus infection in mice, this new inhibitor shows great potential for its use in the clinics, concluded these researchers.

This is important news since there are urgent needs for anti-Zika virus (ZIKV) drugs to prevent mother-to-child transmission of ZIKV, new infections in high-risk populations, and the infection of medical personnel in ZIKV-affected areas.

So far, no specific antiviral has been approved for the treatment of ZIKV infections.

Acetaminophen is usually used to control fever and pain, antihistamines are used for pruritic rashes, and fluids to prevent dehydration in ZIKV-infected patients.

However, acetylsalicylic acid and non-steroidal anti-inflammatory drugs are contraindicated because of an increased risk of hemorrhagic syndrome reported with other flaviviral infections, as well as the risk of Reye’s syndrome after viral infection in children and teenagers, reported a September 2019 study.

The Zika virus is a mosquito-borne flavivirus that recently caused outbreaks in humans in various countries, which resulted in fetal abnormalities, such as microcephaly and neurological diseases in adults including Guillian-Barre syndrome.

ZIKV, which belongs to the Flavivirus genus, is a member of the Flaviviridae family along with several other important vector-borne human pathogens, such as the West Nile virus, dengue virus 1, tick-borne encephalitis virus, and Japanese encephalitis virus.

The flavivirus genus is the largest among the Flaviviridae family with 53 different species and can be further divided into non-vector, tick-borne, and mosquito-borne clusters. Zika (strain MR 766) was first isolated in 1947 in the Zika forest of Uganda.

The first human cases of Zika infections were reported in Africa in the 1950s and later in Asia, but remained restricted to these regions until 2007. A large outbreak occurred in the Federated States of Micronesia, followed by outbreaks in French Polynesia, New Caledonia, and the Cook Islands in 2013 and 204.

Although ZIKV is known to be primarily transmitted through mosquito bites, some studies have shown that it can also be sexually transmitted.

For these reasons, ZIKV was recognized in 2016 as a Public Health Emergency of International Concern by the World Health Organization (WHO).

Recently, the state of Florida reported it is monitoring over 20 pregnant women infected with the Zika virus.

Recent Zika virus news

This new research was supported by the Albert Einstein College of Medicine. And, the authors declare no competing interests.

Zika updates published by Zika News

Sub Title:

DGP antiviral may inhibit Zika and other flaviviruses infections in humans

Reference:

Glycosylated diphyllin as a broad-spectrum antiviral agent against Zika virus

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France Reports 1st Locally-Acquired Zika Case

Don Hackett — Sat, 12 Oct 2019 20:29:29 +0000

Reviewer:

Danielle Reiter, RN

The 1st autochthonous Zika virus case in France during 2019 has been confirmed in Hyères City, Var department, in southeastern France.

The Regional Health Agency (RHA) stated on October 9, 2019, ‘that the patient in care is now cured.’

Additionally, RHA said in this statement the patient had no recent history of travel outside of France, which indicates this was a locally-acquired Zika virus cases.

The City of Hyères has a population of about 56,000 residents, is located on France’s southeast coast near Marseille, and has a hot-summer Mediterranean climate.

Additionally, the ARS, Public Health France and the Interdepartmental Agreement for the Mosquito Control of the Mediterranean (EID) continue their investigations to determine the origin of this Zika case and prevent the further spreading of this serious disease.

Mosquito-borne transmission is the primary mechanism for epidemic spread. A. aegypti is the major vector for horizontal transmission of ZIKV to humans.

The Departmental Council of Var mandated the EID, at the request of the ARS, ‘to carry out a targeted treatment against the mosquito Aedes Albopictus (tiger mosquito), around the residence of the person affected by the Zika virus.

This operation is to prevent the establishment of a local chain of transmission of the Zika disease.

The insecticide spraying operation was completed on October 8th and took between 4 and 8 hours in the district Godillot.

Moreover, Zika is unique among arboviruses in that it can be transmitted during sexual contact and can cause teratogenic outcomes as a consequence of maternal-fetal transmission.

Although the effect of sexual transmission is difficult to assess, estimates are that 1 percent of Zika infections reported in Europe were acquired through sexual transmission.

Previously, a study published in BMC Public Health on July 31, 2019, said ‘The progressive establishment of Aedes albopictus, the tiger mosquito, in southern Europe at the beginning of the 90’s and its establishment in France in about 2004 have increased the potential health threat posed by these arthropods in temperate countries.’

These researchers concluded saying ‘despite the fact that arboviral diseases are increasingly being imported into France, sometimes resulting in sporadic autochthonous transmission, French ID physicians do not perceive the risk as high.’

‘Better communication and education targeting health professionals and citizens will be needed to enhance the effectiveness of the French national plan to prepare against arboviral diseases.’

Previously, French Polynesia reported an estimated 32,000 clinical consultations (11.5% of the total population) from October 2013 to April 2015.

In February 2016, the WHO declared that Zika infection associated with microcephaly and other neurological disorders constitutes a Public Health Emergency of International Concern.

As of July 2019, a total of 87 countries and territories have had evidence of autochthonous mosquito-borne transmission of Zika virus, distributed across the African Region, Region of the Americas, South-East Asia Region, Western Pacific Region, reports the World Health Organization.

France remains listed in the Zika alert website.

Zika virus news

To limit the proliferation of Zika carrying mosquitoes, the French ARS recommends preventive measures, such as the following:

cover the water reserves to avoid colonization
clean gutters and gutters
empty or store any container containing water and avoid wild deposits.

The ability of the Zika virus to cause congenital defects in fetuses, as exemplified by the microcephaly epidemic in Brazil, is an unprecedented feature in a mosquito-borne viral infection, says the WHO.

Recently, the State of Florida Florida said it was monitoring 23 pregnant women with Zika.

And, the Florida Arbovirus Surveillance Week #40 report published on October 5, 2019, said the Zika virus has been reported in 36 individuals with travel history to a country or area experiencing Zika virus activity during 2019.

Zika Virus news published by Zika News

Sub Title:

Hyères City, France reports initial autochthonous Zika virus case in 2019

References:

Présence d’un cas autochtone de Zika dans le département du Var

What is known about the first French case of Zika of the year detected in the Var

Low to medium-low risk perception for dengue, chikungunya and Zika outbreaks by infectious diseases physicians in France

WHO: Zika virus infection – France - French Guiana and Martinique

WHO: Zika: the origin and spread of a mosquito-borne virus

WHO: ZIKA EPIDEMIOLOGY UPDATE Global Overview

CDC: Health Information for Travelers to France

ECDC: COMMUNICABLE DISEASE THREATS REPORT Week 41, 6-12 October 2019

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Travel-Related Zika Cases Increased in the USA

Don Hackett — Sun, 06 Oct 2019 21:43:35 +0000

Reviewer:

Danielle Reiter, RN

According to the Pan American Health Organization, there have been 4,299 Zika virus cases confirmed in the Americas during 2019.

Furthermore, international travelers continue to contract the Zika while abroad and are bringing the virus home with them.

As of October 5, 2019, the states of California (28), Idaho (1), Nebraska (1), New Jersey (2), New York (2), Texas (1), and Utah (1) have reported travel-related Zika cases during 2019. says the US Centers for Disease Control and Prevention (CDC).

In California, the Department of Public Health reported the cities of Berkely (8) and Long Beach (12) confirmed the most cases.

The previous leader in reporting Zika cases during 2019, Florida, appears to have discontinued public reporting for 2019 on their Zika website and to to the CDC.

Meanwhile, the US Territory of Puerto Rico reported 5 additional Zika cases to the CDC during September. This new data increases Puerto Rico’s total to 39 cases, with 37 presumed local mosquito-borne transmissions during 2019.

A new study may have found a few reasons why Puerto Rico’s Zika virus outbreak has been so extensive.

This new study published on September 27, 2019, found less than 25 percent of 2,364 women surveyed in Puerto Rico reported consistent condom use during pregnancy in 2016.

The CDC continues to say ‘pregnant women and their male partners are advised to consistently and correctly use condoms when having intercourse or to abstain from intercourse during pregnancy to reduce the risk for sexual transmission of Zika virus.’

The good news from this CDC study shows healthcare provider counseling was associated with a 3-fold increase in condom use in Puerto Rico.

Furthermore, the recent PAHO report indicates which countries in the Americas are reporting locally-acquired Zika cases during 2019, and which are not disclosing information.

As of October 5, 2019, the PAHO reports the following:

Brazil = 3,322
Peru = 829
Mexico = 50
Bolivia = 27
Columbia = 11
Guatemala = 10

This PAHO data does not include any reporting from Cuba.

Previously, a July 2019 study found international travelers returning to Spain after visiting Cuba in 2017 were carrying the Zika virus.

While the Spanish travelers had visited different countries in Latin America and the Caribbean, the Zika cases were only identified in those who visited Cuba.

“These cases could reflect an absence of herd immunity in the Cuban population, as well as the possibility of it being one of the last places in the Americas with ongoing Zika virus transmission,” explains Alex Almuedo, M.D., first author of this study.

Additionally, Jose Muñoz, study coordinator, Head of the Tropical Medicine Service at the Hospital Clínic, said ‘these results underscore the need to consider possible Zika infection among travelers returning from Cuba.”

“It is also important to note that about 70 percent of the Cuba travelers that got infected with Zika did not seek advice before their trip,” adds Muñoz, highlighting that screening by travel clinics are “a key element to survey and prevent the introduction of these diseases in non-endemic regions.”

From a global perspective, a total of 87 countries and territories have confirmed evidence of autochthonous mosquito-borne transmission of the Zika virus to the World Health Organization, as of July 2, 2019.

As of October 4, 2019, Zika-related Travel Alerts have been issued by the CDC, the Canadian and the UK governments for various countries. As an example, reports indicate Zika in Thailand has become endemic.

To alert international travelers prior to planning a trip abroad, the CDC publishes a ‘map’ of countries reporting Zika cases.

Anyone who has not already been infected with the Zika virus can get it.

While many people with a Zika infection experience no symptoms, the virus poses potentially serious risks to unborn children, says the CDC.

A recent study found pregnant women who become infected with Zika early in pregnancy were 17 times more likely to deliver a baby suffering from a rare neurological condition called Microcephaly, and other negative health conditions.

Furthermore, since there is not a preventive vaccine available today, the CDC continues to recommend that pregnant women should not travel to areas with a Zika outbreak.

But, researchers around the world are trying to develop Zika vaccines using different development platforms. These Zika vaccine candidates include, but are not limited to, the following list:

These Zika vaccine candidates remain in clinical studies and will take more time before they become available to the public.

Vaccine news published by Zika News

Sub Title:

PAHO reports 4,299 Zika virus cases in the Americas during 2019

References:

CDC: Zika Virus 2019 Case Counts in the US

CDPH Monthly Update on Number of Zika Virus Infections in California October 4, 2019

PAHO: Cases of Zika Virus Disease 2019

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Cuba’s Silent Zika Outbreak Impacts Florida

Don Hackett — Sun, 25 Aug 2019 12:59:48 +0000

Reviewer:

Robert Carlson, MD

Danielle Reiter, RN

John Paul Sanchez, PharmD

A new study has discovered Cuba’s Zika virus outbreak during 2017 had unique characteristics, and may still be impacting the international community in 2019.

This innovative study used travel surveillance and virus genomics datasets to reveal significant flaws in Cuba’s disease reporting. And, ‘mosquito control efforts may delay, but not prevent, Zika virus establishment.’

These researchers said on August 22, 2019, ‘Cuba’s unrecognized and delayed Zika outbreak may have “silently” spread the virus to other parts of the world and continues to infect international visitors today.’

This study published in Cell reported 4 significant highlights, which are as follows:

Unreported Zika outbreak 2017:

This study discovered a large Zika outbreak in Cuba that was not reported to the Pan American Health Organization (PAHO) or other public health agencies and thus went undetected to the international community.

Extensive Zika outbreak:

Taking the population size of Cuba into account, we estimated that 5,707 Zika cases likely went unreported in this country, with the majority of these cases having occurred in 2017. This estimated Zika case count makes Cuba's 2017 outbreak comparable to those previously reported in Haiti, Jamaica, and the Dominican Republic in 2016.

Delayed Zika outbreak:

This study uncovered an unreported outbreak in Cuba during 2017, a year after peak transmission in neighboring islands and the Americas. By sequencing the Zika virus, we show that the ensuing outbreak was sparked by long-lived lineages of the Zika virus from other Caribbean Islands.

Cuba visitors in 2019:

This study shows how the Zika virus may still be “silently” spreading to Florida and Europe. Of 91 travel-associated Zika cases identified in Florida from June 2017 to October 2018, the team found that all but one infected individual was returning from Cuba. Likewise, 63 of 64 travel-associated cases caught in Europe during that time frame involved travel to Cuba.

Furthermore, these researchers said, "Due to widespread surveillance gaps and inconsistent reporting, we hypothesized that local Zika outbreaks could still be occurring in the Americas, despite not being realized by the international community."

This study found a total of 4 million air-travelers departed Cuba between June and December of 2017, arriving in 18 countries and US states. And, based on the environmental suitability for the Ae. aegypti mosquito in these locations, they estimated that Florida, Mexico, Panama, Venezuela, and Colombia were the countries most at risk from Cuban travelers bringing the Zika virus with them between June–December 2017.

"In contrast to local case reporting, travel surveillance relies on diagnosing patients that have acquired infections while traveling outside the country of diagnosis," the authors explained.

"As many regions in the Americas affected by the Zika epidemic attract large volumes of international visitors from countries with stronger surveillance systems, we hypothesized that, by creating a framework integrating local case reporting and travel surveillance with genomic epidemiology, we would be able to uncover potentially still-ongoing Zika outbreaks."

As an example, a small study of 366 people living in Puerto Rico during 2016-2017 found 34.4 percent of test subjects were found to be infected with the Zika virus.

And during 2019, the state of Florida has confirmed 31 travel-related Zika cases in 2019. This case count includes 16 pregnant women with the Zika virus.

Zika news

Overall, this study ‘creates a combined framework for how travel-surveillance and genomic epidemiology can be used as a future surveillance network for detecting hidden outbreaks of worldwide emerging infections and reconstructing transmission dynamics when local reporting is absent, withheld, or otherwise insufficient.’

This means, ‘continued surveillance is required to detect the potential further spreading of the Zika virus.’

The Zika virus is an enveloped, positive-sense, single-stranded sRNA, arthropod-borne virus that is classified in the genus Flavivirus, family Flaviviridae, says the US Centers for Disease Control and Prevention (CDC).

Zika virus is closely related to other viruses of medical importance, such as dengue, West Nile, and yellow fever viruses.

Many people infected with the Zika virus won’t have symptoms or will only have mild symptoms. The most common symptoms of Zika are fever, rash, and a headache.

However, the CDC says a ‘Zika infection while pregnant could cause significant harm to un-born infants.’

For their analysis, the researchers searched for travel-associated Zika, dengue virus, and chikungunya virus cases in data accrued by Florida's Department of Health between 2014 and 2018, along with related disease and travel data collected by the Pan American Health Organization, the European Centre for Disease Prevention and Control's European Surveillance System, and the US Centers for Disease Control and Prevention GeoSentinal Global Surveillance Network.

Published by Zika News

Sub Title:

Zika in Florida reaches 31 cases during 2019

References:

Travel Surveillance and Genomics Uncover a Hidden Zika Outbreak during the Waning Epidemic

Florida Arbovirus Surveillance Week 33: August 11-17, 2019

Zika Free Florida

CDC: Zika Virus 2019 Case Counts in the US

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