Fatal Zika virus disease in adults: A critical reappraisal of an under-recognized clinical entity

Enhanced Zika virus-like particle development using Baculovirus spp. constructs

Zika virus (ZIKV) is one of several examples of an unprecedented pandemic spread and against which there is currently no suitable vaccine or treatment. Here, we constructed and characterized recombinant baculovirus-derived ZIKV-like particles (Zika VLPs) to study ZIKV-antibody interactions. These VLPs, uniquely consisted of the full-length ZIKV capsid (C), pre-membrane (prM), and envelope (E) proteins with either: a) the viral nonstructural NS2B and NS3 protease unit under one or two different promoters or b) an alternative host-cell furin protease encoding cleavage sequence inserted between the C and prM genes, together with lobster tropomyosin leader and honeybee signal sequences with one promoter for increased extracellular secretion. All these Zika VLPs displayed typical virion morphology in transmission electron microscopic analysis when expressed in both insect (Sf9) and mammalian (HEK293T) cells and no uncleaved prM glycoprotein was detected, as are present on immature virions. The importance of glycosylation of the E glycoprotein was shown by the effects on both polyclonal and monoclonal antibody reactions after these N-linked carbohydrate residues were disrupted by oxidation or enzymatic cleavage. Importantly, the construct which contained the host-cell furin protease cleavage sequence together with a lobster tropomyosin leader and honeybee signal sequences under one promoter produced higher Zika VLP titers and protein concentrations and which can now be tested as a superior construct in multifunctional diagnostic (ELISA and neutralization/antibody-dependent enhancement) assays and immunogenic assessments possibly leading to vaccine trials.

SARS-CoV-2 jumping the species barrier: Zoonotic lessons from SARS, MERS and recent advances to combat this pandemic virus

Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome - Coronavirus-2) of the family Coronaviridae, appeared in China in December 2019. This disease was declared as posing Public Health International Emergency by World Health Organization on January 30, 2020, attained the status of a very high-risk category on February 29, and now having a pandemic status (March 11). COVID-19 has presently spread to more than 215 countries/territories while killing nearly 0.75 million humans out of cumulative confirmed infected asymptomatic or symptomatic cases accounting to almost 20.5 million as of August 12, 2020, within a short period of just a few months. Researchers worldwide are pacing with high efforts to counter the spread of this virus and to design effective vaccines and therapeutics/drugs. Few of the studies have shown the potential of the animal-human interface and zoonotic links in the origin of SARS-CoV-2. Exploring the possible zoonosis and revealing the factors responsible for its initial transmission from animals to humans will pave ways to design and implement effective preventive and control strategies to counter the COVID-19. The present review presents a comprehensive overview of COVID-19 and SARS-CoV-2, with emphasis on the role of animals and their jumping the cross-species barriers, experiences learned from SARS- and MERS-CoVs, zoonotic links, and spillover events, transmission to humans and rapid spread, and highlights the new advances in diagnosis, vaccine and therapies, preventive and control measures, one health concept along with recent research developments to counter this pandemic disease.

Spatial distribution of dengue in Honduras during 2016-2019 using a geographic information systems (GIS)-Dengue epidemic implications for public health and travel medicine

BACKGROUND

After serious epidemics of chikungunya (CHIKV) and Zika (ZIKV) in the Americas, dengue (DENV) have reemerged in most countries. We analyzed the incidence, incidence rates, and evolution of DENV cases in Honduras from 2015 to 2018 and the ongoing 2019 epidemic.

METHODS

Using epidemiological weeks (EW) surveillance data on the DENV in Honduras, we estimated incidence rates (cases/100,000 population), and developed maps at national, departmental, and municipal levels.

RESULTS

From January 1, 2016 to July 21, 2019, a total of 109,557 cases of DENV were reported, 28,603 in 2019, with an incidence rate of 312.32 cases/100,000 population this year; 0.13% laboratory-confirmed. The highest peak was reached on the EW 28°, 2019 (5299 cases; 57.89 cases/100,000 population). The department with the highest number of cases and incidence rate was Cortes (8404 cases, 479.68 cases/100,000 population in 2019).

DISCUSSION

The pattern and evolution of DENV epidemic in 2019 in Honduras has been similar to that which occurred for in 2015. As previously reported, this epidemic involved the north and central areas of the country predominantly, reaching municipality incidences there >1000 cases/100,000 population (or 1%). Studies using geographical information systems linked with clinical disease characteristics are necessary to obtain accurate epidemiological data for public health systems. Such information is also useful for assessment of risk for travelers who visit specific areas in a destination country.

Zika Virus Pathogenesis: From Early Case Reports to Epidemics

For the first 60 years following its isolation, Zika virus (ZIKV) remained a relatively poorly described member of the Flaviviridae family. However, since 2007, it has caused a series of increasingly severe outbreaks and is now associated with neurological symptoms such as Guillain-Barré syndrome and congenital Zika syndrome (CZS). A number of reports have improved our understanding of rare complications that may be associated with ZIKV infection in adults, the areas of the body to which it spreads, and viral persistence in various tissues. Likewise, studies on the effect of ZIKV infection during pregnancy have identified risk factors for CZS and the impact this syndrome has on early childhood. Understanding these outcomes and the factors that drive ZIKV pathogenesis are key to developing vaccination and therapeutic approaches to avoid these severe and potentially debilitating symptoms.

Fatal Zika virus infection in the Americas: A systematic review

INTRODUCTION

While death due to Zika virus (ZIKV) infection has been described, reports of fatal cases have been infrequent and no systematic reviews on the subject have been published.

METHODS

A systematic review of the literature in four databases was performed to assess fatal outcomes of postnatal ZIKV infection and the available evidence that links ZIKV infection to death.

RESULTS

Three hundred and eleven articles were retrieved; 20 of them were epidemiological reports from surveillance agencies and ministries of health. After screening by abstract and title, 59 articles were selected for full-text assessment. Of these, 35 were excluded (with reasons) and 24 were finally included for qualitative analysis. A total of 51 reported deaths associated with ZIKV infection in nine countries were identified. The majority of cases (56.9%) were not related to Guillain-Barré syndrome. Cases from three countries accounted for 67.6% of the deaths. ZIKV infection was laboratory-confirmed in the majority of cases (64.7%).

DISCUSSION

ZIKV was not considered to be a dangerous, and much less a lethal pathogen, until very recently. However, an increasing number of fatalities have been published in the literature since the first death was reported in 2016. Additional research is needed to elucidate factors that may mediate the pathogenesis of severe, atypical, and fatal disease.