Detection of dengue, chikungunya, and Zika RNA in blood donors from Southeast Asia

Biased virus transmission following sequential coinfection of Aedes aegypti with dengue and Zika viruses

BACKGROUND

Mosquito-borne arboviruses are expanding their territory and elevating their infection prevalence due to the rapid climate change, urbanization, and increased international travel and global trade. Various significant arboviruses, including the dengue virus, Zika virus, Chikungunya virus, and yellow fever virus, are all reliant on the same primary vector, Aedes aegypti. Consequently, the occurrence of arbovirus coinfection in mosquitoes is anticipated. Arbovirus coinfection in mosquitoes has two patterns: simultaneous and sequential. Numerous studies have demonstrated that simultaneous coinfection of arboviruses in mosquitoes is unlikely to exert mutual developmental influence on these viruses. However, the viruses' interplay within a mosquito after the sequential coinfection seems intricated and not well understood.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted experiments aimed at examining the phenomenon of arbovirus sequential coinfection in both mosquito cell line (C6/36) and A. aegypti, specifically focusing on dengue virus (DENV, serotype 2) and Zika virus (ZIKV). We firstly observed that DENV and ZIKV can sequentially infect mosquito C6/36 cell line, but the replication level of the subsequently infected ZIKV was significantly suppressed. Similarly, A. aegypti mosquitoes can be sequentially coinfected by these two arboviruses, regardless of the order of virus exposure. However, the replication, dissemination, and the transmission potential of the secondary virus were significantly inhibited. We preliminarily explored the underlying mechanisms, revealing that arbovirus-infected mosquitoes exhibited activated innate immunity, disrupted lipid metabolism, and enhanced RNAi pathway, leading to reduced susceptibility to the secondary arbovirus infections.

CONCLUSIONS/SIGNIFICANCE

Our findings suggest that, in contrast to simultaneous arbovirus coinfection in mosquitoes that can promote the transmission and co-circulation of these viruses, sequential coinfection appears to have limited influence on arbovirus transmission dynamics. However, it is important to note that more experimental investigations are needed to refine and expand upon this conclusion.

Prevalence of Dengue, Chikungunya and Zika Viruses in Blood Donors in the State of Pará, Northern Brazil: 2018-2020

Arboviruses have been reported over the years as constant threats to blood transfusion recipients, given the high occurrence of asymptomatic cases and the fact that the presence of viremia precedes the onset of symptoms, making it possible that infected blood from donors act as a source of dissemination. This work aims to identify the prevalence of dengue virus (DENV), Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection in blood donors during epidemic and non-epidemic periods; classify the donor as symptomatic or asymptomatic; and verify the need to include DENV, CHIKV and ZIKV in the nucleic acid test (NAT) platform in northern Brazil. We investigated 36,133 thousand donations in two years of collection in Northern Brazil. One donor was positive for DENV and one for CHIKV (0.002% prevalence). As the prevalence for arboviruses was low in this study, it would not justify the individual screening of samples from donors in a blood bank. Thus, DENV- and CHIKV-positive samples were simulated in different amounts of sample pools, and both were safely detected by molecular biology even in a pool of 14 samples, which would meet the need to include these three viruses in the routine of blood centers in endemic countries such as Brazil.

Nervous System Manifestations of Arboviral Infections

Purpose of Review

Complex environmental factors and human intervention influence the spread of arthropod vectors and the cycle of transmission of arboviruses. The spectrum of clinical manifestations is diverse, ranging from serious presentations like viral hemorrhagic fever (e.g., dengue, yellow fever, rift valley fever) or shock syndromes (e.g., dengue virus) to organ-specific illness like meningoencephalitis.

Recent Findings

A spectrum of clinical neurologic syndromes with potential acute devastating consequences or long-term sequelae may result from some arboviral infections.

Summary

In this review, we describe some of the most frequent and emerging neuro-invasive arboviral infections, spectrum of neurologic disorders including encephalitis, meningitis, myelitis or poliomyelitis, acute demyelinating encephalomyelitis, Guillain-Barré syndrome, and ocular syndromes.

Overview on Chikungunya Virus Infection: From Epidemiology to State-of-the-Art Experimental Models

Chikungunya virus (CHIKV) is currently one of the most relevant arboviruses to public health. It is a member of the Togaviridae family and alphavirus genus and causes an arthritogenic disease known as chikungunya fever (CHIKF). It is characterized by a multifaceted disease, which is distinguished from other arbovirus infections by the intense and debilitating arthralgia that can last for months or years in some individuals. Despite the great social and economic burden caused by CHIKV infection, there is no vaccine or specific antiviral drugs currently available. Recent outbreaks have shown a change in the severity profile of the disease in which atypical and severe manifestation lead to hundreds of deaths, reinforcing the necessity to understand the replication and pathogenesis processes. CHIKF is a complex disease resultant from the infection of a plethora of cell types. Although there are several in vivo models for studying CHIKV infection, none of them reproduces integrally the disease signature observed in humans, which is a challenge for vaccine and drug development. Therefore, understanding the potentials and limitations of the state-of-the-art experimental models is imperative to advance in the field. In this context, the present review outlines the present knowledge on CHIKV epidemiology, replication, pathogenesis, and immunity and also brings a critical perspective on the current in vitro and in vivo state-of-the-art experimental models of CHIKF.

Human Platelet Lysate for Good Manufacturing Practice-Compliant Cell Production

Numerous cell-based therapeutics are currently being tested in clinical trials. Human platelet lysate (HPL) is a valuable alternative to fetal bovine serum as a cell culture medium supplement for a variety of different cell types. HPL as a raw material permits animal serum-free cell propagation with highly efficient stimulation of cell proliferation, enabling humanized manufacturing of cell therapeutics within a reasonable timeframe. Providers of HPL have to consider dedicated quality issues regarding identity, purity, potency, traceability and safety. Release criteria have to be defined, characterizing the suitability of HPL batches for the support of a specific cell culture. Fresh or expired platelet concentrates from healthy blood donors are the starting material for HPL preparation, according to regulatory requirements. Pooling of individual platelet lysate units into one HPL batch can balance donor variation with regard to essential platelet-derived growth factors and cytokines. The increasingly applied pathogen reduction technologies will further increase HPL safety. In this review article, aspects and regulatory requirements of whole blood donation and details of human platelet lysate manufacturing are presented. International guidelines for raw materials are discussed, and defined quality controls, as well as release criteria for safe and GMP-compliant HPL production, are summarized.