Chikungunya Fever During Pregnancy and in Children: An Overview on Clinical and Research Perspectives

Chikungunya fever (CF) is an arboviral disease in worldwide expansion due to the plasticity of its pathogen and vector. Chikungunya virus (CHIKV), a positive-sense, single-stranded RNA alphavirus, is transmitted by Aedes (Stegomyia) aegypti and Aedes albopictus mosquitoes, two hegemonic anthropophilic day-biting mosquitoes capable of colonizing very different environments. This expert review discusses the molecular epidemiology, pathophysiology, clinical features, diagnosis, management, and prevention of CF during pregnancy, infancy, and childhood. Specifically, it will focus not only on the issue and challenges of perinatal mother-to-child transmission of CHIKV, its pathogenesis, and effects on neurodevelopment, but also on CHIKV-associated central nervous system disease in children, two previously ill-characterized features of the infection

Development of biocompatible small-molecule spacers as metal oxide nanoparticles\u27 stabilizing agents

Development and study of the magnetic nanoparticles for biological and clinical applications remains one of the challenging research areas in chemistry and materials science. The performance of these particles as, for example, drug delivery, MRI, hyperthermia or cell tracking agents, depends on their magnetic susceptibility. Their ability to form stable aqueous colloids, the mobility, and diffusion properties in biological media, rely on organic coating, which is usually composed of hydrophilic biocompatible polymers such as dextrans or poly(ethylene glycol)s. Some areas of biomedical imaging, labeling and delivery application can benefit from magnetic nanoparticles with higher mobility and penetration, stronger interaction with fluids and tissues, and that can be easily conjugated to biological molecules. The idea of this work was to develop a non-polymeric organic coating of an adjustable size, which might offer a simpler way to obtaining particles with these properties. Our target capping ligands were based on aromatic polycarboxylic acids that would strongly bind to the nanoparticle’s surface, and assure the adduct’s stability in aqueous colloids. The precursor acids were functionalized with oligomeric ethylene oxide and glycerol derivatives and covalently bound to the surface of 5 nm γ-Fe2O3 nanoparticles in reaction with their surfactant-free diethylene glycol colloids. Results of colloidal studies on these adducts will be presented. Please click Additional Files below to see the full abstract

Do Antenatal Parasite Infections Devalue Childhood Vaccination?

On a global basis, both potent vaccine efficacy and high vaccine coverage are necessary to control and eliminate vaccine-preventable diseases. Emerging evidence from animal and human studies suggest that neglected tropical diseases (NTDs) significantly impair response to standard childhood immunizations. A review of efficacy and effectiveness studies of vaccination among individuals with chronic parasitic infections was conducted, using PUBMED database searches and analysis of data from the authors' published and unpublished studies. Both animal models and human studies suggest that chronic trematode, nematode, and protozoan infections can result in decreased vaccine efficacy. Among pregnant women, who in developing countries are often infected with multiple parasites, soluble parasite antigens have been shown to cross the placenta and prime or tolerize fetal immune responses. As a result, antenatal infections can have a significant impact on later vaccine responses. Acquired childhood parasitic infections, most commonly malaria, can also affect subsequent immune response to vaccination. Additional data suggest that antiparasite therapy can improve the effectiveness of several human vaccines. Emerging evidence demonstrates that both antenatal and childhood parasitic infections alter levels of protective immune response to routine vaccinations. Successful antiparasite treatment may prevent immunomodulation caused by parasitic antigens during pregnancy and early childhood and may improve vaccine efficacy. Future research should highlight the varied effects that different parasites (alone and in combination) can have on human vaccine-related immunity. To optimize vaccine effectiveness in developing countries, better control of chronic NTDs may prove imperative

Risks and Challenges of Arboviral Diseases in Sudan: The Urgent Need for Actions

The risk of emergence and/or re-emergence of arthropod-borne viral (arboviral) infections is rapidly growing worldwide, particularly in Africa. The burden of arboviral infections and diseases is not well scrutinized because of the inefficient surveillance systems in endemic countries. Furthermore, the health systems are fully occupied by the burden of other co-existing febrile illnesses, especially malaria. In this review we summarize the epidemiology and risk factors associated with the major human arboviral diseases and highlight the gap in knowledge, research, and control in Sudan. Published data in English up to March 2019 were reviewed and are discussed to identify the risks and challenges for the control of arboviruses in the country. In addition, the lack of suitable diagnostic tools such as viral genome sequencing, and the urgent need for establishing a genomic database of the circulating viruses and potential sources of entry are discussed. Moreover, the research and healthcare gaps and global health threats are analyzed, and suggestions for developing strategic health policy for the prevention and control of arboviruses with focus on building the local diagnostic and research capacity and establishing an early warning surveillance system for the early detection and containment of arboviral epidemics are offered

Risk factors associated with Rift Valley fever epidemics in South Africa in 2008–11

Rift Valley fever (RVF) is a zoonotic and vector-borne disease, mainly present in Africa, which represents a threat to human health, animal health and production. South Africa has experienced three major RVF epidemics (1950–51, 1973–75 and 2008–11). Due to data scarcity, no previous study has quantified risk factors associated with RVF epidemics in animals in South Africa. Using the 2008–11 epidemic datasets, a retrospective longitudinal study was conducted to identify and quantify spatial and temporal environmental factors associated with RVF incidence. Cox regressions with a Besag model to account for the spatial effects were fitted to the data. Coefficients were estimated by Bayesian inference using integrated nested Laplace approximation. An increase in vegetation density was the most important risk factor until 2010. In 2010, increased temperature was the major risk factor. In 2011, after the large 2010 epidemic wave, these associations were reversed, potentially confounded by immunity in animals, probably resulting from earlier infection and vaccination. Both vegetation density and temperature should be considered together in the development of risk management strategies. However, the crucial need for improved access to data on population at risk, animal movements and vaccine use is highlighted to improve model predictions

Postepidemic Analysis of Rift Valley Fever Virus Transmission in Northeastern Kenya: A Village Cohort Study

RVFV infection causes significant disease in both human and animal populations, resulting in significant agricultural, economic and public health consequences. We conducted a cohort study on residents of a high-risk area to measure human anti-RVFV seroprevalence, to identify risk factors, and to estimate the durability of prior RVFV immunity. One hundred two individuals tested for RVFV exposure before the 2006–2007 RVF outbreak were restudied to determine interval anti-RVFV seroconversion and persistence of humoral immunity since 2006. Ninety-two additional subjects were enrolled from randomly selected households to help identify risk factors for current seropositivity. Seroprevalence in the region was high (23%). 1/85 at-risk individuals restudied in the follow-up cohort had seroconverted since early 2006. 29% of newly tested individuals were seropositive. After adjustment in multivariable logistic models, age, village, and drinking raw milk were significantly associated with RVFV seropositivity. Visual impairment (defined as ≤20/80) was much more likely in the RVFV-seropositive group. Among those with previous exposure, RVFV titers remained at protective levels (>1∶40) for more than 3 years. This study highlights the high seroprevalence among Northeastern Kenyans and the ongoing surge in seroprevalence with each RVF outbreak