The Journal of infectious diseases
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Next generation sequencing (NGS) combined with bioinformatics has successfully been used in a vast array of analyses for infectious disease research of public health relevance. For instance, NGS and bioinformatics approaches have been used to identify outbreak origins, track transmissions, investigate epidemic dynamics, determine etiological agents of a disease, and discover novel human pathogens. However, implementation of high-quality NGS and bioinformatics in research and public health laboratories can be challenging. ⋯ We review sequencing approaches that have been used for various pathogens and study questions, as well as the most common difficulties associated with these approaches that should be considered when implementing in a public health or research setting. In addition, we provide a review of some common bioinformatics tools and procedures used for pathogen discovery and genome assembly, along with the most common challenges and solutions. Finally, we summarize the bioinformatics of advanced viral, bacterial, and parasite pathogen characterization, including types of study questions that can be answered when utilizing NGS and bioinformatics.
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Next-generation sequencing (NGS) technologies have revolutionized multiple areas in the field of infectious diseases, from pathogen discovery to characterization of genes mediating drug resistance. Consequently, there is much anticipation that NGS technologies may be harnessed in the realm of diagnostic methods to complement or replace current culture-based and molecular microbiologic techniques. In this context, much consideration has been given to hypothesis-free, culture-independent tests that can be performed directly on primary clinical samples. ⋯ While many limitations to the use of NGS in clinical microbiology laboratories are being overcome with decreasing technology costs, expanding curated pathogen sequence databases, and better data analysis tools, there remain many challenges to the routine use and implementation of these methods. This review summarizes recent advances in applications of targeted amplicon and shotgun-based metagenomics approaches to infectious disease diagnostic methods. Technical and conceptual challenges are considered, along with expectations for future applications of these techniques.
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Dengue endemicity varies but comparative, multi-country data are extremely limited. An improved understanding is needed to prioritize prevention, including vaccination, which is currently recommended only under specific epidemiological conditions. We used serological study data from 46 geographical sites in 13 countries to estimate dengue force of infection (FOI, the proportion of children seroconverting per year) under assumptions of either age-constant or age-varying FOI, and the age at which 50% and 80% of children had been infected. ⋯ Estimated constant FOI varied widely, from 1.7% (Singapore) to 24.1% (the Philippines). In the site-level analysis 44 sites (96%) reached 50% seroconversion, and 35 sites (75%) reached 80% seroconversion, by age 18, with significant heterogeneity. These findings confirm that children living in dengue-endemic countries receive intense early dengue exposure, increasing risk of secondary infection, and imply serosurveys at fine spatial resolutions are needed to inform vaccination campaigns.
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Stimulator of interferon genes (STING) is a key cytosolic receptor for small nucleotides and plays a key role in anticancer and antiviral immunity. Cyclic dinucleotide STING agonists may comprise a novel class of vaccine adjuvants capable of inducing cellular immune responses and protective efficacy against intracellular pathogens. ⋯ We report a strategy of delivering a STING agonist from within live BCG. Overproduction of the STING agonist c-di-AMP significantly enhanced the protective efficacy of BCG against pulmonary and extrapulmonary tuberculosis. Our findings support the development of BCG-vectored STING agonists as a tuberculosis vaccine strategy.
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In 2017, the Democratic Republic of the Congo (DRC) recorded its eighth Ebola virus disease (EVD) outbreak, approximately 3 years after the previous outbreak. ⋯ A single spillover event into the human population is responsible for this DRC outbreak. Human-to-human transmission resulted in limited dissemination of the causative agent, a novel Ebola virus variant closely related to the initial Mayinga variant isolated in 1976-1977 in the DRC.