Nudiviruses (Nudiviridae) are double-stranded DNA viruses with enveloped and rod-shaped virions. Several insect orders (e.g., Diptera, Lepidoptera, Coleoptera, Orthoptera) and aquatic crustaceans are susceptible to nudivirus infections, which can result in varied degrees of disease in all developmental host stages. Their pathogenicity endangers insect rearing and crustacean aquacultures, but has also proven effective in biocontrol against Oryctes rhinoceros infestations. This literature review aims to present all known nudivirus species and provide a comprehensive Nudiviridae phylogeny by including recently described nudiviral isolates, and discuss this phylogeny in comparison to current opinions and taxonomical propositions. Moreover, we aim to clarify biological, pathological and genomic differences or similarities between nudiviruses and related entomopathogenic viruses, including baculoviruses (Baculoviridae) and bracoviruses (Polydnaviridae). A phylogenetic analysis using 17 concatenated nudivirus core genes resulted in the expected structure with the genera Alphanudivirus and Betanudivirus, as well as the most recently recognized genera Gammanudivirus and Deltanudivirus. The hymenopteran Osmia cornuta nudivirus (OcNV) groups closest with the hymenopteran Fopius arisanus endogenous nudivirus (FaENV) and does not share a most common ancestor with the hymenopteran bracoviruses. Except for one node, all clades are highly supported. The proposition of a recent study to assign subgroups to the alphanudiviruses might be legitimate, but more hymenopteran and orthopteran nudiviruses, especially in bees and cricket, need to be identified to resolve this proposal. In addition, freshwater and marine nudiviruses might form taxonomic subgroups among gammanudiviruses as well, but more aquatic nudiviruses need to be identified and sequenced for better resolution. Furthermore, the search for nudiviruses in insects with (semi)aquatic life stages may aid in finding the missing link that led to the manifestation of aquatic nudiviruses.

Early detection is one of the ways to deal with DNA virus widespread prevalence, and it is necessary to know new diagnostic methods and techniques. Colorimetric assays are one of the most advantageous methods in detecting viruses. These methods are based on color change, which can be seen either with the naked eye or with special devices. The aim of this study is to introduce and evaluate effective colorimetric methods based on amplification, nanoparticle, CRISPR/Cas, and Lateral flow in the diagnosis of DNA viruses and to discuss the effectiveness of each of the updated methods. Compared to the other methods, colorimetric assays are preferred for faster detection, high efficiency, cheaper cost, and high sensitivity and specificity. It is expected that the spread of these viruses can be prevented by identifying and developing new methods.

BACKGROUND: Chronic hepatitis B is often complicated with different degrees of hepatic fibrosis, which affects the quality of life. Nucleoside analogs are recommended by almost all guidelines in the world for the treatment of chronic hepatitis B. At present, there is no specific and effective chemical and biological agents for hepatic fibrosis. In China, Chinese compound prescription combined with nucleoside analogs have been used to treat hepatic fibrosis of chronic hepatitis B patients in more and more cases, and good results have been achieved. Several Chinese compound prescriptions that have been made into proprietary Chinese medicine for the convenience of use. This article aims to systematically evaluate the efficacy and safety of Chinese medicine compounds assisting nucleoside analogs in the treatment of hepatic fibrosis in chronic hepatitis B patients.
METHODS: The following databases will be searched from their inception to September 2019: PubMed, EMBASE, EBSCOhost, The Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Biomedical literature Database (CBM), VIP Database, Wanfang Database. Languages are limited to Chinese and English. The study includes randomized controlled trials using Chinese compound prescription combined with entecavir and Chinese compound prescription combined with tenofovir disoproxil fumarate to treat hepatic fibrosis of chronic hepatitis B patients. The primary outcomes including effective rate and biochemical parameters (levels of hyaluronic acid, laminin, pre-type-III collagen and type IV collagen will be tested. Additional outcomes include liver function indexes (levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin) and levels of hepatitis B virus DNA. Stata14.0 software will be used for meta-analysis.
RESULTS: The efficacy and safety of Chinese compound prescriptions assisting nucleoside analogs for hepatic fibrosis of chronic hepatitis B patients will be assessed from the effective rate, biochemical parameters, liver function indexes, and levels of hepatitis B virus DNA.
CONCLUSIONS: The conclusion of this study will be used to evaluate the efficacy and safety of Chinese compound prescriptions assisting nucleoside analogs in the treatment of hepatic fibrosis of chronic hepatitis B patients, as well as the adjuvant effectiveness of Chinese compound prescriptions in combined therapy.
UNASSIGNED: CRD42020156859.

BACKGROUND: In recent decades, several viruses have jumped from animals to humans, triggering sizable outbreaks. The current unprecedent outbreak SARS-COV-2 is prompting a search for new cost-effective therapies to combat this deadly pathogen. Suitably functionalized polysubstituted quinoxalines show very interesting biological properties (antiviral, anticancer, and antileishmanial), ensuring them a bright future in medicinal chemistry.
OBJECTIVE: Focusing on the promising development of new quinoxaline derivatives as antiviral drugs, this review forms part of our program on the anti-infectious activity of quinoxaline derivatives.
METHODS: Study compiles and discusses recently published studies concerning the therapeutic potential of the antiviral activity of quinoxaline derivatives, covering the literature between 2010 and 2020.
RESULTS: A final total of 20 studies included in this review.
CONCLUSIONS: This review points to a growing interest in the development of compounds bearing a quinoxaline moiety for antiviral treatment. This promising moiety with different molecular targets warrants further investigation, which may well yield even more encouraging results regarding this scaffold.

Ivermectin proposes many potentials effects to treat a range of diseases, with its antimicrobial, antiviral, and anti-cancer properties as a wonder drug. It is highly effective against many microorganisms including some viruses. In this comprehensive systematic review, antiviral effects of ivermectin are summarized including in vitro and in vivo studies over the past 50 years. Several studies reported antiviral effects of ivermectin on RNA viruses such as Zika, dengue, yellow fever, West Nile, Hendra, Newcastle, Venezuelan equine encephalitis, chikungunya, Semliki Forest, Sindbis, Avian influenza A, Porcine Reproductive and Respiratory Syndrome, Human immunodeficiency virus type 1, and severe acute respiratory syndrome coronavirus 2. Furthermore, there are some studies showing antiviral effects of ivermectin against DNA viruses such as Equine herpes type 1, BK polyomavirus, pseudorabies, porcine circovirus 2, and bovine herpesvirus 1. Ivermectin plays a role in several biological mechanisms, therefore it could serve as a potential candidate in the treatment of a wide range of viruses including COVID-19 as well as other types of positive-sense single-stranded RNA viruses. In vivo studies of animal models revealed a broad range of antiviral effects of ivermectin, however, clinical trials are necessary to appraise the potential efficacy of ivermectin in clinical setting.

Double-stranded (ds) DNA virus infections often occur concomitantly in immunocompromised patients. We performed a systematic search of published in vitro activity for nine approved and investigational antivirals to understand the spectrum of in vitro activity against dsDNA viruses.
A literature search was performed (PubMed and the WoS Core Collection) using keywords related to: 1) targeted approved/developmental antivirals (acyclovir, artesunate, brincidofovir, cidofovir, cyclopropavir (filociclovir), foscarnet, ganciclovir, letermovir, and maribavir); 2) pathogenic dsDNA viruses; 3) in vitro activity. We summarized data from 210 publications.
Activity against ≤3 viruses was documented for maribavir (cytomegalovirus, Epstein-Barr virus), and letermovir, while activity against > 3 viruses was shown for ganciclovir, cidofovir, acyclovir, foscarnet, cyclopropavir, artesunate, and brincidofovir. The EC50 values of brincidofovir were the lowest, ranging from 0.001 to 0.27 μM, for all viruses except papillomaviruses. The next most potent agents included cidofovir, ganciclovir, foscarnet, and acyclovir with EC50 values between 0.1 μM and >10 μM for cytomegalovirus, herpes simplex virus, and adenovirus.
Most of the identified antivirals had in vitro activity against more than one dsDNA virus. Brincidofovir and cidofovir have broad-spectrum activity, and brincidofovir has the lowest EC50 values. These findings could assist clinical practice and developmental research.

Viruses enter host cells via several mechanisms, including endocytosis, macropinocytosis, and phagocytosis. They can also fuse at the plasma membrane and can spread within the host via cell-to-cell fusion or syncytia. The mechanism used by a given viral strain depends on its external topology and proteome and the type of cell being entered. This comparative review discusses the cellular attachment receptors and entry pathways of dsDNA viruses belonging to the families Adenoviridae, Baculoviridae, Herpesviridae and nucleocytoplasmic large DNA viruses (NCLDVs) belonging to the families Ascoviridae, Asfarviridae, Iridoviridae, Phycodnaviridae, and Poxviridae, and giant viruses belonging to the families Mimiviridae and Marseilleviridae as well as the proposed families Pandoraviridae and Pithoviridae. Although these viruses have several common features (e.g., topology, replication and protein sequence similarities) they utilize different entry pathways to infect wide-range of hosts, including humans, other mammals, invertebrates, fish, protozoa and algae. Similarities and differences between the entry methods used by these virus families are highlighted, with particular emphasis on viral topology and proteins that mediate viral attachment and entry. Cell types that are frequently used to study viral entry are also reviewed, along with other factors that affect virus-host cell interactions.

Numerous infections by viral pathogens have been described from wild and cultured crustacean hosts, yet relatively few of these pathogens have been formally characterised and classified. To date viruses have generally been tentatively assigned to families based upon morphological and developmental characteristics and their location of infection within the host cell. Often nucleotide sequence information is unavailable. Some of these viral infections have caused well-documented devastating consequences on the global crustacean farming industry whilst their effects on wild populations remain largely unstudied. This paper provides an up to date review of all known viruses described infecting crustacean hosts. Full characterisation and harmonisation of these descriptions utilising specifications proposed by the International Committee on Taxonomy of Viruses (ICTV) is required to synonymise numerous examples of differential naming or abbreviation of naming, of the same virus in some cases. Development and application of techniques such as viral purification and high throughput sequencing of viral genomes will assist with these full descriptions and, provide appropriate diagnostic targets for surveillance of known and novel relatives. This review also highlights the importance of comparative study with viruses infecting insects and other arthropods to assist this process.

OBJECTIVE: To review clinical outcomes data for patients treated with oral ribavirin for noninfluenza respiratory viral infections (NIRVIs).
METHODS: MEDLINE, EMBASE, and PubMed Central (1972 to June 1, 2015) were queried with the following search term combinations: \"Oral\" AND \"ribavirin\" AND (\"respiratory syncytial virus\" OR \"metapneumovirus\" OR \"parainfluenza\" OR \"coronavirus\" OR \"rhinovirus\" OR \"enterovirus\" OR \"adenovirus\").
METHODS: Included studies must have characterized the clinical outcomes of a cohort of patients treated with oral ribavirin for symptomatic NIRVIs. Case reports and series with <5 cases, conference abstracts, and articles written in languages other than English were excluded.
RESULTS: Of the 1256 unique reports, 15 met inclusion criteria: 12 retrospective, 3 prospective, and 3 comparative with untreated control groups. All studies except for 2 Middle East respiratory syndrome coronavirus (MERS-CoV) studies were in immunocompromised patients (9 malignancy/stem cell transplant, 4 lung transplant). The mortality rate ranged from 0% to 31% in malignancy/stem cell transplant recipients treated with oral ribavirin, and 1/108 (0.9%) ribavirin-treated lung transplant recipients died at 30 days. Three studies (one each for malignancy, lung transplant, and MERS-CoV) suggested a clinical outcomes benefit with oral ribavirin compared with supportive care alone; however, the nonrandomized design precludes efficacy determination. Hemolysis was the most common adverse reaction, occurring in 14% (54/375) of patients. Ribavirin was discontinued in 4% of patients secondary to adverse reactions.
CONCLUSIONS: Oral ribavirin should be considered for the treatment of NIRVI in immunocompromised adults (malignancy/stem cell transplant or lung transplant) or adults with MERS-CoV.

In 2000, a pathogenic virus was discovered in juvenile Caribbean spiny lobsters Panulirus argus from the Florida Keys, U.S.A. Panulirus argus virus 1 (PaV1) is the first naturally occurring pathogenic virus reported from lobsters, and it profoundly affects their ecology and physiology. PaV1 is widespread in the Caribbean with infections reported in Florida (U.S.A.), St. Croix, St. Kitts, Yucatan (Mexico), Belize, and Cuba. It is most prevalent and nearly always lethal in the smallest juvenile lobsters, but this declines with increasing lobster size; adults harbor the virus, but do not present the characteristic signs of the disease. No other PaV1 hosts are known. The prevalence of PaV1 in juvenile lobsters from the Florida Keys has been stable since 1999, but has risen to nearly 11% in the eastern Yucatan since 2001. Heavily infected lobsters become sedentary, cease feeding, and die of metabolic exhaustion. Experimental routes of viral transmission include ingestion, contact, and for newly settled juveniles, free virus particles in seawater. Prior to infectiousness, healthy lobsters tend to avoid diseased lobsters and so infected juvenile lobsters mostly dwell alone, which appears to reduce disease transmission. However, avoidance of diseased individuals may result in increased shelter competition between healthy and diseased lobsters, and greater predation on infected lobsters. Little is known about PaV1 outside of Mexico and the USA, but it poses a potential threat to P. argus fisheries throughout the Caribbean.