Emerging viral infections

Potential neurological manifestations of COVID-19: a narrative review

Neurological manifestations are increasingly reported in a subset of COVID-19 patients. Previous infections related to coronaviruses, namely Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS) also appeared to have neurological effects on some patients. The viruses associated with COVID-19 like that of SARS enters the body via the ACE-2 receptors in the central nervous system, which causes the body to balance an immune response against potential damage to nonrenewable cells. A few rare cases of neurological sequelae of SARS and MERS have been reported. A growing body of evidence is accumulating that COVID-19, particularly in severe cases, may have neurological consequences although respiratory symptoms nearly always develop prior to neurological ones. Patients with preexisting neurological conditions may be at elevated risk for COVID-19-associated neurological symptoms. Neurological reports in COVID-19 patients have described encephalopathy, Guillain-Barré syndrome, myopathy, neuromuscular disorders, encephalitis, cephalgia, delirium, critical illness polyneuropathy, and others. Treating neurological symptoms can pose clinical challenges as drugs that suppress immune response may be contraindicated in COVID-19 patients. It is possible that in some COVID-19 patients, neurological symptoms are being overlooked or misinterpreted. To date, neurological manifestations of COVID-19 have been described largely within the disease trajectory and the long-term effects of such manifestations remain unknown.

Drug Repurposing: A Strategy for Discovering Inhibitors against Emerging Viral Infections

BACKGROUND

Viral diseases are responsible for several deaths around the world. Over the past few years, the world has seen several outbreaks caused by viral diseases that, for a long time, seemed to possess no risk. These are diseases that have been forgotten for a long time and, until nowadays, there are no approved drugs or vaccines, leading the pharmaceutical industry and several research groups to run out of time in the search for new pharmacological treatments or prevention methods. In this context, drug repurposing proves to be a fast and economically viable technique, considering the fact that it uses drugs that have a well-established safety profile. Thus, in this review, we present the main advances in drug repurposing and their benefit for searching new treatments against emerging viral diseases.

METHODS

We conducted a search in the bibliographic databases (Science Direct, Bentham Science, PubMed, Springer, ACS Publisher, Wiley, and NIH's COVID-19 Portfolio) using the keywords "drug repurposing", "emerging viral infections" and each of the diseases reported here (CoV; ZIKV; DENV; CHIKV; EBOV and MARV) as an inclusion/exclusion criterion. A subjective analysis was performed regarding the quality of the works for inclusion in this manuscript. Thus, the selected works were those that presented drugs repositioned against the emerging viral diseases presented here by means of computational, high-throughput screening or phenotype-based strategies, with no time limit and of relevant scientific value.

RESULTS

291 papers were selected, 24 of which were CHIKV; 52 for ZIKV; 43 for DENV; 35 for EBOV; 10 for MARV; and 56 for CoV and the rest (72 papers) related to the drugs repurposing and emerging viral diseases. Among CoV-related articles, most were published in 2020 (31 papers), updating the current topic. Besides, between the years 2003 - 2005, 10 articles were created, and from 2011 - 2015, there were 7 articles, portraying the outbreaks that occurred at that time. For ZIKV, similar to CoV, most publications were during the period of outbreaks between the years 2016 - 2017 (23 articles). Similarly, most CHIKV (13 papers) and DENV (14 papers) publications occur at the same time interval. For EBOV (13 papers) and MARV (4 papers), they were between the years 2015 - 2016. Through this review, several drugs were highlighted that can be evolved in vivo and clinical trials as possible used against these pathogens showed that remdesivir represent potential treatments against CoV. Furthermore, ribavirin may also be a potential treatment against CHIKV; sofosbuvir against ZIKV; celgosivir against DENV, and favipiravir against EBOV and MARV, representing new hopes against these pathogens.

CONCLUSION

The conclusions of this review manuscript show the potential of the drug repurposing strategy in the discovery of new pharmaceutical products, as from this approach, drugs could be used against emerging viral diseases. Thus, this strategy deserves more attention among research groups and is a promising approach to the discovery of new drugs against emerging viral diseases and also other diseases.

Neurological Components in Coronavirus Induced Disease: A Review of the Literature Related to SARS, MERS, and COVID-19

Background. COVID-19 has been declared the pandemic of the 21st century, causing more than 45,000 deaths worldwide. The abrupt release of SARS-CoV-2 demonstrated the potential infection, morbidity, and lethality of zoonotic viruses and human-to-human transmission. Fever, cough, and fatigue are reported as the most common symptoms of the disease, including acute respiratory distress syndrome, and also signs of severe illness, such as shock, acute cardiac injury, and renal lesions, are described. Considering the previous works related to human coronavirus and other zoonotic infections, it has been demonstrated that the neuroinvasive propensity is a common characteristic of coronaviruses, especially in SARS-CoV and MERS-CoV. Objective. In the present review, we analyzed the potential neurological components involved in coronavirus infections and detailed the neurological syndromes related to COVID-19. We also examined the mechanism of transmission and CNS pathology related to other viruses with similar structures such as SARS-CoV and MERS-CoV. Methods. A comprehensive search of different original articles and clinical, experimental, and review studies was conducted in MEDLINE/PubMed, Scopus, and Web of Science. We selected 92 articles that have been published in journals or preprints according to the search words and the inclusion and exclusion criteria. Results. COVID-19 patients may experience neurological symptoms such as headache, impaired mental status, confusion, dizziness, nausea and vomiting, anosmia/hyposmia, and dysgeusia/hypogeusia as initial symptoms, with more severe manifestations such as seizures or coma later on. The neurological signs shown are clinical symptoms similar to those reported for SARS-CoV and MERS-CoV. Given that both SARS-CoV and MERS-CoV have similar structures, these viruses may share comparable neurological symptoms and similar progression. Coronaviruses are linked to central nervous system dysfunction, and they are also reported as the probable cause of multiple sclerosis, encephalitis, and meningitis.

The neurological insights of the emerging coronaviruses

Emerging Viral diseases are incredibly infectious and proficient in inducing pandemics. Unlike the previous emerging coronaviruses (ECoVs) which neurological complexities were uncommon, with neurological features exhibition at 14-25 days post-onset, yet with critical outcomes exhibiting >50% mortality in central nervous (CNS) presenting pathologies. The COVID 19 neurological consequences occur more frequently even in mild cases, presenting with CNS involvement in up to 25%, musculoskeletal and peripheral manifestation (PNM). Through preceding ECoVs case reports, the PNM not linked to fatal outcomes, however, required, repeated neuro-imaging as notable CT and MRI changes appeared as late as 21 days while the likelihood of Cerebrospinal fluid to test positive for ECoV was 25%, only in the CNS presenting cases. Owing to 44-60% myalgia presentation, risk of the high inflammatory state, and coagulation cascade abnormalities reported in ECoVs, testing for C-reactive protein, serum creatine kinase, and D-dimer level is mandatory. Presently, there is no antiviral medication or vaccination for the ECoVs, early induction of antiviral drugs remains the backbone of management. Neurologically, the therapeutic dosages of anticoagulants are linked to the high incidence of thrombotic complexities, while methylprednisolone is associated with myopathy. Future studies expected to apply more neuro-imaging techniques for CNS exploration and further explore the pathogenesis of the COVID 19 myalgia, anosmia/ageusia reported in the majority of the initial cases.

Neurotropic mechanisms in COVID-19 and their potential influence on neuropsychological outcomes in children

Children have shown more physical resilience to COVID-19 than adults, but there is a cohort of vulnerable infants and young children who may experience disease burden, both in the acute phase and chronically. Children may have had early undocumented exposure to COVID-19. Even when the risk of exposure was known, developmental variables may have made the avoidance of physical proximity difficult for children. Preliminary hypotheses concerning neurotropic factors have been documented by researchers. Children with COVID-19 and comorbid physical or mental disorders may be vulnerable to exacerbations of neurotropic factors and comorbidities, the neural impact of which has been documented for other coronaviruses. Researchers are investigating COVID-19 symptom descriptions, neurotropic mechanisms at the genomic and transcriptomatic levels, neurological manifestations, and the impact of comorbid health complications. Neuropsychologists need information concerning the likely impact of COVID-19 on children. With a view toward that goal, this article provides recommendations for some initial updates in neuropsychology practice.

The Role of Bats as Reservoir Hosts of Emerging Neuroviruses

Recent studies have clearly shown that bats are the reservoir hosts of a wide diversity of novel viruses with representatives from most of the known animal virus families. In many respects bats make ideal reservoir hosts for viruses: they are the only mammals that fly, thus assisting in virus dispersal; they roost in large numbers, thus aiding transmission cycles; some bats hibernate over winter, thus providing a mechanism for viruses to persist between seasons; and genetic factors may play a role in the ability of bats to host viruses without resulting in clinical disease. Within the broad diversity of viruses found in bats are some important neurological pathogens, including rabies and other lyssaviruses, and Hendra and Nipah viruses, two recently described viruses that have been placed in a new genus, Henipaviruses in the family Paramyxoviridae. In addition, bats can also act as alternative hosts for the flaviviruses Japanese encephalitis and St Louis encephalitis viruses, two important mosquito-borne encephalitogenic viruses, and bats can assist in the dispersal and over-wintering of these viruses. Bats are also the reservoir hosts of progenitors of SARS and MERS coronaviruses, although other animals act as spillover hosts. This chapter presents the physiological and ecological factors affecting the ability of bats to act as reservoirs of neurotropic viruses, and describes the major transmission cycles leading to human infection.

Umbilical cord accidents and legal implications

Umbilical cord accidents (UCA) are a significant cause of stillbirth. Although infrequent, litigation may occur when there is a poor outcome associated with UCA. With advances in imaging, the ability to identify UCA by ultrasound and magnetic resonance imaging raises awareness of the risk of a poor outcome. Management of a pregnancy with an identified UCA may require more fetal surveillance by both the mother and caregiver. This is especially important if there is a previous history of UCA with or without stillbirth. UCA should be an acknowledged risk which is part of prenatal screening. In the event of a poor outcome associated with UCA, it is recommended that the patient be fully informed of all prenatal information including images. Excellent communication with parents who are looking for answers after a tragic outcome may help to decrease litigation risk.